bluuebunny/crossref_metadata_2025 huggingface dataset:
A symmetry analysis of mechanisms in rotating rings of tetrahedra
Authors: Fowler P.W , Guest S.D
Published: May 2005

Rotating rings of tetrahedra are well known from recreational mathematics. Rings of
N
tetrahedra with
N
even are analysed by symmetry-adapted versions of classical counting rules of mechanism analysis. For
N
 ≥ 6, a single state of self-stress is found, together with
N
−5 symmetry-distinct mechanisms, which include the eponymous rotating mechanism. For
N
=4 in a generic configuration, a single mechanism remains together with three states of self-stress, but, uniquely in this case, the mechanism path passes through a bifurcation at which the number of mechanisms and states of self-stress is raised by one.
Three-dimensional analytical solutions for shakedown of cohesive-frictional materials under moving surface loads
Authors: Yu H.S
Published: May 2005

This paper develops analytical solutions for shakedown limits of a cohesive-frictional half-space under a three-dimensional moving surface load. Melan's lower-bound shakedown theorem has been adopted as the theoretical basis for deriving shakedown limits. Rigorous lower-bound solutions are obtained for shakedown limits by establishing a self-equilibrated residual stress field that, together with the applied elastic stress fields, lies within the Mohr–Coulomb yield criterion throughout the half-space. By searching through the half-space, this study shows that the most critical location for satisfying the yield condition lies on the central plane. The analytical solutions derived in the paper can be used to benchmark numerical shakedown results, as well as to serve as a theoretical basis for the development of an analytical design method for pavements under moving traffic loads.
The energy of scattering solitons in the Ward model
Authors: Ioannidou T , Manton N.S
Published: May 2005

The energy density of a scattering soliton solution in Ward's integrable chiral model is shown to be instantaneously the same as the energy density of a static multi-lump solution of the

sigma model. This explains the quantization of the total energy in the Ward model.
Red deer stags use formants as assessment cues during intrasexual agonistic interactions
Authors: Reby David , McComb Karen , Cargnelutti Bruno , Darwin Chris , Fitch W. Tecumseh , Clutton-Brock Tim
Published: May 2005

While vocal tract resonances or formants are key acoustic parameters that define differences between phonemes in human speech, little is known about their function in animal communication. Here, we used playback experiments to present red deer stags with re-synthesized vocalizations in which formant frequencies were systematically altered to simulate callers of different body sizes. In response to stimuli where lower formants indicated callers with longer vocal tracts, stags were more attentive, replied with more roars and extended their vocal tracts further in these replies. Our results indicate that mammals other than humans use formants in vital vocal exchanges and can adjust their own formant frequencies in relation to those that they hear.
Scaling of mammalian ethmoid bones can predict olfactory organ size and performance
Authors: Pihlström Henry , Fortelius Mikael , Hemilä Simo , Forsman Roger , Reuter Tom
Published: May 2005

The relation between size and performance is central for understanding the evolution of sensory systems, and much interest has been focused on mammalian eyes and ears. However, we know very little about olfactory organ size (OOS), as data for a representative set of mammals are lacking. Here, we present a cranial endocast method for estimating OOS by measuring an easily accessible part of the system, the perforated part of the ethmoid bone, through which the primary olfactory axons reach the olfactory bulb. In 16 species, for which relevant data are available, the area of the perforated ethmoid bone is directly proportional to the area of the olfactory epithelium. Thus, the ethmoid bone is a useful indicator enabling us to analyse 150 species, and describe the distribution of OOS within the class Mammalia. In the future, a method using skull material may be applied to fossil skulls. In relation to skull size, humans, apes and monkeys have small olfactory organs, while prosimians have OOSs typical for mammals of their size. Large ungulates have impressive olfactory organs. Relating anatomy to published thresholds, we find that sensitivity increases with increasing absolute organ size.
Trustworthy but not lust-worthy: context-specific effects of facial resemblance
Authors: DeBruine Lisa M
Published: May 2005

If humans are sensitive to the costs and benefits of favouring kin in different circumstances, a strong prediction is that cues of relatedness will have a positive effect on prosocial feelings, but a negative effect on sexual attraction. Indeed, positive effects of facial resemblance (a potential cue of kinship) have been demonstrated in prosocial contexts. Alternatively, such effects may be owing to a general preference for familiar stimuli. Here, I show that subtly manipulated images of other-sex faces were judged as more trustworthy by the participants they were made to resemble than by control participants. In contrast, the effects of resemblance on attractiveness were significantly lower. In the context of a long-term relationship, where both prosocial regard and sexual appeal are important criteria, facial resemblance had no effect. In the context of a short-term relationship, where sexual appeal is the dominant criterion, facial resemblance decreased attractiveness. The results provide evidence against explanations implicating a general preference for familiar-looking stimuli and suggest instead that facial resemblance is a kinship cue to which humans modulate responses in a context-sensitive manner.
Limited genetic exchanges between populations of an insect pest living on uncultivated and related cultivated host plants
Authors: Vialatte Aude , Dedryver Charles-Antoine , Simon Jean-Christophe , Galman Marina , Plantegenest Manuel
Published: May 2005

Habitats in agroecosystems are ephemeral, and are characterized by frequent disturbances forcing pest species to successively colonize various hosts belonging either to the cultivated or to the uncultivated part of the agricultural landscape. The role of wild habitats as reservoirs or refuges for the aphidSitobion avenaethat colonize cultivated fields was assessed by investigating the genetic structure of populations collected on both cereal crops (wheat, barley and oat) and uncultivated hosts (Yorkshire fog, cocksfoot, bulbous oatgrass and tall oatgrass) in western France.

