bluuebunny/crossref_metadata_2025_split huggingface dataset:
Islet isolation from adult designated pathogen‐free pigs: use of the newer bovine nervous tissue–free enzymes and a revised donor selection strategy would improve the islet graft function
Authors: Jin Sang‐Man , Shin Jun Seop , Kim Kang Seok , Gong Chang‐Hoon , Park Su Kyoung , Kim Jung‐Sik , Yeom Su‐Cheong , Hwang Eung Soo , Lee Choon Taek , Kim Sang‐Joon , Park Chung‐Gyu 
Published: December 2011

Jin S‐M, Shin JS, Kim KS, Gong C‐H, Park SK, Kim J‐S, Yeom S‐C, Hwang ES, Lee CT, Kim S‐J, Park C‐G. Islet isolation from adult designated pathogen‐free pigs: use of the newer bovine nervous tissue–free enzymes and a revised donor selection strategy would improve the islet graft function. Xenotransplantation 2011; 18: 369–379. © 2011 John Wiley & Sons A/S.Abstract:  Background:  In clinical trials using adult porcine islet products, islets should be isolated from the designated pathogen‐free (DPF) pigs under the current good manufacturing practice (GMP) regulations. Our previous studies suggested that male DPF pigs are better donors than retired breeder pigs and histomorphometrical parameters of donor pancreas predict the porcine islet quality. We aimed to investigate whether the use of the newer bovine nervous tissue–free enzymes and a revised donor selection strategy could improve the islet graft function in the context of islet isolation with DPF pigs.Methods:  Using 30 DPF pigs within a closed herd, we compared the islet yield of porcine islets isolated with Liberase PI (n = 11, as a historical control group), Liberase MTF C/T, which is a GMP‐grade enzyme (n = 12), and CIzyme collagenase MA/BP protease (n = 7). We analyzed the relationship between the diabetes reversal rate of recipient NOD/SCID mice (n = 75) and histomorphometric parameters of each donor pancreas as well as donor characteristics.Results:  Proportion of islets larger than 200 μm from the biopsied donor pancreas (P = 0.006) better predicted islet yield than age (P = 0.760) or body weight (P = 0.371) of donor. The proportion of islets larger than 200 μm from the biopsied donor pancreas was not related to the sex of the donor miniature pig (P = 0.358). The islet yield obtained with the three enzymes did not differ, even after stratification of the donor with the histomorphometric parameters of the biopsied donor pancreas and the sex of donor. The use of the newer bovine nervous tissue–free enzymes (P < 0.001), a higher proportion of large islets in donor pancreas (P = 0.006), and a male sex of the donor (P = 0.025) were independent predictors of earlier diabetes reversal.Conclusions:  Use of the newer bovine nervous tissue–free enzymes including a GMP‐grade enzyme resulted in better islet quality than that of islet isolated using Liberase PI. To obtain high‐quality islet from DPF pigs, the donor should be male pig and histomorphometrical parameters from donor pancreas should be considered.
Pre‐clinical model of composite foetal pig pancreas fragment/renal xenotransplantation to treat renal failure and diabetes
Authors: Hawthorne Wayne J. , Simond Denbigh M. , Stokes Rebecca , Patel Anita T. , Walters Stacey , Burgess Jane , O’Connell Philip J. 
Published: December 2011

