Journal articles: 'Lateral ramp. eng' – Grafiati (2024)

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

1. In the companion paper the gain of the stretch reflex in the ankle extensor muscles of normal cats was shown to increase after decerebration. The objectives of this study were 1) to identify the origin of the increased reflex and 2) to evaluate the contribution from afferents other than ankle extensor muscle afferents to the short-latency reflex. 2. Six cats were trained to stand unaided on four pedestals. Three cats were also trained to control the force exerted with the left hindlimb. The left soleus (SOL) and lateral gastrocnemius (LG) electromyogram (EMG), length, force, and temperature were recorded by chronically implanted electrodes and transducers. Measurements were taken before and after decerebration at the premammillary level. After decerebration limb temperature was returned to its normal range by the use of radiant heat. 3. Reproducible ramp-and-hold stretches and releases of the ankle extensor muscles were produced by a servo-controlled motor that rotated the left rear pedestal about the ankle joint. The length of the ankle extensor muscles changed by 2-3 mm within 30-35 ms after the onset of a ramp perturbation. Reflex responses before and after decerebration were compared at matched background values of muscle length and force. 4. In both the SOL and LG muscles, a short-latency EMG burst appeared 8-12 ms after stretch onset and lasted approximately 20 ms. After decerebration the onset of the rectified and smoothed EMG burst remained unchanged, but its area was increased by 36-89%. 5. The lateral gastrocnemius-soleus (LG-S) electroneurogram (ENG) was chronically recorded in two cats with a nerve cuff recording electrode implanted on the LG-S nerve. LG-S ENG activity started to increase soon after stretch onset and remained high during the entire ramp phase. The stretch-evoked LG-S ENG burst started approximately 8 ms earlier than the short-latency SOL and LG EMG bursts. It was interpreted to reflect mainly an increase in the activity of Group Ia and Ib muscle afferents, caused by increases in both muscle length and muscle force during the stretch. After the cats were decerebrated, for matched postural conditions, the area of the stretch-evoked LG-S ENG burst was increased by 29-35%. Because the length and force changes sensed by the muscle receptors before and after decerebration were similar, this suggests that the sensitivity of muscle spindles was increased as a consequence of altered activity in fusimotor neurons after decerebration.(ABSTRACT TRUNCATED AT 400 WORDS)

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Abstract This paper presents thirteen square columns to study the behavior of nano-concrete-filled steel tubular columns with end plates after lateral impact. The failure modes of the square columns subjected to lateral impact damage or not subjected to lateral impact damage were compared. The lateral impact loading height, steel tubular thickness, and column height were set as the test parameters in these tests. The effects of test parameters on the ultimate capacity, initial stiffness, and ductility of columns are discussed in this paper. The bearing capacity of square columns is decreased because of the lateral impact loading which can also be concluded from the test results. And with the steel tube thickness increasing, the bearing capacity and initial stiffness of columns are increased and ductility has no obvious change. However, with the column height increasing, the bearing capacity and stiffness of columns are decreased and ductility is increased. Furthermore, the strain development of the columns under axial compressive loading is also discussed in the paper. The results indicated that the corner of the square column is more easily damaged under compressive loading. According to the test results, the calculated formula is proposed to predict the ultimate capacity of nano-concrete-filled steel tubular columns with end plates after lateral impact. The calculated results have a good agreement with the test results.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

It was recently demonstrated that an O2 extraction reserve, as assessed by the near-infrared spectroscopy (NIRS)-derived deoxygenation signal ([HHb]), exists in the superficial region of vastus lateralis (VL) muscle during an occlusion performed at the end of a ramp-incremental test. However, it is unknown whether this reserve is present and/or different in magnitude in other portions and depths of the quadriceps muscles. We tested the hypothesis that an O2 extraction reserve would exist in other regions of this muscle but is greater in deep compared with more superficial portions. Superficial (VL-s) and deep VL (VL-d) as well as superficial rectus femoris (RF-s) were monitored by a combination of low- and high-power time-resolved (TRS) NIRS. During the occlusion immediately post-ramp-incremental test there was a significant overshoot in the [HHb] signal ( P < 0.05). However, the magnitude of this increase was greater in VL-d (93.2 ± 42.9%) compared with VL-s (55.0 ± 19.6%) and RF-s (47.8 ± 14.0%) ( P < 0.05). The present study demonstrated that an O2 extraction reserve exists in different pools of active muscle fibers of the quadriceps at the end of a ramp exercise to exhaustion. The greater magnitude in the reserve observed in the deeper portion of VL, however, suggests that this portion of muscle may present a greater surplus of oxygenated blood, which is likely due to a greater population of slow-twitch fibers. These findings add to the notion that the plateau in the [HHb] signal toward the end of a ramp-incremental exercise does not indicate the upper limit of O2 extraction. NEW & NOTEWORTHY Different portions of the quadriceps muscles exhibited an untapped O2 extraction reserve during a blood flow occlusion performed at the end of a ramp-incremental exercise. In the deeper portion of the vastus lateralis muscle, this reserve was greater compared with superficial vastus lateralis and rectus femoris. These data suggest that the O2 extraction reserve may be dependent on the vascular and/or oxidative capacities of the muscles.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Background and objectivesThe erector spinae plane (ESP) block is a relatively new interfascial block technique. Previous cadaveric studies have shown extensive cephalocaudal spread with a single ESP injection at the thoracic level. However, little data exist for lumbar ESP block. The objective of this study was to examine the anatomical spread of dye following an ultrasound-guided lumbar ESP block in a human cadaveric model.MethodsAn ultrasound-guided ESP block was performed in unembalmed human cadavers using an in-plane approach with a curvilinear transducer oriented longitudinally. 20 mL of 0.166% methylene blue was injected into the plane between the distal end of the L4 transverse process and erector spinae muscle bilaterally in four specimens and unilaterally in one specimen (nine ESP blocks in total). The superficial and deep back muscles were dissected, and the extent of dye spread was documented in both cephalocaudal and medial–lateral directions.ResultsThere was cephalocaudal spread from L3 to L5 in all specimens with extension to L2 in four specimens. Medial–lateral spread was documented from the multifidus muscle to the lateral edge of the thoracolumbar fascia. There was extensive dye in and around the erector spinae musculature and spread to the dorsal rami in all specimens. There was no dye spread anteriorly into the dorsal root ganglion, ventral rami, or paravertebral space.ConclusionsA lumbar ESP injection has limited craniocaudal spread compared with injection in the thoracic region. It has consistent spread to dorsal rami, but no anterior spread to ventral rami or paravertebral space.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

The Himalaya orogenic belt produces frequent large earthquakes that affect population centers along a length of over 2500 km. The 2015 Gorkha, Nepal earthquake (Mw 7.8) ruptured the Main Himalayan Thrust (MHT) and allows direct measurements of the behavior of the continental collision zone. We study the MHT using seismic waveforms recorded by local stations that completely cover the aftershock zone. The MHT exhibits clear lateral variation along geologic strike, with the Lesser Himalayan ramp having moderate dip on the MHT beneath the mainshock area and a flatter and deeper MHT beneath the eastern end of the aftershock zone. East of the aftershock zone, seismic wave speed increases at MHT depths, perhaps due to subduction of an Indian basem*nt ridge. A similar magnitude wave speed change occurs at the western end of the aftershock zone. These gross morphological structures of the MHT controlled the rupture length of the Gorkha earthquake.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

SynopsisThe evolution, ecological processes, aerodynamics, and morphology of incipient or new foredunes on the upper beach is reviewed. Four types of incipient foredunes may be distinguished, namely: type 1, those initiated by shadow dune formation within zones of discrete individual pioneer annuals (e.g. Cakile spp.), and perennials (e.g. Spinifex spp.; Ammophila spp.); type 2, those initiated by dunelet or hummock formation within discrete colonies of perennial grasses and herbs; type 3, those initiated by sand deposition within laterally extensive colonies of pioneer seedlings; and type 4, those initiated by sand deposition within a laterally extensive plant rhizome cover.Type 1 dunes are dominated by high, local flow deceleration and 3-D flow separation. Shadow dunes form within and downwind of the discrete plants. If colonised by annual plants, invasion by perennial plants is necessary for survival. Later lateral plant spread and accretion produces hummocky terraces and ridges. Type 2 dunes (dunelets) are characterised by local landward flow deceleration and marginal high velocity side flows. Sand deposition results in the formation of low, discrete, semi-circular convex mounds (seedlings), or more elongate hummocks and mounds (rhizomes). Types 3 and 4 dunes are characterised by laterally extensive, often hom*ogeneous vegetation canopies. High canopies display more rapid landward flow deceleration than low canopies, thus narrow, asymmetric ridges and longer convex ridges result respectively. High plant densities result in rapid down-canopy flow deceleration, maximum traction load retardation and the formation of narrow asymmetric ridges. Dune height decreases and dune length increases as plant densities decrease. Maximum deposition zones occur for each wind velocity range. Whether ramp, terrace or ridge morphologies are formed depends on mode of beach colonisation, plant density and distribution, sand volume, wind speed, and plant species type and morphology.A range of variables which affect foredune morphology and evolution, including plant canopy density, height and distribution, wind velocity, and various ecological environmental processes are examined.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Equine chorionic gonadotrophin (eCG or PMSG) is a hormone with FSH/LH effect that has been widely used in ewes and cows to induce follicle development. However, the possible positive effects of its administration to males have been rarely studied. ECG stimulates testosterone secretion and increases rams’ ability to stimulate ovulation in anoestrous ewes (the ‘ram effect’), but it is still not known if this effect is at least partially explained by an enhancement of a ram’s sexual behaviour. Thus, the aim was to determine if the administration of eCG induces an increase in testosterone concentration, and thus improves sexual behaviour of Saint Croix rams during both the breeding and the non-breeding seasons. Two doses of 1000 IU of eCG were administered separated by 4 days to 10 rams during the breeding and five rams during the non-breeding seasons, with the same number of animals as untreated controls. Administration of eCG increased testosterone concentration during the breeding (P = 0.008) and the non-breeding (P = 0.0009) seasons. The number of ano-genital sniffings, lateral approaches, as well as total courtship behaviours were greater in treated than untreated rams during the breeding season. Treated rams also tended to mount and mate more during the breeding season. During the non-breeding season, treated rams tended to display more ano-genital sniffs, lateral approaches and total courtship behaviours than untreated rams 6 days after the first dose. Overall, eCG increased testosterone concentrations the breeding and the non-breeding seasons, and was associated with a greater display of sexual behaviours during the former.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