Classical genetic analyses and Bayesian clustering algorithms indicate that genetic differentiation is high between populations collected on uncultivated hosts and on crops, revealing a relatively limited gene flow between the uncultivated margins and the cultivated part of the agroecosystem. A closer genetic relatedness was observed between populations living on plants belonging to the same tribe (Triticeae, Poeae and Aveneae tribes) where aphid genotypes appeared not to be specialized on a single host, but rather using a group of related plant species. Causes of this ecological differentiation and its implications for integrated pest management ofS. avenaeas cereals pest are discussed.
The cost of resistance toBacillus thuringiensisvaries with the host plant ofTrichoplusia ni
Authors: Janmaat Alida F , Myers Judith H
Published: May 2005

Selection for resistance to insecticides, diseases and parasitoids is assumed to be costly and often requires tradeoffs with reproductive fitness. The costs of resistance, however, are often difficult to measure. Cabbage looper,Trichoplusia ni, a generalist Lepidopteran herbivore, has become highly resistant following the extensive use of the microbial insecticide,Bacillus thuringiensis kurstaki(Bt) in vegetable greenhouses. We compared the growth rate, pupal size and survival of resistant, susceptible and hybridT. nilarvae fed on tomato, bell pepper and cucumber. Performance was best on cucumber and worst on pepper, and the magnitude of fitness costs associated withBtresistance increased with declining host plant suitability. This supports the hypothesis that in this system, resistance costs are condition dependent and are greatest in the most stressful environment. Management strategies that rely on the presence of fitness costs to reduce the frequency of resistance genes must consider this variation and should be more successful on crops that are less suitable food plants. In general, condition dependence should be considered in studies designed to measure the costs of resistance.
The Late Triassic pseudosuchianRevueltosaurus callenderiand its implications for the diversity of early ornithischian dinosaurs
Authors: Parker William G , Irmis Randall B , Nesbitt Sterling J , Martz Jeffrey W , Browne Lori S
Published: May 2005

A new discovery of skeletons ofRevueltosaurus callenderifrom the Upper Triassic Chinle Formation of Petrified Forest National Park, Arizona clearly shows thatRevueltosaurusis not an ornithischian dinosaur as previously supposed. Features such as the presence of a postfrontal, crocodile-normal ankle and paramedian osteoderms with anterior bars placeR. callenderiwithin the Pseudosuchia, closer to crocodylomorphs than to dinosaurs. Therefore, dental characters previously used to placeRevueltosauruswithin the Ornithischia evolved convergently among other archosaur taxa, and cannot be used to diagnose ornithischian dinosaur teeth. As a result, all other putative North American Late Triassic ornithischians, which are all based exclusively on teeth, are cast into doubt. The only reasonably well-confirmed Late Triassic ornithischians worldwide arePisanosaurus mertiiand an unnamed heterodontosaurid from Argentina. This considerably changes the understanding of early dinosaur diversity, distribution and evolution in the Late Triassic.
Cost of reproduction in a long-lived bird: incubation effort reduces immune function and future reproduction
Authors: Hanssen Sveinn Are , Hasselquist Dennis , Folstad Ivar , Erikstad Kjell Einar
Published: May 2005

Life-history theory predicts that increased current reproductive effort should lead to a fitness cost. This cost of reproduction may be observed as reduced survival or future reproduction, and may be caused by temporal suppression of immune function in stressed or hard-working individuals. In birds, consideration of the costs of incubating eggs has largely been neglected in favour of the costs of brood rearing. We manipulated incubation demand in two breeding seasons (2000 and 2001) in female common eiders (Somateria mollissima) by creating clutches of three and six eggs (natural range 3–6 eggs). The common eider is a long-lived sea-duck where females do not eat during the incubation period. Mass loss increased and immune function (lymphocyte levels and specific antibody response to the non-pathogenic antigens diphtheria and tetanus toxoid) was reduced in females incubating large clutches. The increased incubation effort among females assigned to large incubation demand did not lead to adverse effects on current reproduction or return rate in the next breeding season. However, large incubation demand resulted in long-term fitness costs through reduced fecundity the year after manipulation. Our data show that in eiders, a long-lived species, the cost of high incubation demand is paid in the currency of reduced future fecundity, possibly mediated by reduced immune function.
First identifiable Mesozoic harvestman (Opiliones: Dyspnoi) from Cretaceous Burmese amber
Authors: Giribet Gonzalo , Dunlop Jason A
Published: May 2005

