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21.
A sequence of deoxyribonucleic acid of 2.7 times 10-6 to 3.3 times 10-6 daltons which includes the TEM beta-lactamase gene is present on the small plasmid RSF 1030 (R-Amp). This same sequence is present on plasmid derivatives that have received a translocation of deoxyribonucleic acid specifying the TEM beta-lactamase and is also present on naturally occurring plasmids of the F1, F11, N, X, O, I, C, and W incompatibility groups that do not specify ampicillin resistance or specify O-type beta-lactamases. 相似文献
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Lees K. J. MacNeil M. A. Hedges K. J. Hussey N. E. 《Reviews in Fish Biology and Fisheries》2021,31(1):25-51
Reviews in Fish Biology and Fisheries - Mark-recapture approaches are among the most powerful fisheries methods for estimating demographic parameters relating to survival, components of mortality... 相似文献
24.
Andrés Moreno-Estrada Simon Gravel Fouad Zakharia Jacob L. McCauley Jake K. Byrnes Christopher R. Gignoux Patricia A. Ortiz-Tello Ricardo J. Martínez Dale J. Hedges Richard W. Morris Celeste Eng Karla Sandoval Suehelay Acevedo-Acevedo Paul J. Norman Zulay Layrisse Peter Parham Juan Carlos Martínez-Cruzado Esteban González Burchard Michael L. Cuccaro Eden R. Martin Carlos D. Bustamante 《PLoS genetics》2013,9(11)
The Caribbean basin is home to some of the most complex interactions in recent history among previously diverged human populations. Here, we investigate the population genetic history of this region by characterizing patterns of genome-wide variation among 330 individuals from three of the Greater Antilles (Cuba, Puerto Rico, Hispaniola), two mainland (Honduras, Colombia), and three Native South American (Yukpa, Bari, and Warao) populations. We combine these data with a unique database of genomic variation in over 3,000 individuals from diverse European, African, and Native American populations. We use local ancestry inference and tract length distributions to test different demographic scenarios for the pre- and post-colonial history of the region. We develop a novel ancestry-specific PCA (ASPCA) method to reconstruct the sub-continental origin of Native American, European, and African haplotypes from admixed genomes. We find that the most likely source of the indigenous ancestry in Caribbean islanders is a Native South American component shared among inland Amazonian tribes, Central America, and the Yucatan peninsula, suggesting extensive gene flow across the Caribbean in pre-Columbian times. We find evidence of two pulses of African migration. The first pulse—which today is reflected by shorter, older ancestry tracts—consists of a genetic component more similar to coastal West African regions involved in early stages of the trans-Atlantic slave trade. The second pulse—reflected by longer, younger tracts—is more similar to present-day West-Central African populations, supporting historical records of later transatlantic deportation. Surprisingly, we also identify a Latino-specific European component that has significantly diverged from its parental Iberian source populations, presumably as a result of small European founder population size. We demonstrate that the ancestral components in admixed genomes can be traced back to distinct sub-continental source populations with far greater resolution than previously thought, even when limited pre-Columbian Caribbean haplotypes have survived. 相似文献
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Oliver E. Craig Luca Bondioli Luciano Fattore Tom Higham Robert Hedges 《American journal of physical anthropology》2013,152(3):345-352
The stable carbon (δ13C) and nitrogen (δ15N) isotope values of bone collagen are frequently used in paleodietary studies to assess the marine contribution to an individual's diet. Surprisingly, the relationship between stable isotope these values characteristics and the percentage of marine foods in diet has never been effectively demonstrated. To clarify this relationship, the stable isotope values and radiocarbon dates of nine humans and one sheep from Herculaneum, all who perished simultaneously during the AD 79 eruption of Vesuvius, were determined. Significant differences were found in the radiocarbon dates which are attributable to the incorporation of “old” carbon from the marine reservoir. The magnitude of the observed differences was linearly correlated with both δ13C and δ15N values allowing the response of each isotope to increasing marine carbon in collagen to be independently verified. Regression analyses showed that for every 1‰ enrichment in δ13C and δ15N, 56 years and 34 years were added to the radiocarbon age, respectively. Predictions of the maximum marine reservoir age differed considerably depending on which stable isotope was considered. This discrepancy is attributed to some degree of macronutrient scrambling whereby nitrogen from marine protein is preferentially incorporated in collagen over marine carbon. It is suggested that the macronutrient scrambling explains the observed relationship between δ13C and δ15N from Roman coastal sites and should be considered when interpreting any diet which is not dominated by protein. Nevertheless, without knowing the degree of macronutrient scrambling in different dietary scenarios, the accuracy of dietary reconstructions is severely compromised. Am J Phys Anthropol 152:345–352, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
27.
Hedges JF Buckner DL Rask KM Kerns HM Jackiw LO Trunkle TC Pascual DW Jutila MA 《Cellular immunology》2007,246(1):8-16
To better understand the roles of gammadelta T cells in mucosal infection, we utilized Salmonella enterica serovar Typhimurium (Salmonella serovar Typhimurium) infection in cattle as it closely approximates Salmonella serovar Typhimurium-induced enterocolitis in humans. Protein and gene expression in alphabeta and gammadelta T cells derived from lymphatic ducts draining the gut mucosa in Salmonella serovar Typhimurium-infected calves were analyzed. In calves with enterocolitis, general gene expression trends in gammadelta T cells suggested subtle activation and innate response, whereas alphabeta T cells were relatively quiescent following Salmonella serovar Typhimurium infection. An increase in IL-2R alpha expression on gammadelta T cells from infected calves and results from in vitro assays suggested that gammadelta T cells were primed by Salmonella serovar Typhimurium LPS to better respond to IL-2 and IL-15. Together with gene expression trends in vivo, these data support early priming activation of target tissue gammadelta T cells during Salmonella serovar Typhimurium infection. 相似文献
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Carbon and nitrogen isotopic analysis of body tissues is one of the few techniques that can furnish quantitative information about the diet of archaeological humans. The study of the effects of various diets on modern human isotopic values can help to refine palaeodietary theories, and such work also enables the testing of palaeodietary theories independent of archaeological remains and interpretations. This report discusses the use of modern human hair as a sample material for isotopic analysis. The biogenic carbon and nitrogen isotopic signal is well preserved in hair, and the isotopic values of the keratin can be related to diet. We show that atmospheric and cosmetic contamination of hair keratin does not appear to affect the measured isotopic values. In a small study of Oxford residents, we demonstrate that the magnitude of the nitrogen isotopic values of hair keratin reflects the proportion of animal protein consumed in the diet: omnivores and ovo-lacto-vegetarians have higher delta15N than vegans. There was an observed relationship between the reported amount of animal protein eaten (either meat or secondary animal products) and the nitrogen isotopic values within the two groups of omnivores and ovo-lacto-vegetarians, indicating that an increasing amount of animal protein in the diet results in an increase in the delta15N of hair keratin. This provides the first independent support for a long-held theory that, for individuals within a single population, a diet high in meat equates to elevated nitrogen isotopic values in the body relative to others eating less animal protein. The implications of such results for the magnitude of the trophic level effect are discussed. Results presented here also permit a consideration of the effects of a change of diet in the short and long term on hair keratin isotopic values. 相似文献
30.
Nancy L. Wilczynski R. Brian Haynes John N. Lavis Ravi Ramkissoonsingh Alexandra E. Arnold-Oatley The HSR Hedges Team 《CMAJ》2004,171(10):1179-1185