bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of the transmissibility of the agent of bovine spongiform encephalopathy to the domestic chicken
Authors: Moore Jo , Hawkins Stephen AC , Austin Anthony R , Konold Timm , Green Robert B , Blamire Ian W , Dexter Ian , Stack Michael J , Chaplin Melanie J , Langeveld Jan PM , Simmons Marion M , Spencer Yvonne I , Webb Paul R , Dawson Michael , Wells Gerald AH 
Published: February 2012

Abstract

Background
Transmission of the prion disease bovine spongiform encephalopathy (BSE) occurred accidentally to cattle and several other mammalian species via feed supplemented with meat and bone meal contaminated with infected bovine tissue. Prior to United Kingdom controls in 1996 on the feeding of mammalian meat and bone meal to farmed animals, the domestic chicken was potentially exposed to feed contaminated with the causal agent of BSE. Although confirmed prion diseases are unrecorded in avian species a study was undertaken to transmit BSE to the domestic chicken by parenteral and oral inoculations. Transmissibility was assessed by clinical monitoring, histopathological examinations, detection of a putative disease form of an avian prion protein (PrP) in recipient tissues and by mouse bioassay of tissues. Occurrence of a progressive neurological syndrome in the primary transmission study was investigated by sub-passage experiments.

Results
No clinical, pathological or bioassay evidence of transmission of BSE to the chicken was obtained in the primary or sub-passage experiments. Survival data showed no significant differences between control and treatment groups. Neurological signs observed, not previously described in the domestic chicken, were not associated with significant pathology. The diagnostic techniques applied failed to detect a disease associated form of PrP.

Conclusion
Important from a risk assessment perspective, the present study has established that the domestic chicken does not develop a prion disease after large parenteral exposures to the BSE agent or after oral exposures equivalent to previous exposures via commercial diets. Future investigations into the potential susceptibility of avian species to mammalian prion diseases require species-specific immunochemical techniques and more refined experimental models.
Feasibility, reliability, and clinical validity of the Test of Attentional Performance for Children (KiTAP) in Fragile X syndrome (FXS)
Authors: Knox Andrew , Schneider Andrea , Abucayan Floridette , Hervey Crystal , Tran Christina , Hessl David , Berry-Kravis Elizabeth 
Published: February 2012

AbstractBackgroundAttention and inhibition are core executive-function deficits in FRagile X syndrome (FXS). This pilot study evaluated the feasibility, reproducibility, and clinical relevance of the KiTAP, a computer-based pictorial measure of attention and inhibition with an enchanted-castle theme, in an FXS cohort.MethodsThe 8-subtest KiTAP battery (as many subtests as each could perform) was given to 36 subjects with FXS, of variable age and cognitive/behavioral functioning, and 29 were retested, with an interval of 2 to 4 weeks between sessions. Subjects were rated by parents on the Aberrant Behavior Checklist-Community Edition (ABC-C) and Behavior Assessment System for Children, Second Edition (BASC-2). Feasibility, ceiling and basal effects, and data range and distribution analyses were used to eliminate outliers and invalid data points. Reproducibility of scores was analyzed using intraclass correlation coefficients (ICCs) and validity/clinical relevance was assessed by correlating KiTAP scores with ABC-C and BASC-2 scores.ResultsMost of the participants with FXS were able to complete the Alertness, Distractibility, Flexibility, and Go/NoGo subtests.About 50 to 60% completed the Visual Scanning and Vigilance subtests, and 20 to 25% completed the Sustained Attention and Divided Attention subtests. A panel of seven scores from four subtests were identified as feasible for most subjects, lacked excessive ceiling, basal, or learning effects, exhibited an acceptable range and distribution of scores, had good reproducibility (ICC > 0.7), and correlated with behavioral ratings for hyperactivity or attention (P< 0.01). Only minor differences in performance on the KiTAP were seen between mental age-matched cohorts of subjects with FXS and non-FXS intellectual disability.ConclusionsThe KiTAP can be administered to cohorts with FXS over a wide range of function with valid reproducible scores. With additional validation, it could represent a useful outcome measure for assessment of attention/executive-function abilities in clinical trials targeted to these core deficits in FXS.
Patient safety in pre-hospital emergency tracheal intubation: a comprehensive meta-analysis of the intubation success rates of EMS providers
Authors: Lossius Hans Morten , Røislien Jo , Lockey David J 
Published: February 2012