Two inclusions in a piece of Upper Cretaceous (Albian) Burmese amber from Myanmar are described as a harvestman (Arachnida: Opiliones),
Halitherses grimaldii
new genus and species. The first Mesozoic harvestman to be named can be referred to the suborder Dyspnoi for the following reasons: prosoma divided into two regions, the posterior formed by the fusion of the meso- and metapeltidium; palp lacking a terminal claw, with clavate setae, and tarsus considerably shorter than the tibia. The bilobed, anteriorly projecting ocular tubercle is reminiscent of that of ortholasmatine nemastomatids. The status of other Mesozoic fossils referred to Opiliones is briefly reviewed.
Early development of the facial region in a non-avian theropod dinosaur
Authors: Rauhut Oliver W. M , Fechner Regina
Published: May 2005

An isolated maxilla of the theropod dinosaur
Allosaurus
from the Late Jurassic (the Kimmeridgian, 153 million years ago) of Portugal is the first cranial remain of a non-coelurosaurian theropod hatchling reported so far, and sheds new light on the early cranial development of non-avian theropods.
Allosaurus
hatchlings seem to have been one-seventh or less of the adult length and are thus comparable in relative size to hatchlings of large extant crocodile species, but are unlike the relatively larger hatchlings in coelurosaurs. The snout experienced considerable positive allometry and an increase in tooth count during early development. The element is especially noteworthy for the abundant and well-developed features associated with the paranasal pneumatic system. Pneumatic structures present include all those found in adult allosaurids and most are even more developed than in adult skulls. Together with evidence on the ontogeny of the tympanic pneumatic system in allosaurids, these findings demonstrate that cranial pneumaticity developed early in theropod ontogeny. The strong development of pneumatic features in early ontogenetic stages of non-avian theropods supports the hypothesis that pneumatization of cranial bones was opportunistic and indicates that heterochrony played an important role in the evolution of craniofacial pneumaticity in this group.
The cortical column: a structure without a function
Authors: Horton Jonathan C , Adams Daniel L
Published: May 2005

This year, the field of neuroscience celebrates the 50th anniversary of Mountcastle's discovery of the cortical column. In this review, we summarize half a century of research and come to the disappointing realization that the column may have no function. Originally, it was described as a discrete structure, spanning the layers of the somatosensory cortex, which contains cells responsive to only a single modality, such as deep joint receptors or cutaneous receptors. Subsequently, examples of columns have been uncovered in numerous cortical areas, expanding the original concept to embrace a variety of different structures and principles. A ‘column’ now refers to cells in any vertical cluster that share the same tuning for any given receptive field attribute. In striate cortex, for example, cells with the same eye preference are grouped into ocular dominance columns. Unaccountably, ocular dominance columns are present in some species, but not others. In principle, it should be possible to determine their function by searching for species differences in visual performance that correlate with their presence or absence. Unfortunately, this approach has been to no avail; no visual faculty has emerged that appears to require ocular dominance columns. Moreover, recent evidence has shown that the expression of ocular dominance columns can be highly variable among members of the same species, or even in different portions of the visual cortex in the same individual. These observations deal a fatal blow to the idea that ocular dominance columns serve a purpose. More broadly, the term ‘column’ also denotes the periodic termination of anatomical projections within or between cortical areas. In many instances, periodic projections have a consistent relationship with some architectural feature, such as the cytochrome oxidase patches in V1 or the stripes in V2. These tissue compartments appear to divide cells with different receptive field properties into distinct processing streams. However, it is unclear what advantage, if any, is conveyed by this form of columnar segregation. Although the column is an attractive concept, it has failed as a unifying principle for understanding cortical function. Unravelling the organization of the cerebral cortex will require a painstaking description of the circuits, projections and response properties peculiar to cells in each of its various areas.
Mapping brains without coordinates
Authors: Kötter Rolf , Wanke Egon
Published: May 2005

Brain mapping has evolved considerably over the last century. While most emphasis has been placed on coordinate-based spatial atlases, coordinate-independent parcellation-based mapping is an important technique for accessing the multitude of structural and functional data that have been reported from invasive experiments, and provides for flexible and efficient representations of information. Here, we provide an introduction to motivations, concepts, techniques and implications of coordinate-independent mapping of microstructurally or functionally defined brain structures. In particular, we explain the problems of constructing mapping paths and finding adequate heuristics for their evaluation. We then introduce the three auxiliary concepts of acronym-based mapping (AM), of a generalized hierarchy (GM ontology), and of a topographically oriented regional map (RM) with adequate granularity for mapping between individual brains with different cortical folding and between humans and non-human primates. Examples from the CoCoMac database of primate brain connectivity demonstrate how these concepts enhance coordinate-independent mapping based on published relational statements. Finally, we discuss the strengths and weaknesses of spatial coordinate-based versus coordinate-independent microstructural brain mapping and show perspectives for a wider application of parcellation-based approaches in the integration of multi-modal structural, functional and clinical data.
Cortical visual areas in monkeys: location, topography, connections, columns, plasticity and cortical dynamics
Authors: Gattass Ricardo , Nascimento-Silva Sheila , Soares Juliana G.M , Lima Bruss , Jansen Ana Karla , Diogo Antonia Cinira M , Farias Mariana F , Botelho Marco Marcondes, Eliã P , Mariani Otávio S , Azzi João , Fiorani Mario
Published: May 2005

