Concern about the biological hazards involved in microbiological research, especially research involving laboratory animals, has increased in recent years. Working in an animal biosafety level 2 facility （ABSL-2）, c...Concern about the biological hazards involved in microbiological research, especially research involving laboratory animals, has increased in recent years. Working in an animal biosafety level 2 facility （ABSL-2）, commonly used for research on infectious diseases, poses various biological hazards. Here, the regulations and standards related to laboratory biosafety in China are introduced, the potential biological hazards present in ABSL-2 facilities are analyzed, and a series of strategies to control the hazards are presented.展开更多
You are what you eat (diet) and where you eat (trophic level) in the food web. The relative abundance of pairs of stable isotopes of the organic elements carbon (e.g., the isotope ratio of <sup>13</sup>C v...You are what you eat (diet) and where you eat (trophic level) in the food web. The relative abundance of pairs of stable isotopes of the organic elements carbon (e.g., the isotope ratio of <sup>13</sup>C vs<sup> 12</sup>C), nitrogen, and sulfur, among others, in the tissues of a consumer reflects a weighted-average of the isotope ratios in the sources it consumes, after some corrections for the processes of digestion and assimilation. We extended a Bayesian mixing model to infer trophic positions of consumer organisms in a food web in addition to the degree to which distinct resource pools (diet sources) support consumers. The novel features in this work include: 1) trophic level estimation (vertical position in foodweb) and 2) the Bayesian exposition of a biologically realistic model [1] including stable isotope ratios and concentrations of carbon, nitrogen, and sulfur, isotopic fractionations, elemental assimilation efficiencies, as well as extensive use of prior information. We discuss issues of parameter identifiability in the complex and most realistic model. We apply our model to simulated data and to bottlenose dolphins (Tursiops truncatus) feeding on several numerically abundant fish species, which in turn feed on other fish and primary producing plants and algae present in St. George Sound, FL, USA. Finally, we discuss extensions from other work that apply to this model and three important general ecological applications. Online supplementary materials include data, OpenBUGS scripts, and simulation details.展开更多
The aim was to clarify effects of ad libitum and restricted feeding with Ca:P ratios on foot welfare in blue foxes. Experiment was started at weaning on August 6th and finished at pelting on November 26th, 2013. Treat...The aim was to clarify effects of ad libitum and restricted feeding with Ca:P ratios on foot welfare in blue foxes. Experiment was started at weaning on August 6th and finished at pelting on November 26th, 2013. Treatments were: 1) restricted feeding, Ca:P ratio 1.5:1;2) restricted feeding, Ca:P ratio 2.9:1;3) restricted feeding Ca:P ratio control level;4) ad libitum feeding, Ca:P ratio 1.5:1;5) ad libitum feeding, Ca:P-ratio 2.9:1;6) ad libitum feeding Ca:P ratio control level. Body growth variables, feed intake and welfare variables were measured. The behaviour was video recorded. Foreleg carpal joint angle as an indicator of leg weakness and the fox’s ability to move were evaluated. During weeks 32 - 35 and 37 - 47 animals from restricted groups ate 60% - 65% and 67% - 68% of the given feed, respectively. Body weight gain was faster in foxes fed ad libitum than with a restricted diet (P ad libitum groups compared to restricted ones. The body condition score was significantly (P ad libitum animals. Body length was greater for ad libitum than for restricted groups (P ad libitum and restricted groups展开更多
基金supported by the National Science and Technology Major Projects of Infectious Disease(2012ZX10004-404)
文摘Concern about the biological hazards involved in microbiological research, especially research involving laboratory animals, has increased in recent years. Working in an animal biosafety level 2 facility （ABSL-2）, commonly used for research on infectious diseases, poses various biological hazards. Here, the regulations and standards related to laboratory biosafety in China are introduced, the potential biological hazards present in ABSL-2 facilities are analyzed, and a series of strategies to control the hazards are presented.
文摘You are what you eat (diet) and where you eat (trophic level) in the food web. The relative abundance of pairs of stable isotopes of the organic elements carbon (e.g., the isotope ratio of <sup>13</sup>C vs<sup> 12</sup>C), nitrogen, and sulfur, among others, in the tissues of a consumer reflects a weighted-average of the isotope ratios in the sources it consumes, after some corrections for the processes of digestion and assimilation. We extended a Bayesian mixing model to infer trophic positions of consumer organisms in a food web in addition to the degree to which distinct resource pools (diet sources) support consumers. The novel features in this work include: 1) trophic level estimation (vertical position in foodweb) and 2) the Bayesian exposition of a biologically realistic model [1] including stable isotope ratios and concentrations of carbon, nitrogen, and sulfur, isotopic fractionations, elemental assimilation efficiencies, as well as extensive use of prior information. We discuss issues of parameter identifiability in the complex and most realistic model. We apply our model to simulated data and to bottlenose dolphins (Tursiops truncatus) feeding on several numerically abundant fish species, which in turn feed on other fish and primary producing plants and algae present in St. George Sound, FL, USA. Finally, we discuss extensions from other work that apply to this model and three important general ecological applications. Online supplementary materials include data, OpenBUGS scripts, and simulation details.
文摘The aim was to clarify effects of ad libitum and restricted feeding with Ca:P ratios on foot welfare in blue foxes. Experiment was started at weaning on August 6th and finished at pelting on November 26th, 2013. Treatments were: 1) restricted feeding, Ca:P ratio 1.5:1;2) restricted feeding, Ca:P ratio 2.9:1;3) restricted feeding Ca:P ratio control level;4) ad libitum feeding, Ca:P ratio 1.5:1;5) ad libitum feeding, Ca:P-ratio 2.9:1;6) ad libitum feeding Ca:P ratio control level. Body growth variables, feed intake and welfare variables were measured. The behaviour was video recorded. Foreleg carpal joint angle as an indicator of leg weakness and the fox’s ability to move were evaluated. During weeks 32 - 35 and 37 - 47 animals from restricted groups ate 60% - 65% and 67% - 68% of the given feed, respectively. Body weight gain was faster in foxes fed ad libitum than with a restricted diet (P ad libitum groups compared to restricted ones. The body condition score was significantly (P ad libitum animals. Body length was greater for ad libitum than for restricted groups (P ad libitum and restricted groups