Abstract
Introduction
Pre-hospital airway management is a controversial subject, but there is general agreement that a small number of seriously ill or injured patients require urgent emergency tracheal intubation (ETI) and ventilation. Many European emergency medical services (EMS) systems provide physicians to care for these patients while other systems rely on paramedics (or, rarely, nurses). The ETI success rate is an important measure of provider and EMS system success and a marker of patient safety.

Methods
We conducted a systematic search of Medline and EMBASE to identify all of the published original English-language articles reporting pre-hospital ETI in adult patients. We selected all of the studies that reported ETI success rates and extracted information on the number of attempted and successful ETIs, type of provider, level of ETI training and the availability of drugs on scene. We calculated the overall success rate using meta-analysis and assessed the relationships between the ETI success rate and type of provider and between the ETI success rate and the types of drugs available on the scene.

Results
From 1,070 studies initially retrieved, we identified 58 original studies meeting the selection criteria. Sixty-four per cent of the non-physician-manned services and 54% of the physician-manned services reported ETI success rates but the success rate reporting was incomplete in three studies from non-physician-manned services. Median success rate was 0.905 (0.491, 1.000). In a weighted linear regression analysis, physicians as providers were significantly associated with increased success rates, 0.092 (P = 0.0345). In the non-physician group, the use of drug-assisted intubation significantly increased the success rates. All physicians had access to traditional rapid sequence induction (RSI) and, comparing these to non-physicians using muscle paralytics or a traditional RSI, there still was a significant difference in success rate in favour of physicians, 0.991 and 0.955, respectively (P = 0.047).

Conclusions
This comprehensive meta-analysis suggests that physicians have significantly fewer pre-hospital ETI failures overall than non-physicians. This finding, which remains true when the non-physicians administer muscle paralytics or RSI, raises significant patient safety issues. In the absence of pre-hospital physicians, conducting basic or advanced airway techniques other than ETI should be strongly considered.
Paneth cell ablation in the presence of Klebsiella pneumoniae induces necrotizing enterocolitis (NEC)-like injury in immature murine small intestine
Authors: Zhang Chunxian , Sherman Michael P. , Prince Lawrence S. , Bader David , Weitkamp Jörn-Hendrik , Slaughter James C. , McElroy Steven J. 
Published: February 2012

Summary
Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in premature infants. During NEC pathogenesis, bacteria are able to penetrate innate immune defenses and invade the intestinal epithelial layer causing subsequent inflammation and tissue necrosis. Normally the Paneth cells appear in the intestinal crypts during the first trimester of human pregnancy. Paneth cells constitute a major component of the innate immune system by producing multiple antimicrobial peptides and pro-inflammatory mediators. To better understand the possible role of Paneth cell disruption in NEC, we quantified the number of Paneth cells present in infants with NEC and found they were significantly decreased compared to age matched controls. We were able to model this loss in the intestine of P14-16 day old mice by treating them with the zinc chelator dithizone. Intestines from dithizone treated animals retained approximately half the number of Paneth cells as controls. Furthermore, by combining dithizone treatment with exposure to Klebsiella pneumoniae we were able to induce intestinal injury and inflammatory induction that resembles human NEC. Additionally, this novel Paneth cell ablation model produces NEC-like pathology consistent with other currently used animal models, but is simpler to use, can be used in older animals that have been dam fed, and represents a novel line of investigation to study NEC pathogenesis and treatment.
The hydrodynamic function of shark skin and two biomimetic applications
Authors: Oeffner Johannes , Lauder George V. 
Published: February 2012