The visual system is constantly challenged to organize the retinal pattern of stimulation into coherent percepts. This task is achieved by the cortical visual system, which is composed by topographically organized analytic areas and by synthetic areas of the temporal lobe that have more holistic processing. Additional visual areas of the parietal lobe are related to motion perception and visuomotor control. V1 and V2 represent the entire visual field. MT represents only the binocular field, and V4 only the central 30°–40°. The parietal areas represent more of the periphery. For any eccentricity, the receptive field grows at each step of processing, more at anterior areas in the temporal lobe. Minimal point image size increases towards the temporal lobe, but remains fairly constant toward the parietal lobe. Patterns of projection show asymmetries. Central V2 and V4 project mainly to the temporal lobe, while peripherals V2 (more than 30°) and V4 (more than 10°) also project to the parietal lobe. Visual information that arrives at V1 projects to V2, MT and PO, which then project to other areas. Local lateral propagation and recursive loops corroborate to perceptual completion and filling in. Priority connections to temporal, parietal and parieto-temporal cortices help construct crude early representations of objects, trajectories and movements.
Tension and stress in the rat and rabbit stomach are location‐ and direction‐dependent
Authors: Zhao J. , Liao D. , Gregersen H.
Published: May 2005

Abstract  Distension studies in the stomach are very common. It is assumed in pressure–volume (barostat) studies of tone and tension in the gastric fundus that the fundus is a sphere, i.e. that the tension in all directions is identical. However, the complex geometry of the stomach indicates a more complex mechanical behaviour. The aim of this study was to determine uniaxial stress–strain properties of gastric strips obtained from rats (n = 12) and rabbits (n = 10). Furthermore, we aimed to study the gastric zero‐stress state since the stomach is one of the remaining parts of the gastrointestinal tract where residual strain studies have not been conducted. Longitudinal strips (in parallel with the lesser curvature) and circumferential strips (perpendicular to the lesser curvature) were cut from the gastric fundus (glandular part) and forestomach (non‐glandular part). The residual stress was evaluated as bending angles (unit: degree per unit length and negative when bending outwards). The residual strain was computed from the change in length between the zero‐stress state and no‐load state. The stress–strain test was performed using a tensile test machine. The thickness and width of each strip were measured from digital images. The strips data were compared with data obtained in the intact stomach in vitro. Most residual stresses and strains were bigger in the glandular part than in the forestomach, and in general the rat stomach had higher values than the rabbit stomach. The glandular strips were stiffer than the forestomach strips and the longitudinal glandular strips were stiffer than the circumferential glandular strips (P < 0.05). The gastric strips were stiffer in rats than in rabbits (P < 0.01). The data obtained in the intact rat stomach confirmed the strips data and indicated that those were obtained in the physiological range. In conclusion, the biomechanical properties of the gastric strips from the rat and rabbit are location‐dependent, direction‐dependent and species‐dependent. The assumption in physiological pressure–volume studies that the stomach is a sphere with uniform tension is not valid. Three‐dimensional geometric data obtained using imaging technology and mechanical data are needed for evaluation of the stomach function.
5‐HT4 receptors located on cholinergic nerves in human colon circular muscle
Authors: Leclere P. G. , Prins N. H. , Schuurkes J. A. J. , Lefebvre R. A.
Published: May 2005

Abstract  5‐Hydroxytryptamine 4 (5‐HT4) receptor agonists promote colonic propulsion. The alteration of circular muscle (CM) motility underlying this involves inhibition of contractility via smooth muscle 5‐HT4 receptors and proximal colonic motility stimulation, the mechanism of the latter not having been characterized. Our aim was to identify and characterize a 5‐HT4 receptor‐mediated stimulation of human colon CM contractile activity. 5‐HT4 receptor ligands were tested on electrical field stimulation (EFS)‐induced contractions of human colonic muscle strips cut in the circular direction (called ‘whole tissue’ strips). Additionally, after incubation of tissues with [3H]‐choline these compounds were tested on EFS‐induced release of tritium in whole tissue strips and in ‘isolated’ CM strips, obtained by superficial cutting in the CM layer. Tetrodotoxin and atropine blocked EFS‐induced contractions of whole tissue CM strips. Prucalopride (0.3 μmol L−1) evoked a heterogenous response on EFS‐induced contraction, ranging from inhibition (most frequently observed) to enhancement. In the release experiments, EFS‐induced tritium efflux was blocked by tetrodotoxin. Prucalopride increased EFS‐induced tritium and [3H]‐acetylcholine efflux in whole tissue and in isolated CM strips. All effects of prucalopride were antagonized by the selective 5‐HT4 receptor antagonist GR113808. The results obtained indicate the presence of excitatory 5‐HT4 receptors on cholinergic nerves within the CM of human colon.
Irritable bowel syndrome in developing countries – a disorder of civilization or colonization?
Authors: Gwee K.‐a.
Published: May 2005

