29 research outputs found

    Report on Midden Exposed by Coastal Erosion in Lapakahi State Historical Park, North Kohala District, Hawai‘i Island

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    Climate change is impacting coastal sites at an alarming rate.We report on coastal midden exposed by storm damage in the archaeological interpretive area of Lapakahi State Historical Park, North Kohala District, Hawai‘i Island, specifically, Site 50-10-02-04043, a canoe shed (halau). Site 04043 was first recorded, but not excavated, in the 1970s. Radiocarbon dating reported here suggests deposits did not begin accumulating until ca. cal AD 1700–1900, surprisingly late given its coastal location and previous dating of leeward Kohala sites. To help understand this we considered how the coastline has changed over time. We estimate, based on high-resolution airborne LiDAR bathometry, that this location was around 100m inland at the time people first arrived in the Hawaiian Islands. The subsidence of Hawai‘i Island slowly brought the coastline closer and it would have been around 10m from this location when deposits began accumulating. The contents of the midden are consistent with previous studies of subsistence in leeward Kohala.We attempted to improve on the specificity of the faunal inventory through ancient DNA but failed to recover intact DNA in fragmentary faunal bone samples. We note that reporting negative results is important for the judicious use of this technique. In sum, our results highlight the critical importance of a targeted, systematic study of early settlement—something that has never been done in the Hawaiian Islands—rather than relying on the type of salvage excavations described here

    Assessing the association between changing NRTIs when initiating second-line ART and treatment outcomes.

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    BACKGROUND After first-line antiretroviral therapy (ART) failure, the importance of change in nucleoside reverse transcriptase inhibitor (NRTI) in second-line is uncertain due to the high potency of protease inhibitors used in second-line. SETTING We used clinical data from 6,290 adult patients in South Africa and Zambia from the International Epidemiologic Databases to Evaluate AIDS-Southern Africa cohort. METHODS We included patients who initiated on standard first-line ART and had evidence of first-line failure. We used propensity score-adjusted Cox proportional hazards models to evaluate the impact of change in NRTI on second-line failure compared to remaining on the same NRTI in second-line. In South Africa, where viral load monitoring was available, treatment failure was defined as two consecutive viral loads >1,000 copies/mL. In Zambia, it was defined as two consecutive CD4 counts <100 cells/mm. RESULTS Among patients in South Africa initiated on zidovudine, the adjusted hazard ratio for second-line virologic failure was 0.25 (95% CI: 0.11, 0.57) for those switching to tenofovir vs. remaining on zidovudine. Among patients in South Africa initiated on tenofovir, switching to zidovudine in second-line was associated with reduced second-line failure (adjusted hazard ratio = 0.35 [95% CI: 0.13, 0.96]). In Zambia where viral load monitoring was not available, results were less conclusive. CONCLUSION Changing NRTI in second-line was associated with better clinical outcomes in South Africa. Additional clinical trial research regarding second-line NRTI choices for patients initiated on tenofovir or with contraindications to specific NRTIs is needed

    Sulfatide Recognition by Colonization Factor Antigen CS6 from Enterotoxigenic Escherichia coli

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    The first step in the pathogenesis of enterotoxigenic Escherichia coli (ETEC) infections is adhesion of the bacterium to the small intestinal epithelium. Adhesion of ETEC is mediated by a number of antigenically distinct colonization factors, and among these, one of the most commonly detected is the non-fimbrial adhesin coli surface antigen 6 (CS6). The potential carbohydrate recognition by CS6 was investigated by binding of recombinant CS6-expressing E. coli and purified CS6 protein to a large number of variant glycosphingolipids separated on thin-layer chromatograms. Thereby, a highly specific binding of the CS6-expressing E. coli, and the purified CS6 protein, to sulfatide (SO3-3Galβ1Cer) was obtained. The binding of the CS6 protein and CS6-expressing bacteria to sulfatide was inhibited by dextran sulfate, but not by dextran, heparin, galactose 4-sulfate or galactose 6-sulfate. When using recombinantly expressed and purified CssA and CssB subunits of the CS6 complex, sulfatide binding was obtained with the CssB subunit, demonstrating that the glycosphingolipid binding capacity of CS6 resides within this subunit. CS6-binding sulfatide was present in the small intestine of species susceptible to CS6-mediated infection, e.g. humans and rabbits, but lacking in species not affected by CS6 ETEC, e.g. mice. The ability of CS6-expressing ETEC to adhere to sulfatide in target small intestinal epithelium may thus contribute to virulence

    Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

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    Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P &lt; 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

    Systematic Ancient DNA Species Identification Fails to Find Late Holocene Domesticated Cattle in Southern Africa