SUMMARYIt has long been suspected that the denticles on shark skin reduce hydrodynamic drag during locomotion, and a number of man-made materials have been produced that purport to use shark-skin-like surface roughness to reduce drag during swimming. But no studies to date have tested these claims of drag reduction under dynamic and controlled conditions in which the swimming speed and hydrodynamics of shark skin and skin-like materials can be quantitatively compared with those of controls lacking surface ornamentation or with surfaces in different orientations. We use a flapping foil robotic device that allows accurate determination of the self-propelled swimming (SPS) speed of both rigid and flexible membrane-like foils made of shark skin and two biomimetic models of shark skin to measure locomotor performance. We studied the SPS speed of real shark skin, a silicone riblet material with evenly spaced ridges and a Speedo® ‘shark skin-like’ swimsuit fabric attached to rigid flat-plate foils and when made into flexible membrane-like foils. We found no consistent increase in swimming speed with Speedo® fabric, a 7.2% increase with riblet material, whereas shark skin membranes (but not rigid shark skin plates) showed a mean 12.3% increase in swimming speed compared with the same skin foils after removing the denticles. Deformation of the shark skin membrane is thus crucial to the drag-reducing effect of surface denticles. Digital particle image velocimetry (DPIV) of the flow field surrounding moving shark skin foils shows that skin denticles promote enhanced leading-edge suction, which might have contributed to the observed increase in swimming speed. Shark skin denticles might thus enhance thrust, as well as reduce drag.
Mechanisms underlying parallel reductions in aerobic capacity in non-migratory threespine stickleback (Gasterosteus aculeatus) populations
Authors: Dalziel Anne C. , Ou Michelle , Schulte Patricia M. 
Published: February 2012

SUMMARYNon-migratory, stream-resident populations of threespine stickleback, Gasterosteus aculeatus, have a lower maximum oxygen consumption (ṀO2,max) than ancestral migratory marine populations. Here, we examined laboratory-bred stream-resident and marine crosses from two locations (West and Bonsall Creeks) to determine which steps in the oxygen transport and utilization cascade evolved in conjunction with, and thus have the potential to contribute to, these differences in ṀO2,max. We found that West Creek stream-resident fish have larger muscle fibres (not measured in Bonsall fish), Bonsall Creek stream-resident fish have smaller ventricles, and both stream-resident populations have evolved smaller pectoral adductor and abductor muscles. However, many steps of the oxygen cascade did not evolve in stream-resident populations (gill surface area, hematocrit, mean cellular hemoglobin content and the activities of mitochondrial enzymes per gram ventricle and pectoral muscle), arguing against symmorphosis. We also studied F1 hybrids to determine which traits in the oxygen cascade have a genetic architecture similar to that of ṀO2,max. In West Creek, ṀO2,max, abductor and adductor size all showed dominance of marine alleles, whereas in Bonsall Creek, ṀO2,max and ventricle mass showed dominance of stream-resident alleles. We also found genetically based differences among marine populations in hematocrit, ventricle mass, pectoral muscle mass and pectoral muscle pyruvate kinase activity. Overall, reductions in pectoral muscle mass evolved in conjunction with reductions in ṀO2,max in both stream-resident populations, but the specific steps in the oxygen cascade that have a genetic basis similar to that of ṀO2,max, and are thus predicted to have the largest impact on ṀO2,max, differ among populations.
Effects of different substrates on the sprint performance of lizards
Authors: Tulli Maria Jose , Abdala Virginia , Cruz Felix B. 
Published: February 2012

