92 research outputs found

    A preliminary assessment of age at death determination using the nuclear weapons testing 14C activity of dentine and enamel

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    Calibration (using CALIBomb) of radiocarbon measurements made on the enamel of human teeth from people born during the nuclear era typically produce 2 possible age ranges that potentially reflect the period of tooth formation. These ranges correspond to periods before and after the 1963 atmospheric 14C maximum. Further measurements made on the collagen component of the combined dentine and cementum from the roots of the same teeth enable the appropriate age range to be selected. Using this range and the formation times for individual teeth, we estimated the year of birth of the individuals and compared these to the known dates of birth. The results were relatively accurate and confirmed those of a previous study by another research group. The present study demonstrates that it is possible to produce a good estimate of the year of birth from a single tooth

    Humics - their history in the radiocarbon inter-comparisons studies

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    Over the past 30 years, the format of the radiocarbon (14C) intercomparison studies has changed, however, the selection of sample types used in these studies has remained constant—namely, natural and routinely dated materials that could subsequently be used as in-house reference materials. One such material is peat which has been used 12 times, starting with the ICS in 1988. Peat from Iceland (TIRI), Ellanmore (TIRI), Letham Moss (ICS, VIRI, and SIRI), and St Bees, UK (FIRI and VIRI) have been used, as well as a near-background peat from Siberia. In the main, these peat samples have been provided as the humic acid fraction, with the main advantage being that the humic acid is extracted in solution and then precipitated (the solution phase providing the homogenisation) which is a key requirement for a reference material. In this paper, we will revisit the peat results and explore their findings. In addition, for the last 8 years, the Letham Moss sample has been used in the SUERC 14C laboratory as an in-house standard or reference material. This has resulted in several thousand measurements. Such a rich data set is explored to illustrate the benefits arising from the intercomparison program

    Race, Class, and Whiteness in Gifted and Talented Identification: A Case Study

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    What began fifteen years ago as a volunteer effort to promote desegregation via a gifted and talented magnet school has become a case study analyzing inequalities in the identification of young children for gifted and talented services. We use Cheryl Harris’ (1993) argument that “whiteness” is a form of property that creates and maintains inequalities through the conjoining of race and class. We show how gifted and talented status meets the criteria of white property interests and is defended by recourse to law and policy. Efforts to improve identification of students for gifted services reveal that the implicit operation of these Interests is an important reason why identification practices favoring white and middle-class children have been resistant to change. Dismantling underlying white property interests in gifted and talented identification is a necessary, though not sufficient step, toward a more just educational system

    Combined aerobic and resistance exercise program improves task performance in patients with heart failure

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    OBJECTIVES: To assess the effects of a home-based aerobic and resistance training program on the physical function of adults with New York Heart Association (NYHA) class II and III patients and systolic heart failure (HF). DESIGN: Randomized controlled trial. SETTING: Home based. PARTICIPANTS: Stable patients (N=24; mean age, 60±10y; left ventricular ejection fraction, 25%±9%; 50% white; 50% women) with New York Heart Association (NYHA) classes II and III (NYHA class III, 58%) systolic heart failure (HF). INTERVENTION: A 12-week progressive home-based program of moderate-intensity aerobic and resistance exercise. Attention control wait list participants performed light stretching and flexibility exercises. MAIN OUTCOME MEASURES: A 10-item performance-based physical function measure, the Continuous Scale Physical Functional Performance test (CS-PFP10), was the major outcome variable and included specific physical activities measured in time to complete a task, weight carried during a task, and distance walked. Other measures included muscle strength, HRQOL (Minnesota Living With Heart Failure Questionnaire, Epworth Sleepiness Scale), functional capacity (Duke Activity Status Index), and disease severity (brain natriuretic peptide) levels. RESULTS: After the exercise intervention, 9 of 10 specific task activities were performed more rapidly, with increased weight carried by exercise participants compared with the attention control wait list group. Exercise participants also showed significant improvements in CS-PFP10 total score (P<.025), upper and lower muscle strength, and HRQOL (P<.001) compared with the attention control wait list group. Adherence rates were 83% and 99% for the aerobic and resistance training, respectively. CONCLUSIONS: Patients with stable HF who participate in a moderate-intensity combined aerobic and resistance exercise program may improve performance of routine physical activities of daily living by using a home-based exercise approach. Performance-based measures such as the CS-PFP10 may provide additional insights into physical function in patients with HF that more commonly used exercise tests may not identify. Early detection of subtle changes that may signal declining physical function that are amenable to intervention potentially may slow further loss of function in this patient population

