Lateral Bars Research Articles

Shank lateral bar in motion analysis protocols: Artifacts affecting ankle kinematics

Shank lateral bar in motion analysis protocols: Artifacts affecting ankle kinematics

In Situ Fronto-Orbital Advancement With Medial Orbital Osteotomies for Trigonocephaly-Associated Hypotelorism

In treating trigonocephaly, the value of direct surgical correction of orbital hypotelorism is controversial. In many cases of hypotelorism, the distance between the orbits increases over time after traditional fronto-orbital advancement. Still, more severe hypotelorism is not fully corrected and may benefit from a more definitive surgical intervention. We describe an in situ fronto-orbital advancement that improves severe hypotelorism and simplifies the surgical treatment of trigonocephaly. The key modification to traditional fronto-orbital advancement is an in situ medial orbital osteotomy that extends along the medial orbit, posterior to the medial canthus, and then across the inferior orbital rim into the piriform aperture. The procedure is indicated only in patients with more severe hypotelorism on physical examination. Rather than creating a freely removable bandeau during the operation, the bone segment composed of the supraorbital bar and superior orbits remains attached at the medial canthi. A midline osteotomy allows the respective orbital segments to be independently mobilized with the medial canthi left attached, and the space between them widened with gentle lateral traction and placement of an interpositional bone graft. Concomitantly, the lateral orbits and lateral supraorbital bar are contoured, advanced, and fixed with resorbable plates and screws. Representative results are shown. In situ fronto-orbital advancement with medial orbital osteotomies is a safe, efficient, and relatively simple technique that results in immediate improvement of hypotelorism and may be a worthwhile maneuver to consider in selected cases.

Laser Additive Manufacturing of Modified Implant Surfaces with Osseointegrative Characteristics

Additive Manufacturing technology, such as Selective Laser Melting, allows fabrication of complex metal parts with freeform surfaces. Using biocompatible metal alloys, e.g. TiAl6V4, medical implants can be produced. To increase osseointegrative behavior the ability to fabricate filigree lattice structures can be utilized to achieve a modified implant surface. In order to increase dimensional accuracy when applying a lattice structure on a curved surface, process constraints for single lattice bars are studied. The investigated lattice structure was thereupon applied on the surface of a medical implant.

Non-linearity of reach hydraulic geometry relations

Summary Reach-average hydraulic geometry (RHG) defines the relations between the average hydraulic variables estimated at river reach (water depth, velocity, channel width) and the discharge. Single log-linear models are classically used by fluvial geomorphologists, hydrologists and ecologists to represent these relations. In this paper, we show that these single log-linear models are not relevant in most of cases and so can lead to significant errors. RHG estimated on 15 alluvial river reaches (the catchment sizes vary from 10 km 2 to 1700 km 2 ) were found non-linear for two-thirds of the river reaches when considering discharges ranging from low to bankfull flows. So we propose using two power functions (or log-linear) to model these relations, i.e. the log piecewise linear model. This model can detect a discharge Qbreak, i.e. a physical transition or “break point” between both relations. From very low flows (about 30% of the median discharge) to Qbreak, a first relation is comparable to the RHG found in the literature for aquatic habitat analysis. The second relation is relevant for flows ranging from Qbreak to bankfull discharge, and therefore may be more useful for sediment transport and flood routing analysis. Averaging along a reach including several pool–riffle units makes it difficult to clearly ascribe the form of RHG to particular physical processes. The non-linearity of RHG may have multiple origins: the presence of lateral gravel bars, the hydraulic conditions of riffle cross-sections, a change in the resistance to flow with water depth (vegetation, sediment influences). Further research is needed to focus on the physical processes that govern the RHG non-linearity.

Ankle–foot simulator development for testing ankle–foot orthoses

The fatigue failure of thermoplastic ankle–foot orthoses (AFOs) was observed in clinics. However, there was no standard evaluation for the AFOs to enhance the understanding of how AFOs become more readily acceptable to patients. Therefore, this study aimed to develop an ankle–foot simulator (AFS) as a testing apparatus for AFOs, and performed a pilot test to investigate the failure mechanism of anterior ankle–foot orthosis (AAFO). The accuracy and repeatability of the AFS during cyclic walking, cyclic stepping and cyclic stepping with the AAFO in sagittal plane were measured. The root mean square errors (RMSEs) of cyclic walking of AFS compared to a target gait data were less than 80.52N and 2.55° in the vertical ground reaction force and in the kinematics, respectively. The RMSE of ankle plantarflexion and dorsiflexion of AFS in the cyclic stepping tests were less than 1.25°. The repeatability was assessed by standard deviation, which were less than 9.46N and 0.72° in all testing conditions. A typical failure progression of five AAFOs was observed and graded for four phases under cyclic stepping test. Failure always initiated at the junction of anterior tarsal bar and lateral (or medial) bar of the AAFOs, from which the rest failures were extended. It is suggested that this junction must be reinforced or prevented the stress concentration to elongate the endurance of AAFO.