Abstract  While irritable bowel syndrome (IBS) is common in the West, early studies suggest that the prevalence is low in developing countries. However, recent studies point to increasing prevalence in newly developed Asian economies. The presentation appears to differ from the West, with a lack of female predominance, a greater frequency of upper abdominal pain and defecatory symptoms perceived as being less bothersome. This difference, together with the preoccupation with organic disease, could explain why we may be missing IBS in Asia and also why excess surgery has been observed in some Asian countries. While a recent study from China, consistent with western studies, support an important role for infection and inflammation, early studies from India reporting no association between amoebic infection and IBS appear to dispute this observation. To reconcile these seemingly contradictory observations, an hygiene hypothesis model is proposed. Exposure to a variety of microorganisms early in life could result in the colonization of the intestine with microflora that can respond more efficiently to an episode of gastroenteritis. Together with the changes with evolution of Asian economies such as westernization of the diet and increased psychosocial stress, it is proposed that loss of this internal protective effect, could give rise to a more uniform worldwide prevalence of IBS.
Assessment of gastric volume changes with sonometry compared with barostat
Authors: Ouyang H. , Chen J. D. Z.
Published: May 2005

Abstract  Aim:  The aim was to investigate the validity of sonometry on the assessment of gastric volumes in comparison with gastric barostat.

Method:  Six dogs were implanted with gastric serosal electrodes, sonometric sensors, and a gastric cannula. Experiments were performed to assess sensor distance when an intragastric balloon was inflated with different volumes, after a meal with or without a balloon, and with gastric electrical stimulation.

Results:  (i) The distance measured using sonometry was reproducible and stable, and there was a correlation between sensor distance and the gastric volume measured with barostat. (ii) Simultaneous recordings by sonometry and barostat showed a similar postprandial response, while the postprandial increase of the sensor distance was much smaller without the balloon (3.2 ± 0.2 mm vs 9.7 ± 1.5 mm, P < 0.02). (iii) The sensor distance was increased with gastric electrical stimulation.

Conclusions:  Sonometry is able to detect gastric volume changes as validated by gastric perturbations with distensions, food ingestion and electrical stimulation. The postprandial increase in gastric volume measured by sonometry with barostat balloon is greater because of the presence of the intragastric balloon.
Disposable balloon‐based oesophageal motility catheters: comparison with solid‐state transducers*
Authors: Tutuian R. , Agrawal A. , Mainie I. , Freeman J. , Castell D. O.
Published: May 2005

Abstract  Background:  Current oesophageal manometry systems use either water‐perfused or solid‐state pressure transducers. Recently developed single‐use disposable catheters use small balloons prefilled with air that transmit the pressure of oesophageal contractions to external transducers.

Aim:  To compare data obtained from single‐use disposable balloon catheters to data from solid‐state systems.

Methods:  Healthy volunteers, patients with ineffective oesophageal motility and nutcracker oesophagus were studied to include a broad range of pressures. A single‐use disposable Clinical Innovations (CI) catheter was placed adjacent to a solid‐state Konigsberg Instruments (KI) catheter with pressure transducers at 5, 10, 15 and 20 cm above the lower oesophageal sphincter (LOS). Subjects received liquid and viscous swallows at 30‐s intervals. Healthy volunteers received additional sets of swallows while having only one catheter in the oesophagus.

Results:  When both catheters were present in the oesophagus, no differences were noted between mean pressure measurements in the distal oesophagus and there was good correlation between pressures recorded in response to individual swallows. When present alone in the oesophagus the CI catheter recorded lower mean pressures compared with the KI catheter. Overall there was good agreement in classifying swallows as normal, ineffective and simultaneous.

Conclusion:  Single‐use oesophageal manometry catheters are promising alternatives to solid‐state manometry systems in measuring intra‐oesophageal pressures.
Assessment of oesophageal motor function using combined perfusion manometry and multi‐channel intra‐luminal impedance measurement in normal subjects
Authors: Nguyen N. Q. , Rigda R. , Tippett M. , Conchillo J. , Smout A. J. P. M. , Holloway R. H.
Published: May 2005

Abstract  Multichannel intraluminal impedance (MII) is being used increasingly to assess oesophageal bolus clearance. However, there is no good standardization of the impedance parameters that define ‘effective bolus clearance’. The aim of this study was to define these important impedance parameters and to determine their normal values. Concurrent perfusion manometry and MII were performed in 42 healthy volunteers. Ten, 5‐mL liquid (saline) boluses and then, 10 × 5‐mL low impedance viscous boluses were tested in each subject in the right‐lateral position. Normal values for bolus presence time (BPT) at each site and total bolus transit time (TBTT) were determined from either ‘normal’ peristaltic responses (amplitude ≥30 mmHg in distal oesophagus) or ‘super‐normal’ peristaltic responses (amplitudes ≥50 mmHg at all sites). The relationship between BPT and TBTT within a response and per‐individual performance was determined. A total of 840 swallows of liquids and viscous responses were analysed. BPT and TBTT of viscous swallows were longer than those for liquids. Non‐peristaltic responses were significantly more likely not to clear a viscous than a liquid bolus. Within a response, the number of sites with prolonged BPT strongly predicted the incidence of prolonged TBTT. Using impedance criteria, normal oesophageal bolus clearance is defined when an individual completely clears at least 70% of liquid responses and at least 60% of viscous responses. This study provides normal values for impedance measurement of bolus clearance when combined with perfusion manometry. These values will allow standardization of impedance application in oesophageal function testing, in both research and clinical setting.
Disruption of the blood–brain barrier during TNBS colitis
Authors: Natah S. S. , Mouihate A. , Pittman Q. J. , Sharkey K. A.
Published: May 2005

