Search Results
Results 451 - 500 of 1312
< 5 6 7 8 9 10 11 12 13 14 15 >
Fauchald Per - - 2011
In a "wasp-waist" ecosystem, an intermediate trophic level is expected to control the abundance of predators through a bottom-up interaction and the abundance of prey through a top-down interaction. Previous studies suggest that the North Sea is mainly governed by bottom-up interactions driven by climate perturbations. However, few studies have ...
Griesser Michael - - 2011
One of the most striking aspects of animal groups is their remarkable variation in size, both within and between species. While a number of mechanistic models have been proposed to explain this variation, there are few comprehensive datasets against which these models have been tested. In particular, we only vaguely ...
Basu Saonli - - 2011
Studying one locus or one single nucleotide polymorphism (SNP) at a time may not be sufficient to understand complex diseases because they are unlikely to result from the effect of only one SNP. Each SNP alone may have little or no effect on the risk of the disease, but together ...
Howard Kirsten - - 2011
Transplantation is the treatment of choice for people with severe organ failure. However, demand substantially exceeds supply of suitable organs; consequently many people wait months, or years to receive an organ. Reasons for the chronic shortage of deceased organ donations are unclear; there appears to be no lack of 'in ...
Li Jun - - 2011
Few studies have explored the role of Cenozoic tectonic evolution in shaping patterns and processes of extant animal distributions within East Asian margins. We select Hynobius salamanders (Amphibia: Hynobiidae) as a model to examine biogeographical consequences of Cenozoic tectonic events within East Asian margins. First, we use GenBank molecular data ...
Eichele Tom - - 2011
Independent component analysis (ICA) is a powerful method for source separation and has been used for decomposition of EEG, MRI, and concurrent EEG-fMRI data. ICA is not naturally suited to draw group inferences since it is a non-trivial problem to identify and order components across individuals. One solution to this ...
Lehmann Laurent - - 2011
Intraspecific coalitional aggression between groups of individuals is a widespread trait in the animal world. It occurs in invertebrates and vertebrates, and is prevalent in humans. What are the conditions under which coalitional aggression evolves in natural populations? In this article, I develop a mathematical model delineating conditions where natural ...
Gebregziabher Mulugeta - - 2011
Many studies have investigated racial/ethnic disparities in medication non-adherence in patients with type 2 diabetes using common measures such as medication possession ratio (MPR) or gaps between refills. All these measures including MPR are quasi-continuous and bounded and their distribution is usually skewed. Analysis of such measures using traditional regression ...
Monteiro Leandro R - - 2011
The phyllostomid bats present the most extensive ecological and phenotypic radiation known among mammal families. This group is an important model system for studies of cranial ecomorphology and functional optimisation because of the constraints imposed by the requirements of flight. A number of studies supporting phyllostomid adaptation have focused on ...
Gagliardo Anna - - 2011
A large body of evidence has shown that anosmic pigeons are impaired in their navigation. However, the role of odours in navigation is still subject to debate. While according to the olfactory navigation hypothesis homing pigeons possess a navigational map based on the distribution of environmental odours, the olfactory activation ...
Bever Gabe S - - 2011
The internal braincase anatomy of the holotype of Alioramus altai, a relatively small-bodied tyrannosauroid from the Late Cretaceous of Mongolia, was studied using high-resolution computed tomography. A number of derived characters strengthen the diagnosis of this taxon as both a tyrannosauroid and a unique, new species (e.g., endocranial position of ...
Mann Richard P - - 2011
The emergence of similar collective patterns from different self-propelled particle models of animal groups points to a restricted set of "universal" classes for these patterns. While universality is interesting, it is often the fine details of animal interactions that are of biological importance. Universality thus presents a challenge to inferring ...
Wolc Anna - - 2011
Genomic selection involves breeding value estimation of selection candidates based on high-density SNP genotypes. To quantify the potential benefit of genomic selection, accuracies of estimated breeding values (EBV) obtained with different methods using pedigree or high-density SNP genotypes were evaluated and compared in a commercial layer chicken breeding line. The ...