1. To compare the basic hindlimb synergies for backward (BWD) and forward (FWD) walking, electromyograms (EMG) were recorded from selected flexor and extensor muscles of the hip, knee, and ankle joints from four cats trained to perform both forms of walking at a moderate walking speed (0.6 m/s). For each muscle, EMG measurements included burst duration, burst latencies referenced to the time of paw contact or paw off, and integrated burst amplitudes. To relate patterns of muscle activity to various phases of the step cycle, EMG records were synchronized with kinematic data obtained by digitizing high-speed cine film. 2. Hindlimb EMG data indicate that BWD walking in the cat was characterized by reciprocal flexor and extensor synergies similar to those for FWD walking, with flexors active during swing and extensors active during stance. Although the underlying synergies were similar, temporal parameters (burst latencies and durations) and amplitude levels for specific muscles were different for BWD and FWD walking. 3. For both directions, iliopsoas (IP) and semitendinosus (ST) were active as the hip and knee joints flexed at the onset of swing. For BWD walking, IP activity decreased early, and ST activity continued as the hip extended and the knee flexed. For FWD walking, in contrast, ST activity ceased early, and IP activity continued as the hip flexed and the knee extended. For both directions, tibialis anterior (TA) was active throughout swing as the ankle flexed and then extended. A second ST burst occurred at the end of swing for FWD walking as hip flexion and knee extension slowed for paw contact. 4. For both directions, knee extensor (vastus lateralis, VL) activity began at paw contact. Ankle extensor (lateral gastrocnemius, LG) activity began during midswing for BWD walking but just before paw contact for FWD walking. At the ankle joint, flexion during the E2 phase (yield) of stance was minimal or absent for BWD walking, and ankle extension during BWD stance was accompanied by a ramp increase in LG-EMG activity. At the knee joint, the yield was also small (or absent) for BWD walking, and increased VL-EMG amplitudes were associated with the increased range of knee extension for BWD stance. 5. Although the uniarticular hip extensor (anterior biceps femoris, ABF) was active during stance for both directions, the hip flexed during BWD stance and extended during FWD stance.(ABSTRACT TRUNCATED AT 400 WORDS)

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

The relationship between muscle deoxygenation and activation was examined in three different muscles of the quadriceps during cycling ramp exercise. Seven young male adults (24 ± 3 yr; mean ± SD) pedaled at 60 rpm to exhaustion, with a work rate (WR) increase of 20 W/min. Pulmonary oxygen uptake was measured breath-by-breath, while muscle deoxygenation (HHb) and activity were measured by time-resolved near-infrared spectroscopy (NIRS) and surface electromyography (EMG), respectively, at the vastus lateralis (VL), rectus femoris (RF), and vastus medialis (VM). Muscle deoxygenation was corrected for adipose tissue thickness and normalized to the amplitude of the HHb response, while EMG signals were integrated (iEMG) and normalized to the maximum iEMG determined from maximal voluntary contractions. Muscle deoxygenation and activation were then plotted as a percentage of maximal work rate (%WRmax). The HHb response for all three muscle groups was fitted by a sigmoid function, which was determined as the best fitting model. The c/d parameter for the sigmoid fit (representing the %WRmax at 50% of the total amplitude of the HHb response) was similar between VL (47 ± 12% WRmax) and VM (43 ± 11% WRmax), yet greater ( P < 0.05) for RF (65 ± 13% WRmax), demonstrating a “right shift” of the HHb response compared with VL and VM. The iEMG also showed that muscle activation of the RF muscle was lower ( P < 0.05) compared with VL and VM throughout the majority of the ramp exercise, which may explain the different HHb response in RF. Therefore, these data suggest that the sigmoid function can be used to model the HHb response in different muscles of the quadriceps; however, simultaneous measures of muscle activation are also needed for the HHb response to be properly interpreted during cycle ramp exercise.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Vehicle springs and stabilizer bar are critical suspension components impacting vehicle riding and handling experience. Diagnostics and prognostics of springs and stabilizer bar can improve customer perceived quality, reduce repair cost and increase up-time for fleet vehicles. It’s even more important for autonomous vehicles, since there is no human driver to sense fault symptoms. Currently, there is no production solution to automatically diagnose and prognose spring and stabilizer bar failures, and most research work is suffered by various noise factors. In this work, a novel solution based on static ramp test is proposed to isolate and localize spring and stabilizer bar faults. With limited number of longitudinal and lateral acceleration measurements, the solution can quickly and effectively isolate faulty spring, disconnected stabilizer bar, loose bushing and loose end link. The validation results from a MY17 Bolt EV demonstrate the effectiveness and robustness of the proposed solution.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

1. We have tested the hypothesis that the basal ganglia initiate some one or several modes of movement by recording the change in discharge frequency of pallidal neurons during visually triggered step and visually paced ramp moves in relation to the visual stimulus onset, the change in the electromyograph (EMG), and the movement onset of trained rhesus monkeys. 2. The modal times of change for globus pallidus pars interna (GPi) were significantly later than those for forearm agonist muscle EMG. By contrast, the modal time of change for the cerebellar dentate nucleus preceded that for wrist agonist EMG. 3. The direction of change in discharge frequency of the GPi cells was for 71% an increase and for 29% a decrease. 4. Because of the relatively late change of activity of GPi neurons, we propose that GPi neurons cannot initiate these movements, as others have also suggested. The commands for the initiation of these movements may instead be generated by structures that include the lateral cerebellum and the anterior cerebral cortex. 5. We have also tested the hypothesis that the pallidum of the basal ganglia or the dentate of the lateral cerebellum may control the direction and other parameters of the trajectory by recording from both structures to see whether cell discharge correlated with the parameter and whether the correlation was consistent across tasks. Two rhesus monkeys were trained to perform hold-ramp-hold and hold-step-hold visually guided movements in opposite directions by flexing and extending the wrist with and against uniform oppositely directed torque loads (0.2 Nm). Wrist position, velocity, force, and EMG were recorded simultaneously. Movement amplitudes and directional intent were computed and inferred, respectively. 6. Task related neurons were classified as follows: 1) directional, if the discharge rate was reciprocal for opposite movements or if it increased or decreased during movement in one direction only; 2) bidirectional, if the discharge rate increased or decreased during movement in both directions; and 3) "other," if it was directional under one load and bidirectional under the other. During step tracking, 34 GPi, 47 globus pallidus pars externa (GPe), and 44 cerebellar dentate nuclear neurons were related to the task. Of the GPi cells, 14 (41%) were directional, 6 (18%) bidirectional, and 14 (41%) other. Of the GPe neurons, 13 (28%) were directional, 19 (40%) bidirectional, and 15 (32%) other. Of the dentate cerebellar nuclear cells, 5 (11%) were bidirectional, 31 (70%) bidirectional, and 8 (18%) other.(ABSTRACT TRUNCATED AT 400 WORDS)

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Near the exposed Grenville craton, a two-layer crust with velocities of 6.2 km s–1 and 6.65 km s–1 and low gradient is measured. The 6.65 km s–1 velocity is observed at the shallow depth of 15 km and the Moho at greater than 40 km depth. Towards the Appalachian orogen, a southwards dipping ramp is developed in the mid crust on the top of the 6.65 km s–1 layer. A collinear reflection profile confirms the southwards dipping ramp, the shallowing Moho and the lateral changes in the lower crust. A published refraction profile that crosses this reflection profile near the southern end confirms the termination of the 6.65 km s–1 layer and its replacement by a slower velocity. With the publishing of wide angle reflection–refraction (WAR) profile 88-2, two pairs of lines are now available in the gulf that cross the craton into the orogen with both WAR and deep seismic reflection coverage. The combined data sets are used to distinguish the Grenville lower crustal block based on patterns of reflectivity and associated velocities. Near the Gaspé, the Grenville lower crustal block extends southwestward and, by extrapolation of the tectonostratigraphic zones offshore, underlies the Humber zone. In contrast, profiles in the gulf to the west of Newfoundland imply the continuous Grenville lower crustal block terminates seaward of the Humber surface terrane. Along-strike variations in the extent of Grenville lower crustal block beneath the northern Appalachians are suggested as an important factor in determining the style of crustal deformation.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Isometric knee extension force and average integrated EMG of the vastus lateralis muscle were obtained from 27 healthy subjects using a maximum effort, ramp and hold protocol. In each of the 125 total trials mat were included in the analysis, a 2-s plateau region was extracted and divided into two adjacent 1000-ms bins. Variability and reliability of bin-to-bin measurements of force and EMG were then evaluated across 14 different integration intervals ranging from 10 to 1000 ms. Statistical analyses of bin-to-bin variability measures demonstrated that integration intervals of 250 ms and longer significantly reduced variability and improved reliability of average integrated EMG values during maximum effort isometric exertions. Bin-to-bin EMG reliability increased from .728 at 10 ms to .991 at 1000 ms. Force parameters appeared less sensitive to changes in length of the integration interval. It was suggested that longer intervals might also improve the validity of the EMG-force relationship during maximum effort isometric exertions by reducing problems associated with electromechanical delay.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

The slow component of pulmonary O2 uptake (V̇o2) during constant work rate (CWR) high-intensity exercise has been attributed to the progressive recruitment of (type II) muscle fibers. We tested the following hypotheses: 1) the V̇o2 slow component gain would be greater in a 3-min all-out cycle test than in a work-matched CWR test, and 2) the all-out test would be associated with a progressive decline, and the CWR test with a progressive increase, in muscle activation, as estimated from the electromyogram (EMG) of the vastus lateralis muscle. Eight men (aged 21–39 yr) completed a ramp incremental test, a 3-min all-out test, and a work- and time-matched CWR test to exhaustion. The maximum V̇o2 attained in an initial ramp incremental test (3.97 ± 0.83 l/min) was reached in both experimental tests (3.99 ± 0.84 and 4.03 ± 0.76 l/min for all-out and CWR, respectively). The V̇o2 slow component was greater ( P < 0.05) in the all-out test (1.21 ± 0.31 l/min, 4.2 ± 2.2 ml·min−1·W−1) than in the CWR test (0.59 ± 0.22 l/min, 1.70 ± 0.5 ml·min−1·W−1). The integrated EMG declined by 26% ( P < 0.001) during the all-out test and increased by 60% ( P < 0.05) during the CWR test from the first 30 s to the last 30 s of exercise. The considerable reduction in muscle efficiency in the all-out test in the face of a progressively falling integrated EMG indicates that progressive fiber recruitment is not requisite for development of the V̇o2 slow component during voluntary exercise in humans.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Santelmoais diagnosed by the following characters: anterior portion of frontals fused; scapular foramen open; anterior ceratohyal–posterior ceratohyal (=epihyal) articulation interdigitating; cranium narrowed; supratemporal commissure and occipital pores absent; intercalar reaching the prootic; ascending rami of the parasphenoid wing high; palatal arch well developed; posterior hyomandibular ramus short; post-temporal ventral ramus well developed; six branchiostegal rays; vertebrae asymmetrical; pelvic fin rays ensheathed; scales, lateral line, pyloric caeca, palatine and vomerine teeth present. A new species ofSantelmoa, Santelmoa elviraesp. nov., is described on the basis of four specimens collected from the Bellingshausen Sea, Southern Ocean, at a depth of 1837 m. The new species can be distinguished fromSantelmoa carmenae, the type species of the genus and the sole knownSantelmoaspecies, by the following characters: mouth inferior; vertical folds on posterior end of the upper lip and on the lower lip lobe; oral valve nearly reaching the anterior edge of vomer; two posterior nasal pores; lateral line double with ventral and medio-lateral branches; single row of palatine teeth; dorsal fin rays 108–111; anal fin rays 93–94; pectoral fin rays 18–19 and vertebrae asymmetrical, 26–27 + 90–93 = 116–119.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