A new species of parasitic copepod of the genus Hatschekia Poche, 1902 (Siphonostomatoida: Hatschekiidae) from filefishes (Pisces: Tetraodontiformes: Monacanthidae) from off Okinawa, Japan

Hatschekia khahajya n. sp. is described from the gill filaments of two monacanthid fishes, Cantherhines dumerilii (Hollard) and Amanses scopes (Cuvier), caught off Okinawa, Japan. The new species can be distinguished from its congeners by the possession of the following combination of characters: cephalothorax length/trunk length ratio greater than 0.40; cephalothorax with a pair of lateral bars on the chitinous ring and a posterior pair of surface ridges; trunk with a bifurcate chitinous frame extending over its anterior third and with well-developed posterior lobes that extend beyond the abdomen; and four processes plus two spinular rows on the distal margin of the intercoxal sclerite of legs 1 and 2.

Threatened fishes of the world: Squalidus banarescui Chen and Chang, 2007 (Cyprinidae)

Common names: Banarescu’s gudgeon; Ba-Shih-Yin-Ju (Mandarin). Conservation status: Critically endangered for governmental conservation-list, but not listed IUCN Red-list. Identification: D 3+7; P 1+13; A 3+6; LL 34– 36; PreD10-11; Ph 5.3-3.5. Body elongate, compressed. Eye large. Mouth terminal. Two short barbels present. Body greenish-silver dorsally, silver-white ventrally. Dorsal side scattered with black spots. Snout with lateral black bar. Each lateral-line scale with L-shaped

Threatened fishes of the world: Percina bimaculata (Haldeman, 1844) (Percidae: Etheostomatinae)

Keywords Percina.Logperch.ChesapeakeCommon name: Chesapeake logperch. Conservationstatus: “Threatened” in Maryland (MD), U.S.A.applied to Percina caprodes until the state recognizesrevived specific epithet due to recent removal fromsynonymy with P. bimaculata (Near 2008). Noconservation status in Pennsylvania (PA) and nofederal status. Identification: Conical snout, 7–11irregular lateral bars that anastomose mid-dorsum,narrow orange submarginal band on first dorsal fin,diffuse in females. Maximum length 109 mm SL(Haldeman 1844;Near2008). Illustration by D.A.Neely. Distribution: Extirpated from Potomac Riverand tributaries within Washington D.C. (Lee et al.1981; Smith and Bean 1899). Extant populationsin lower Susquehanna River (above and belowConowingo Dam) and lower reaches of tributariesincluding Broad, Conowingo, Deer, Northeast, andOctoraro creeks, MD, and Fishing Creek, MichaelRun, Muddy, and Octoraro creeks, PA. Abundance:Infrequent, but occasionally locally abundant.Habitat and ecology: Unknown; likely similar to P.caprodes (Winn 1958a, b;Thomas1970) and otherclosely related logperches (Thompson 1995, 1997).Most recently collected in a range of habitat includingstreams, tributary impoundments, and large rivers.Flips unembedded gravel with snout in search ofaquaticinsects.Reproduction: Unknown; likely similarto P. caprodes (Winn 1958a, b). Threats: Impairedwater quality, habitat degradation, siltation of gravelsubstrates, and land use alteration (U.S. Fish WKazyaketal.2005). Non-native species sympatric with P. bimaculata;Etheostomablennioides,andE. zonale (Van Snik Grayet al. 2005; Neely and George 2006). Conservationactions: Some populations incidentally protected byE. sellare (U.S. Fish & Wildlife Service 1985)orstate lands. Conservation recommendations: Conductdetailed studies on life history, ecology, distribution,and environmental stressors. Investigate populationgenetics among seemingly disjunct populations andgenetics of Potomac River specimens. Require bestmanagement practices to minimize effects of land usealteration on water and habitat quality.