Burger Claudia - - 2011
Environmental conditions under which species reproduce have major consequences on breeding success and subsequent fitness. Therefore breeding habitat choice is ultimately important. Studies rarely address the potential fitness pay-offs of alternative natural breeding habitats by experimental translocation. Here we present a new tool to study fitness consequences of free living ...
López-López Pascual - - 2011
Man-induced mortality of birds caused by electrocution with poorly-designed pylons and power lines has been reported to be an important mortality factor that could become a major cause of population decline of one of the world rarest raptors, the Spanish imperial eagle (Aquila adalberti). Consequently it has resulted in an ...
Khullar Siddharth - - 2011
A common pre-processing challenge associated with group level fMRI analysis is spatial registration of multiple subjects to a standard space. Spatial normalization, using a reference image such as the Montreal Neurological Institute brain template, is the most common technique currently in use to achieve spatial congruence across multiple subjects. This ...
Abou Elseoud Ahmed - - 2011
Resting-state networks (RSNs) can be reliably and reproducibly detected using independent component analysis (ICA) at both individual subject and group levels. Altering ICA dimensionality (model order) estimation can have a significant impact on the spatial characteristics of the RSNs as well as their parcellation into sub-networks. Recent evidence from several ...
Rousselet Guillaume A - - 2011
Hundreds of studies have investigated the early ERPs to faces and objects using scalp and intracranial recordings. The vast majority of these studies have used uncontrolled stimuli, inappropriate designs, peak measurements, poor figures, and poor inferential and descriptive group statistics. These problems, together with a tendency to discuss any effect ...
Rebholz-Schuhmann Dietrich - - 2011
Competitions in text mining have been used to measure the performance of automatic text processing solutions against a manually annotated gold standard corpus (GSC). The preparation of the GSC is time-consuming and costly and the final corpus consists at the most of a few thousand documents annotated with a limited ...
Pacheco M Andreína - - 2011
Timing the origin of human malarias has been a focus of great interest. Previous studies on the mitochondrial genome concluded that Plasmodium in primates, including those parasitic to humans, radiated relatively recently during a process where host switches were common. Those investigations, however, assumed constant rate of evolution and tightly ...
Rabotti Chiara C Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, the - - 2011
Electrophysiological measurement of uterine contractions, referred to as electrohysterogram (EHG), is potentially more informative than methods currently used during pregnancy for timely recognition of complications such as preterm labor. Unfortunately, EHG measurement and interpretation remain challenging. Recently, some attention has been dedicated to the analysis of the EHG propagation, which ...
D'Angelo Gina M GM Division of Biostatistics, Washington University School of Medicine, St Louis, MO 63130, USA. - - 2011
An Alzheimer's fMRI study has motivated us to evaluate inter-regional correlations between groups. The overall objective is to assess inter-regional correlations at a resting-state with no stimulus or task. We propose using a generalized estimating equation (GEE) transition model and a GEE marginal model to model the within-subject correlation for ...
Roldán Eva M Cirugeda EM Computer Science Department, Politechnic University of Valencia, EPSA, Alcoy Campus, 03801 Alcoy, Alicante, Spain. - - 2011
This study is aimed at characterizing three signal entropy measures, Approximate Entropy (ApEn), Sample Entropy (SampEn) and Multiscale Entropy (MSE) over real EEG signals when a number of samples are randomly lost due to, for example, wireless data transmission. The experimental EEG database comprises two main signal groups: control EEGs ...
Kirkness J P JP Johns Hopkins Sleep Disorders Center, Division of Pulmonary Medicine, Johns Hopkins University, Baltimore, MD, - - 2011
Existing physiological databases have not been sufficiently detailed to provide relevant and important information for characterizing the pathophysiology of obstructive sleep apnea. Critical collapsing pressure (P(CRIT)) is a standard method for determining upper airway patency during sleep, however is labor intensive and prohibits large-scale studies. Based on previously published data ...
González-Suárez A A Biomedical Synergy, Electronic Engineering Department, Universidad Politécnica de Valencia, Spain. - - 2011
Although some types of bipolar electrodes have been broadly employed in clinical practice to coagulate biological tissue by means of radiofrequency (RF) currents, there is still scanty available information about their electrical-thermal behaviour. We are focused on internally cooled bipolar electrodes. The goal of our study was to know more ...