✓ Perforating branches of the middle cerebral artery (MCA) were examined under magnification in 50 formalin-fixed brain hemispheres. Perforating vessels varied in number from three to 18, with an average of nine. The greater the number of vessels, the smaller was their diameter. In this study, the perforating arteries were divided into medial, middle, and lateral groupings. Those in the medial group usually arose directly from the MCA main trunk close to the carotid bifurcation. There were usually three vessels in the middle group, which originated not only from the MCA trunk, but also from the MCA collateral (cortical) branches. Common stems, when present, gave rise to individual perforating vessels and occasionally to thin olfactory and insular rami. Perforating arteries in the lateral group varied from one to nine in number. In addition to an origin from the MCA trunk, they also arose from cortical branches supplying the frontal and temporal lobes. The fact that lateral perforating vessels often originated from division sites and from terminal branches of the MCA is of clinical significance, because aneurysms are more commonly located at the MCA bifurcation. Anastomoses were not found among the perforating arteries. In two specimens, a fusion between a perforating artery and the MCA trunk was noted. Since the perforating vessels are obviously end arteries, injury to them must be avoided during operations for MCA aneurysms.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

While inclined walking is a frequent daily activity, muscle forces during this activity have rarely been examined. Musculoskeletal models are commonly used to estimate internal forces in healthy populations, but these require a priori validation. The aim of this study was to compare estimated muscle activity using a musculoskeletal model with measured EMG data during inclined walking. Ten healthy male participants walked at different inclinations of 0°, ± 6°, ± 12°, and ± 18° on a ramp equipped with 2 force plates. Kinematics, kinetics, and muscle activity of the musculus (m.) biceps femoris, m. rectus femoris, m. vastus lateralis, m. tibialis anterior, and m. gastrocnemius lateralis were recorded. Agreement between estimated and measured muscle activity was determined via correlation coefficients, mean absolute errors, and trend analysis. Correlation coefficients between estimated and measured muscle activity for approximately 69% of the conditions were above 0.7. Mean absolute errors were rather high with only approximately 38% being ≤ 30%. Trend analysis revealed similar estimated and measured muscle activities for all muscles and tasks (uphill and downhill walking), except m. tibialis anterior during uphill walking. This model can be used for further analysis in similar groups of participants.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Our understanding of pull-apart basins and their fault systems has been enhanced by analog experiments and simulations. However, there has been scarce interest to compare the faults that bound pull-apart basins with surface ruptures during earthquakes. In this study, we investigated the effects of a 2018 earthquake (Mw 7.5) on a pull-apart basin in the Palu–Koro fault system, Sulawesi Island, Indonesia, using geomorphic observations on digital elevation models and optical correlation with pre- and post-earthquake satellite images. A comparison of active fault traces determined by geomorphology with the locations of surface ruptures from the 2018 earthquake shows that some of the boundary faults of the basin are inactive and that active faulting has shifted to basin-shortcut faults and relay ramps. We also report evidence of lateral spreading, in which alluvial fan materials moved around the end of the alluvial fan. These phenomena may provide insights for anticipating the location of future surface ruptures in pull-apart basins.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

A triangle zone, which commonly occurs along the external margin of a foreland thrust and fold belt with a buried thrust front, is underlain by a subhorizontal, blind, foreland-verging thrust that ends against a foreland-dipping, hinterland-verging thrust. These contemporaneous thrusts, active towards the end of orogenesis, enclose an intercutaneous wedge that moved towards the foreland. During orogenesis, a triangle zone evolves through periodic replacement of faults bounding the active wedge. Replacements occur in cycles during each of which a lower fault tends to be replaced by one in a lower stratigraphic horizon, an upper fault by one farther away from the foreland. Each cycle ends with the lower fault moving to a younger horizon where it joins a new, more external upper fault.Near Coalspur, the triangle zone exposes the remnants of several wedges involving Upper Cretaceous and Paleocene molasse. Most of these wedges developed during the last cycle but one and have a combined displacement of about 5 km. Within this cycle, the younger the wedge, the older the strata at its extremity. The upper fault of each wedge cuts the lower fault of the preceding wedge. The upper fault of one of the wedges has a lateral ramp.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

BackgroundCryoneurolysis of peripheral nerves uses localised intense cold to induce a prolonged block over multiple weeks that has the promise of providing potent analgesia outlasting the duration of postoperative pain following surgery, as well as treat other acute and chronic pain states. However, it remains unclear whether persistent functional motor deficits remain following cryoneurolysis of mixed sensorimotor peripheral nerves, greatly limiting clinical application of this modality. To help inform future research, we used a rat peroneal nerve injury model to evaluate if cryoneurolysis results in persistent deficits in motor function.MethodsMale Lewis rats (n=30) had their common peroneal nerves exposed bilaterally at the proximal lateral margin of the knee and subsequently underwent cryoneurolysis on one limb and sham treatment on the contralateral limb. Outcomes were evaluated on days 3, 14, 30, 90 and 180. The primary end point was motor function, based on ankle dorsiflexion torque. In addition, sensory function was tested based on von Frey’s filament sensitivity to the peroneal sensory distribution. A subset of animals was sacrificed following functional testing at each time point, and general tissue morphology, connective tissue deposition, and axon counts were evaluated.ResultsMotor deficits in treated limbs were observed at 3 and 14 days but had resolved at time points beyond 1 month. Bilateral sensory deficits were also observed at 3 and 14 days, and also resolved within 1 month. Consistent with motor functional deficits, axon counts trended lower in treated nerves compared with contralateral controls at 3 days; however, axon counts were not significantly different at later time points.ConclusionsWhen applied to a mixed sensorimotor nerve, cryoneurolysis did not result in persistent motor deficits.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

The locations, within the brain stem, of vagal efferent preganglionic neurones with axons in the two pairs of cardiac vagal rami of the dogfish have been defined by the retrograde intra-axonal transport of horseradish peroxidase (HRP). HRP was applied to the cardiac rami in one of two ways: either as crystals placed on the cut central end of the nerve or as a dried concentrated solution administered into the nerve on the tip of a fine pin. No difference was observed in the number of labelled cell bodies identified using either method. Labelled branchial cardiac vagal motoneurones were found ipsilaterally in the medial division of the vagal motor column, in the lateral division of the vagal motor column, and scattered between these two locations. In contrast, visceral cardiac vagal motoneurones were confined to the ipsilateral medial division of the vagal motor column. We suggest that the dual location of cell bodies supplying axons to the branchial cardiac branch of the vagus may represent a separation of function with respect to the two types of activity conducted by this nerve. Cardiac efferent fibres are confined in their exit from the brain to a middle group of vagal rootlets. This corresponds to the topographical representation of cardiac efferent somata within the extent of the vagal motor column.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Laterally discontinuous, mixed carbonate–siliciclastic sandstones in the upper Vaureal and lower Ellis Bay formations of Anticosti Island were deposited on an equatorial carbonate ramp with a slope of less than 1°. The 10–18 m thick sandstones are interpreted as subaqueous sand-wave complexes analogous to detached parts of modern shoreface-connected sand ridges. These record storm-enhanced, tidal modification of a northerly derived shoal retreat massif that may have formed in response to recovery from global sea-level lowstands in the Late Ordovician (Ashgill: late Rawtheyan – Hirnantian). The sand-wave complexes formed within a tidal embayment that was confined by the Precambrian Shield to the north and northwest by rising tectonic highlands of the Humber Zone in Newfoundland to the east, and by active tectonic highlands in the Quebec Appalachians (Gaspésie) to the south. Paleocurrent distributions, parallel to the western margins of the Strait of Belle Isle, suggest that the north end of the embayment was closed in Late Ordovician time. Low-diversity faunas within the sand units consist mostly of sowerbyellid, strophomenid, and rhynchonellid brachiopods, bivalves, gastropods, large aulacerid stromatoporoids, and large, domed favositid corals. These "sandy fades" faunas belong to communities significantly different from those found in the laterally interfingering and overlying carbonates and shales, suggesting that the sand waves played an important role in local community modification.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

This study aimed to examine, at the level of the active muscles, whether the plateau in oxygen (O2) extraction normally observed near the end of a ramp incremental (RI) exercise test to exhaustion is caused by the achievement of an upper limit in O2 extraction. Eleven healthy men (27.3 ± 3.0 yr, 81.6 ± 8.1 kg, 183.9 ± 6.3 cm) performed a RI cycling test to exhaustion. O2 extraction of the vastus lateralis (VL) was measured continuously throughout the test using the near-infrared spectroscopy (NIRS)-derived deoxygenated hemoglobin [HHb] signal. A leg blood flow occlusion was performed at rest (LBFOCC1) and immediately after the RI test (LBFOCC2). The [HHb] values during the resting occlusion (108.1 ± 21.7%; LBFOCC1) and the peak values during exercise (100 ± 0%; [HHb]plateau) were significantly greater than those observed at baseline (0.84 ± 10.6% at baseline 1 and 0 ± 0% at baseline 2) ( P < 0.05). No significant difference was found between LBFOCC1 and [HHb]plateau ( P > 0.05) or between the baseline measurements ( P > 0.05). [HHb] values at LBFOCC2 (130.5 ± 19.7%) were significantly greater than all other time points ( P < 0.05). These results support the existence of an O2 extraction reserve in the VL muscle at the end of a RI cycling test and suggest that the observed plateau in the [HHb] signal toward the end of a RI test is not representative of an upper limit in O2 extraction.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Background: The sacroiliac (SI) joint is a common cause of low back pain, for which radiofrequency (RF) denervation has been shown to provide long-term relief. However, controversy exists surrounding the innervation, which treatment paradigm to utilize, and how best to select patients who might benefit. Objective: To describe a patient with terminal breast cancer and tumor infiltration of the sacroiliac joint who was treated with cooled RF of the sacral lateral branches as an end-oflife palliative measure. The objectives of this review are to provide insight into the innervation of the SI joint; address controversial issues surrounding the targeted nerves in a patient with transitional anatomy; outline risk-mitigation strategies; and highlight the need for individually tailored treatment plans. Methods: Case-based focused literature review in a patient treated with cooled RF ablation of the L4-S3 primary dorsal rami and lateral branches. Results: Treatment was tailored to facilitate the rapid treatment of this terminal patient by performing the prognostic blocks and RF ablation at the same visit. Until her death 5 days post-procedure, the patient reported significant pain relief and began to ambulate and use the bathroom on her own, activities she could not do before treatment. In addition to functional improvement, she was also able to significantly reduce her opioid intake. Conclusion: This is the first report of cooled SI joint RF ablation to treat cancer pain. Our patient’s positive response to the procedure suggests the possibility that the lateral branches innervate not only the posterior ligaments, but also the bony articulation. The decision to proceed with RF ablation on the same day as a prognostic lateral branch block was based on our patient’s terminal condition, and the fact that cooled RF does not require sensory stimulation to ensure proximity to the target nerves. Because of her transitional anatomy, we elected to target L4. Key words: Cancer, denervation, innervation, radiofrequency, sacroiliac joint, transitional anatomy

