236 research outputs found

    The Middle to Later Stone Age transition at Panga ya Saidi, in the tropical coastal forest of eastern Africa

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    The Middle to Later Stone Age transition is a critical period of human behavioral change that has been variously argued to pertain to the emergence of modern cognition, substantial population growth, and major dispersals of Homo sapiens within and beyond Africa. However, there is little consensus about when the transition occurred, the geographic patterning of its emergence, or even how it is manifested in the stone tool technology that is used to define it. Here, we examine a long sequence of lithic technological change at the cave site of Panga ya Saidi, Kenya, that spans the Middle and Later Stone Age and includes human occupations in each of the last five Marine Isotope Stages. In addition to the stone artifact technology, Panga ya Saidi preserves osseous and shell artifacts, enabling broader considerations of the covariation between different spheres of material culture. Several environmental proxies contextualize the artifactual record of human behavior at Panga ya Saidi. We compare technological change between the Middle and Later Stone Age with on-site paleoenvironmental manifestations of wider climatic fluctuations in the Late Pleistocene. The principal distinguishing feature of Middle from Later Stone Age technology at Panga ya Saidi is the preference for fine-grained stone, coupled with the creation of small flakes (miniaturization). Our review of the Middle to Later Stone Age transition elsewhere in eastern Africa and across the continent suggests that this broader distinction between the two periods is in fact widespread. We suggest that the Later Stone Age represents new short use-life and multicomponent ways of using stone tools, in which edge sharpness was prioritized over durability

    Year-round shellfish exploitation in the Levant and implications for Upper Palaeolithic hunter-gatherer subsistence

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    Recent studies have shown that the use of aquatic resources has greater antiquity in hominin diets than pre- viously thought. At present, it is unclear when hominins started to habitually consume marine resources. This study examines shellfish exploitation from a behavioural ecology perspective, addressing how and when past hunter-gatherers from the Levant used coastal resources for subsistence purposes. We investigate the seasonality of shellfish exploitation in the Levantine Upper Palaeolithic through oxygen isotope analysis on shells of the intertidal rocky shore mollusc Phorcus (Osilinus) turbinatus from the key site Ksñr ‘Akil (Lebanon). At this rockshelter, multi-layered archaeological deposits contained remains of both marine and terrestrial molluscs in relatively large quantities, which were consumed and used as tools and ornaments by the occupants of the site. Our results indicate that at the start of the Initial Upper Palaeolithic (IUP), there is no evidence for shellfish consumption. Humans started to take fresh shellfish to the rockshelter from the second half of the IUP onward, albeit in low quantities. During the Early Upper Palaeolithic (EUP) shellfish exploitation became increasingly frequent. Oxygen isotope data show that shellfish exploitation was practised in every season throughout most of the Upper Palaeolithic (UP), with an emphasis on the colder months. This suggests that coastal resources had a central role in early UP foraging strategies, rather than a seasonally restricted supplementary one. Year-round shellfish gathering, in turn, suggests that humans occupied the rockshelter at different times of the year, al- though not necessarily continuously. Our oxygen isotope data is complemented with broader-scale exploitation patterns of faunal resources, both vertebrate and invertebrate, at the site. The inclusion of coastal marine re- sources signifies a diversification of the human diet from the EUP onward, which is also observed in foraging practices linked to the exploitation of terrestrial fauna.H2020 Marie SkƂodowska-Curie fellowship “EU-BEADS”, project number: 656325 and the Max Planck Society

    Alternatively Activated Mononuclear Phagocytes from the Skin Site of Infection and the Impact of IL-4Rα Signalling on CD4+T Cell Survival in Draining Lymph Nodes after Repeated Exposure to Schistosoma mansoni Cercariae

