826 research outputs found

    Luminescence investigations at Quendale (Broo Peninsula, Shetland)

    Get PDF
    This report is concerned with optically stimulated luminescence (OSL) investigations of sediment samples collected from ongoing University of Southern Maine archaeological excavations at the Links of Quendale, southern Shetland, investigating the early-modern township of Broo. 11 sediment samples were submitted to the luminescence laboratory at SUERC for OSL dating by Ian Simpson. This report summaries the protocols, and laboratory analysis, employed in quartz single aliquot regenerative (SAR) OSL dating, as used to construct an OSL chronology for wind-blown sands in proximity to the Broo excavations, in association with archaeological structures (5 samples), and for sands in the coastal and inland dune systems (6 samples). The chronology established for the inland sands, in contexts associated with the Broo 2 building and enclosure, spans from AD1540 ± 40 (SUTL2441) through to AD1810 ± 25 (SUTL2519), encompassing the archaeological period of interest. The dates obtained for sands within the enclosed and unenclosed areas to the immediate east and southwest of the excavated Broo site, are AD1760 ± 30 - AD1760 ± 25, and AD1810 ± 25 (SUTL2517-2518 and 2519, respectively), are consistent with the expectation that the clean sands which infill these structures, post-date the period in which the Broo township was abandoned. The coastal sand accumulations, as so far dated, yielded luminescence ages of 2380 ± 230 BC (SUTL2526), 1510 ± 270 BC (SUTL2527), AD 1030 ± 80 (SUTL2528), AD 1690 ± 50 (SUTL2529), AD 1720 ± 20 (SUTL2530) and a mixed-age sample with youngest component at AD 1955 ± 15 (SUTL2531), implying periods of sand mobilisation, synchronous with sand deposition in Orkney and northern Scotland, in the late Neolithic, the Early Bronze Age, the Norse period, the early-modern, and modern periods. This work suggests that the present-day physio-geographical setting of the Quendale Links, comprised of the coastal sand barrier, and the inland dune fields, is a product of a prolonged history of sand mobilisation, erosion and deposition from the Neolithic to the present day. Furthermore, the emerging temporal framework, coupled with the spatial distribution of dune forms across the Links, raises questions as to whether Little Ice Age storms were responsible for deposition, or erosive destruction of older dune-forms, and the re-mobilisation of this sediment. To test these ideas, profiling methods, both field- and laboratory- based, could be employed to obtain a more complete temporal and spatial characterisation of the dune systems and excavated sequences. Further OSL sampling and dating would be needed to define the vertical and lateral chronostratigraphies of the environmental features in the landscape and their relationships to archaeological structures

    Attitudes about collective bargaining in a non-bargaining state

    Get PDF
    Arkansas law requires that teachers be involved in the development of personnel policies and some districts utilize negotiations as a mechanism to satisfy this requirement

    Geochronologies from the Kathmandu Valley UNESCO World Heritage Site: Optically Stimulated Luminescence measurement of monument foundation sediments and radiocarbon measurement of timbers

    Get PDF
    Nepal was struck by two major earthquakes on the 25th April and the 12th May 2015, which devastated large areas of the county, with substantial loss of life and livelihoods, and destroying both rural and urban infrastructure and property. The earthquakes and associated aftershocks damaged and destroyed much of Nepal’s unique cultural heritage, including monuments within the Kathmandu Valley’s UNESCO World Heritage Site of Universal Outstanding Value. These damaged monuments are currently subject to a major program of consultation, reconstruction and conservation. As part of this, geoarchaeological investigations are underway on the foundation sediments of the collapsed monuments within the damaged Durbar Squares of Hanuman Dhoka and Bhaktapur and the temple complex of Pashupati. This report summaries: a) the OSL investigations on foundation sediments to the Changu Narayan and Vatsala Temples (Bhaktapur) and Jaisideval, Kathamandap, Pashupati and Trailokya Mohan Temples (Kathmandu; Table 1).; b) the radiocarbon measurements from timbers salvanged from the Kasthsmandap monument

    Neurospora crassa suppressors act on amber

    Get PDF
    Neurospora crassa suppressors act on ambe

    Access and non–access site bleeding after percutaneous coronary intervention and risk of subsequent mortality and major adverse cardiovascular events:Systematic review and meta-analysis