Hawthorne WJ, Simond DM, Stokes R, Patel AT, Walters S, Burgess J, O’Connell PJ. Pre‐clinical model of composite foetal pig pancreas fragment/renal xenotransplantation to treat renal failure and diabetes. Xenotransplantation 2011; 18: 390–399. © 2011 John Wiley & Sons A/S.Abstract:  Background:  Development of a limitless source of β cells for xenotransplantation into patients suffering type 1 diabetes and renal failure that can control their diabetes and provide normal renal function in one procedure would be a major achievement. For the islet tissue to survive transplantation, as an islet‐kidney composite graft this would have significant advantages. It would simplify the surgical procedure; remove the complications caused by the exocrine pancreas whilst reversing diabetes and uraemia. It was our hypothesis that a composite foetal porcine pancreas fragment (FPPF)/renal graft could achieve these objectives in a large pre‐clinical animal model as a means to establish whether this would be feasible before moving to the clinic.Methods:  Inbred ‘Westran’ pig FPPF were transplanted under the kidney capsule of syngeneic Westran pig recipients without immunosuppression. Following maturation of the FPPF under the renal subcapsular space of this recipient, this kidney bearing the composite FPPF piggyback graft was removed and transplanted into another nephrectomized and pancreatectomized recipient to demonstrate function.Results:  Under the kidney capsule of the first transplant group (n = 6), the FPPF‐transplanted tissue developed and matured to form islet cell nests. These composite FPPF/renal grafts were then successfully removed and transplanted into the second functional assessment recipient group. This second group of six composite FPPF/renal‐grafted pigs had normal renal function for more than 44 days and normal glucose homoeostasis without exogenous insulin as assessed by normal glucose tolerance tests, K values and normal glucagon secretion. Histological analysis showed despite the ischaemic insult during the composite kidney transplant procedure, there was appropriate development of islet‐like structures up to and beyond 224 days after the original transplantation under the kidney capsule.Conclusions:  This study shows that the use of composite FPPF/renal grafts can cure both diabetes and renal failure with a single‐transplant procedure. Using such composite grafts for xenotransplantation would simplify the surgical procedure and protect the islet graft from the immediate innate immune response.
The Evolution of Large Testes: Sperm Competition or Male Mating Rate?
Authors: Vahed Karim , Parker Darren J. 
Published: December 2011

AbstractA positive relationship across species between the extent to which females mate with more than one male and relative testes mass has been demonstrated in a wide range of vertebrate taxa and certain insects. At least two hypotheses, which are not necessarily mutually exclusive, could account for this pattern: (1) the numerical sperm competition hypothesis, which assumes that larger testes enable the male to transfer more sperm to each female, giving the male an advantage in sperm competition and (2) the male mating rate hypothesis, which proposes that larger testes allow the male to produce a greater number of (potentially smaller) ejaculates to engage in frequent copulations with different females. Of these hypotheses, the former has won broad acceptance, while the latter has tended to be dismissed. Here, we argue that the lines of evidence commonly used to support the numerical sperm competition hypothesis in favour of the male mating rate hypothesis are not as clear cut or generally applicable as they are purported to be and that, consequently, the male mating rate hypothesis cannot be excluded with confidence on the basis of the current evidence. Furthermore, some evidence, such as the finding that ejaculate mass and/or sperm number is negatively correlated with testes mass across species in some insects and that larger testes in Drosophila can evolve in response to an increase in the number of females available for mating in the laboratory, provides support for the male mating rate hypothesis. Further work is needed to disentangle the relative effects of these selective pressures on the evolution of testes size.
Aggressive Signal Design in the Jacky Dragon (Amphibolurus muricatus): Display Duration Affects Efficiency
Authors: Woo Kevin L. , Rieucau Guillaume 
Published: December 2011

AbstractDesign characteristics of signals, such as their duration, may have evolved to maximize signal efficiency. It is commonly assumed that constraints on signal design have usually shaped the most optimal display characteristics to improve signal transmission and information transfer of the signaller, and detection by intended receivers. In this study, we tested whether the characteristics (duration, speed and frequency) of an aggressive display, the push‐up body rock, exhibited by the Jacky dragon (Amphibolurus muricatus) have likely evolved for optimal signal efficiency, as it is able to draw attention to the signaller. We performed two video playback experiments using high‐resolution 3D animations testing the effect of variation in push‐up body rock structure. In experiment 1, we manipulated push‐up body rock display structure. We gradually increased the number of push‐ups exhibited by a digitally animated Jacky dragon increasing the overall display duration. In experiment 2, we developed four stimuli based on population‐typical push‐up body rock display for duration (short and long), and frequency of push‐ups (1 or 5 consecutive push‐ups) by manipulating push‐ups’ speed. In both experiments, we measured the probability of an orienting response and response latency of focal lizards when being exposed to the different stimuli. Our results showed that display duration is critically important for signal efficiency in the aggressive push‐up body rock display. If we are to understand the design characteristics of signals used in animal communication, then it appears important to consider the possible trade‐off between signal efficiency and costs.
Mallards Feed Longer to Maintain Intake Rate under Competition on a Natural Food Distribution
Authors: van Dijk Jacintha G. B. , Duijns Sjoerd , Gyimesi Abel , de Boer Willem F. , Nolet Bart A. 
Published: December 2011