MacCallum Justin L JL Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York, USA. - - 2011
We assess performance in the structure refinement category in CASP9. Two years after CASP8, the performance of the best groups has not improved. There are few groups that improve any of our assessment scores with statistical significance. Some predictors, however, are able to consistently improve the physicality of the models. ...
Feenders Gesa G Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom. - - 2011
Pending changes in European legislation ban the use of wild-caught animals in research. This change is partly justified on the assumption that captive-breeding (or hand-rearing) increases welfare of captive animals because these practices result in animals with reduced fear of humans. However, there are few actual data on the long-term ...
Estévez Jorge - - 2011
In this work kinetic data were obtained for different paraoxon concentrations incubated with chicken serum and the soluble fraction of chicken peripheral nerve. A kinetic model equation was deduced by assuming a multienzymatic system with three different simultaneously occurring molecular phenomena: (1) inhibition; (2) simultaneous spontaneous reactivation; (3) "ongoing" inhibition ...
Virkkala Raimo - - 2011
Human land-use effects on species populations are minimized in protected areas and population changes can thus be more directly linked with changes in climate. In this study, bird population changes in 96 protected areas in Finland were compared using quantitative bird census data, between two time slices, 1981-1999 and 2000-2009, ...
Sénéchal Edith - - 2011
The strategy of relying extensively on stored resources for reproduction has been termed capital breeding and is in contrast to income breeding, where needs of reproduction are satisfied by exogenous (dietary) resources. Most species likely fall somewhere between these two extremes, and the position of an organism along this gradient ...
Fournié G - - 2011
Live bird markets (LBMs) act as a network 'hub' and potential reservoir of infection for domestic poultry. They may therefore be responsible for sustaining H5N1 highly pathogenic avian influenza (HPAI) virus circulation within the poultry sector, and thus a suitable target for implementing control strategies. We developed a stochastic transmission ...
Tark Kwan-Chul - - 2010
In the present study, we used the diabetic mouse as a model of delayed wound healing to investigate the effects of human cord blood mesenchymal stem cells (CB-MSC) on wound healing. A delayed wound healing model was used by db/db mice. Study models were divided by an injection of human ...
McKenzie Valerie J - - 2010
In the present study, we examined whether bird community composition can predict the annual number of human West Nile virus (WNV) cases on a per county basis in the Colorado Front Range, a region that experienced high numbers of human cases during the early part of the North American epidemic. ...
Howie J A - - 2010
1. This study is the first to quantitatively compare the structure of feeding behaviour of broilers, ducks and turkeys as recorded by electronic feeders. It tests the hypothesis that this structure is so similar that the same models would be suitable to group the feeding behaviour of these species into ...
Casco-Robles Martin Miguel - - 2010
Newts have been recognized as an ideal model for body-parts regeneration after traumatic injury since the 18(th) century. However, molecular mechanisms underlying regeneration remain a mystery because of technical limitations. In the current study, to break this obstacle, we established a simple and efficient transgenic protocol for the newt Cynops ...
Sheehan-Rooney Kelly K Faculty of Life Sciences and Dental School, Manchester Academic Health Sciences Centre, Michael Smith Building, University of Manchester, Manchester, United Kingdom. - - 2010
Mutation of SATB2 causes cleft palate in humans. To understand the role of SATB2 function in palatogenesis, SATB2 analyses in vertebrate model systems will be essential. To facilitate these analyses, we have performed a cross-species comparison of SATB2 structure and function across three vertebrate model systems: mouse, chick, and zebrafish. ...
Mehta Cyrus R - - 2011
This paper discusses the benefits and limitations of adaptive sample size re-estimation for phase 3 confirmatory clinical trials. Comparisons are made with more traditional fixed sample and group sequential designs. It is seen that the real benefit of the adaptive approach arises through the ability to invest sample size resources ...
