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排序方式: 共有4142条查询结果,搜索用时 15 毫秒
971.
972.
Adriaan M. Dokter Peter Desmet Jurriaan H. Spaaks Stijn van Hoey Lourens Veen Liesbeth Verlinden Cecilia Nilsson Günther Haase Hidde Leijnse Andrew Farnsworth Willem Bouten Judy Shamoun‐Baranes 《Ecography》2019,42(5):852-860
Weather surveillance radars are increasingly used for monitoring the movements and abundances of animals in the airspace. However, analysis of weather radar data remains a specialised task that can be technically challenging. Major hurdles are the difficulty of accessing and visualising radar data on a software platform familiar to ecologists and biologists, processing the low‐level data into products that are biologically meaningful, and summarizing these results in standardized measures. To overcome these hurdles, we developed the open source R package bioRad, which provides a toolbox for accessing, visualizing and analyzing weather radar data for biological studies. It provides functionality to access low‐level radar data, process these data into meaningful biological information on animal speeds and directions at different altitudes in the atmosphere, visualize these biological extractions, and calculate further summary statistics. The package aims to standardize methods for extracting and reporting biological signals from weather radars. Here we describe a roadmap for analyzing weather radar data using bioRad. We also define weather radar equivalents for familiar measures used in the field of migration ecology, such as migration traffic rates, and recommend several good practices for reporting these measures. The bioRad package integrates with low‐level data from both the European radar network (OPERA) and the radar network of the United States (NEXRAD). bioRad aims to make weather radar studies in ecology easier and more reproducible, allowing for better inter‐comparability of studies. 相似文献
973.
974.
Cecilia M Shing Jonathan Peake Katsuhiko Suzuki Mitsuharu Okutsu Rosie Pereira Lesley Stevenson David G Jenkins Jeff S Coombes 《Journal of applied physiology》2007,102(3):1113-1122
The aim of this study was to investigate the influence of low-dose bovine colostrum protein concentrate (CPC) supplementation on selected immune variables in cyclists. Twenty-nine highly trained male road cyclists completed an initial 40-km time trial (TT(40)) and were then randomly assigned to either a supplement (n = 14, 10 g bovine CPC/day) or placebo group (n = 15, 10 g whey protein concentrate/day). After 5 wk of supplementation, the cyclists completed a second TT(40). They then completed 5 consecutive days of high-intensity training (HIT) that included a TT(40), followed by a final TT(40) in the following week. Venous blood and saliva samples were collected immediately before and after each TT(40), and upper respiratory illness symptoms were recorded over the experimental period. Compared with the placebo group, bovine CPC supplementation significantly increased preexercise serum soluble TNF receptor 1 during the HIT period (bovine CPC = 882 +/- 233 pg/ml, placebo = 468 +/- 139 pg/ml; P = 0.039). Supplementation also suppressed the postexercise decrease in cytotoxic/suppressor T cells during the HIT period (bovine CPC = -1.0 +/- 2.7%, placebo = -9.2 +/- 2.8%; P = 0.017) and during the following week (bovine CPC = 1.4 +/- 2.9%, placebo = -8.2 +/- 2.8%; P = 0.004). Bovine CPC supplementation prevented a postexercise decrease in serum IgG(2) concentration at the end of the HIT period (bovine CPC = 4.8 +/- 6.8%, P = 0.88; placebo = -9.7 +/- 6.9%, P = 0.013). There was a trend toward reduced incidence of upper respiratory illness symptoms in the bovine CPC group (P = 0.055). In summary, low-dose bovine CPC supplementation modulates immune parameters during normal training and after an acute period of intense exercise, which may have contributed to the trend toward reduced upper respiratory illness in the bovine CPC group. 相似文献
975.
