84 research outputs found

    Boat and ship engravings at Al Zubarah, Qatar: the dāw exposed?

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    This is the author accepted manuscript. The final version is available from ArchaeopressOn-going excavations at the site of the 18th–19th century walled town of Al Zubarah, Qatar, have uncovered a number of engravings of seagoing craft etched into the dry plasterwork of buildings within the settlement. The engravings are essentially graffiti, carved into the interiors of rooms without aesthetic reference to the original decorative schema of their settings. The resulting images are of varying sophistication and detail — dependent, no doubt, on the skill and inclination of their executors. While the crudest images are rudimentary outlines of hulls, others show detail that demonstrates the familiarity of their creators with boat construction and type — not surprising in a settlement whose raison d’être was the livings to be made from the sea. This iconographic vestige provides an insight into the types of vessel their creators used and encountered, and allows us to venture our own identifications of them. It also prompts us to reflect on the nature of the relationship between Al Zubarah’s some-time residents and the sea: the vessels depicted are for the most part a mixture of ocean-going types built within the Gulf or western Indian Ocean region. One, however, is of a European naval vessel, perhaps suggesting the shadow of British imperial power in the Gulf. Finally, the process of identification of these watercraft inspires renewed reflection on the word ‘dhow’ and its variants, from both a typological and an etymological perspective; these new reflections are presented at the end of this paper

    Bioarchaeology-related studies in the Arabian Gulf: potentialities and shortcomings

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    Archaeological studies provide a powerful tool to understand the prehistoric societies, especially when combined to cutting-edge morphological and molecular anthropological analyses, allowing reconstructing past population dynamics, admixture events, and socio-cultural changes. Despite the advances achieved in the last decades by archaeological studies worldwide, several regions of the World have been spared from this scientific improvement due to various reasons. The Arabian Gulf represents a unique ground to investigate, being the passageway for human migrations and one of the hypothesized areas in which Neanderthal introgression occurred. A number of archaeological sites are currently present in the Arabian Gulf and have witnessed the antiquity and the intensiveness of the human settlements in the region. Nevertheless, the archaeological and anthropological investigation in the Gulf is still in its infancy. Data collected through archaeological studies in the area have the potential to help answering adamant questions of human history from the beginning of the structuring of genetic diversity in human species to the Neolithisation process. This review aims at providing an overview of the archaeological studies in the Arabian Gulf with special focus to Qatar, highlighting potentialities and shortcomings

    Accretion-powered chromospheres in classical T Tauri stars

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    (Abridged) Optical spectra of classical T Tauri stars (cTTS) are rich in emission lines of low-excitation species that are composed of narrow and broad components, related to two regions with different kinematics, densities, and temperatures. The photospheric spectrum is often veiled by an excess continuous emission. This veiling is usually attributed to radiation from a heated region beneath the accretion shock. The aim of this research is to clarify the nature of the veiling, and whether the narrow chromospheric lines of Fe I and other metals represent a standard chromosphere of a late-type star, or are induced by mass accretion. From high-resolution spectroscopy of DR Tauri we found that the amount of veiling in this star varies from practically nothing to factors more than 10 times the stellar continuum intensity, and that the veiling is caused by both a non-photospheric continuum and chromospheric line emission filling in the photospheric absorption lines. This effect can be shown to exist in several other T Tauri stars. We conclude that enhanced chromospheric emission in cTTS is linked not only to solar-like magnetic activity, but is powered to a greater extent by the accreting gas. We suggest that the area of enhanced chromospheric emission is induced by mass accretion, which modifies the local structure of stellar atmosphere in an area that is more extended than the hot accretion spot. The narrow emission lines from this extended area are responsible for the extra component in the veiling through line-filling of photospheric absorption lines.Comment: 11 pages, 13 figure

    Circadian Desynchrony Promotes Metabolic Disruption in a Mouse Model of Shiftwork