Abstract  Well‐documented central nervous system changes during colitis suggest possible alterations of blood–brain barrier (BBB) permeability, yet the integrity of the BBB has not been fully evaluated in experimental colitis. Our aim was to investigate whether trinitrobenzene sulphonic acid (TNBS) colitis was associated with an increase in the permeability of the BBB. Sprague–Dawley rats were given an intracolonic injection of saline or TNBS and studied 1, 2, 3, 7 and 21 days after treatment. The extravasation of endogenous immunoglobulin G, a large molecule, was not altered at any time after TNBS treatment. In contrast, significant increases in the BBB leakage of sodium fluorescein, a much smaller molecule, were observed 1 and 2 days after the induction of colitis, in and around the circumventricular organs; the organum vasculosum of the lamina terminalis, subfornical organ and median eminence of the hypothalamus. TNBS‐treated rats also exhibited sodium fluorescein leakage in focal areas in the brain parenchyma. The expression of endothelial barrier antigen, a protein associated with the BBB, was reduced about 60% 48 h after the induction of colitis. This returned to control values by 3 weeks, when colitis had largely subsided. In conclusion, experimental colitis transiently increased permeability of the brain to small molecules through a mild disruption of the BBB.
Reflections of occupational therapists working as members of a research team
Authors: Finlayson Marcia , Shevil Eynat , Mathiowetz Virgil , Matuska Kathleen
Published: May 2005

Aim:  This qualitative study explored the effects of clinician participation in a randomised clinical trial on subsequent practice.

Method:  Eight occupational therapists responded to open‐ended questions delivered by email about their reflections on participating in clinical research and its impact on their practice. Qualitative analysis uncovered therapists’ motivation to participate in research, what they felt that they gained, and if and how research participation influenced practice.

Results:  Clinicians learned about research, practice, and their own clinical biases through their participation in clinical research.

Conclusion:  Our findings suggest that participation in research may contribute to shrinking the research‐practice gap.
Towards facilitating change in service delivery: An illustrative example
Authors: Boshoff Kobie
Published: May 2005

Background:  The management of change in organisations is a challenge facing many occupational therapists in practice today. This article presents an example of a program implemented to facilitate the process of change in paediatric service delivery. It presents the principles and design of the program, as well as the program's implementation and resultant findings.

Methods:  The principles and process of organisational change laid the foundation of the program and were utilised as measurement of changes occurring in the perceptions of participants. Interviews and online focus groups were utilised as data‐gathering methods.

Results:  The findings of the study illustrate the process of change that participants were undergoing.

Conclusions:  The article provides an example of how managers can facilitate change in service delivery by using the principles of organisational change and adult learning. Recommendations are made for application of similar change management processes in other organisations and the future use of the online discussion medium as research tool and in practice.
Interventions for improving self‐awareness following acquired brain injury
Authors: Lucas Sarah E. , M. Fleming Jennifer
Published: May 2005

Accurate self‐awareness in clients who have had an acquired brain injury (ABI) has been associated with positive outcomes. However, providing intervention that improves clients’ self‐awareness is a challenging task for occupational therapists. The present paper provides an overview of the literature regarding models to guide intervention, intervention considerations, descriptions of interventions, and research evidence for interventions. Professionals can draw upon cognitive rehabilitation models and specific models of self‐awareness. Facilitatory interventions, such as education, feedback, behaviour therapy and psychotherapy have been recommended to a greater extent than compensatory interventions. The development of interventions for improving self‐awareness is at an early stage, and research on the effectiveness of interventions is limited. Future research is required into the effectiveness of interventions to improve clients’ self‐awareness before structured intervention guidelines can be developed.
FGF19‐FGFR4 signaling elaborates lens induction with the FGF8‐L‐Maf cascade in the chick embryo
Authors: Kurose Hitomi , Okamoto Mayumi , Shimizu Miyuki , Bito Takaaki , Marcelle Cristophe , Noji Sumihare , Ohuchi Hideyo
Published: May 2005

