28,937 research outputs found

    A Holocene paleoenvironmental record based on ungulate stable isotopes from Lukenya Hill, Kenya

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    Investigating the development of Holocene behavioral adaptations requires knowing how and why different human groups are distributed on the landscape. An expanded dataset of site-specific environmental and habitat reconstructions from eastern Africa are crucial contextual components necessary for pushing this line of inquiry forward. This paper provides localized paleoenvironmental data from Holocene deposits at the multi-site Lukenya Hill archaeological complex on the Athi-Kapiti Plains of Kenya. Lukenya Hill preserves two temporal units, an early-mid Holocene (~9.0–4.6 ka) and a late Holocene (~2.3–1.2 ka), which span the end of the African Humid Period and the onset of late Holocene aridification. Carbon isotope analysis of herbivore tooth enamel (n = 22) indicates an increase in open grasslands over time with the early-mid Holocene having a woodier signal than the late Holocene and Recent populations in the Athi ecosystem. This pattern deviates from local environmental sequences in the Lake Victoria and Lake Turkana basins, providing additional evidence of heterogeneous habitat conditions during the Holocene of eastern Africa. The expansion of locally specific paleoecological datasets in eastern Africa allows for an examination of the role climate and ecology played in human economic and behavioral development during the Holocene.Accepted manuscrip

    Hex

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    The game hex has simple rules but complex game play. A computer program was used to analyze different boards. This yielded an interesting insight in making the optimal Hex program

    A Painful Yet to Be

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    Design Your Career - Design Your Life

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    This research investigates the current plague of unemployment and underemployment that nearly half of qualified individuals in the field of Visual Communications are met with after graduation. Students who major in this field dedicate a tremendous amount of time, money, and energy toward developing a broad skillset that resolves critical matters of communication through visual solutions. Research has demonstrated that despite conditions that are subject to ongoing change of economy, industry, and marketplace there are contributing factors that must be addressed to overcome un/underemployment regardless of circumstances. These include an underdeveloped network of professional contacts, deficiency in recognizing or responding to changing conditions, and a limited ability to customize one’s career around their unique specialization. The purpose of this study is to provide students who major in Visual Communications the information and tools needed to incorporate their ability to adapt and problem solve from their skillset into their search for work. To explore this issue, information was gathered through secondary research that involved data from federal databases, case studies, literature review, and secondary research in general. Return on investment for one’s education is measured in consideration of three primary themes: job satisfaction, income, and quality of life, which may provide hopeful opportunity for professionals in Visual Communications to overcome un/underemployment through career customization

    How Late Can First Births Be Postponed? Some Illustrative Population-level Calculations

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    I shift, stretch, and transform the observed cohort age-schedule of first birth for Danish women born in 1963 to see how late the mean age at first birth could plausibly shift. Constraints of two kinds are placed on the ultimate distribution of first births. First, no more than one-third of first births can occur after age 35. This constraint allows postponement without radical changes in childlessness or parity distribution. Second, I preserve some variability in the age at first birth by keeping the standard deviation of first birth above 4 years, the minimum value observed for Denmark during the baby boom years. Under these constraints, I find that mean ages at first birth of at least 33 years are plausible. This would represent a further increase of about 4 years in the mean age at first birth seen in recent periods. I conclude that the depressed levels of fertility seen due to postponement could continue for decades before limits are reached.

    Solar Neutrino Results from the Sudbury Neutrino Observatory

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    We describe here the measurement of the flux of neutrinos created by the decay of solar ^8B by the Sudbury Neutrino Observatory (SNO). The neutrinos were detected via the charged current (CC) reaction on deuterium and by the elastic scattering (ES) of electrons. The CC reaction is sensitive exclusively to νe\nu_e's, while the ES reaction also has a small sensitivity to νμ\nu_{\mu}'s and ντ\nu_{\tau}'s. The flux of νe\nu_e's from ^8B decay measured by the CC reaction rate is ϕCC(νe)=1.75±0.07(stat.)0.11+0.12(sys.)±0.05(theor.)×106cm2s1\phi^CC (\nu_e) = 1.75 \pm 0.07 (stat.)^{+0.1 2}_{-0.11} (sys.) \pm 0.05 (theor.) \times 10^6 cm^-2 s^-1. Assuming no flavor transformation, the flux inferred from the ES reaction rate is ϕES(νx)=2.39±0.34(stat.)0.14+0.16(sys.)×106cm2s1\phi^ES (\nu_x)=2.39\pm 0.34 (stat.) ^{+0.16}_{-0.14} (sys.) \times 10^6 cm^-2 s^-1. Comparison of ϕCC(νe)\phi^CC (\nu_e) to the Super-Kamiokande Collaboration's precision value of ϕES(νx)\phi^ES (\nu_x) yields a 3.3σ3.3\sigma difference, assuming the systematic uncertainties are normally distributed, providing evidence that there is a non-electron flavor active neutrino component in the solar flux. The total flux of active ^8B neutrinos is thus determined to be 5.44±0.99×106cm2s15.44\pm 0.99 \times 10^6 cm^-2 s^-1, in close agreement with the predictions of solar models.Comment: Talk given at the XX International Symposium on Lepton and Photon Interactions at High Energie
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