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    Shiftwork is associated with adverse metabolic pathophysiology, and the rising incidence of shiftwork in modern societies is thought to contribute to the worldwide increase in obesity and metabolic syndrome. The underlying mechanisms are largely unknown, but may involve direct physiological effects of nocturnal light exposure, or indirect consequences of perturbed endogenous circadian clocks. This study employs a two-week paradigm in mice to model the early molecular and physiological effects of shiftwork. Two weeks of timed sleep restriction has moderate effects on diurnal activity patterns, feeding behavior, and clock gene regulation in the circadian pacemaker of the suprachiasmatic nucleus. In contrast, microarray analyses reveal global disruption of diurnal liver transcriptome rhythms, enriched for pathways involved in glucose and lipid metabolism and correlating with first indications of altered metabolism. Although altered food timing itself is not sufficient to provoke these effects, stabilizing peripheral clocks by timed food access can restore molecular rhythms and metabolic function under sleep restriction conditions. This study suggests that peripheral circadian desynchrony marks an early event in the metabolic disruption associated with chronic shiftwork. Thus, strengthening the peripheral circadian system by minimizing food intake during night shifts may counteract the adverse physiological consequences frequently observed in human shift workers

    2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease

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    The recommendations listed in this document are, whenever possible, evidence based. An extensive evidence review was conducted as the document was compiled through December 2008. Repeated literature searches were performed by the guideline development staff and writing committee members as new issues were considered. New clinical trials published in peer-reviewed journals and articles through December 2011 were also reviewed and incorporated when relevant. Furthermore, because of the extended development time period for this guideline, peer review comments indicated that the sections focused on imaging technologies required additional updating, which occurred during 2011. Therefore, the evidence review for the imaging sections includes published literature through December 2011

    Found: the Palaeolithic of Qatar

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    The seeming lack of evidence for a Palaeolithic presence in Qatar has been enigmatic. This has now changed. Here we report on discoveries made by the PADMAC Unit during 2013/2014 and the far-reaching implications of these findings. Our preliminary analysis of the Qatar lithic assemblages — QSS25, QSS29 (PADMAC Unit collection) and A-group Site I and A-group Site III (Kapel collection) — revealed the presence of large chopping tools and crude ‘Abbevillian’ cores, both indicative of an early stage within the lower Palaeolithic period, while the absence of classic Acheulean hand axes might even suggest a date exceeding one million years. Furthermore, the particular suite of technological traits we identified in Umm Taqa ‘B-group’ Site XXXIV (Kapel collection) lithic assemblage, are characteristic of middle–upper Palaeolithic transitional industries found in the Levant, Nile Valley, and southern Arabia. Hence, we tentatively assign the ‘Taqan’ industry to the upper Palaeolithic. Specific lithics from the QSS32 (PADMAC Unit collection) assemblage, allude to further ‘Taqan’ sites in southern Qatar

    Found: the Palaeolithic of Qatar

    No full text
    The seeming lack of evidence for a Palaeolithic presence in Qatar has been enigmatic. This has now changed. Here we report on discoveries made by the PADMAC Unit during 2013/2014 and the far-reaching implications of these findings. Our preliminary analysis of the Qatar lithic assemblages — QSS25, QSS29 (PADMAC Unit collection) and A-group Site I and A-group Site III (Kapel collection) — revealed the presence of large chopping tools and crude ‘Abbevillian’ cores, both indicative of an early stage within the lower Palaeolithic period, while the absence of classic Acheulean hand axes might even suggest a date exceeding one million years. Furthermore, the particular suite of technological traits we identified in Umm Taqa ‘B-group’ Site XXXIV (Kapel collection) lithic assemblage, are characteristic of middle–upper Palaeolithic transitional industries found in the Levant, Nile Valley, and southern Arabia. Hence, we tentatively assign the ‘Taqan’ industry to the upper Palaeolithic. Specific lithics from the QSS32 (PADMAC Unit collection) assemblage, allude to further ‘Taqan’ sites in southern Qatar

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