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Doanh Nguyen-Ngoc, Thuy Nguyen-Phuong
We investigate a system of two species exploiting a common resource. We consider both abiotic (i.e. with a constant resource supply rate) and biotic (i.e. with resource reproduction and self-limitation) resources. We are interested in the asymmetric competition where a given consumer is the locally superior resource exploiter (LSE) and the other is the locally inferior resource exploiter (LIE). They also interact directly via interference competition in the sense that LIE individuals can use two opposite strategies to compete with LSE individuals: we assume, in the first case, that LIE uses an avoiding strategy, i...
October 21, 2016: Acta Biotheoretica
Dongdong Chai, Hong Jiang, Qifang Li
OBJECTIVE: Previously, we found that the inhaled anesthetic isoflurane up-regulated the transcriptional factor hypoxia inducible factor (HIF)-1α protein levels during induction of neurodegeneration in the brain of neonatal rats. Here, we investigated the role of HIF-1α and the underlying signaling pathway in the neurodegenration induced by isoflurane in rodent developing brain. METHODS: Primary hippocampal neurons were exposed to isoflurane (0.4mM) for 12h. Neuron injury was analyzed by 3-(4,5-dimethyithiazol-2-yl)-2,5-diphenyl-tetra-zolium bromide (MTT) test and quantification of lactate dehydrogenaserelease...
October 18, 2016: Brain Research
Aurélie Stallivieri, Ludovic Colombeau, Gulim Jetpisbayeva, Albert Moussaron, Bauyrzhan Myrzakhmetov, Philippe Arnoux, Samir Acherar, Régis Vanderesse, Céline Frochot
Recent researches in photodynamic therapy have focused on novel techniques to enhance tumour targeting of anticancer drugs and photosensitizers. Coupling a photosensitizer with folic acid could allow more effective targeting of folate receptors which are over-expressed on the surface of many tumour cells. In this study, different folic acid-OEG-conjugated photosensitizers were synthesized, characterized and their photophysical properties were evaluated. The introduction of an OEG does not significantly improve the hydrophilicity of the FA-porphyrin...
October 10, 2016: Bioorganic & Medicinal Chemistry
Diyendo Massilani, Silvia Guimaraes, Jean-Philip Brugal, E Andrew Bennett, Malgorzata Tokarska, Rose-Marie Arbogast, Gennady Baryshnikov, Gennady Boeskorov, Jean-Christophe Castel, Sergey Davydov, Stéphane Madelaine, Olivier Putelat, Natalia N Spasskaya, Hans-Peter Uerpmann, Thierry Grange, Eva-Maria Geigl
BACKGROUND: Climatic and environmental fluctuations as well as anthropogenic pressure have led to the extinction of much of Europe's megafauna. The European bison or wisent (Bison bonasus), one of the last wild European large mammals, narrowly escaped extinction at the onset of the 20th century owing to hunting and habitat fragmentation. Little is known, however, about its origin, evolutionary history and population dynamics during the Pleistocene. RESULTS: Through ancient DNA analysis we show that the emblematic European bison has experienced several waves of population expansion, contraction, and extinction during the last 50,000 years in Europe, culminating in a major reduction of genetic diversity during the Holocene...
October 21, 2016: BMC Biology
Tong Zhao, Lingxiao Yang, Weida Yan, Junmei Zhang, Wei Lu, Yumeng Yang, Jianmin Chen, Wenxing Wang
Daytime and night-time PM1 and PM2.5 samples were simultaneously collected at the summit of Mount Tai during summer and autumn 2014. The mass concentrations and chemical compositions were analysed to determine the temporal variations of PM1 and PM2.5 and their contributions to visibility impairment. In summer, the average mass concentrations of PM1 and PM2.5 were 38.16μg/m(3) and 53.33μg/m(3), respectively. In autumn, the values were 42.75μg/m(3) and 59.16μg/m(3). Water-soluble inorganic ions were the most abundant species in both PM1 and PM2...
October 18, 2016: Science of the Total Environment
E Levy, M Byrne, D J Coates, B M Macdonald, S McArthur, S van Leeuwen
The influence of geographic range on species persistence has long been of interest and there is a need for a better understanding of the genetic consequences for species with restricted distributions, particularly with the increasing rate of global species extinctions. However, the genetic effects of restricted range are often confounded by the impacts of population distribution. We compared chloroplast and nuclear genetic diversity and differentiation in two acacias, the restricted, patchily distributed Acacia atkinsiana and the widespread, semi-continuously distributed A...
2016: PloS One
Lars Marstaller, Hana Burianová, David C Reutens
Safety learning describes the ability to learn that certain cues predict the absence of a dangerous or threatening event. Although incidental observations of activity within the default mode network (DMN) during the processing of safety cues have been reported previously, there is as yet no evidence demonstrating that the DMN plays a functional rather than a corollary role in safety learning. Using functional magnetic resonance imaging and a Pavlovian fear conditioning and extinction paradigm, we investigated the neural correlates of danger and safety learning...