A new species of Ptychochromis from northeastern Madagascar (Teleostei: Cichlidae), with an updated phylogeny and revised diagnosis for the genus

A new species belonging to the endemic Malagasy cichlid genus Ptychochromis is described. Ptychochromis ernestmagnusi is known only from the middle to lower reaches of the Mananara River in northeastern Madagascar. Based on a unique configuration of the palatine, the new species is placed among the species of Ptychochromis considered to have an eastern-type palatine morphology by Stiassny and Sparks (2006). The new species is further distinguished from members of the “western clade” of Ptychochromis by anterior displacement of the first supraneural such that it overlies the dorsoposterior margin of the supraoccipital. Among species of Ptychochromis with eastern-type palatine morphology, P. ernestmagnusi shares with P. makira the possession of supraneurals with a characteristically flattened dorsal profile. Although P. makira and P. ernestmagnusi both possess paired lateral barring pigmentation patterns, the lateral flank bars in P. makira are distinctively V-shaped, whereas in P. ernestmagnusi they are oriented vertically. Ptychochromis ernestmagnusi is further distinguished from P. makira by prominent iridescent spangling on the flank and dorsal fin near its base, dusky grayish-green base coloration (vs. whitish), four laterosensory foramina on the lachrymal (vs. three), and a series of seven (vs. six) infraorbital bones. In addition, an updated phylogeny and diagnosis for Ptychochromis is presented, including anatomical data for the new species and novel anatomical data for the genus.

Architecture of an Oligocene fluvial ribbon sandstone in the Ebro Basin, North-eastern Spain

Fluvial ribbon sandstone bodies are ubiquitous in the Ebro Basin in North-eastern Spain; their internal organization and the mechanics of deposition are as yet insufficiently known. A quarrying operation in an Oligocene fluvial ribbon sandstone body in the southern Ebro Basin allowed for a three-dimensional reconstruction of the sedimentary architecture of the deposit. The sandstone is largely a medium-grained to coarse-grained, moderately sorted lithic arenite. In cross-section, the sandstone body is 7 m thick, occupies a 5 m deep incision and wedges out laterally, forming a ‘wing’ that intercalates with horizontal floodplain deposits in the overbank region. Three architectural units were distinguished. The lowest and highest units (Units A and C) mostly consist of medium-grained to coarse-grained sandstone with medium-scale trough cross-bedding and large-scale inclined stratasets. Each of Units A and C comprises a fining-up stratal sequence reflecting deposition during one flood event. The middle unit (Unit B) consists of thinly bedded, fine-grained sandstone/mudstone couplets and represents a time period when the channel was occupied by low-discharge flows. The adjoining ‘wing’ consists of fine-grained sandstone beds, with mudstone interlayers, correlative to strata in Units A and C in the main body of the ribbon sandstone. In plan view, the ribbon sandstone comprises an upstream bend and a downstream straight reach. In the upstream bend, large-scale inclined stratasets up to 3 m in thickness represent four bank-attached lateral channel bars, two in each of Units A and C. The lateral bars migrated downflow and did not develop into point bars. In the straight downstream reach, a tabular cross-set in Unit A represents a mid-channel transverse bar. In Unit C, a very coarse-grained, unstratified interval is interpreted as deposited in a riffle zone, and gives way downstream to a large mid-channel bar. The relatively simple architecture of these bars suggests that they developed as unit bars. Channel margin-derived slump blocks cover the upper bar. The youngest deposit is fine-grained sandstone and mudstone that accumulated immediately before avulsion and channel abandonment. Deposition of the studied sandstone body reflects transport-limited sediment discharges, possibly attaining transient hyperconcentrated conditions.

The gill slits and pre-oral ciliary organ of Protoglossus (Hemichordata: Enteropneusta) are filter-feeding structures

898..907 Observations on the hemichordate worm Protoglossus graveolens demonstrate that the gill slits, pre-oral ciliary organ (POCO), and the lining of the cylindrical pharynx are used in filter feeding. Pumping of water is generated by cilia that line the lateral gill bars and the POCO directs water from the dorsal surface of the proboscis to the mouth. Particles are trapped and concentrated on the primary and secondary gill bars and transported ventrally and posteriorly by cilia that line the pharynx. The oesophageal organ functions as a barrier to water flow and to squeeze excess water from the mucus-food cord. Particles that passed freely through the gill pores were a maximum of 1.28 mm in size. Diluted milk entered the mouth and was pumped through the pharynx at a rate up to 4.05 mm s -1 . The Reynolds number and propulsive efficiency of the filter-feeding structures are estimated using algebraic models. Protoglossus elegantly orchestrates the movements of food particles captured by simultaneous filter feeding and deposit feeding or may, from one moment to the next, switch back and forth between deposit and filter feeding. Structural and functional similarities with the cephalochordate pharynx suggest that a wheel organ/ POCO and a filter-feeding pharynx may have been present in the common ancestor to the deuterostomes. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 898‐906. ADDITIONAL KEYWORDS: chordate origins ‐ deuterostome evolution ‐ Enteropneusta ‐ pharynx.