SUMMARYThe variation in substrate structure is one of the most important determinants of the locomotor abilities of lizards. Lizards are found across a range of habitats, from large rocks to loose sand, each of them with conflicting mechanical demands on locomotion. We examined the relationships among sprint speed, morphology and different types of substrate surfaces in species of lizards that exploit different structural habitats (arboreal, saxicolous, terrestrial and arenicolous) in a phylogenetic context. Our main goals were to assess which processes drive variability in morphology (i.e. phylogeny or adaptation to habitat) in order to understand how substrate structure affects sprint speed in species occupying different habitats and to determine the relationship between morphology and performance. Liolaemini lizards show that most morphological traits are constrained by phylogeny, particularly toe 3, the femur and foot. All ecological groups showed significant differences on rocky surfaces. Surprisingly, no ecological group performed better on the surface resembling its own habitat. Moreover, all groups exhibited significant differences in sprint speed among the three different types of experimental substrates and showed the best performance on sand, with the exception of the arboreal group. Despite the fact that species use different types of habitats, the highly conservative morphology of Liolaemini species and the similar levels of performance on different types of substrates suggest that they confer to the ‘jack of all trades and master of none’ principle.
Polarotactic tabanids find striped patterns with brightness and/or polarization modulation least attractive: an advantage of zebra stripes
Authors: Egri Ádám , Blahó Miklós , Kriska György , Farkas Róbert , Gyurkovszky Mónika , Åkesson Susanne , Horváth Gábor 
Published: February 2012

SUMMARYThe characteristic striped appearance of zebras has provoked much speculation about its function and why the pattern has evolved, but experimental evidence is scarce. Here, we demonstrate that a zebra-striped horse model attracts far fewer horseflies (tabanids) than either homogeneous black, brown, grey or white equivalents. Such biting flies are prevalent across Africa and have considerable fitness impact on potential mammalian hosts. Besides brightness, one of the likely mechanisms underlying this protection is the polarization of reflected light from the host animal. We show that the attractiveness of striped patterns to tabanids is also reduced if only polarization modulations (parallel stripes with alternating orthogonal directions of polarization) occur in horizontal or vertical homogeneous grey surfaces. Tabanids have been shown to respond strongly to linearly polarized light, and we demonstrate here that the light and dark stripes of a zebra’s coat reflect very different polarizations of light in a way that disrupts the attractiveness to tabanids. We show that the attractiveness to tabanids decreases with decreasing stripe width, and that stripes below a certain size are effective in not attracting tabanids. Further, we demonstrate that the stripe widths of zebra coats fall in a range where the striped pattern is most disruptive to tabanids. The striped coat patterns of several other large mammals may also function in reducing exposure to tabanids by similar mechanisms of differential brightness and polarization of reflected light. This work provides an experimentally supported explanation for the underlying mechanism leading to the selective advantage of a black-and-white striped coat pattern.
Geometry of compensatory feeding and water consumption inDrosophila melanogaster
Authors: Fanson Benjamin G. , Yap Sarsha , Taylor Phillip W. 
Published: February 2012

SUMMARYFeeding behaviour is an expression of an animal’s underlying nutritional strategy. The study of feeding decisions can hence delineate nutritional strategies. Studies of Drosophila melanogaster feeding behaviour have yielded conflicting accounts, and little is known about how nutrients affect feeding patterns in this important model species. Here, we conducted two experiments to characterize nutrient prioritization and regulation. In a choice experiment, we allowed female flies to self-regulate their intake of yeast, sucrose and water by supplying individual flies with three microcapillary tubes: one containing only yeast of varying concentrations, another with just sucrose of varying concentrations, and the last with just water. Flies tightly regulated yeast and sucrose to a constant ratio at the expense of excess water intake, indicating that flies prioritize macronutrient regulation over excess water consumption. To determine the relative importance of yeast and sucrose, in a no-choice experiment, we provided flies with two microcapillary tubes: the first with one of the 28 diets varying in yeast and sucrose content and the other with only water. Flies increased total water intake in relation to yeast consumption but not sucrose consumption. Additionally, flies increased diet intake as diet concentration decreased and as the ratio of sugar to yeast equalized. Using a geometric scaling approach, we found that the patterns of diet intake can be explained by flies prioritizing protein and carbohydrates equally and by the lack of substitutability between the nutrients. We conclude by illustrating how our results harmonize conflicting results in the literature once viewed in a two-dimensional diet landscape.
Impact of Performance-Based Contracting on Product Reliability: An Empirical Analysis
Authors: Guajardo Jose A. , Cohen Morris A. , Kim Sang-Hyun , Netessine Serguei 
Published: February 2012

