4 resultados para Radioactive tracers in biochemistry.

em DigitalCommons@University of Nebraska - Lincoln


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Biochemistry is the most fascinating subject as it deals with the chemical language of life. The ultimate goal of biochemistry is to describe the phenomena that distinguish living from non-living in the language of chemistry and physics. Researchers in biochemistry use specific techniques native to biochemistry, but increasingly combine these with techniques and ideas from genetics, molecular biology and biophysics. In India at present around 75,000 students are enrolled in research and nearly 11,000 are awarded PhDs every year, of which 50 percent are from science and technology disciplines. Theses and dissertations reflect the scholarly communication process. Scientometrics and citation characteristics of dissertations like the subject fields of dissertations, the number of citations and their distribution by type of source, years, and by number of authors etc., have been studied with a view to identify the basic features of the scholarly communication process in different fields of study. The purpose of the present study is to determine the bibliometric characteristics of the biochemistry research in the university of Kerala, India including subject distribution, bibliographic forms of cited documents, most cited journals, collaboration in authorship, etc. A total of 168 doctoral dissertations awarded between 1966 and 2007 at the Department of Biochemistry of University of Kerala were used as a source.

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Top predators in the marine environment integrate chemical signals acquired from their prey that reflect both the species consumed and the regions from which the prey were taken. These chemical tracers—stable isotope ratios of carbon and nitrogen; persistent organic pollutant (POP) concentrations, patterns and ratios; and fatty acid profiles—were measured in blubber biopsy samples from North Pacific killer whales (Orcinus orca) (n = 84) and were used to provide further insight into their diet, particularly for the offshore group, about which little dietary information is available. The offshore killer whales were shown to consume prey species that were distinctly different from those of sympatric resident and transient killer whales. In addition, it was confirmed that the offshores forage as far south as California. Thus, these results provide evidence that the offshores belong to a third killer whale ecotype. Resident killer whale populations showed a gradient in stable isotope profiles from west (central Aleutians) to east (Gulf of Alaska) that, in part, can be attributed to a shift from off-shelf to continental shelf-based prey. Finally, stable isotope ratio results, supported by field observations, showed that the diet in spring and summer of eastern Aleutian Island transient killer whales is apparently not composed exclusively of Steller sea lions.

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Top predators in the marine environment integrate chemical signals acquired from their prey that reflect both the species consumed and the regions from which the prey were taken. These chemical tracers—stable isotope ratios of carbon and nitrogen; persistent organic pollutant (POP) concentrations, patterns and ratios; and fatty acid profiles—were measured in blubber biopsy samples from North Pacific killer whales (Orcinus orca) (n = 84) and were used to provide further insight into their diet, particularly for the offshore group, about which little dietary information is available. The offshore killer whales were shown to consume prey species that were distinctly different from those of sympatric resident and transient killer whales. In addition, it was confirmed that the offshores forage as far south as California. Thus, these results provide evidence that the offshores belong to a third killer whale ecotype. Resident killer whale populations showed a gradient in stable isotope profiles from west (central Aleutians) to east (Gulf of Alaska) that, in part, can be attributed to a shift from off-shelf to continental shelf-based prey. Finally, stable isotope ratio results, supported by field observations, showed that the diet in spring and summer of eastern Aleutian Island transient killer whales is apparently not composed exclusively of Steller sea lions.

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Maxine Frank Singer began her education in the New York City public schools and earned her baccalaureate degree from Swarthmore College and her Ph.D. in biochemistry from Yale University. Dr. Singer has had a long association with the National Institutes of Health and served as Chief, Laboratory of Biochemistry, National Cancer Institute, where she now carries the title of Scientist Emerita. In 1988, she became President of the Carnegie Institution of Washington and served in that capacity until 2002 when she was named President Emerita and Senior Scientific Advisor to the Carnegie Academy for Science Education.