Downstream trends in sediment size and composition of channel-bed, bar, and bank deposits related to hydrologic and lithologic controls in the Llano River watershed, central Texas, USA

The downstream fining of fluvial sediments is a fundamental tenet of drainage systems and, for decades, has been the subject of considerable research. Most of this research has focused on variability in channel-bed material. Other sedimentological components such as channel bars and banks, however, represent distinctively different processes occurring at various flow magnitudes and durations and thus provide an opportunity to examine a more comprehensive set of controls on the larger fluvial system. This study analyses downstream patterns of sediment size and composition for channel-bed material, bars, and banks in the Llano River watershed (11,568 km 2) in central Texas, USA. Fluvial deposits in the study area were characterized through field, laboratory, and statistical analyses and standard sedimentary indices ( d 16, d 50, d 84, sorting) were computed. Two hundred thirty-eight sediment samples were collected at 15 sites along the main-stem channel with sampling occurring at the low-flow channel (thalweg), lateral bars, banks, and overbank locations. Channel-bar deposits are characterized by a downstream reduction in particle size, but low-flow-channel deposits have a substantially weaker trend, a discrepancy possibly attributed to uniformity and continuity of hydraulic sorting mechanisms during moderate and high flows. Channel-bar deposits reveal an abrupt downstream reduction in gravel size in the upper watershed, which is attributed to an increase in drainage area. Further, an abrupt gravel-to-sand transition occurs immediately downstream of a distinct lithologic change from mostly carbonate rocks to igneous and metamorphic rocks. The downstream decrease in channel-bar particle size occurs despite an increasingly constricted alluvial valley, commonly associated with greater unit stream power and relatively coarse sediment. Contrasting with channel-bed material, particle size of channel banks increases downstream, which is attributed to the addition of sand-sized sediment from igneous and metamorphic rocks. The consideration of distinctive sedimentological components of a dynamic fluvial system represents a more comprehensive and nuanced study of the topic of downstream sediment trends than prior studies, which is important to a range of engineering, biological, and planning issues at the watershed scale.

SU-FF-T-242: Evaluation of Tomo Quality Assurance™ (TQA™) Performance for Daily Quality Assurance

Purpose: To investigate and evaluate the utility of TomoTherapy Incorporated's Hi-Art® treatment system Tomo Quality Assurance™ (TQA™) software application for daily quality assurance. Method and Materials: Data collected over a 5-month period utilized the TQA™ predefined application modules, ‘Basic Dosimetry’, ‘Step Wedge Static’, and ‘System Monitor’. Each module contained multiple tests. ‘Basic Dosimetry’ provided rotational and dosimetric information. The ‘Step Wedge Static’ module measures IEC-xyz coordinate offsets, and its transmission characteristics. The ‘System Monitor’ module records environmental and mechanical values. Tests modules are initiated by selecting preprogrammed routines located on the operator's console. The data is collect by the TQA™ software that compares the data with acceptance parameters. Results: Review of the data revealed results that provided useful information with one exception. TQA™ results revealed IEC-z offset variations from −4.62 to +5.24 mm, with an average of 0.68 mm and σ = 2.79 mm. Tolerance for the IEC-z offset is ±3 mm. The failing IEC-z offset data could not be collaborated with checks of the z-plane laser accuracy. Further investigation found that the step wedge phantom rested on the lateral (IECx) adjustment bar located at the head of the couch. The bar is elevated about 2–3 mm higher than the couch creating an alignment problem with the z-plane laser. Incidental target failure necessitated a retrospective review of the data revealing abrupt changes in dosimetry prior to the failure. Conclusion: This investigation indicates that the TQA™ software is a functional tool with the exception that the IEC-z offset is not a reliable indicator of actual conditions. It is believed that the presence of the lateral adjustment bar may create a problem with the test algorithm. Dosimetric data revealed some early indicators of the target failure. This could lead to preemptive replacement of the target to avoid treatment interruptions.