AbstractAnimals foraging in groups may benefit from a faster detection of food and predators, but competition by conspecifics may reduce intake rate. Competition may also alter the foraging behaviour of individuals, which can be influenced by dominance status and the way food is distributed over the environment. Many studies measuring the effects of competition and dominance status have been conducted on a uniform or highly clumped food distribution, while in reality prey distributions are often in‐between these two extremes. The few studies that used a more natural food distribution only detected subtle effects of interference and dominance. We therefore conducted an experiment on a natural food distribution with focal mallards Anas platyrhynchos foraging alone and in a group of three, having a dominant, intermediate or subordinate dominance status. In this way, the foraging behaviour of the same individual in different treatments could be compared, and the effect of dominance was tested independently of individual identity. The experiment was balanced using a 4 × 4 Latin square design, with four focal and six non‐focal birds. Individuals in a group achieved a similar intake rate (i.e. number of consumed seeds divided by trial length) as when foraging alone, because of an increase in the proportion of time feeding (albeit not significant for subordinate birds). Patch residence time and the number of different patches visited did not differ when birds were foraging alone or in a group. Besides some agonistic interactions, no differences in foraging behaviour between dominant, intermediate and subordinate birds were measured in group trials. Possibly group‐foraging birds increased their feeding time because there was less need for vigilance or because they increased foraging intensity to compensate for competition. This study underlines that a higher competitor density does not necessarily lead to a lower intake rate, irrespective of dominance status.
Movements and Conflicts in a Flock of Foraging Black‐Tailed Godwits (Limosa limosa): The Influence of Feeding Rates on Behavioural Decisions
Authors: Sirot Etienne , Maes Philippe , Gélinaud Guillaume 
Published: December 2011

AbstractWe studied movements and conflicts within a small flock of free‐living black‐tailed godwits foraging on benthic invertebrates in a brackish lagoon. To interpret our results in the framework of foraging theory, we studied the influence of individual feeding rate on the decisions to move and to attack flock companions. Birds changed their position within the flock more often when their intake rate was low and sometimes attacked conspecifics to supplant them from their feeding place. Aggressors significantly avoided front attacks and were almost always successful. They attacked individuals having higher feeding rates than themselves and their own feeding rate significantly increased after the attack, although victims were not chased off to particularly poor sites. Our results suggest that aggressors could obtain reliable information about the quality of the foraging site they coveted by observing their victim’s feeding activity before attacking. Although aggression seemed to be caused by a low intake rate, we show that displacing another bird was more time‐consuming than independent foraging. We conclude that it was not the most profitable behaviour in terms of energy intake. Foraging site displacement probably also had social functions, such as reinforcement of social status in a flock of birds preparing for pre‐breeding migration.
Shelter Availability, Occupancy, and Residency in Size‐Asymmetric Contests Between Rusty Crayfish,Orconectes rusticus
Authors: Klar Nathan M. , Crowley Philip H. 
Published: December 2011