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Two year old Romney rams from the Massey University fleeceweight-selected (FW) and control (C) lines, five from each line, were given arterial catheters into a branch of the deep circumflex artery on each side of the sheep, to permit local infusion into patches of skin on each lateral abdominal flank. One side of each sheep was infused with saline to give a direct FW v. C comparison, while the other side was infused with low levels of either growth hormone, thyroxine, prolactin or insulin for 4 days. At the end of the infusion period, biopsy samples were taken from each flank for measurement of follicle activity, particularly bulb cell proliferation using intracutaneous injections of 5-bromo-2'-deoxyuridine (BrDU). After a period of recovery, the saline and treated sides were reversed and another series of infusions were performed and biopsies undertaken. Wool from the FW sheep had greater fibre length growth rate and fibre diameter than the C wool (P < 0.05). This was associated with larger follicle bulbs (P < 0.05) and greater numbers of BrDU labelled cells (P < 0.05) in the bulbs of the FW skin. In a restricted number of samples from two sheep, where BrDU was successfully given as repeated intracutaneous injections into the same site (one at 72 h and one at 6 h prior to biopsy), 55-60% of the numbers of BrDU cells in a section of bulb appeared in a section of the shaft of the same follicle. When converted to three dimensions, the efficiency of labelled bulb cell movement into the shaft was 30-40%. Hormonal infusions showed few significant effects with the restricted numbers of animals in each treatment. Thyroxine reduced the size of follicle bulbs (P <0.05) and the numbers of labelled bulb cells in skin from the infused area.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Locomotor state transitions are challenging for transfemoral (TF) amputees due to the lack of active knee control even in the current powered prosthetic devices. Myoelectric activation has been used successfully to classify steady-state locomotion states, but classification of transitions between locomotion states remains a challenge, especially for TF amputees. The purpose of this study was to determine if lower-extremity muscle activation differences between pre-transition and transition gait cycles occur in the involved or uninvolved limb of TF amputees during locomotion state transitions. Surface electromyography (EMG) was collected from residual muscles on the involved limb and from the uninvolved limb from five TF amputees as they transitioned between different locomotion states (level ground, ramp ascent/descent, stair ascent/descent). Statistical parametric mapping (SPM) was used to assess differences in activation. When analyzed as a group, the only significant differences were observed in the vastus lateralis of the uninvolved limb. High inter-subject variation reduced the significance of other pattern differences. Further inspection revealed that the individual subjects expressed three different recruitment patterns. These recruitment patterns may indicate compensatory strategies adopted by the subjects over the years since amputation. Furthermore, the separate recruitment patterns suggest the need for individualized locomotion transition classification algorithms rather than a general classification scheme.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

The early time course of adaptation of pulmonary O2 uptake (V̇o2p) (reflecting muscle O2 consumption) and muscle deoxygenation kinetics (reflecting the rate of O2 extraction) were examined during high-intensity interval (HIT) and lower-intensity continuous endurance (END) training. Twelve male volunteers underwent eight sessions of either HIT (8–12 × 1-min intervals at 120% maximal O2 uptake separated by 1 min of rest) or END (90–120 min at 65% maximal O2 uptake). Subjects completed step transitions to a moderate-intensity work rate (∼90% estimated lactate threshold) on five occasions throughout training, and ramp incremental and constant-load performance tests were conducted at pre-, mid-, and posttraining periods. V̇o2p was measured breath-by-breath by mass spectrometry and volume turbine. Deoxygenation (change in deoxygenated hemoglobin concentration; Δ[HHb]) of the vastus lateralis muscle was monitored by near-infrared spectroscopy. The fundamental phase II time constants for V̇o2p (τV̇o2) and deoxygenation kinetics {effective time constant, τ′ = (time delay + τ), Δ[HHb]} during moderate-intensity exercise were estimated using nonlinear least-squares regression techniques. The τV̇o2 was reduced by ∼20% ( P < 0.05) after only two training sessions and by ∼40% ( P < 0.05) after eight training sessions (i.e., posttraining), with no differences between HIT and END. The τ′Δ[HHb] (∼20 s) did not change over the course of eight training sessions. These data suggest that faster activation of muscle O2 utilization is an early adaptive response to both HIT and lower-intensity END training. That Δ[HHb] kinetics (a measure of fractional O2 extraction) did not change despite faster V̇o2p kinetics suggests that faster kinetics of muscle O2 utilization were accompanied by adaptations in local muscle (microvascular) blood flow and O2 delivery, resulting in a similar “matching” of blood flow to O2 utilization. Thus faster kinetics of V̇o2p during the transition to moderate-intensity exercise occurs after only 2 days HIT and END training and without changes to muscle deoxygenation kinetics, suggesting concurrent adaptations to microvascular perfusion.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Introducción: El síndrome del espacio cuadrilátero (QSS) es un cuadro clínico causado por la compresión nerviosa y/o vascular a nivel del espacio axilar lateral. La prevalencia de este síndrome se desconoce y se cree que es baja, sin embargo, formas de presentación incompleta podrían llevar a que el mismo sea subdiagnosticado. Objetivo: Describir un protocolo diagnóstico utilizado en una serie de casos consecutivos de pacientes con omalgia inespecífica y sospecha de QSS. Materiales y Métodos: De manera prospectiva se evaluaron 10 pacientes con omalgia agravada con la rotación externa forzada, uno de ellos con síntomas bilaterales. Se realizó electromiografía (EMG) de deltoides y redondo menor bilaterales, con estudios de conducción nerviosa. Los valores se compararon con el hombro sano, y con un grupo control. El diagnóstico se confirmó mediante resonancia magnética nuclear (RMN). Resultados: El EMG mostró en todos los casos atrapamiento con compromiso axonal de la rama para el redondo menor, con preservación de la inervación del deltoides. La RMN mostró en los 11 hombros afectados atrofia selectiva del redondo menor. Conclusión: El QSS en sus formas incompletas suele ser subdiagnosticado, siendo necesario mantener un alto índice de sospecha clínica frente a un cuadro de omalgia inespecífica. Palabras Claves: espacio cuadrilátero, omalgia, electromiografía, redondo menor, nervio axilar. Introduction: The quadrilateral space syndrome (QSS) has clinical features caused by a nervous and /or vascular compression at the lateral axillary space. The prevalence of this syndrome is unknown but it is believed to be low. Nevertheless, some cases with an incomplete clinical presentation might be misdiagnosed. Purpose: To describe a diagnostic protocol used in a series of consecutive cases of patients with non-specific omalgia and suspected QSS. Materials and Methods: Ten patients of both genders suffering shoulder pain aggravated by forced external rotation were prospectively evaluated. One of them had bilateral symptoms. Evaluation included clinical examination, electromyography (EMG) and nerve conduction studies of the deltoid and teres minor bilaterally. The results were compared with an age-matched control group. Diagnosis was confirmed by magnetic resonance imaging (MRI). Results: The EMG showed in all the cases a selective entrapment of the branch for the teres minor, with preservation of the innervation of the deltoid. The RMN showed in the 11 affected shoulders selective atrophy of the teres minor. Conclusion: Incomplete presentations of the QSS are usually underdiagnosed, making it necessary to maintain a high index of clinical suspicion in front of any non-specific omalgia case. Key words: quadrilateral space, omalgia, electromyography, teres minor, axillary nerve.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

A ground squirrel is a hibernator, which hibernation lasts, depending on the age and sex, since the end of the summer until the spring. During this period in the body of ground squirrel, as well as in other hibernators, starts lowering of all vital functions, what has been proven by numerous physiological, biochemical and histological examinations of some organ systems of this animal. The objective of our work was to investigate a part of cardiovascular system of ground squirrel so in that way to contribute to a better knowledge of this animal body structure and accordingly to comparative anatomy in general. The investigation included 6 ground squirrels, of both gender, body weight 200-300 grams. For obtaining head and neck arterial vascularization, after exsanguination of the animal, contrast mass of gelatin coloured with tempera was injected into thoracic aorta (Aorta thoracica). After injecting, the blood vessels were prepared and photographed. For obtaining the corrosive preparations of head and neck arterial blood vessels, after exsanguination of the animal, Biocryl (a mixture of liquid biocryl - methil - methacrylate monomer and biocryl in powder - methil - methacrylate polymer) was injected into thoracic aorta (Aorta thoracica). After injecting the preparations were placed into 5% NaOH, for 96 hours or into 10% NaOH for 48 hours. After that they were rinsed in hot water and photographed. A. facialis in ground squirrel is an extension of A. maxillaris. The branches of A. facialis are: A. labialis inferior, A. bursae buccalis dorsalis, A. labialis superior, A. dorsalis nasi and A. angularis oculi. The obtained results regarding A. facialis in ground squirrel (Citellus citellus) were compared to the same ones in rats. In rats, A. facialis is the biggest branch separating from A. carotis externa. The branches of A. facialis in rats are: Ramus glandularis, A. submentalis, A. masseterica ventralis, A. labialis inferior, A. angularis oris, A. labialis superior, Rami musculares, A. lateralis nasi and A. angularis oculi. Based on the above mentioned results, it can be concluded that both in ground squirrel and rat A. facialis branches into A. labialis inferior, A. labialis superior and A. angularis oculi. In ground squirrel the branches of A. facialis are also A. bursae buccalis dorsalis and A. dorsalis nasi, and in rat those are Ramus glandularis, A. submentalis, A. masseterica ventralis, A. angularis oris, Rami musculares and A. lateralis nasi.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Four rhesus monkeys were trained to perform visually guided wrist tracking movements (50). While they performed tasks by wrist flexion or extension from a neutral position, simple-spike (SS) and complex-spike (CS) discharges of a single Purkinje cell (P-cell) were recorded from intermediate and lateral parts of cerebellar hemispheres (lobules IV to VI) ipsilateral to the task-performing wrist. Of approximately 400 P-cells observed, 215 (54%) significantly increased or decreased their SS discharge rate during task performance (task-related P-cells). Of these, 161 were selected for analysis of CS activity; in these P-cells, we could reliably discriminate between CS and background SS by a spike discriminator. The 161 P-cells were further classified into response locked (n = 65) and poorly locked (n = 96) cells according to temporal coupling of the SS frequency modulation to the onset of wrist movements. About 60% of the response-locked P-cells showed a phasic increase (statistical significance level: P less than 0.01) of CS firing rate at the onset of wrist tracking movement. In a few P-cells, a phasic decrease (statistically insignificant) of CS firing rate was observed with the wrist movement. In most P-cells, an increase of CS firing rate was observed with both rapid- and slow-tracking wrist movements. The increase was larger with faster step-tracking movement than with slower ramp-tracking movement. In most P-cells, the CS activity increased with both wrist flexion and extension; in some cells, however, it increased only with either flexion or extension. In most of the response-locked P-cells, the increase of CS firing rate occurred during motor time, i.e., after the onset of the EMG change in prime movers and before the beginning of wrist tracking movement. The increase occurred phasically at the onset and/or at the recovery phase of SS frequency modulation. At neutral wrist position, the maintained frequency of the CS was 0.72 +/- 0.29 CS/s (mean and SD for 161 task-related P-cells). Compared with the frequency at neutral position, the CS frequency did not change tonically during maintained flexed or extended wrist position in any response-locked P-cells. There was no increase of CS firing rate when the monkey returned the handle to center position after completing the tracking task, even in P-cells that had shown a significant increase of CS activity during tracking.(ABSTRACT TRUNCATED AT 400 WORDS)