The fibroblast growth factor (FGF) family is known to be involved in vertebrate eye development. However, distinct roles of individual FGF members during eye development remain largely elusive. Here, we show a detailed expression pattern of Fgf19 in chick lens development. Fgf19 expression initiated in the forebrain, and then became restricted to the distal portion of the optic vesicle abutting the future lens placode, where FGF receptor 4 (Fgfr4), a receptor for FGF19, was expressed. Fgf8, a positive regulator for L‐Maf, was expressed in a portion of the optic vesicle. To examine the role of FGF19 signaling during early eye development, Fgf19 was misexpressed near the presumptive lens ectoderm; however, no alteration in the expression of lens marker genes was observed. Conversely, a secreted form of FGFR4 was misexpressed to inhibit an FGF19 signal, resulting in the induction of L‐Maf expression. To further define the relationship between L‐Maf and Fgf19, L‐Maf misexpression was performed, resulting in ectopic induction of Fgf19 expression by Hamburger and Hamilton's stage 12/13. Furthermore, misexpression of Fgf8 induced Fgf19 expression in addition to L‐Maf. These results suggest that FGF19‐FGFR4 signaling plays a role in early lens development in collaboration with FGF8 signaling and L‐Maf transcriptional system.
Sp1‐like transcription factors are regulators of embryonic development in vertebrates
Authors: Zhao Chengtian , Meng Anming
Published: May 2005

Sp1‐like family is an expanding transcription factor family. Members of this family bind to the GC‐box or GT‐box elements in the promoter/enhancers and regulate the expression of the target genes. Currently, this family consists of at least nine members, which may act as a transactivator or a repressor on target promoters. Sp1‐like transcription factors are expressed during development of vertebrate embryos in ubiquitous or tissue‐specific manners and play various roles in embryonic development. This review mainly summarises their expression patterns and functions during vertebrate embryogenesis.
Activation of Rac1 or Cdc42 during early morphogenesis of eye discs induces ectopic antennae in Drosophila
Authors: Go Masahiro J.
Published: May 2005

The Rho family small guanosine triphosphatases (GTPases) play important roles in many cellular processes, especially in regulation of cytoskeletal organization. In this study, I examined the functions of Rac1 and Cdc42 for disc morphogenesis in Drosophila. I expressed either a constitutively active form or a dominant negative form of each protein during early morphogenesis of eye discs. Inactivation of Rac1 or Cdc42 resulted in small eye phenotypes. On the other hand, I found that activation of either Rac1 or Cdc42 induces ectopic antennae. In some cases, an almost complete antenna was observed instead of an eye, which was possibly transformation from an eye to an antenna. As a molecular evidence for the ectopic antennae, I found that the Distal‐less protein, which is essential for the distalization process, was ectopically induced in the eye discs. I also found that the Decapentaplegic and Wingless proteins, which are upstream morphogenetic signaling proteins of the distalization process, could be ectopically induced by activation of Rac1 or Cdc42. My observations suggest novel functions of Rac1 and Cdc42 for disc morphogenesis.
Postnatal changes in the expression of p60c‐Src in mouse testes
Authors: Gye Myung Chan , Choi Jin Kook , Ahn Hyun Soo , Kim Young Soo
Published: May 2005

Src family non‐receptor tyrosine kinases are involved in signaling pathways which mediate cell growth, differentiation, transformation and tissue remodeling in various organs. In an effort to elucidate functional involvement of p60c‐Src (c‐Src) in spermatogenesis, the postnatal changes in c‐src mRNA and c‐Src protein together with kinase activity and subcellular localization were examined in mouse testes. c‐src mRNA levels in testes increased during the first 2 weeks of postnatal development (PND). Following a decrease at puberty (PND 28), the c‐src mRNA levels re‐increased at adulthood (PND 50). Src kinase activity of testes was low at PND 7 but sharply increased prepubertally (PND 15) and highest at adulthood. Upon Western blotting, the level of c‐Src protein was the highest in prepubertal testes but rather decreased in adult testes at PND 50. In adult testes, ubiquitination of c‐Src proteins was apparent compared with immature one at PND 7, suggesting active turnover of c‐Src by ubiquitination. In immature testes, c‐Src immunoreactivity was largely found in the cytoplasm of the Sertoli cells. By contrast, in pubertal and adult testes intense immunoreactivity was localized at the adluminal and basal cytoplasm of Sertoli cells bearing elongated spermatids and early germ cells, respectively. The immunoreactivity of c‐Src in the Leydig cells was increased during pubertal development, suggesting the functional involvement of c‐Src in differentiated adult Leydig cells. Throughout postnatal development, some spermatogonia and spermatocytes showed intensive c‐Src immunoreactivity compared with other germ cells, suggesting a possible role of c‐Src in germ cell death. Taken together, it is suggested that c‐Src may participate in the remodeling of the seminiferous epithelia and functional differentiation of Leydig cells during the postnatal development of mouse testes.
Isolation of the choanocyte in the fresh water sponge, Ephydatia fluviatilis and its lineage marker, Ef annexin
Authors: Funayama Noriko , Nakatsukasa Mikiko , Hayashi Tetsutaro , Agata Kiyokazu
Published: May 2005