AbstractContest outcomes are usually determined by differences in resource‐holding potential, the social histories of the combatants, and perceptions of resource value. One aspect of gaining an advantage is the residency effect. Prior occupancy of a particular place can affect the knowledge and motivation of the resident. There could be a tactical advantage in knowing the terrain or an increased willingness to fight to maintain control of a familiar area. In this study, we evaluated the importance of shelter residency effects relative to size differences between rusty crayfish (Orconectes rusticus) as potential competitors for access to shelter. The intensity of any residency effects was manipulated by altering the number of shelters in the arena. Our results suggest that any residency effect is very weak in this system, and if present, may often be masked by the strong and pervasive influence on contest outcome of the relative body sizes of the contestants. We also found that both shelter number and crayfish size asymmetries had strong, independent effects on levels of aggression. Dominance, but not residency status, was a factor in shelter use.
Isotopic Data Do Not Support Food Sharing Within Large Networks of Female Vampire Bats (Desmodus rotundus)
Authors: Voigt Christian C. , Voigt‐Heucke Silke L. , Schneeberger Karin 
Published: December 2011

AbstractReciprocal altruism is considered to be particularly stable when occurring in small networks. Using a stable isotope approach, we tested in colonies of vampire bats (Desmodus rotundus) whether food sharing occurs among few or many females; vampires are known to regurgitate recently ingested blood for starving conspecifics. Accordingly, the isotopic signatures of vampires depend not only on individual prey choice but also on the extent of food sharing among isotopically contrasting conspecifics. By measuring the stable carbon isotope ratio in tissues with varying isotopic retention in individual vampires (blood: approx. 2 wk; wing membrane tissue: approx. 2 mo; fur: >6 mo), we estimated the variation in the percentages of carbon derived from pasture (via blood from cattle and horses). We expected to find narrow ranges of percentages in individual vampires, because we anticipated food sharing only within small female networks if food sharing happened at all. Overall, vampire bats obtained 79.2 ± 12.3% of carbon from grazers. The range of percentages was small within the majority of individuals in relation to that across all individuals, suggesting that most vampires were isotopic specialists. We expected females to be more isotopically generalistic than males, as food sharing was observed to occur more often between females than between males. Indeed, stable isotope evidence suggested that more females obtained carbon from isotopically contrasting sources than males. This pattern is consistent with food sharing in small groups of female vampires, provided that food sharing occurred at all.
Efficacy and tolerability of pegylated interferon‐α‐2a in chronic hepatitis B: A multicenter clinical experience
Authors: Ratnam Dilip , Dev Anouk , Nguyen Tin , Sundararajan Vijaya , Harley Hugh , Cheng Wendy , Lee Alice , Rusli Ferry , Chen Robert , Bell Sally , Pianko Stephen , Sievert William 
Published: December 2011

AbstractBackground and Aim:  Pegylated interferon‐α (PEG‐IFN) provides potential advantages over nucleos(t)ide analogues in the treatment of chronic hepatitis B (CHB) given its finite course, durability and lack of drug resistance. Much of the evidence is derived from controlled studies and it is unclear whether these results can be replicated in an everyday, non‐controlled setting. The aim of this study was to examine the efficacy and tolerability of PEG‐IFN‐α2A in CHB patients in a clinical setting.Methods:  Chronic hepatitis B patients treated with PEG‐IFN‐α2A (180 µg/week, 48 weeks) at five tertiary hospitals were retrospectively identified. Baseline demographic and clinical data, on‐treatment virological and serological responses and adverse events (AE) were recorded. Treatment outcomes were defined as alanine aminotransferase (ALT) normalization, hepatitis B virus DNA < 351 IU/mL and hepatitis B e antigen (HBeAg) seroconversion.Results:  Sixty three HBeAg positive patients were identified (65% male, 80% born in Asia, 84% with viral loads > 6log IU/mL, 9.5% advanced fibrosis). Six months after therapy 46% achieved normalization of ALT, 16% had viral loads < 351 IU/mL and 32% achieved HBeAg seroconversion. 29 HBeAg negative patients were treated (75% male, 86% born in Asia, 48% had viral loads > 6log IU/mL, 24% advanced fibrosis). Six months post‐treatment, 55% and 36% maintained a normalized ALT and HBV DNA < 351 IU/mL, respectively. Optimal viral suppression was maintained in 50–75% of patients over 2 years of follow up. 6.5% of all patients discontinued therapy due to AEs.Conclusion:  In everyday clinical practice PEG‐IFN therapy in CHB is well tolerated and can achieve a similar efficacy to that seen in large controlled trials.
Body mass index distribution affects discrepancies in weight classifications in children
Authors: Tuan Nguyen T , Butte Nancy F , Nicklas Theresa A 
Published: December 2011