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    Establishing robust temporal control of the arrival of domesticated stock and the associated husbandry skills and lifeways in Southern Africa remains frustrated by the osteological similarities between domestic stock and wild endemic fauna. We report the results of a systematic ancient DNA survey of appropriately sized bovid remains from Later Stone Age deposits in four South African archaeological sites. We show that none of the tested remains originated in domesticated cattle. The precise date of arrival of domestic cattle in the region awaits further study, although we also report new radiocarbon determinations which further refine the local chronology

    Dispersal, Isolation, and Interaction in the Islands of Polynesia: A Critical Review of Archaeological and Genetic Evidence

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    Integration of archaeology, modern genetics, and ancient DNA holds promise for the reconstruction of the human past. We examine the advances in research on the indigenous peoples of Polynesia to determine: (1) what do archaeological and genetic data (ancient and modern DNA) tell us about the origins of Polynesians; and, (2) what evidence is there for long-distance travel and contacts between Polynesians and indigenous populations of the Americas? We note that the general dispersal pattern of founding human populations in the remote islands of the Pacific and long-distance interaction spheres continue to reflect well-established models. New research suggests that the formation of an Ancestral Polynesia Culture in Western Polynesia may have involved differential patterns of dispersal followed by significant later migrations. It has also been suggested that the pause between the settlement of Western and Eastern Polynesia was centuries longer than currently thought, followed by a remarkably rapid pulse of island colonization. Long-distance travel between islands of the Pacific is currently best documented through the sourcing of artifacts, while the discovery of admixture of Native American DNA within the genome of the people from Easter Island (Rapa Nui) is strong new evidence for sustained contacts between Polynesia and the Americas

    Dispersal, Isolation, and Interaction in the Islands of Polynesia: A Critical Review of Archaeological and Genetic Evidence

    No full text
    Integration of archaeology, modern genetics, and ancient DNA holds promise for the reconstruction of the human past. We examine the advances in research on the indigenous peoples of Polynesia to determine: (1) what do archaeological and genetic data (ancient and modern DNA) tell us about the origins of Polynesians; and, (2) what evidence is there for long-distance travel and contacts between Polynesians and indigenous populations of the Americas? We note that the general dispersal pattern of founding human populations in the remote islands of the Pacific and long-distance interaction spheres continue to reflect well-established models. New research suggests that the formation of an Ancestral Polynesia Culture in Western Polynesia may have involved differential patterns of dispersal followed by significant later migrations. It has also been suggested that the pause between the settlement of Western and Eastern Polynesia was centuries longer than currently thought, followed by a remarkably rapid pulse of island colonization. Long-distance travel between islands of the Pacific is currently best documented through the sourcing of artifacts, while the discovery of admixture of Native American DNA within the genome of the people from Easter Island (Rapa Nui) is strong new evidence for sustained contacts between Polynesia and the Americas

    Maternal Relationships among Ancient and Modern Southern African Sheep: Newly Discovered Mitochondrial Haplogroups

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    We investigated the genetic diversity and historic relationships among southern African sheep as well as the relationships between them and sheep outside the continent by sourcing both archaeological and modern sheep samples. Archaeological sheep samples derived from the site Die Kelders 1, near Cape Town, date to approximately 1500 years ago. The modern samples were taken as ear snips from Damara, Namaqua Afrikaner, and Ronderib Afrikaner sheep on a farm in Prieska in the Northern Cape. Illumina sequencing libraries were constructed for both ancient and modern specimens. Ancient specimens were enriched for the mitochondrial genome using an in-solution hybridization protocol and modern specimens were subjected to shotgun sequencing. Sequences were mapped to the Ovis aries reference genome, assigned to haplogroups and subhaplogroups, and used to calculate a phylogenetic tree using previously published, geographically dispersed mitochondrial genome sheep sequences. Genetic diversity statistics show that southern African sheep have lower diversity than sheep in other regions. Phylogenetic analysis reveals that many modern southern African sheep are likely descended from prehistoric indigenous sheep populations and not from sheep imported from Europe during the historic period

    Setting the stage – Building and working in an ancient DNA laboratory

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    With the introduction of next generation high throughput sequencing in 2005 and the resulting revolution in genetics, ancient DNA research has rapidly developed from an interesting but marginal field within evolutionary biology into one that can contribute significantly to our understanding of evolution in general and the development of our own species in particular. While the amount of sequence data available from ancient human, other animal and plant remains has increased dramatically over the past five years, some key limitations of ancient DNA research remain. Most notably, reduction of contamination and the authentication of results are of utmost importance. A number of studies have addressed different aspects of sampling, DNA extraction and DNA manipulation in order to establish protocols that most efficiently generate reproducible and authentic results. As increasing numbers of researchers from different backgrounds become interested in using ancient DNA technology to address key questions, the need for practical guidelines on how to construct and use an ancient DNA facility arises. The aim of this article is therefore to provide practical tips for building a state-of-the-art ancient DNA facility. It is intended to help researchers new to the field of ancient DNA research generally, and those considering the application of next generation sequencing, in their planning process
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