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

OBJECTIVES/SPECIFIC AIMS: Computed tomography (CT) enables 3-dimensional (3D) visualization of cortical bone structures with high spatial resolution, and thus has been the gold-standard method for evaluation and diagnosis of craniofacial skeletal pathologies. However, ionizing radiation and, in particular, repeated scanning for presurgery and postsurgery assessments, is of concern when applied to infants and young children. Recent advances in solid-state MRI allow the capture of the short-T2 signals in cortical bone while suppressing the signal from soft-tissue protons having T2 relaxation time 1–2 orders of magnitude longer (50–100 ms). One approach, a dual-radiofrequency (RF) pulse and ultrashort echo time (UTE) imaging based method, exploits different sensitivities of bone and soft tissue to different RF pulse widths and TEs. This study aims to demonstrate the feasibility of producing 3D renderings of the human skull and visualization of cranial sutures using the bone-selective MRI technique in comparison to CT. METHODS/STUDY POPULATION: Imaging technique: Two RF pulses differing in duration and amplitude are alternately applied in successive repetition time (TR) along the pulse train. Within each TR, 2 echoes are acquired. Acquisition of the first echo starts at the ramp-up of the encoding gradient (TE1), allowing for capture of signals with very short lifetimes (bone), while that of the second starts after a longer delay (TE2). In total, 4 echoes are obtained: ECHO11 (RF1TE1), ECHO12 (RF1TE2), ECHO21 (RF2TE1), and ECHO22 (RF2TE2). During reconstruction, ECHO11 is combined with ECHO21 and ECHO12 is combined with ECHO22, resulting in 2 images. The subtraction of these 2 images yields an enhanced bone contrast. Data acquisition/processing: The pulse sequence described above was applied for MR imaging of a human cadaveric skull and 2 adult human subjects in vivo, at 3T field strength (Siemens Prisma, Erlangen, Germany). Imaging parameters: TR/TE1/TE2=7/0.06/2.46 ms, RF1/RF2 durations=40/520 μs, flip angle=12°, matrix size=2563, field of view=2803 mm3, voxel size=1.1 mm isotropic, number of radial spokes=25,000, and scan time=6 minutes. Segmentation of bone voxels was performed using ITK-SNAP in a semi-automatic fashion, leading to 3D renderings of the skull. For comparison, a CT scan was also performed in the human cadaveric skull with 1 mm isotropic resolution. Validation: The biometric accuracy was assessed by measuring eight anatomic distances: (1) Maximum craniocaudal aperture of the right orbit. (2) Maximum craniocaudal aperture of the left orbit. (3) Maximum height of the mandible from chin point in the midline. (4) Maximum cranial length (5) Maximum cranial width. (6) Maximum height of piriform aperture. (7) Distance between lateral most aspect of mandibular condyles. (8) Distance between lateral most aspect of posterior hard palate in both CT- and MRI-based 3D renderings of the human cadaveric skull using Mimics software (Materialise®, Ghent, Belgium). These distances were compared with those directly measured on the cadaveric skull. RESULTS/ANTICIPATED RESULTS: Compares CT with the proposed MRI method on cadaveric human skull images, along with corresponding 3D renderings. Compared with CT, the 3D rendered images maintain most features over the entire head (e.g., zygomatic arch), except for appearance of some artifacts in the mandibular region. In vivo head images in 2 adult subjects: axial magnitude images and 3D rendering. In the axial images, bone voxels as well as the inner table of the cranium are clearly visualized, and cranial and spinal bone structures are well depicted in the 3D renderings. Some voxels were erroneously included or excluded in the renderings. The mean difference in measurements of the 8 anatomic distances was 6, 4, and 2 mm when comparing MRI Versus CT, MRI Versus in situ, and CT Versus in situ, respectively. DISCUSSION/SIGNIFICANCE OF IMPACT: Bone proton magnetization exhibits a substantial level of signal decay during the relatively long duration of RF2 due to its very short T2 relaxation time. In contrast, soft-tissue retains nearly the same level of signal intensities over all echoes. Thus, subtraction of ECHO22 from ECHO11, when compared with the difference between ECHO11 and ECHO12, enhances bone contrast from soft tissue. The proposed, dual-RF dual-echo 3D UTE imaging technique produces isotropic high-resolution bone-specified images in the whole head within a clinically feasible imaging time (6 min), leading to clear visualization of craniofacial skeletal structures. These are key components necessary for translation to the clinical setting. Optimization of postprocessing for more realistic 3D renderings and thus accurate anatomic measurements is currently being implemented. The proposed method’s potential as a nonradiative alternative to CT will then be thoroughly evaluated in pediatric patients.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Abstract The Upper Liassic series in the western border of Iberia (Lusitanian Basin, Portugal), show an important lutitic sedimentation, characterized generally by a monotonous marl/limestone alternation. Small scale siliceous sponge mudmounds occur in these deposits from Middle Toarcian to Lower Aalenian age. The scope of this work is to pinpoint the stratigraphical and sedimentological context and to characterize controlling factors of the spongioliths. Stratigraphic and facies analysis. Relevant sections were observed and investigated in different locations of the Lusitanian Basin (e.g., Alvaiazere, Porto de Mos, Rabacal, Coimbra and Cantanhede) (fig. 1). The siliceous sponge facies correspond to the upper part of the S. Giao Unit and to the lower part of the Povoa da Lomba Unit (fig. 2). Considering the sequential scheme of Duarte [1997], the sediments correspond to groups of third-order depositional sequences MST3 and MST4 (mainly in the upper part of this sequence: MST4B). The sedimentary evolution of these units shows a stacking pattern composed of shallowing upward sequences deposited in an outer hom*oclinal ramp setting, dipping northwestwards. Both units increase in thickness from south to north (fig. 3) and their vertical facies associations correspond to a very bioturbated (Chondrites, Zoophycos, Planolites and Thalassinoides) marl/limestone succession (figs. 4 and 5). MST3 is demonstrably more marly than MST4B. The base of MST4 [MST4A in Duarte, 1997] corresponds to a marl/marly limestone alternation, very poor in siliceous sponge mudmounds. The first unit (MST3) which includes sponge mudmounds is dated as uppermost Bifrons zone through the base of the Bonarellii zone. The majority of the siliceous sponge mudmounds occur within this time slice. These mounds are characterized by a great diversity of accompanying fauna mainly composed of brachiopods (rhynchonellids and terebratulids), crinoids and bivalves. The initial growth of the sponge build-ups can be correlated basin-wide to the intra Bifrons regional flooding surface (MST2/MST3 boundary). The second unit (MST4), particularly its upper part (MST4B), corresponds to the top of the Meneghinni-Opalinum interval and is related to a carbonate progradational phase. In the eastern part of the basin, the calcareous facies of MST4B are more bioclastic. Siliceous sponge mudmounds. The Toarcian mudmounds of the Lusitanian Basin are usually only a few decimetres thick and most display irregular knob-like to flat lenticular morphologies. Some build-ups are round and can reach 1,5 metres in thickness and ten metres in diametre. Also worth mentioning is a siliceous sponge biostrome developed at the base of MST3 in the Porto de Mos section (figs. 3 and 6). The upper mound surface is normally rough and uneven. In both sequences they are always related laterally with carbonate beds, which corresponds to the top of fourth order sequences. The mudmounds consist of mostly brownish iron-rich calcified siliceous sponges and a greyish, sometimes peloidal allochthonous micritic matrix. In general, the sponges themselves consist of dense leiolitic microbolites [automicrites sensu Reitner and Neuweiler, 1993]. The sponge spicules are diagenetically transformed into calcite. The great majority of the sponge specimens belong to the Hexactinosa (Class Hexactinellida) and are unknown and undescribed to date. "Lithistides" (polyphyletic desma-bearing demosponges) are very rare and only occur as forms encrusting Hexactinosan sponges. The benthic macrofauna is abundant and consists of monospecific crinoids, rhynchonellids, terebratulids and bivalves (mainly pectinids and ostreids). Encrusting organisms are serpulids, bryozoans and foraminifera, as well as "Lithistids" mentioned above. They are entirely restricted to the stratonomical surfaces of the siliceous sponges. The sponge bioherms consist of several microfacies types (wackestones, packstones, floatstones and boundstones). All of them are micrite dominated and represent low energy environments. They differ mainly in the amount of siliceous sponges, micrite, microbialites and the accompanying fauna. Palaeoenvironmental significance. The amount of microbial induced carbonate clearly mirrors the importance of microbial activity in respect of the reef building potential. Furthermore, three other controlling factors played an important role in the initiation of the siliceous sponge mudmounds of the Lusitanian Basin: bathymetry, sea-floor morphology and sedimentation rate. The role of the first two factors is evident because the siliceous sponge mudmounds are particularly important (abundance and volumetric expression) in the eastern part of the basin (Rabacal-Alvaiazere region). They are practically absent towards the west (essentially in MST4B) where the series show hemipelagic sedimentologic features (figs. 7 and 8). Reduced sedimentation rate is a precondition for the settlement of siliceous sponges and Hexactinosa in particular. Compared to all other Toarcian sequential units, MST3 and MST4B are the thinnest and therefore reflect the lowest sedimentation rates (fig. 8).