Technical modifications in stabilisers and in bar removal in the Nuss procedure

Pectus excavatum is a congenital deformity that can require surgical treatment. Since Nuss proposed a correction technique, several modifications have been proposed in order to achieve more safety and efficiency in the placement and removal of both bars. Our objective is to describe the technique of placing and removing the bars by proposing three technical modifications: two in bar placement and one in the bar removal. We describe two cases where Nuss bars were placed and one case where the bar was removed as per the technical modification proposed herein. According to the original technique, bar stabilisers were placed close to the lateral bar edges. We propose a more medial position in order to reduce bar displacement. New stabilisers were designed with central grooves in the posterior surface, which allow better sliding. The technical modification suitable for bar removal was the use of a protective film around the bars to protect the surrounding tissues from the sharp edges, and thereby minimise the risk of injuries. All the proposed modifications were performed without any additional surgical risk or perioperative complication. These three technical modifications can be easily and safely performed, and seem to reduce the risk of bleeding with no additional perioperative complications.

Do parafluvial zones have an impact in regulating river pollution? Spatial and temporal dynamics of nutrients, carbon, and bacteria in a large gravel bar of the Doubs River (France)

The changes in both physical and chemical properties of interstitial water were investigated within a large gravel bar to determine if the parafluvial zone was a hotspot for nutrient transformations in a lowland eutrophic river, the Doubs (Eastern France). Interstitial water was sampled in 30 piezometers along five transects across the gravel bar, surface water was sampled in main and chute channels. Five campaigns of sampling were performed among summer and winter. In both interstitial and surface samples, water chemistry (electrical conductivity, pH, chloride, dissolved oxygen concentrations—DO) and nutrient concentrations (nitrate—NO3 −, ammonium—NH4 +, soluble reactive phosphorus—SRP, dissolved organic carbon—DOC) were measured. Moreover, temperature, water level, sediment grain size distribution and total bacterial abundance were assessed along a flowpath through a lateral gravel bar of the Doubs River. Measurements of water table elevation in the bar, main and chute channels indicated that the parafluvial flowpath was perpendicular to the main channel. Very low changes in chloride concentration and electrical conductivity showed minor groundwater input along the flowpath. The parafluvial zone was 0.9 m thick under the mean piezometric level, hydraulic gradients along the flowpath were 0.3%, and the discharge of interstitial water through the bar calculated at low flow was 40.6 m3 day−1. Most changes in interstitial nutrients occurred during the warm season, suggesting that biotic mechanisms occurred. Along the flowpath, DO, DOC, and bacterial abundance declined, while phosphate increased. Temporal trends of nitrate were less clear, exhibiting a slight increase during spring (organic matter biodegradation) and a decrease during summer (denitrification). Using the parafluvial discharge and nutrient concentrations of water infiltrating into and seeping from the gravel bar, the retention capacity of the bar was 171 gC day−1 for DOC and 48.3 gN day−1 for nitrate. Phosphate production ranged from 0.65 to 2.3 gP day−1. These values were low compared to the nutrient fluxes in the river Doubs, suggesting a minimal local impact of the parafluvial zone in regulating of river pollution.

Integrating hydraulic conductivity with biogeochemical gradients and microbial activity along river–groundwater exchange zones in a subtropical stream

The pervious lateral bars (parafluvial zone) and beds (hyporheic zone), where stream water and groundwater exchange, are dynamic sites of hydrological and biological retention. The significance of these biogeochemical ‘hotspots’ to stream and groundwater metabolism is largely controlled by filtration capacity, defined as the extent to which subsurface flowpaths and matrix hydraulic conductivity modify water characteristics. Where hydraulic conductivity is high, gradients in biogeochemistry and microbial activity along subsurface flowpaths were hypothesized to be less marked than where hydraulic conductivity is low. This hypothesis was tested in two riffles and gravel bars in an Australian subtropical stream. At one site, gradients in chemical and microbial variables along flowpaths were associated with reduced hydraulic conductivity, longer water residence time and reduced filtration capacity compared with the second site where filtration capacity was greater and longitudinal biogeochemical trends were dampened. These results imply that factors affecting the sediment matrix in this subtropical stream can alter filtration capacity, interstitial microbial activity and biogeochemical gradients along subsurface flowpaths. This hydroecological approach also indicates potential for a simple field technique to estimate filtration capacity and predict the prevailing hyporheic gradients in microbial activity and biogeochemical processing efficiency, with significant implications for stream ecosystem function.