Canesi L Ciacci C Lorusso LC Betti M Gallo G Pojana G Marcomini A 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2007,145(3):464-472
Pharmaceuticals and Personal Care Products (PPCPs) are a class of emerging environmental pollutants with the potential of affecting various aquatic organisms through unexpected modes of action. Triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether) (TCS), is a common antibacterial agent that is found in significant amounts in the aquatic environment. In this work, the possible effects and modes of action of TCS were investigated in the marine bivalve Mytilus galloprovincialis Lam. In mussel immune cells, the hemocytes, in vitro short-term exposure to TCS in the low microM range reduced lysosomal membrane stability (LMS) and induced extracellular release of lysosomal hydrolytic enzymes. The effects on LMS were mediated by activation of ERK MAPKs (Extracellularly Regulated Mitogen Activated Protein Kinases) and PKC (protein kinase C) alpha and betaII isoforms, as demonstrated by both specific kinase inhibitors and Western blotting with specific anti-phospho-antibodies. The effects of TCS were confirmed in vivo, in the hemocytes of mussels injected with different concentrations of TCS (corresponding to 0.29, 2.9 and 29 ng/g dry weight) and sampled at 24 h post-injection. The possible in vivo effects of TCS were also evaluated on the activity of different enzymes in the digestive gland, the tissue mainly involved in accumulation and metabolism of organic contaminants in mussels. Significant increases were observed in the activity of the glycolytic enzymes PFK (phosphofructokinase) and PK (pyruvate kinase), as well as of GST (GSH transferase) and GSR (GSSG reductase), whereas a decrease in catalase activity was observed. The results demonstrate that in mussels TCS can act on kinase-mediated cell signalling, lysosomal membranes and redox balance in different systems/organs. Although further studies are needed in order to evaluate possible consequences of environmental exposure to TCS on mussel health, the results represent the first data on the possible modes of action of this widespread antibacterial in aquatic invertebrates. 相似文献
976.
977.
Presynaptic nerve terminals are equipped with a number of presynaptic auto- and heteroreceptors, including ionotropic P2X
and metabotropic P2Y receptors. P2 receptors serve as modulation sites of transmitter release by ATP and other nucleotides
released by neuronal activity and pathological signals. A wide variety of P2X and P2Y receptors expressed at pre- and postsynaptic
sites as well as in glial cells are involved directly or indirectly in the modulation of neurotransmitter release. Nucleotides
are released from synaptic and nonsynaptic sites throughout the nervous system and might reach concentrations high enough
to activate these receptors. By providing a fine-tuning mechanism these receptors also offer attractive sites for pharmacotherapy
in nervous system diseases. Here we review the rapidly emerging data on the modulation of transmitter release by facilitatory
and inhibitory P2 receptors and the receptor subtypes involved in these interactions. 相似文献
978.
David S Horner Konstantinos Lefkimmiatis Aurelio Reyes Carmela Gissi Cecilia Saccone Graziano Pesole 《BMC evolutionary biology》2007,7(1):16
Background
Phylogenetic relationships between Lagomorpha, Rodentia and Primates and their allies (Euarchontoglires) have long been debated. While it is now generally agreed that Rodentia constitutes a monophyletic sister-group of Lagomorpha and that this clade (Glires) is sister to Primates and Dermoptera, higher-level relationships within Rodentia remain contentious. 相似文献979.
Mendoza M Diaz E Alvarado P Romero E Bastardo de Albornoz MC 《Revista iberoamericana de micología》2007,24(4):317-319
The dimorphic fungus Sporothrix schenckii is the etiological agent of sporotrichosis, a subcutaneous mycosis frequently found in Latin America. The isolation of this fungus from the environment and other sources has been widely reported. Nevertheless, to our knowledge this fungus has not been isolated from the endemic areas of Venezuela. In studies related to a clinical case of sporotrichosis in "Colonia Tovar", produced by traumatism after manipulating soil samples, the fungus was isolated from the soil of that particular area. This is the first report of the isolation of S. schenckii from environmental sources in an endemic area of Venezuela. 相似文献
980.
OBJECTIVES: The presence of the antibodies against Helicobacter pylori was tested in 163 subjects (children and adults) in the outpatient department, in the years 2005 and 2006. METHODS: Of the 163 investigated patients 108 (66.3%) were females and 55 (33.7%) were males. The antibodies against Helicobacter pylori were determined by "One Step Helicobacter pylori Test Device (Serum/Plasma)" (ACON Laboratories, Inc.), a rapid, high quality chromatographic immunoassay using human antibodies against IgG immobilized and particles covered with Helicobacter pylori antigen, in contact with the serum of the tested subjects. RESULTS: Of the 163 investigated subjects, 60 (36.8%) presented a positive test suggesting the passage through the infection with Helicobacter pylori. The positive tests were found in adults, 1 case was a boy of 12 years and 5 cases were teenagers between 16 and 18 years. The incidence of the antibodies increased with age. Only 40% of the patients with positive test had a clinical diagnosis of gastritis or gastro-duodenal ulcer, the remaining patients presenting symptoms of chronic hepatitis, cholecystitis or urticaria. CONCLUSIONS: Antibody assay is considered by many authors as a simple, noninvasive, rapid method, applicable in the diagnosis of Helicobacter pylori infection. Other authors asserted that the performance of these assays is less satisfactory and the results should be confirmed by other tests, such as ureea breath test. High levels of antibodies against Helicobacter spp. were encountered in liver and biliary chronic diseases, suggesting a possible role of these bacteria in the development of hepatitis or cholecystitis. 相似文献