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Abstract Southeastern Indonesia is located at a convergent triple junction of 3 plates : the Pacific (including the Caro-line and Philippines plates), the Australian and the Southeast Asian plates (fig. 1). The age of the different basins : the North Banda Sea (Sula Basin), the South Banda Sea (Wetar and Damar Basins) and the Weber Trough has been debated for a long time. Their great depth was a reason to interpret them as remnants of oceanic domains either of Indian or Pacific ocean affinities. It has now been demonstrated from geochronological studies that these basins have formed during the Neogene [Réhault et al., 1994 ; Honthaas et al., 1998]. The crust has been sampled only in the Sula Basin, where basalts or trachyandesites with back-arc geochemical signatures have been dredged. Their ages range from 11.4 ± 1.15 to 7.33 ± 0.18 Ma [Réhault et al., 1994 ; Honthaas et al., 1998]. The study of the magnetic anomaly pattern of these basins confirms this interpretation and defines an age between 12.5 and 7.15 Ma for the North Banda Basin and between 6.5 to 3.5 Ma for the South Banda Basin [Hinschberger et al., 2000 ; Hinschberger et al., 2001]. Furthermore, the existence of volcanic arcs linked to subducted slabs suggests that these basins resulted from back-arc spreading and subduction slab roll-back. Lastly, the Weber Trough which exceeds 7 300 m in depth and is one of the deepest non subduction basins in the world, remains enigmatic. A compilation of existing bathymetric data allows us to present a new bathymetric map of the region (fig. 2 and 3). A comparison with the previous published maps [Mammerickx et al., 1976 ; Bowin et al., 1982] shows numerous differences at a local scale. This is especially true for the Banda Ridges or in the Sula Basin where new tectonic directions are expressed. In the North Banda Basin, the Tampomas Ridge, which was striking NE-SW in the previous maps, is actually NW-SE parallel to the West Buru Fracture Zone and to the Hamilton Fault scarp (fig. 6). This NW-SE direction represents the initial direction of rifting and oceanic spreading. In this basin, only the southeastern rifted margin morphology is preserved along the Sinta Ridges. The basin is presently involved in an overall compressional motion and its buckled and fractured crust is subducted westwards beneath East Sulawesi (fig. 4a, 5 and 6). The northern border of the North Banda Basin is reactivated into sinistral transcurrent motion in the South Sula Fracture Zone continued into the Matano fault in Sulawesi. The South Banda Sea Basin is divided in two parts, the Wetar and Damar Basins with an eastward increase in depth. The Wetar and Damar Basins are separated by the NNW-SSE Gunung Api Ridge, characterized by volcanoes, a deep pull apart basin and active tectonics on its eastern flank (fig. 4b and 7). This ridge is interpreted as a large sinistral strike-slip fracture zone which continues across the Banda Ridges and bends towards NW south of Sinta Ridge. The Banda Ridges region, separating the North Banda Basin from the southern Banda Sea (fig. 5 and 7), is another place where many new morphological features are now documented. The Sinta Ridge to the north is separated from Buru island by the South Buru Basin which may constitute together with the West Buru Fracture Zone a large transcurrent lineament striking NW-SE. The central Rama Ridge is made of 2 narrow ridges striking NE-SW with an « en-echelon » pattern indicating sinistral strike slip comparable to the ENE-WSW strike-slip faulting evidenced by focal mechanisms in the northern border of the Damar Basin [Hinschberger, 2000]. Dredging of Triassic platform rocks and metamorphic basem*nt on the Sinta and Rama Ridges suggests that they are fragments of a continental block [Silver et al., 1985 ; Villeneuve et al., 1994 ; Cornée et al., 1998]. The Banda Ridges are fringed to the south by a volcanic arc well expressed in the morphology : the Nieuwerkerk-Emperor of China and the Lucipara volcanic chains whose andesites and arc basalts have been dated between 8 and 3.45 Ma [Honthaas et al., 1998]. Eastern Indonesia deep oceanic basins are linked to the existence of 2 different subduction zones expressed by 2 different downgoing slabs and 2 volcanic arcs : the Banda arc and the Seram arc [Cardwell et Isacks, 1978 ; Milsom, 2001]. They correspond respectively to the termination of the Australian subduction and to the Bird’s head (Irian Jaya) subduction under Seram (fig. 5). Our bathymetric study helps to define the Seram volcanic arc which follows a trend parallel to the Seram Trench from Ambelau island southeast of Buru to the Banda Island (fig. 2 and 5). A new volcanic seamount discovered in the southeast of Buru (location of dredge 401 in figure 7) and a large volcano in the Pisang Ridge (location of dredge 403 in figure 7 and figure 8) have been surveyed with swath bathymetry. Both show a sub-aerial volcanic morphology and a further subsidence evidenced by the dredging of reefal limestones sampled at about 3000 m depth on their flank. We compare the mean basem*nt depths corrected for sediment loading for the different basins (fig. 9). These depths are about 5 000 m in the Sula Basin, 4 800 m in the Wetar basin and 5 100 m in the Damar basin. These values plot about 1 000 m below the age-depth curve for the back-arc basins [Park et al., 1990] and about 2000 m below the Parsons and Sclater’s curve for the oceanic crust [Parsons et Sclater, 1977]. More generally, eastern Indonesia is characterized by large vertical motions. Strong subsidence is observed in the deep basins and in the Banda Ridges. On the contrary, large uplifts characterize the islands with rates ranging between 20 to 250 cm/kyr [De Smet et al., 1989a]. Excess subsidence in the back-arc basins has been attributed to large lateral heat loss due to their small size [Boerner et Sclater, 1989] or to the presence of cold subducting slabs. In eastern Indonesia, these mechanisms can explain only a part of the observed subsidence. It is likely that we have to take into account the tectonic forces linked to plate convergence. This is supported by the fact that uplift motions are clearly located in the area of active collision. In conclusion, the bathymetry and morphology of eastern Indonesian basins reveal a tectonically very active region where basins opened successively in back-arc, intra-arc and fore-arc situation in a continuous convergent geodynamic setting.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Abstract In the South Aquitain sector, salt bodies of varying sizes present two geographical gradients. The first gradient, south to north, associated with the proximity of the Pyrenees shows a decreasing deformation of the structures towards the north. The second gradient explains their increasing depth of burial from the west (extrusive structures) to the east (intrusive structures). This organization has been studied from the western sector (Tercis-Bénesse and Bastennes-Louer) to the eastern sector (Viella-Labarthète and Nogaro-Lussagnet). Other more modest structures, revealed by hydrographical anomalies, illustrate halokinetic events during the Quaternary. Then the detailed study of the Geaune dome shows a neotectonic phenomenon dating from the Mio-Pliocene. The radial annular drainage pattern of this structure is guided by recurrent faulting during the Quaternary. Thus the halokinetic dynamics consist in three phases: deformation of the diapirs (overthrusts) during the Oligocene, resuming of halokinesis during the middle of the Miocene and recurrent faulting during the Riss. A model of geomorphological evolution of the domes is then proposed. The first phase (stages of positive relief) is characterized by the centrifugal drainage pattern of the dome. The second phase (stages of inverted relief) is distinguished by the erosion of the center of the structure, by an inversion of the drainage pattern and by the sedimentary accretion in the central depression. Regional frame of the southern-Aquitaine diapirism. – Figure 1 shows the main saliferous bodies. They present a double geographical gradient. The first, S-N, is linked to the Pyrenean tectonics. On the south of the Frontal Overthrust the Trias participated in the overthrusts (St-Jean-de-Pied-de-Port Basin, St-Palais and Salies-de-Béarn structures, etc…). Then in the Outer Sub-Pyrenean zone, the salt forms the axial part of the E-W Pyrenean structures ; finally in the north, in the Aquitaine basin, the diapirs are only slightly deformed. The second gradient, E-W, is linked to the Gulf of Gascogne dynamics where the height of the salt structures decreases from west to east. In Aquitaine, diapirism is a nearly continuous event that has followed the different stages of the history of the basin. The evaporites are deposed in Keuper (Initiation = rifting). The real opening begins in the Albian with the initiation of the turbiditic basins. The main compression begins in the Palaeocene. During the Miocene, the tectonic movements take over with a left lateral transpression on direction N110oE conjugated with recurrent faults N140. Diapirism is reactivated. Certain structures come to the surface. From this rapid historic overview we must retain not only the permanence of diapirism but also the interactive movements between the ascending domes and the subsiding of compensation synclines Evolution of salt structures from West to East. – The cases studied correspond to megastructures (anticlines N140, N090 and multi-kilometric domes) and to the extrusive or intrusive mesostructures (kilometrical domes) which are organized on the ancient Triassic Armorican fault trough. The fact that a E-W global gradient exists for these salt structures is worthnoting: in the eastern sector, the domes are covered with 800 m to 2 000 m of molasse (Lussagnet, Nogaro, Viella-Labarthe, and Geaune) ; coexisting in the western sector are structures of varied forms with an exposed (Tercis, Bénesse, Bastennes) or sub-exposed (Dax) Triassic core. The presence of numerous drainage anomalies (annular and radio-annular drainage patterns) in the east as well as in the west reveals the existence of more modest deep structures. Their morphological expression on the surface shows the continuance of salt deformations during the Quaternary. An exemplary structure: the Geaune salt dome. – It is situated on a trend oriented N060oE. This “ ripple ” has existed since the Upper Jurassic. In fact it concerns an ancient Triassic rift where evaporites accumulated. Afterwards, this Upper Trias deposit underwent a diapiric process which spanned from the Jurassic (middle ? Upper ?) until the present. Geomorphological organization . – The sub-circular structure corresponds both to the valley or dale floor and to flat or convex interfluves. The organization of the drainage shows anomalies characterized by linear and curved structures. Several lineaments in a N140 direction are visible on the eastern half of the dome. They appeared as parallel drains aligned on both sides of the Marcusse brook. Sub-circular structures clearly appear on the sectors A and B of the eroded dome. These curved lineaments are arranged in arcs inside and following the form of the dome. This corresponds to the drainage patterns of the sedimentary domes or exposed diapirs. In the case of the Geaune dome, it concerns a type of complex radio-annular drainage pattern for which the radial drains are largely controlled by the recent fracturing. Dynamics . – Since the Miocene, the history of the Geaune sector has integrated the evolution of the entire gascon piedmont with the deposing of continental sediments (Upper Cenozoic) generating a higher surface followed by, from the Quaternary, the development of the drainage pattern, the formation of present relief and the deposition of alluvial terraces. The diapiric dynamics since Oligocene. – In the Pyrenean foreground, the Oligocene is the paroxysmal phase. The diapiric structures already formed are picked up in the overthrusting ramps (Tercis, Audignon, Riscle). Mio-Pliocene . – In Gascogne, the N140 faults move (in extension ?): they favour a renewal of diapirism which deforms the middle Miocene deposits (Bastennes and Geaune). An inversion with detumescence of the domes then occurs ; the whole is enclosed by the truncation of the higher surface. Quaternary. – The diapir takes over weakly and becomes more pronounced during the Riss. It is associated with toppled boulders orientated N140. The motor is the mobility of the Gulf of Gascogne which participates in the rotation of the Pyrenean rivers towards the west. The inversion occurs at the end of the Riss with a centripetal drainage on the Geaune dome. A type of original model: the inversion ring. – In the northern Pyrenean piedmont, intrusive and extrusive saliferous domes coexist. The analysis of the surface morphostructures which are generated by the rising of these Triassic elements makes the proposal of a detailed model of evolution possible (fig.13). There are five stages regrouped in two phases. In the course of phase I (stage I of positive relief) the drainage is principally centrifugal and radial. During phase II (inversion stages 3, 4 and 5) the center of the dome grows and centripetal radial drains form. The final stage is marked by the filling of the depression. As well as the interest given to the evolution of these structures, the analysis of drainage pattern anomalies and of the forms constitutes an efficient tool of reconnaissance permitting the illustration of, or confirming the presence of deep intrusive saliferous domes.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Introduction/purpose: This study tested the hypothesis that the respiratory compensation point (RCP) and breakpoint in deoxygenated [heme] (deoxy[heme]BP, assessed via near-infrared spectroscopy (NIRS)) during ramp incremental exercise would occur at the same metabolic rate in the upright (U) and supine (S) body positions. Methods: Eleven healthy men completed ramp incremental exercise tests in U and S. Gas exchange was measured breath-by-breath and time-resolved-NIRS was used to measure deoxy[heme] in the vastus lateralis (VL) and rectus femoris (RF). Results: RCP (S: 2.56 ± 0.39, U: 2.86 ± 0.40 L.min-1, P = 0.02) differed from deoxy[heme]BP in the VL in U (3.10 ± 0.44 L.min-1, P = 0.002), but was not different in S in the VL (2.70 ± 0.50 L.min-1, P = 0.15). RCP was not different from the deoxy[heme]BP in the RF for either position (S: 2.34 ± 0.48 L.min-1, U: 2.76 ± 0.53 L.min-1, P > 0.05). However, the deoxy[heme]BP differed between muscles in both positions (P < 0.05), and changes in deoxy[heme]BP did not relate to delta RCP between positions (VL: r = 0.55, P = 0.080, RF: r = 0.26, P = 0.44). The deoxy[heme]BP was consistently preceded by a breakpoint in total[heme], and was, in turn, itself preceded by a breakpoint in muscle surface electromyography (EMG). Conclusions: RCP and the deoxy[heme]BP can be dissociated across muscles and different body positions and, therefore, do not represent the same underlying physiological phenomenon. The deoxy[heme]BP may, however, be mechanistically related to breakpoints in total[heme] and muscle activity.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Abstract Introduction Myositis is a broad diagnosis with a number of potential causes. There are numerous drugs that can lead to myotoxicity. We discuss a case of a patient with known rheumatoid arthritis who developed myositis with no evidence of an additional autoimmune condition and where the most likely cause seems to be leflunomide. Case description A 46-year-old Asian lady with a background of seropositive rheumatoid arthritis and overactive bladder developed increasing muscle weakness. Disease activity was well-controlled on leflunomide which had been started four years ago after an initial trial of methotrexate proved ineffective. Other regular medications include tolterodine and rigevidon (combined oral contraceptive pill), paracetamol and co-codamol. She presented to her GP in February with generalised muscle weakness, fatigue, dry mouth, hair loss and occasional shortness of breath on exertion. Blood tests showed elevated CK at 1132 u/l, ALT 57 u/l (AST normal), LDH 302 u/L, CRP 4 mg/l and ESR 25mm/h. Further tests were subsequently arranged following rheumatology review including ANA and ENA (both negative), an extended myositis panel and HMGCoAR antibodies (also negative). MRI of her lower limbs showed bilateral oedema within the anterior and lateral muscle compartments of her thighs, worse on the left, and in keeping with myositis. Given the possibility of leflunomide being the cause of her symptoms it was stopped. Her CK one month after stopping leflunomide had decreased to 819 u/l and then 389 u/l after four months. The patient reported improvement in her muscle weakness, CK is currently being monitored, and she is awaiting an EMG. A muscle biopsy has been discussed with her previously and although she had refused initially, in view of persistent mild elevation in CK, the biopsy and leflunomide washout will be discussed again with her again. As she is clinically asymptomatic and not keen to try new medications, further immunosuppression has not been started. Discussion Myositis is seen in a wide range of conditions with numerous possible causes. It can be drug-induced, secondary to viral infections or caused by autoimmune conditions including overlap conditions and idiopathic inflammatory myopathies. Drug-induced myositis is most commonly associated with statins, but has been seen with many different medications. Leflunomide is a disease-modifying anti rheumatic drug used particularly in the treatment of inflammatory arthritis but has also been used in treatment resistant dermatomyositis. It inhibits the mitochondrial enzyme, dihydroorotate dehydrogenase to reduce the reproduction of rapidly dividing cells. A rise in CK is considered a common side effect. We have only found one other case report where leflunomide was suspected to have induced polymyositis, also in a patient with rheumatoid arthritis. Both biochemical and clinical improvement following cessation of leflunomide, with no other inventions raises the likelihood of this being a leflunomide-induced myositis. Key learning points When faced with a patient with rheumatoid arthritis presenting with symptoms suggestive of myositis, whilst an overlap autoimmune condition is a possibility, it is important to consider potential drug causes. Numerous drugs have been implicated through both direct myotoxicity and immunologically mediated myotoxicity. Importantly for rheumatologists these can include glucocorticoids, antimalarial drugs, colchicine and tumour necrosis factor inhibitors. According to the summary of product characteristics a rise in CK is commonly seen with leflunomide but clinical myositis has only been reported rarely. Conflicts of interest The authors have declared no conflicts of interest.

