2,149 research outputs found

    Redating shuidonggou locality 1 and implications for the initial upper paleolithic in east asia

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    A review of recently published temporal data from Shuidonggou Locality 1 indicates that a 40-43 cal ka date for the inception of Initial Upper Paleolithic (IUP) blade-oriented technologies in East Asia is warranted. Comparison of the dates from Shuidonggou to other Asian IUP dates in Korea, Siberia, and Mongolia supports this assertion, indicating that the initial appearance of the IUP in East Asia generally corresponds in time to the fluorescence of the IUP in eastern Europe and western Asia. This conclusion preliminarily suggests that either a version of the IUP originated independently in East Asia just prior to 40 cal ka, or more likely, that an early, initial diffusion of the IUP into East Asia occurred ~41 cal ka, a hypothesis consistent with current estimates for the evolution or arrival of modern humans in the region. © 2014 by the Arizona Board of Regents on behalf of the University of Arizona

    Agricultural origins and the isotopic identity of domestication in northern China

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    Stable isotope biochemistry (δ 13C and δ 15N) and radiocarbon dating of ancient human and animal bone document 2 distinct phases of plant and animal domestication at the Dadiwan site in northwest China. The first was brief and nonintensive: at various times between 7900 and 7200 calendar years before present (calBP) people harvested and stored enough broomcorn millet (Panicum miliaceum) to provision themselves and their hunting dogs (Canis sp.) throughout the year. The second, much more intensive phase was in place by 5900 calBP: during this time both broomcorn and foxtail (Setaria viridis spp. italica) millets were cultivated and made significant contributions to the diets of people, dogs, and pigs (Sus sp.). The systems represented in both phases developed elsewhere: the earlier, low-intensity domestic relationship emerged with hunter-gatherers in the arid north, while the more intensive, later one evolved further east and arrived at Dadiwan with the Yangshao Neolithic. The stable isotope methodology used here is probably the best means of detecting the symbiotic human-plantanimal linkages that develop during the very earliest phases of domestication and is thus applicable to the areas where these connections first emerged and are critical to explaining how and why agriculture began in East Asia

    Surface electrons at plasma walls

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    In this chapter we introduce a microscopic modelling of the surplus electrons on the plasma wall which complements the classical description of the plasma sheath. First we introduce a model for the electron surface layer to study the quasistationary electron distribution and the potential at an unbiased plasma wall. Then we calculate sticking coefficients and desorption times for electron trapping in the image states. Finally we study how surplus electrons affect light scattering and how charge signatures offer the possibility of a novel charge measurement for dust grains.Comment: To appear in Complex Plasmas: Scientific Challenges and Technological Opportunities, Editors: M. Bonitz, K. Becker, J. Lopez and H. Thomse

    HFE C282Y and H63D in adults with malignancies in a community medical oncology practice

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    BACKGROUND: We sought to compare frequencies of HFE C282Y and H63D alleles and associated odds ratios (OR) in 100 consecutive unrelated white adults with malignancy to those in 318 controls. METHODS: Data from patients with more than one malignancy were analyzed according to each primary malignancy. For the present study, OR ≥2.0 or ≤0.5 was defined to be increased or decreased, respectively. RESULTS: There were 110 primary malignancies (52 hematologic neoplasms, 58 carcinomas) in the 100 adult patients. Allele frequencies were similar in patients and controls (C282Y: 0.0850 vs. 0.0896, respectively (OR = 0.9); H63D: 0.1400 vs. 0.1447, respectively (OR = 0.9)). Two patients had hemochromatosis and C282Y homozygosity. With C282Y, increased OR occurred in non-Hodgkin lymphoma, myeloproliferative disorders, and adenocarcinoma of prostate (2.0, 2.8, and 3.4, respectively); OR was decreased in myelodysplasia (0.4). With H63D, increased OR occurred in myeloproliferative disorders and adenocarcinomas of breast and prostate (2.4, 2.0, and 2.0, respectively); OR was decreased in non-Hodgkin lymphoma and B-chronic lymphocytic leukemia (0.5 and 0.4, respectively). CONCLUSIONS: In 100 consecutive adults with malignancy evaluated in a community medical oncology practice, frequencies of HFE C282Y or H63D were similar to those in the general population. This suggests that C282Y or H63D is not associated with an overall increase in cancer risk. However, odds ratios computed in the present study suggest that increased (or decreased) risk for developing specific types of malignancy may be associated with the inheritance of HFE C282Y or H63D. Study of more patients with these specific types of malignancies is needed to determine if trends described herein would remain and yield significant differences

    Maternal Condition Does Not Influence Birth Sex Ratios in Anubis Baboons (Papio anubis)

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    Trivers and Willard predicted that when parental condition has differential effects on the fitness of male and female offspring, parents who are in good condition will bias investment toward the sex that benefits most from additional investment. Efforts to test predictions derived from Trivers and Willard's model have had mixed results, perhaps because most studies have relied on proxy measures of parental condition, such as dominance rank. Here, we examine the effects of female baboons condition on birth sex ratios and post-natal investment, based on visual assessments of maternal body condition. We find that local environmental conditions have significant effects on female condition, but maternal condition at conception has no consistent relationship with birth sex ratios. Mothers who are in poorer condition at the time of conception resume cycling significantly later than females who are in better condition, but the sex of their infants has no effect on the time to resumption of cycling. Thus, our findings provide strong evidence that maternal condition influences females' ability to reproduce, but females do not facultatively adjust the sex ratio of their offspring in relation to their dominance rank or current condition

    Teaching Robust Argumentation Informed by the Nature of Science to Support Social Justice. Experiences from Two Projects in Lower Secondary Schools in Norway

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    Under embargo until: 2022-09-09This chapter suggests a set of design principles for science curricula that will enable students to produce evidence-based arguments expressing views related to their own interests. It is based on the assumption that the ability to construct evidence-based arguments strengthens students’ ability to promote their own views in the interest of social justice. This is of special importance for students not enculturated into such argumentation through their upbringing. To promote one’s own views in a debate means to critique others’ arguments, and especially to ensure one’s own arguments are resistent to criticism. Insight into the nature of science includes insights in how to construct sound arguments based on facts and research results. The discussion of design principles is based on an analysis of two science projects in two lower secondary schools in Norway (Grade 8). In the first project, students produced scientific claims based on evidence from their own practical experiments. In the second project, the students developed and applied a method for estimating energy use and carbon dioxide (CO2) emissions. The students used their findings to construct arguments related to local transport plans. The analysis focuses on challenges and successes in scaffolding students at different competence levels to successfully produce evidence-based arguments.acceptedVersio

    LEAN MASS, MUSCLE STRENGTH AND GENE EXPRESSION IN COMMUNITY DWELLING OLDER MEN

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    Sarcopenia is associated with morbidity and mortality. Cellular pathways involved in the regulation of growth and atrophy affect myofibre size and subsequently, muscle strength. The objective of this study was to investigate whether skeletal muscle gene expression was associated with altered lean mass and grip strength in community-dwelling older men
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