October 21, 2016: Human Brain Mapping
Kenneth M McCullough, Dennis Choi, Jidong Guo, Kelsey Zimmerman, Jordan Walton, Donald G Rainnie, Kerry J Ressler
Molecular characterization of neuron populations, particularly those controlling threat responses, is essential for understanding the cellular basis of behaviour and identifying pharmacological agents acting selectively on fear-controlling circuitry. Here we demonstrate a comprehensive workflow for identification of pharmacologically tractable markers of behaviourally characterized cell populations. Thy1-eNpHR-, Thy1-Cre- and Thy1-eYFP-labelled neurons of the BLA consistently act as fear inhibiting or 'Fear-Off' neurons during behaviour...
October 21, 2016: Nature Communications
J T Nielsen, A Guffanti, S Sarkar
The 'standard' model of cosmology is founded on the basis that the expansion rate of the universe is accelerating at present - as was inferred originally from the Hubble diagram of Type Ia supernovae. There exists now a much bigger database of supernovae so we can perform rigorous statistical tests to check whether these 'standardisable candles' indeed indicate cosmic acceleration. Taking account of the empirical procedure by which corrections are made to their absolute magnitudes to allow for the varying shape of the light curve and extinction by dust, we find, rather surprisingly, that the data are still quite consistent with a constant rate of expansion...
October 21, 2016: Scientific Reports
Yu Hua Wong, Halimah Muhamad, Faridah Abas, Oi Ming Lai, Kar Lin Nyam, Chin Ping Tan
The effects of frying duration, frying temperature and concentration of sodium chloride on the formation of 3-monochloropropane-1,2-diol (3-MCPD) esters and glycidyl esters (GEs) of refined, bleached and deodorized (RBD) palm olein during deep-fat frying (at 160°C and 180°C) of potato chips (0%, 1%, 3% and 5% NaCl) for 100min/d for five consecutive days in eight systems were compared in this study. All oil samples collected after each frying cycle were analyzed for 3-MCPD esters, GEs, free fatty acid (FFA) contents, specific extinction at 232 and 268 nm (K232 and K268), p-anisidine value (pAV), and fatty acid composition...
March 15, 2017: Food Chemistry
Vazrick Nazari, B Christian Schmidt, Sean Prosser, Paul D N Hebert
Analysis of the DNA barcode region of the cytochrome c oxidase 1 gene from a specimen of the extinct Jamaican sunset moth, Urania sloanus, places this species as a sister to the Central American U. fulgens. We found that all Urania F. species were closely related (<2.8% maximum divergence at COI), with the Cuban endemic U. boisduvalii appearing as sister to the rest. The low divergence in DNA barcodes and genitalic structures indicate that the Cuban U. poeyi and eastern Brazilian U. brasiliensis are geographic segregates of U...
2016: PloS One
Vendela K Lagerholm, Edson Sandoval-Castellanos, Amélie Vaniscotte, Olga R Potapova, Teresa Tomek, Zbigniew M Bochenski, Paul Shepherd, Nick Barton, Marie-Claire Van Dyck, Rebecca Miller, Jacob Höglund, Nigel G Yoccoz, Love Dalén, John R Stewart
Global warming is predicted to cause substantial habitat rearrangements, with the most severe effects expected to occur in high-latitude biomes. However, one major uncertainty is whether species will be able to shift their ranges to keep pace with climate-driven environmental changes. Many recent studies on mammals have shown that past range contractions have been associated with local extinctions rather than survival by habitat tracking. Here, we have used an interdisciplinary approach that combines ancient DNA techniques, coalescent simulations and species distribution modelling, to investigate how two common cold-adapted bird species, willow and rock ptarmigan (Lagopus lagopus and Lagopus muta), respond to long-term climate warming...
October 20, 2016: Global Change Biology
Michael P Chu, Jitra Kriangkum, Christopher P Venner, Irwindeep Sandhu, Joanne Hewitt, Andrew R Belch, Linda M Pilarski
Cancer heterogeneity is a significant factor in response to treatment and escape leading to relapse. Within an individual cancer, especially blood cancers, there exists multiple subclones as well as distinct clonal expansions unrelated to the clinically detected, dominant clone. Over time, multiple subclones and clones undergo emergence, expansion, and extinction. Although sometimes this intra-clonal and inter-clonal heterogeneity can be detected and/or quantified in tests that measure aggregate populations of cells, frequently, such heterogeneity can only be detected using single cell analysis to determine its frequency and to detect minor clones that may subsequently emerge to become drug resistant and dominant...