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Re-Framing Participation in the Architecture Studio Recently, within design literature, significant attention has been given to collaboration across different disciplines (see for instance, Nicolini et al.; Carlile), as well as consideration of the breakdown of traditional disciplinarity and the corresponding involvement of users in co-generation (Sanders and Stappers, “Co-Creation” 11–12) through the development and deployment of structured methods and toolkits (Sanders et al., “Framework”; Sanders and Stappers, “Probes”). Relatively less attention has been paid to the workings of the “communities of practice” (Wenger) operating within the disciplinary domain of architecture. The discourse around concept design in architecture has tended to emphasise individualist approaches driven by personal philosophies, inspirations, imitation of a more experienced designer, and emphasis on latent talent or genius (for instance, Moneo). This can be problematic because without a shared language and methods there are limited opportunities for making meaning to facilitate participation between collaborators in architectural studio settings. It is worth asking then: are there things that “Architecture” might learn from “Design” about the deployment of structured methods, and might this interdisciplinary exchange promote participatory practices in studio-based cultures? We address this question by connecting and building on two important concepts relevant to design methods, meta-design as described in the open design literature (De Mul 36–37), and design frames as described by Schön and formalised by Dorst (‘Core’; Frame; see also Weedon). Through this combination, we propose a theory of participation by making shared meaning in architectural design. We animate our theoretical contribution through a design toolkit we have developed, refined, and applied over several years in typologically focused architectural design studios in Australian university contexts. One important contribution, we argue, is to the area of design theory-building, by taking two previously unrelated concepts from the design methods literature. We draw them together using an example from our own design practices to articulate a new term and concept for making shared meaning in design. The other contribution made is to the translation of this concept into the context of studio-based architectural practice, a setting that has traditionally struggled to accept structured methods. The existence of other form-metaphor design tools available for architecture and the theoretical basis of their development and connection to design literature more broadly has not always been clearly articulated (see for example Di Mari and Yoo; Lewis et al.). The rationale for giving an account of the construction and deployment of our own toolkit is to illustrate its theoretical contribution while providing the basis for future field testing and translation (including by other researchers), noting the established trajectory of this kind of work in the design literature (see, for example, Hoolohan and Browne; Visser et al.; Vaajakallio and Mattelmäki; Sanders and Stappers, “Co-Creation” and ”Probes”). In line with this issue’s thematic and epistemological agenda, we adopt what Cross identifies as “designerly ways of knowing” (223), and is at least partly a reflection on a practice in which we engage with our own disciplines and research interests to propose and deploy design thinking as a kind of critical “reflection-in-action” (Robertson and Simonsen 2). Meta-Framing: Combining Meta-Design and Framing Meta-design is a term used in open design literature to describe approaches aimed toward orchestration of a project in such a way that people are afforded the agency to become effective co-designers, regardless of their pre-existing skills or design-specific knowledge (De Mul 36). According to a meta-design approach, design is conceived of as a shared project of mutual learning instead of an individualistic expression of singular genius. Through the establishment of shared protocols and formats, what Ehn (1) calls “infrastructuring”, individuals with even very limited design experience are provided scaffolds that enable them to participate in a design project. One important way in which meta-design helps “create a pathway through a design space” is through the careful selection and adoption of shared guiding metaphors that provide common meanings between co-designers (De Mul 36). The usefulness of metaphors is also recognised in the context of design frames, the second concept on which we build our theory. Conceptualised as “cognitive shortcuts” for making “sense of complex situations” (Haase and Laursen 21), design frames were first conceived of by Schön (132) as a rational approach to design, one guided by “epistemological norms”. Frames have subsequently been further developed within the design methods literature and are defined as a system of counterfactual design decision-making that uses metaphors to provide a rationale for negotiating ill-structured problems. According to Dorst, frames involve: the creation of a (novel) standpoint from which a problematic situation can be tackled … . Although frames are often paraphrased by a simple metaphor, they are in fact very complex sets of statements that include the specific perception of a problem situation, the (implicit) adoption of certain concepts to describe the situation, a ‘working principle’ that underpins a solution and the key thesis: IF we look at the problem situation from this viewpoint, and adopt the working principle associated with that position, THEN we will create the value we are striving for. (525) Despite Schön choosing to illustrate his original conception of framing through the example of a student’s architectural design project, there has been limited subsequent consideration of framing in architectural studio contexts—an exception being Eissa in 2019. This may be because formalised design methods have tended to be treated with suspicion within architectural culture. For instance, Christopher Alexander’s Pattern Language is one such “highly systemised design process” (Dawes and Ostwald 10) that despite its potential to guide participatory design has had an “uneven reception” (Bhatt 716) within architecture itself. One way architecture as a disciplinary domain and as a profession has attempted to engage with design method is through typology, which is one of the few persistent and recurring notions in architectural discourse (Bandini; Grover et al.). As a system of classification, typology categorises “forms and functions as simply and unequivocally as possible” (Oechslin 37). In addition to being used as a classification system, typology has also been positioned as “a process as much as an object”, one with the potential for an “active role in the process of design” (Lathouri 25). Type and typology have been conceptualised as a particular way of projecting architecture’s “disciplinary agency” (Jacoby 936), and this goes some way to explaining their enduring value. A potentially valid criticism of framing is that it can tend toward “design fixation”, when a pre-existing assumption “inadvertently restricts the designers’ imagination” (Crilly). Similarly, typology-as-method—as opposed to a classification tool—has been criticised for being relatively “inflexible” or “reductive” (Shane 2011) and responsible for perpetuating “conservative, static norms” (Jacoby 932) if applied in a rote and non-reflexive way. We deal with these concerns in the discussion of the deployment of our Typekit below. We are drawing here on our experience teaching in the first two years of undergraduate architecture degrees in Australian university settings. As well as being equipped with a diversity of educational, social, linguistic, and cultural backgrounds, students typically have divergent competencies in the domain-specific skills of their discipline and a limited vocabulary for making shared meaning in relation to an architectural proposal. The challenge for studio-based collaborative work in such a context is developing shared understandings and a common language for working on a design project to enable a variety of different design solutions. The brief for a typical studio project will specify a common site, context, and program. Examples we have used include a bathhouse, fire station, archive, civic centre, and lifesaving club. There will then be multiple design solutions proposed by each studio participant. Significantly we are talking about relatively well-structured problems here, typically a specific building program for a specified site and user group. These are quite unlike the open-ended aims of “problem frames” described in the design thinking literature “to handle ill-defined, open-ended, and ambiguous problems that other problem-solving methodologies fail to handle” (Haase and Laursen 21). However, even for well-structured problems, there is still a multitude of possible solutions possible, generated by students working on a particular project brief. This openness reduces the possibility of making shared meaning and thus hinders participation in architectural design. Designing the Typekit The Typekit was developed heuristically out of our experiences teaching together over several years. As part of our own reflective practice, we realised that we had begun to develop a shared language for describing projects including that of students, our own, precedents and canonical works. Often these took the form of a simple formal or functional metaphor such as “the building is a wall”; “the building is an upturned coracle”; or “the building is a cloud”. While these cognitive shortcuts proved useful for our communication there remained the possibility for this language to become esoteric and exclusionary. On the other hand, we recognised the potential for this approach to be shared beyond our immediate “interpretive community” (Fish 485) of two, and we therefore began to develop a meta-design toolkit. Fig. 1: Hybrid page from the Typekit We began by developing a visual catalogue of formal and functional metaphors already present within the panoply of constructed contemporary architectural projects assembled by surveying the popular design media for relevant source material. Fig. 2: Classification of contemporary architectural built work using Typekit metaphors We then used simple line drawings to generate abstract representations of the observed building metaphors adopting isometry to maintain a level of objectivity and a neutral viewing position (Scolari). The drawings themselves were both revelatory and didactic and by applying what Cross calls “designerly ways of knowing” (Cross 223) the toolkit emerged as both design artefact and output of design research. We recognised two fundamentally different kinds of framing metaphors in the set of architectural projects we surveyed, rule-derived and model-derived—terms we are adapting from Choay’s description of “instaurational texts” (8). Rule-derived types describe building forms that navigate the development of a design from a generic to a specific form (Baker 70–71) through a series of discrete “logical operators” (Choay 134). They tend to follow a logic of “begin with x … perform some operation A … perform some operation B … end up with y”. Examples of such operations include add, subtract, scale-translate-rotate, distort and array. Model-derived framing metaphors are different in the way they aim toward an outcome that is an adapted version of an ideal initial form. This involves selecting an existing type and refining it until it suits the required program, site, and context. Examples of the model-derived metaphors we have used include the hedgehog, caterpillar, mountain, cloud, island, and snake as well as architectural Ur-types like the barn, courtyard, tent, treehouse, jetty, and ziggurat. The framing types we included in the Typekit are a combination of rule-derived and model-derived as well as useful hybrids that combined examples from different categories. This classification provides a construct for framing a studio experience while acknowledging that there are other ways of classifying formal types. Fig. 3: Development of isometric drawings of metaphor-frames After we developed a variety of these line drawings, we carried out a synthesis and