Using a proprietary data set provided by a major manufacturer of aircraft engines, we empirically investigate how product reliability is impacted by the use of two different types of after-sales maintenance support contracts: time and material contracts (T&MC) and performance-based contracts (PBC). We offer a number of competing arguments based on the theory of incentives that establish why product reliability may increase or decrease under PBC. We build a two-stage econometric model that explicitly accounts for the endogeneity of contract choices, and find evidence of a positive and significant effect of PBC on product reliability. The estimation of our model indicates that product reliability is higher by 25%–40% under PBC compared to under T&MC, once the endogeneity of contract choice is taken into account. Our results are consistent with two mechanisms for reliability improvement under PBC: more frequent scheduled maintenance and better care performed in each maintenance event. This paper was accepted by Martin Lariviere, operations management.
Network Progeny? Prefounding Social Ties and the Success of New Entrants
Authors: Roberts Peter W. , Sterling Adina D. 
Published: February 2012

Entrepreneurs that were employed by successful industry incumbents prior to founding tend to confer advantages on their new organizations. We propose and then demonstrate a similar “network progeny” effect rooted in the social relationships that form among entrepreneurs. Our analysis of new entrants into the Ontario wine industry shows that prefounding friendship ties of the founders of one especially prominent entrepreneurial firm led to significantly higher ice wine prices. This attests to the promise of a network progeny extension of the parent–progeny account of new firm success. Follow-on analysis indicates that this effect is not attributable to an entrant's ability to make ice wines of superior quality or to it having access to better distribution knowledge. We therefore conclude that having a social tie to this prominent entrepreneurial firm generated reflected prominence that enhanced the valuations and therefore prices of wines made by connected market entrants.This paper was accepted by Jesper Sørensen, organizations.
Factors affecting the incidence of deep wound infection after hip fracture surgery
Authors: Harrison T. , Robinson P. , Cook A. , Parker M. J. 
Published: February 2012

Prospective data on 6905 consecutive hip fracture patients at a district general hospital were analysed to identify the risk factors for the development of deep infection post-operatively. The main outcome measure was infection beneath the fascia lata. A total of 50 patients (0.7%) had deep infection. Operations by consultants or a specialist hip fracture surgeon had half the rate of deep infection compared with junior grades (p = 0.01). Increased duration of anaesthesia was significantly associated with deep infection (p = 0.01). The method of fracture fixation was also significant. Intracapsular fractures treated with a hemiarthroplasty had seven times the rate of deep infection compared with those treated by internal fixation (p = 0.001). Extracapsular fractures treated with an extramedullary device had a deep infection rate of 0.78% compared with 0% for those treated with intramedullary devices (p = 0.02). The management of hip fracture patients by a specialist hip fracture surgeon using appropriate fixation could significantly reduce the rate of deep infection and associated morbidity, along with extended hospitalisation and associated costs.
Conservative management of patients with an osteoporotic vertebral fracture
Authors: Longo U. G. , Loppini M. , Denaro L. , Maffulli N. , Denaro V. 
Published: February 2012

Osteoporotic vertebral compression fractures (VCFs) are an increasing public health problem. Recently, randomised controlled trials on the use of kyphoplasty and vertebroplasty in the treatment of these fractures have been published, but no definitive conclusions have been reached on the role of these interventions. The major problem encountered when trying to perform a meta-analysis of the available studies for the use of cementoplasty in patients with a VCF is that conservative management has not been standardised. Forms of conservative treatment commonly used in these patients include bed rest, analgesic medication, physiotherapy and bracing.In this review, we report the best evidence available on the conservative care of patients with osteoporotic VCFs and associated back pain, focusing on the role of the most commonly used spinal orthoses. Although orthoses are used for the management of these patients, to date, there has been only one randomised controlled trial published evaluating their value. Until the best conservative management for patients with VCFs is defined and standardised, no conclusions can be drawn on the superiority or otherwise of cementoplasty techniques over conservative management.