In order to investigate the cellular system of the freshwater sponge, Ephydatia fluviatilis, we isolated a molecular marker for the most prominent cell type, the choanocyte. After feeding sponge with fluorescent beads, fluorescent‐labeled choanocytes were collected by fluorescence activated cell sorting (FACS). By protein profiling choanocyte and archeocyte (stem cell)‐rich fractions, proteins characteristic of choanocyte were identified. The partial amino‐acid sequence of one of the proteins characteristic of choanocyte matches the deduced amino‐acid sequence of sponge expression tag (EST) clones and mouse annexin VII. These EST clones overlap and encode a protein, designated Ef annexin, which includes four annexin domains. Whole mount in situ hybridization shows Ef annexin expression in chamber‐forming choanocytes in 7‐day‐old sponge, leading us to conclude that Ef annexin can be used as a choanocyte marker. In the early development stage, Ef annexin expression can be detected in both large single cells, characteristic of archeocytes, and cells forming 2‐, 4‐ and multiple‐cell clusters. These results indicate that Ef annexin is initially expressed in the choanocyte‐committed archeocyte which then undergoes several mitotic cell divisions to form a choanocyte chamber. This suggests that the single choanocyte chamber essentially originates from a single archeocyte.
The Impact of Profit Sharing on the Performance of Financial Services Firms*
Authors: Magnan Michel , St‐Onge Sylvie
Published: May 2005

abstract  Relying on macro theories (agency and organizational control) as well as micro theories (goal setting and expectancy), this study investigates the impact of profit‐sharing plan (PSP) adoption on the value creation process of financial services firms. The study relies on a comprehensive methodological approach that is both quantitative, with a dual cross‐sectional/longitudinal (pre‐post) design that compares PSP adopters with a control group of PSP non‐adopter firms, and qualitative through interviews with some adopting firms’ managing directors. Results show that firms adopting a PSP enhance their profitability in comparison to both their own prior performance and to firms that are not adopting a PSP. Results also show that the adoption of a PSP: (a) positively influences only profit drivers that are under employee control; and (b) is more likely to have a long term, positive impact on external profit drivers than on internal profit drivers. Qualitative data from field interviews corroborate and enrich these quantitative findings.
Aligning Manufacturing Strategy and Business‐Level Competitive Strategy in New Competitive Environments: The Case for Strategic Resonance
Authors: Brown Steve , Blackmon Kate
Published: May 2005

abstract In this paper we make the case forstrategic resonancein the strategy making process within dynamic and highly volatile market conditions. We discuss how managers are faced with competing paradigms of resource‐driven versus market‐led approaches to strategy but we suggest that both paradigms have flaws and may causestrategic dissonanceto occur. Moreover, we offer additional insights into why strategic dissonance can occur within the strategy process of the firm. We suggest that a key omission often lies in the neglect of operations managers’ potentially important contributions to the strategy mainstream process.
The Configuration of Organizational Images Among Firms in the Canadian Beer Brewing Industry*
Authors: Lamertz Kai , Heugens Pursey P. M. A. R. , Calmet Loïc
Published: May 2005

abstract We integrate the literature on organizational image management and neo‐institutional theory to arrive at a better understanding of how organizations routinely represent themselves positively in their external environment. Drawing on a cross‐sectional exploratory study of the website communications of 36 firms in the Canadian brewing industry, we investigate how these organizations construct essential and distinctive organizational images in reference to a map of identity attributes and image categories at the organizational field level. We conclude that organizational self‐categorizations explain the field‐level configuration of images we discovered by establishing legitimacy claims targeted at relevant stakeholders.
In the Name of the Practical: Unearthing the Hegemony of Pragmatics in the Discourse of Environmental Management*
Authors: Prasad Pushkala , Elmes Michael
Published: May 2005

abstract  A prominent feature of the rapidly growing field of Environmental Management (EM) is its strong emphasis on pragmatic considerations. Much of EM's legitimacy stems from its own identity as having practical relevance in resolving contemporary environmental problems. With the help of Critical Discourse Analysis, our paper engages closely with the language of practicality in Environmental Management. We show how the message of practicality emerged through three core messages in the discourse, viz. economic utilitarianism, compromise and inter‐organizational collaboration. We further contend that in the actual material context of the complex biospheric environment, these messages may have less than pragmatic implications. We conclude with a discussion of ecological rationality in redefining the discourse of pragmatics in Environmental Management.
The impact of computer‐mediated and traditional academic task presentation on the performance and behaviour of children with ADHD
Authors: Shaw Rebecca , Lewis Vicky
Published: May 2005

This project aimed to examine whether the use of computers could have a positive impact on the performance of academic tasks and their behaviour whilst completing them of children with ADHD. This small exploratory study therefore investigated the impact of the use of a laptop computer, with and without stimulating animations and features incorporated into task presentation, on Key Stage 2 level science tasks. The effects of these different forms of computer presentation were examined in relation to performance on more traditionally presented, pen and paper, tasks. The results of this study revealed that, in contrast to typically developing children, participants with ADHD produced the greatest number of accurate responses on the more basic computerised tasks (presented as simple Microsoft Word documents) and exhibited significantly more on‐task activity on animated computerised tasks. In summary, computerised presentation significantly improved the accuracy of responses and the on‐task focus of participants with ADHD. These early findings are encouraging and may have wide reaching practical implications in terms of the design and implementation of educational software aimed at promoting improvements for children with ADHD in terms of both their academic performance and, critically, appropriate on‐task focus and behaviour in the classroom.