    Get PDF
    Background: The prognostic impact of site-specific major bleeding complications after percutaneous coronary intervention (PCI) has yielded conflicting data. The aim of this study is to provide an overview of site-specific major bleeding events in contemporary PCI and study their impact on mortality and major adverse cardiovascular event outcomes. Methods and Results: We conducted a meta-analysis of PCI studies that evaluated site-specific periprocedural bleeding complications and their impact on major adverse cardiovascular events and mortality outcomes. A systematic search of MEDLINE and Embase was conducted to identify relevant studies and random effects meta-analysis was used to estimate the risk of adverse outcomes with site-specific bleeding complications. Twenty-five relevant studies including 2 400 645 patients that underwent PCI were identified. Both non–access site (risk ratio [RR], 4.06; 95% confidence interval [CI], 3.21–5.14) and access site (RR, 1.71; 95% CI, 1.37–2.13) related bleeding complications were independently associated with an increased risk of periprocedural mortality. The prognostic impact of non–access site–related bleeding events on mortality related to the source of anatomic bleeding, for example, gastrointestinal RR, 2.78; 95% CI, 1.25 to 6.18; retroperitoneal RR, 5.87; 95% CI, 1.63 to 21.12; and intracranial RR, 22.71; 95% CI, 12.53 to 41.15. Conclusions: The prognostic impact of bleeding complications after PCI varies according to anatomic source and severity. Non–access site-related bleeding complications have a similar prevalence to those from the access site but are associated with a significantly worse prognosis partly related to the severity of the bleed. Clinicians should minimize the risk of major bleeding complications during PCI through judicious use of bleeding avoidance strategies irrespective of the access site used

    Dating agricultural terraces in the Mediterranean using luminescence : recent progress and challenges

    Get PDF
    Funding: This paper derives from the TerraSAgE project (Terraces as Sustainable Agricultural Environments) which is funded by the UK Arts and Humanities Research Council [grant number: AH/T000104/1].Agricultural terraces provide farmers in hilly landscapes with effective ways to increase the area available for crops. They mitigate the risks of soil erosion and promote crop productivity by slowing surface water runoff and retaining moisture. As in other parts of the world, terraces have been constructed and used in the Mediterranean for millennia. The availability of terraced agriculture had important socio-economic, ecological, and environmental implications for past societies. However, the chronology of construction, use, and abandonment of terraces in different regions remains uncertain. A more robust set of chronological data will allow better assessment of whether terrace agriculture was a resilient strategy in the face of past economic or ecological instability and, in turn, inform how terraces could be used to address future agricultural and environmental challenges. In this paper, we review the application of luminescence dating to terrace sediments, the key challenges involved, and the currently published data which include over 250 luminescence ages. We also discuss the use of a multidisciplinary approach involving other geoarchaeological tools (e.g., use of GIS analyses, field-based luminescence readers, and micromorphology) to enhance the ways that past terrace systems can be understood. Terrace systems are inextricably linked to sustainable land use across the Mediterranean. Luminescence dating methods, therefore, have a crucial role to play in understanding the complexities of past and future landscape change.Publisher PDFPeer reviewe

    Cancer event rate and mortality with thienopyridines: a systematic review and meta-analysis

    Get PDF
    Introduction Thienopyridines are a class of antiplatelet drugs widely used in cardiovascular disease prevention and treatment. A recent concern has come to light regarding the safety of thienopyridines because of the possible risk of malignancy. We therefore performed a systematic review and meta-analysis to evaluate the association between thienopyridine exposure and malignancy. Methods We searched the MEDLINE and EMBASE databases in March 2016 for studies that evaluated incident cancer and cancer mortality with and without exposure to thienopyridines. Relevant studies were identified, and data were extracted and analysed using random-effects meta-analysis. Results A total of nine studies (six randomised controlled trials and three cohort studies) that included 282,084 participants were included. The cancer event rate with clopidogrel and prasugrel was 3.25% and 1.58% respectively. When compared with standard aspirin or placebo, thienopyridines are not significantly associated with cancer mortality and event rate (odds ratio [OR] 1.12, 95% confidence interval [CI] 0.80–1.56, n = 3; and OR 0.92, 95% CI 0.52–1.64, n = 2, respectively. Further analyses examining clopidogrel showed no significant association with cancer event rate or malignancy-related death. When comparing prasugrel with clopidogrel, no significant association was noted for cancer event rate (OR 1.10, 95% CI 0.89–1.37, n = 2]. Subanalyses according to cancer location showed that thienopyridines are not significantly associated with malignancy mortality and/or incidence. Conclusions Our results suggest that there is currently insufficient evidence to suggest that thienopyridine exposure is associated with an increased risk of cancer event rate or mortality

    Developments in MRI-targeted prostate biopsy

    Get PDF
    PURPOSE OF REVIEW: MRI-targeted prostate biopsy may be an attractive alternative to systematic biopsy for diagnosing clinically significant prostate cancer. In this narrative review, we discuss the new developments that have occurred in the advancement of MRI-targeted prostate biopsy, over the past 24 months. RECENT FINDINGS: MRI-targeted biopsy offers enhanced diagnostic accuracy, when compared with the current standard of care of systematic transrectal ultrasound-guided (TRUS) biopsy, by decreasing the overall number of biopsies needed, maintaining or improving significant prostate cancer detection, and reducing the detection of clinically insignificant prostate cancer. The necessity of combining systematic prostate biopsy with MRI-targeted biopsy is still debated. The use of MRI--ultrasound fusion systems for lesion-targeting is promising for optimizing significant cancer detection, but recent evidence suggests that additional cognitive biopsy cores are still useful in detecting additional cancers. SUMMARY: MRI-targeted biopsy in selected men with positive MRI offers a number of benefits over systematic biopsy in all men, and as such, may emerge as the new standard of care for the diagnosis of clinically significant prostate cancer
    • …
    corecore