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    In a murine model of repeated exposure of the skin to infective Schistosoma mansoni cercariae, events leading to the priming of CD4 cells in the skin draining lymph nodes were examined. The dermal exudate cell (DEC) population recovered from repeatedly (4x) exposed skin contained an influx of mononuclear phagocytes comprising three distinct populations according to their differential expression of F4/80 and MHC-II. As determined by gene expression analysis, all three DEC populations (F4/80-MHC-IIhigh, F4/80+MHC-IIhigh, F4/80+MHC-IIint) exhibited major up-regulation of genes associated with alternative activation. The gene encoding RELMα (hallmark of alternatively activated cells) was highly up-regulated in all three DEC populations. However, in 4x infected mice deficient in RELMα, there was no change in the extent of inflammation at the skin infection site compared to 4x infected wild-type cohorts, nor was there a difference in the abundance of different mononuclear phagocyte DEC populations. The absence of RELMα resulted in greater numbers of CD4+ cells in the skin draining lymph nodes (sdLN) of 4x infected mice, although they remained hypo-responsive. Using mice deficient for IL-4Rα, in which alternative activation is compromised, we show that after repeated schistosome infection, levels of regulatory IL-10 in the skin were reduced, accompanied by increased numbers of MHC-IIhigh cells and CD4+ T cells in the skin. There were also increased numbers of CD4+ T cells in the sdLN in the absence of IL-4Rα compared to cells from singly infected mice. Although their ability to proliferate was still compromised, increased cellularity of sdLN from 4x IL-4RαKO mice correlated with reduced expression of Fas/FasL, resulting in decreased apoptosis and cell death but increased numbers of viable CD4+ T cells. This study highlights a mechanism through which IL-4Rα may regulate the immune system through the induction of IL-10 and regulation of Fas/FasL mediated cell death

    Assessing the diagnostic accuracy of the identification of hyperkinetic disorders following the introduction of government guidelines in England

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    <p>Abstract</p> <p>Background</p> <p>Previous studies have suggested that both underdiagnosis and overdiagnosis routinely occur in ADHD and hyperkinesis (hyperkinetic disorders). England has introduced governmental guidelines for these disorders' detection and treatment, but there has been no study on clinical diagnostic accuracy under such a regime.</p> <p>Methods</p> <p>All open cases in three Child and Adolescent Mental Health Services (CAMHS) in the South East of England were assessed for accuracy in the detection of hyperkinetic disorders, using a two-stage process employing the Strengths and Difficulties Questionnaire (SDQ) for screening, with the cut-off between "unlikely" and "possible" as the threshold for identification, and the Development And Well-Being Assessment (DAWBA) as a valid and reliable standard.</p> <p>Results</p> <p>502 cases were collected. Their mean age 11 years (std dev 3 y); 59% were clinically diagnosed as having a hyperkinetic disorder including ADHD. Clinicians had missed two diagnoses of hyperkinesis and six of ADHD. The only 'false positive' case was one that had become asymptomatic on appropriate treatment.</p> <p>Conclusion</p> <p>The identification of children with hyperkinetic disorders by three ordinary English CAMHS teams appears now to be generally consistent with that of a validated, standardised assessment. It seems likely that this reflects the impact of Governmental guidelines, which could therefore be an appropriate tool to ensure consistent accurate diagnosis internationally.</p

    Perspectives on advance directives in Japanese society: A population-based questionnaire survey

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    BACKGROUND: In Japan, discussion concerning advance directives (ADs) has been on the rise during the past decade. ADs are one method proposed to facilitate the process of communication among patients, families and health care providers regarding the plan of care of a patient who is no longer capable of communicating. In this paper, we report the results of the first in-depth survey on the general population concerning the preferences and use of ADs in Japan. METHOD: A self-administered questionnaire was sent via mail to a stratified random sampling of 560 residents listed in the residential registry of one district of Tokyo, Japan (n = 165,567). Association between correlating factors and specific preferences toward ADs was assessed using contingency table bivariate analysis and multivariate regression model to estimate independent contribution. RESULTS: Of the 560 questionnaires sent out, a total of 425 participants took part in the survey yielding a response rate of 75.9 %. The results of the present study indicate that: 1) the most important components to be addressed are the specifics of medical treatment at the end of life stage and disclosure of diagnosis and prognosis; 2) the majority of participants found it suitable to express their directives by word to family and/or physician and not by written documentation; 3) there is no strong need for legal measures in setting up an AD; 4) it is permissible for family and physician to loosely interpret one's directives; 5) the most suitable proxy is considered to be a family member, relative, or spouse. Multivariate analysis found the following five factors as significantly associated with preferences: 1) awareness regarding living wills, 2) experience with the use of ADs, 3) preferences for end-of-life treatment, 4) preferences for information disclosure, and 5) intentions of creating a will. CONCLUSIONS: Written ADs might be useful in the Japanese setting when the individual either wishes: 1) to not provide a lot of leeway to surrogates and/or caregivers, and/or 2) to ensure his or her directives in the cases of terminal illness, brain death, and pain treatment, as well as regarding information disclosure
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