Threatened fishes of the world: Zacco chengtui Kimura 1934 (Cyprinidae)

Common name: Chengdu chub. Conservation status: Vulnerable, China Red Data Book of Endangered Animals (Yue and Chen 1998) and China Species Red List (Wang and Xie 2004). Identification: Body length 45–120 mm (Ding 1994; Chen 1998). Body laterally compressed, mouth terminal, posterior tip of maxilla at the anterior eye margin, eyes small, barbels absent. Lateral line complete but not straight. Pelvicfin insertion at origin of dorsal-fin; anal-fin very long, especially in matured males, reaching or surpassing caudal-fin base (Kimura 1934). Scales small, usually 60–67 on lateral line and 11–13 above lateral line (Ding 1994; Chen 1998), the main difference between Chengdu chub and other Zacco species. Colorful in live, with nine or ten lateral bars in males, no obvious bars in females. Nuptial organs present on snout, below eyes, and on anal-fin in matured males (Ding 1994; Chen 1998). Distribution: Endemic, narrowly distributed in the Jianjiang River (a tributary of the Tuojiang River in the upper Yangtze River) in Chengdu City and Pengxian County, Sichuan Province (Ding 1994; Chen 1998). Abundance: Natural populations are small (Yue and Chen 1998). Habitat and ecology: Inhabits small rivers and the tributaries with slow-moving clear water. Reproduction: Details unknown. No reports of captive breeding. Threats: Restricted distribution, streams polluted by industrial wastes. The fishes are inadvertently killed while other fish species are targeted by illegal electrical fishing and poisoning.Conservation action: No protectivemeasures, but listed as vulnerable and protected in Sichuan Province. Conservation recommendations: Habitat protection, pollution control, and fishing restriction. Determine size and genetic diversity of wild populations, initiate artificial propagation for stocking fish into the wild. Remarks: Studies of feeding habits, reproduction and development are necessary to sustain the species. Environ Biol Fish (2009) 84:27–28 DOI 10.1007/s10641-008-9382-2

Effects of residual stress and heat treatment on fatigue strength of weldments

Effects of residual stress and heat treatment on fatigue strength of weldments were investigated with lateral link specimens and sway bar bracket specimens. Residual stresses in the thickness direction at a weld toe location were measured by the X-ray diffraction (XRD) method and the hole drilling method for as-welded and post-heat-treated specimens. Compressive residual stresses on the surface were obtained from the as-welded specimens, while zero or very low tensile residual stresses were obtained from the heat-treated specimens. Microstructural differences between as-welded and heat treated specimens were also investigated in this study. Heat-treated specimens showed fine grains at the weld zone compared to that of as-welded specimens. Fatigue strength of as-welded specimens was found higher than that of heat-treated specimens due to compressive residual stresses induced at the weld toe areas. This study also predicted the fatigue life of as-welded specimens with commercial fatigue software and the life predictions were compared with experimental results.

Perceived relative distance on the ground affected by the selection of depth information

Our visual space does not appear to change when we scan or shift attention between locations. This appearance of stability implies that the depth information selection process is not crucial for constructing visual space. But we present evidence to the contrary. We focused on space perception in the intermediate distance, which depends on the integration of depth information on the ground. We propose a selection hypothesis that states that the integration process is influenced by where the depth information is selected. Specifically, the integration process inaccurately represents the ground when one samples depth information only from the far ground surface, instead of sequentially from the near to the far ground. To test this, observers matched the depth/length of a sagittal bar (test) to the width of a laterally oriented bar (reference) in three conditions in a full-cue environment that compelled the visual system to sample from different parts of the ground. These conditions had the lateral reference bar placed (1) adjacent to the test bar, (2) at the far ground, and (3) at the near ground. We found that the sagittal bar was perceived as shorter in conditions (1) and (2) than in Condition 3. This finding supports the selection hypothesis, since only Condition 3 led to more accurate ground surface integration/representation and less error in relative distance/depth perception. Also, we found that performances in all three conditions were similar in the dark, which has no depth information on the ground, indicating that the results cannot be attributed to asymmetric visual scanning but, rather, to differential information selection.

Entlastung des Hüftgelenkes durch die Thomasschiene

The Thomas Splint is mainly administered to relieve weight from the hip joint. Theoretically the leg is bypassed by transmitting the body weight directly from the pelvis to the floor.--Load transmission via a Thomas Splint was measured with an orthosis strain gauged at the ischial interface area and at the foot plate. The results show, that about one half of the weight will bypass the joint through the orthosis. The Thomas splint ist unsuitable in cases when complete weight relief from the hip joint is necessary.--These results did not depend on whether the floor was flat or ascending, or whether stairs were climbed. The lateral bar never carried more then 25% of the force transmitted.