classification exercise using a version of the KJ method. Like framing, KJ is a technique of abduction developed for dealing objectively with qualitative data without a priori categorisation (Scupin; Kawakita). It has also become an established and widely practiced method within design research (see, for instance, Hanington and Martin 104–5). Themes were developed from the images, and we aimed at balancing a parsimony of typological categories with a saturation of types, that is to capture all observed types/metaphors and to put them in as few buckets as possible. Fig. 4: Synthesis exercise of Typekit metaphors using the KJ method (top); classification detail (bottom) Deploying the Typekit We have successfully deployed the Typekit in architectural design studios at two universities since we started developing it in 2018. As a general process participants adopt a certain metaphor as the starting point of their design. Doing so provides a frame that prefigures other decisions as they move through a concept design process. Once a guiding metaphor is selected, it structures other decision-making by providing a counterfactual logic (Byrne 30). For instance, if a building-as-ramp is chosen as the typology to be deployed this guides a rationale as to where and how it is placed on the site. People should be able to walk on it; it should sit resolutely on the ground and not be floating above it; it should be made of a massive material with windows and doors appearing to be carved out of it; it can have a green occupiable roof; quiet and private spaces should be located at the top away from street noise; active spaces such as a community hall and entry foyer should be located at the bottom of the ramp … and so on. The adoption of the frame of “building-as-ramp” by its very nature is a crucial and critical move in the design process. It is a decision made early in the process that prefigures both “what” and “how” types of questions as the project develops. In the end, the result seems logical even inevitable but there are many other types that could have potentially been explored and these would have posed different kinds of questions and resulted in different kinds of answers during the process. The selection of a guiding metaphor also allows students to engage with historical and contemporary precedents to offer further insights into the development—as well as refinement—of their own projects within that classification. Even given the well-structured nature of the architectural project, precedents provide useful reference points from which to build domain-specific knowledge and benchmarks to measure the differences in approaches still afforded within each typological classification. We believe that our particular meta-framing approach addresses concerns about design fixation and balances mutual learning with opportunities for individual investigation. We position framing less about finding innovative solutions to wicked problems to become more about finding ways for a group of people to reason together through a design problem process by developing and using shared metaphors. Thus our invocation of framing is aligned to what Haase and Laursen term “solution frames” meaning they have an “operational” meaning-making agenda and provide opportunities for developing shared understanding between individuals engaged in a given problem domain (Haase and Laursen 20). By providing a variety of opportunities within an overarching “frame of frames” there are opportunities for parallel design investigation to be undertaken by individual designers. Meta-framing affords opportunities for shared meaning-making and a constructive discourse between different project outcomes. This occurs whether adopting the same type to enable questions including “How is my building-as-snake different from your building-as-snake?”, “Which is the most snake-like?”, or different types (“In what ways is my building-as-ramp different to your building-as-stair?”) By employing everyday visual metaphors, opportunities for “mutual learning between mutual participants” (Robertson and Simonsen 2) are enhanced without the need for substantial domain-specific architectural knowledge at a project’s outset. We argue that the promise of the toolkit and our meta-framing approach more generally is that it actually multiples rather than forecloses opportunities while retaining a shared understanding and language for reasoning through a project domain. This effectively responds to concerns that typology-as-method is a conservative or reductive approach to architectural design. It is important to clarify the role of our toolkit and its relationship to our theory-building agenda. On the basis of the findings accounted for here we do claim to draw specific conclusions about the efficacy of our toolkit. We simply did not collect experimental data relevant to that task. We can, however, use the example of our toolkit to animate, flesh out, and operationalise a model for collaboration in architectural design that may be useful for teaching and practicing architecture in collaborative, team-based contexts. The contribution of this account, therefore, is theoretical. That is, the adaptation of concepts from design literature modified and translated into a new domain to serve new purposes. The Promise of Meta-Framing through Typology Through our work, we have outlined the benefits of adopting formalised design methods in architecture as a way of supporting participation, including using toolkits for scaffolding architectural concept design. Meta-framing has shown itself to be a useful approach to enable participation in architectural design in a number of ways. It provides coherence of an idea and architectural concept. It assists decision-making in any given scenario because a designer can decide which out of a set of choices makes more sense within the “frame” adopted for the project. The question becomes then not “what do I like?” or “what do I want?” but “what makes sense within the project frame?” Finally and perhaps most importantly it brings a common understanding of a project that allows for communication across a team working on the same problem, supporting a variety of different approaches and problem-solving logics a voice. By combining methodologies and toolkits from the design methods literature with architecture’s domain-specific typological classifications we believe we have developed an effective and adaptive model for scaffolding participation and making shared meaning in architecture studio contexts. References Baker, Geoffrey H. Design Strategies in Architecture: An Approach to the Analysis of Form. Taylor and Francis, 2003. Bandini, Micha. “Typology as a Form of Convention.” AA Files 6 (1984): 73–82. Bhatt, Ritu. “Christopher Alexander’s Pattern Language: An Alternative Exploration of Space-Making Practices.” Journal of Architecture 15.6 (2010): 711–29. Byrne, Ruth M.J. The Rational Imagination: How People Create Alternatives to Reality. MIT P, 2005. Carlile, Paul R. “Transferring, Translating, and Transforming: An Integrative Framework for Managing Knowledge across Boundaries”. Organization Science 15.5 (2004): 555–68. Choay, Françoise. The Rule and the Model: On the Theory of Architecture and Urbanism. MIT P, 1997 [1980]. Crilly, Nathan. “Methodological Diversity and Theoretical Integration: Research in Design Fixation as an Example of Fixation in Research Design?” Design Studies 65 (2019): 78–106. Cross, Nigel. “Designerly Ways of Knowing”. Design Studies 3.4 (1982): 221–27. Dawes, Michael J., and Michael J. Ostwald. “Christopher Alexander’s A Pattern Language: Analysing, Mapping and Classifying the Critical Response.” City, Territory and Architecture 4.1 (2017): 1–14. De Mul, Jos. “Redesigning Design”. In Open Design Now: Why Design Cannot Remain Exclusive, eds. Bas Van Abel, Lucas Evers, Roel Klaassen, and Peter Troxler. BIS Publishers, 2011. 34–39. Di Mari, Anthony, and Nora Yoo. Operative Design. BIS Publishers, 2012. Dorst, Kees. “The Core of ‘Design Thinking’ and Its Application”. Design Studies 32.6 (2011): 521–32. <https://doi.org/10.1016/j.destud.2011.07.006>. ———. Frame Innovation: Create New Thinking by Design. Design Thinking, Design Theory. MIT P, 2015. Ehn, Pelle. “Participation in Design Things.” In Proceedings of the Participatory Design Conference 2008. Bloomington, Indiana, 2008. 92–101 Eissa, Doha. “Concept Generation in the Architectural Design Process: A Suggested Hybrid Model of Vertical and Lateral Thinking Approaches.” Thinking Skills and Creativity 33 (2019). Fish, Stanley E. “Interpreting the ‘Variorum’.” Critical Inquiry 2.3 (1976): 465–85. Grover, Robert, Stephen Emmitt, and Alex Copping. “The Language of Typology.” Arq 23.2 (2019): 149–56. <https://doi.org/10.1017/S1359135519000198>. Haase, Louise Møller, and Linda Nhu Laursen. “Meaning Frames: The Structure of Problem Frames and Solution Frames”. Design Issues 35.3 (2019): 20–34. <https://doi.org/10.1162/desi_a_00547>. Hanington, Bruce, and Bella Martin. Universal Methods of Design: 100 Ways to Research Complex Problems, Develop Innovative Ideas, and Design Effective Solutions. Rockport Publishers, 2012. Hoolohan, Claire, and Alison L Browne. “Design Thinking for Practice-Based Intervention: Co-Producing the Change Points Toolkit to Unlock (Un)Sustainable Practices.” Design Studies 67 (2020): 102–32. Jacoby, Sam. “Typal and Typological Reasoning: A Diagrammatic Practice of Architecture.” Journal of Architecture 20.6 (2015): 938–61. <https://doi.org/10.1080/13602365.2015.1116104>. Kawakita, Jiro. “The KJ Method and My Dream towards the ‘Heuristic’ Regional Geography.” Japanese Journal of Human Geography 25.5 (1973): 493–522. Lathouri, Marina. “The City as a Project: Types, Typical Objects and Typologies.” Architectural Design 81.1 (2011): 24–31. Lewis, Paul, Marc Tsurumaki, and David J Lewis. Manual of Section. Princeton Architectural P, 2016. Moneo, José Rafael. Theoretical Anxiety and Design Strategies in the Work of Eight Contemporary Architects. MIT P, 2004. Nicolini, Davide, Jeanne Mengis, and Jacky Swan. “Understanding the Role of Objects in Cross-Disciplinary Collaboration”. Organization Science (Providence, R.I.) 23.3 (2012): 612–29. Oechslin, Werner. “Premises for the Resumption of the Discussion of Typology.” Assemblage 1 (1986): 37–53. Panzano, Megan. “Foreword.” In Operative Design: A Catalogue of Spatial Verbs, by Anthony Di Mari and Nora Yoo. Amsterdam: BIS Publishers, 2012. 6–7. Robertson, Toni, and Jesper Simonsen. “Participatory Design: An Introduction”. In Routledge International Handbook of Participatory Design, eds. Toni Robertson and Jesper Simonsen. Taylor and Francis, 2012. 1–18. Sanders, Elizabeth B.-N., Eva Brandt, and Thomas Binder. “A Framework for Organizing the Tools and Techniques of Participatory Design.” Proceedings of the 11th Biennial Participatory Design Conference. ACM, 2010. 195–98. DOI: 10.1145/1900441.1900476. Sanders, Elizabeth B.-N., and Pieter Jan Stappers. “Co-Creation and the New Landscapes of Design.” Co-Design 4.1 (2008,): 5–18. ———. “Probes, Toolkits and Prototypes: Three Approaches to Making in Codesigning.” CoDesign 10.1 (2014): 5–14. Schön, Donald A. “Problems, Frames and Perspectives on Designing.” Design Studies 5.3 (1984): 132–36. <https://doi.org/10.1016/0142-694X(84)90002-4>. Scolari, Massimo. Oblique Drawing: A History of Anti-Perspective. MIT P, 2012. Scupin, Raymond. “The KJ Method: A Technique for Analyzing Data Derived from Japanese Ethnology.” Human Organization, 1997. 233–37. Shane, David Grahame. "Transcending Type: Designing for Urban Complexity." Architectural Design 81.1 (2011): 128-34. Vaajakallio, Kirsikka, and Tuuli Mattelmäki. “Design Games in Codesign: As a Tool, a Mindset and a Structure.” CoDesign 10.1 (2014): 63–77. <https://doi.org/10.1080/15710882.2014.881886>. Visser, Froukje Sleeswijk, Pieter Jan Stappers, Remko van der Lugt, and Elizabeth B.N. Sanders. “Contextmapping: Experiences from Practice.” CoDesign 1.2 (2005): 119–49. Weedon, Scott. “The Core of Kees Dorst’s Design Thinking: A Literature Review.” Journal of Business and Technical Communication 33.4 (2019): 425–30. <https://doi.org/10.1177/1050651919854077>. Wenger, Etienne. Communities of Practice : Learning, Meaning, and Identity. Learning in Doing. Cambridge UP, 1988. Yaneva, Albena. The Making of a Building: A Pragmatist Approach to Architecture. Peter Lang, 2009.