AbstractBackground:  The aim of the present study was to investigate the effect of body mass index (BMI) distribution, ethnicity and age at menarche on the consistency in the prevalence of underweight and overweight defined by the Centers for Disease Control and Prevention (CDC) and the International Obesity Task Force (IOTF) cut‐off points in 2–17‐year‐old Chinese and US children.Methods:  Data from the China Health and Nutrition Survey (CHNS) 1991 (n= 3895), CHNS 2004 (n= 1902), and the National Health and Nutrition Examination Survey (NHANES) 2003–2004 (n= 3344) were used to define the prevalence of underweight and overweight using the CDC and IOTF BMI cut‐off points.Results:  An upward shift in the BMI distribution was observed from the CHNS 1991 to CHNS 2004, and between the CHNS and NHANES 2004. The prevalence of underweight defined by the IOTF cut‐off points was higher than that obtained using the CDC cut‐off points; absolute differences between IOTF and CDC classifiers were 7%, 5%, and 2% in boys, and 12%, 11%, and 4% in girls in the CHNS 1991, CHNS 2004, and NHANES 2004, respectively. There was a greater consistency in the prevalence of overweight. The consistency of the two classification systems increased with the higher BMI distribution and was not affected significantly by ethnicity or age at menarche.Conclusions:  The BMI distribution of a population can affect the classification of childhood underweight and overweight differentially as defined by the CDC and IOTF cut‐off points, and thus should be considered in the interpretation of results in clinical and population settings.
New technique with combination of felt, Hem‐o‐lok and Lapra‐Ty for suturing the renal parenchyma in laparoscopic partial nephrectomy
Authors: Masumori Naoya , Itoh Naoki , Takahashi Satoshi , Kitamura Hiroshi , Nishida Sachiyo , Tsukamoto Taiji 
Published: December 2011

AbstractWe reported a new technique for closure of the renal parenchyma in laparoscopic partial nephrectomy, shortening the suturing time. Between 2009 and 2011, 41 patients with renal masses 4 cm or smaller in diameter underwent transabdominal laparoscopic partial nephrectomy by a single surgeon in a single institution. The sutures were carried out using 2‐0 vicryl CT‐1 with a 1.2 × 1.2 cm piece of felt, and both sutures were temporarily held using a Hem‐o‐lok. After all sutures (median 3) were completed, they were sequentially fixed by sliding the Hem‐o‐lok, and then locked using the Lapra‐Ty. The median times for suturing the renal parenchyma and ischemic time were 13 min and 28 min, respectively. The arrangement of the wound and hemostasis were good. No patients developed urinoma or postoperative bleeding.
Fracture mechanics of surface fatigue crack growth by ductile striation space measurement in notched Waspaloy
Authors: SUH CHANG‐MIN , SUH MIN‐SOO , KIM SEON‐GAB 
Published: December 2011

ABSTRACTDuctile striation space (DSS), a parameter to predict actual cracks in both direction of length and depth, is proposed for the surface fatigue crack behaviors on notched Waspaloy. Three different lengths (1, 2 and 4 mm) of artificial notches are formed as the initial surface crack for an applied maximum stress of 1,103 MPa at the stress ratio R of 0.05. These notches are similar with the appearance of the surface cracks found from the survey of compressor disk. The results show that, all initial crack sites in the depth direction started from the multiple origination sites. The DSS parameter was clearly confirmed, and it also proves the high effectiveness of the measurement in the range of the stress intensity factors for acquiring the crack growth rate on the fractured surface. The surface cracks on Waspaloy at room temperature in an atmosphere perfectly follow the relation of ΔK versus da/dN and db/dN, even though there are, respectively, earlier and later timing differences on the initiation of cracks for the notch sizes of 1 and 4 mm. The results of ΔK versus da/dN and db/dN relations show a similar slope for three different kinds of notches.