Herranz Daniel - - 2010
The family of protein deacetylases represented by yeast Sir2 has been the focus of intense investigation because of the longevity activity of Sir2 in yeast, worms and flies. Research in mammals has mainly focused on SIRT1, the closest homologue of Sir2. Emerging evidence from mouse models is yielding a sharper ...
van Loon E E - - 2011
Many soaring bird species migrate southwards in autumn from their breeding grounds in Europe and Central Asia towards their wintering grounds. Our knowledge about interactions between migrating birds, thermal selection during migration and mechanisms that lead to flocking or convergent travel networks is still very limited. To start investigating these ...
Evan Andrew P - - 2010
Extensive evidence now supports the role of papillary interstitial deposits-Randall's plaques-in the formation of stones in the idiopathic, calcium oxalate stone former. These plaques begin as deposits of apatite in the basement membranes of the thin limbs of Henle's loop, but can grow to become extensive deposits beneath the epithelium ...
Jamsai Duangporn - - 2011
Limited knowledge of the genetic causes of male infertility has resulted in few treatment and targeted therapeutic options. Although the ideal approach to identify infertility causing mutations is to conduct studies in the human population, this approach has progressed slowly due to the limitations described herein. Given the complexity of ...
Tomino Yasuhiko - - 2011
IgA nephropathy is the most common primary chronic glomerulonephritis in the world and was first described by Berger et al. (J Urol Nephrol 74:694-695;1968). Histopathologically, IgA nephropathy is characterized by expansion of the glomerular mesangial matrix with mesangial cell proliferation. Glomeruli typically contain generalized diffuse granular mesangial deposits of IgA ...
van Tijn Paula - - 2011
Autosomal dominant mutations in the presenilin gene PSEN cause familial Alzheimer's disease (AD), a neurological disorder pathologically characterized by intraneuronal accumulation and extracellular deposition of amyloid-β in plaques and intraneuronal, hyperphosphorylated tau aggregation in neurofibrillary tangles. Presenilins (PS/PSENs) are part of the proteolytic γ-secretase complex, which cleaves substrate proteins within ...
Tjørve Kathleen M C - - 2010
We compare four candidate models (logistic, Gompertz, von Bertalanffy, and extreme value function) for modelling the growth of birds. We fitted the models to two empirical data sets of chick growth (six biometric measurements) of African black oystercatchers Haematopus moquini from South Africa and little stints Calidris minuta from Russia, ...
Wei Fengrong - - 2010
In regression problems where covariates can be naturally grouped, the group Lasso is an attractive method for variable selection since it respects the grouping structure in the data. We study the selection and estimation properties of the group Lasso in high-dimensional settings when the number of groups exceeds the sample ...
Grippo Paul J - - 2010
With the advent of mouse models that recapitulate the cellular and molecular pathology of pancreatic neoplasia and cancer, it is now feasible to recruit and deploy these models for the evaluation of various chemopreventive and/or anticancer regimens. The highly lethal nature of pancreatic ductal adenocarcinoma (PDAC) makes multiple areas of ...
Larsen Melinda - - 2010
Branching morphogenesis is a crucial developmental process in which vertebrate organs generate extensive epithelial surface area while retaining a compact size. In the vertebrate submandibular salivary gland, branching morphogenesis is crucial for the generation of the large surface area necessary to produce sufficient saliva. However, in many salivary gland diseases, ...
Beetz Nadine - - 2011
In the time since its discovery, phosducin's functions have been intensively studied both in vivo and in vitro. Phosducin's most important biochemical feature in in vitro studies is its binding to heterotrimeric G protein βγ-subunits. Data on phosducin's in vivo relevance, however, have only recently been published but expand the ...
Won Jungyeon J The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, - - 2011
The need for mouse models, with their well-developed genetics and similarity to human physiology and anatomy, is clear and their central role in furthering our understanding of human disease is readily apparent in the literature. Mice carrying mutations that alter developmental pathways or cellular function provide model systems for analyzing ...
Ravindran Resmi - - 2010
Multiplex methodologies enable simultaneous detection of antibodies against several infectious agents allowing sample conservation, cost effectiveness, and amenability to high-throughput/automation. We have previously described a multiplex microbead immunoassay for serodetection of ten, high-priority mouse infectious pathogens. Here, we present a validation of this multiplex diagnostic system using approximately four hundred ...
< 5 6 7 8 9 10 11 12 13 14 15 >