October 19, 2016: Cell Biology and Toxicology
Vladimir Kozlov, Sergey Vakulenko, Uno Wennergren
This paper considers a model of foodwebs taking into account species extinction and invasion. We show that system stability depends not only on usual parameters (mortality rates, self-limitation coefficients, and resource abundances), but also on an additional parameter ("biodiversity potential"). The main result is as follows. For foodwebs with random parameters, we obtain an estimate of probability that the foodweb exposed to invasion survives. This estimate involves different system parameters, size and its topological properties...
October 19, 2016: Bulletin of Mathematical Biology
Julia Angélica Gonçalves Silveira, Mirella Lauria D'Elia, Isabela de Oliveira Avelar, Lara Ribeiro de Almeida, Hudson Andrade Dos Santos, Danielle Ferreira de Magalhães Soares, Múcio Flávio Barbosa Ribeiro, Walter Dos Santos Lima, Roselene Ecco
An adult free-ranged female maned wolf was rescued from a periurban area subject to anthropogenic disturbances in the Minas Gerais, Brazil. The animal presented poor body condition and anemia. The clinical condition rapidly deteriorated culminating in dead and a necropsy was performed. The main gross lesions were marked anemia and blood content in the intestines accompanied by many types of parasites. The protozoa Rangelia vitalii was identified by histopathological analysis predominantly within the cytoplasm of endothelial cells of capillaries of the small intestine...
December 2016: International Journal for Parasitology. Parasites and Wildlife
Liat Helpman, Marie-France Marin, Santiago Papini, Xi Zhu, Gregory M Sullivan, Franklin Schneier, Mariana Neria, Erel Shvil, Maria Josefa Malaga Aragon, John C Markowitz, Martin A Lindquist, Tor Wager, Mohammad Milad, Yuval Neria
BACKGROUND: Neurobiological models of posttraumatic stress disorder (PTSD) implicate fear processing impairments in the maintenance of the disorder. Specific deficits in extinction recall, the retention of learned extinction, have been demonstrated. While deficient extinction recall, and the associated activation pattern of prefrontal and hippocampal regions, distinguishes individuals with PTSD from controls, research has not yet examined changes following treatment. We examined the behavioral and neural correlates of extinction recall before and after cognitive behavioral treatment of PTSD...
2016: NeuroImage: Clinical
Samuel Ginot, Lionel Hautier, Laurent Marivaux, Monique Vianey-Liaud
Studies linking postcranial morphology with locomotion in mammals are common. However, such studies are mostly restricted to caviomorphs in rodents. We present here data from various families, belonging to the three main groups of rodents (Sciuroidea, Myodonta, and Ctenohystrica). The aim of this study is to define morphological indicators for the astragalus and calcaneus, which allow for inferences to be made about the locomotor behaviours in rodents. Several specimens were dissected and described to bridge the myology of the leg with the morphology of the bones of interest...
2016: PeerJ
Ben H Chew, Dirk Lange
Open ureterolithotomy and pyelolithotomy used to be first line therapy for treating kidney and ureteral stones. With the advent of shockwave lithotripsy, open stone surgery became less prevalent, but once ureteroscopy became more prevalent, open stone surgery became all but extinct. Advances in smaller, more flexible endoscopes and improvements in intracorporeal lithotripters, ureteroscopy has become a mainstay of therapy for kidney stones. The holmium:YAG laser can be utilized through flexible instruments and fragments any stone no matter what it is composed of...
October 19, 2016: Minerva Urologica e Nefrologica, the Italian Journal of Urology and Nephrology
Q Mahmood, M Hassan, N A Noor
The structural, magnetic and optical characteristics of Zn1-x TM x S/Se (TM  =  Mn, Fe, Co, Ni and x  =  6.25%) have been investigated through the full-potential linearized augmented plane wave method within the framework of density functional theory. The optimized structures have been used to calculate the ferromagnetic and the antiferromagnetic ground-state energies. The stability of the ferromagnetic phase has been confirmed from the formation and the cohesive energies. The Heisenberg model is used to elucidate the Curie temperature (T c) of these alloys...
October 19, 2016: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Mini Mol Menamparambath, Kihyuk Yang, Hyeong Hoon Kim, Oh Seung Bae, Mun Seok Jeong, Jae-Young Choi, Seunghyun Baik
Silver nanowires (Ag NWs) have received considerable attention for flexible transparent conductive films (TCFs) since they provide a relatively low sheet resistance at a high transmittance. However, the diffuse light scattering, haze, has been regarded as a hurdle to achieve clarity of films. Here we revisit the Mie scattering theory to calculate the extinction and scattering coefficients of Ag NWs which were employed to estimate haze of TCFs. The theory predicted a decrease in haze with a decrease in Ag NW diameter which was supported by experimental investigations carried out using Ag NWs with 5 different diameters (17...
October 19, 2016: Nanotechnology
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