    Landscapes for Neolithic People in Mainland, Orkney

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    Neolithic occupation of the Orkney Islands, in the north of Scotland, probably began in the mid fourth millennium cal BC, culminating in a range of settlements, including stone-built houses, varied stone-built tombs and two noteworthy stone circles. The environmental and landscape context of the spectacular archaeology, however, remains poorly understood. We applied the Multiple Scenario Approach (MSA) to Neolithic pollen records from Mainland, Orkney, in order to understand land cover and landscape openness across the timespan 4200–2200cal BC. Interpreted within a framework provided by Bayesian chronological modelling, 406 radiocarbon dates from archaeological contexts and a further 103 from palaeoenvironmental samples provide the basis for the first detailed reconstruction of the spatio-temporal patterns of Neolithic people and their environment. Major alterations to the land cover of Mainland took place from 3400cal BC (reduction in woodland from 20% to 10%) and from 3200cal BC (increase in disturbed land from 3% to 30%). The dramatic increase in disturbed land coincided with the Grooved Ware phenomenon and the establishment of settlements at Skara Brae and Ness of Brodgar. The upturn in the signal for disturbance communities in the pollen record may indicate an increase in the amount of land used as pasture. This accords with the archaeological record, since the Neolithic Orcadian economy probably relied heavily on cattle for subsistence. By 2800cal BC in the core of the Orkney Mainland, most settlements appear to have been ending, with people dispersing into the wider landscape, as the MSA modelling indicates a maintenance of disturbed land, and indeed a subsequent slight increase, implying persistence of human activity elsewhere in Mainland. People exhausted themselves rather than their land; that and its varied resources endured, while the intensive social relationships and practices of the peak of late Neolithic Orkney could not be maintained

    House time: Neolithic settlement development at Racot during the 5th millennium cal b.c. in the Polish lowlands

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    The settlement of Racot 18 in the western Polish lowlands is used as a case study in the investigation of continued development and expansion following initial Neolithic beginnings, and in the formal chronological modelling, in a Bayesian framework, of settlement development. The site belongs to the Late Lengyel culture of the later fifth millennium cal BC, and represents the intake of new land following earlier initial colonisation. The formally estimated chronology for the settlement suggests spans for individual house biographies from as little as a generation to over a century; distinctive substantial buildings, from late in the sequence, may have lasted longest. Racot 18 is compared to its formally modelled context of the later fifth millennium cal BC

    Rows with the neighbours: the short lives of longhouses at the Neolithic site of Versend-Gilencsa

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    Longhouses are a key feature of Neolithic Linearbandkeramik (LBK) settlements in Central Europe, but debate persists concerning their usage, longevity and social significance. Excavations at Versend-Gilencsa in south-west Hungary (c. 5200 cal BC) revealed clear rows of longhouses. New radiocarbon dates suggest that these houses experienced short lifespans. This paper produces a model for the chronology of Versend, and it considers the implications of the new date estimates for a fuller understanding of the layout and duration of LBK longhouse settlements

    Interwoven strands for refining the chronology of the Neolithic tell of VinÄŤa-Belo Brdo, Serbia

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    A formally modeled radiocarbon chronology for a new profile through the great Neolithic tell of Vinča-Belo Brdo, Serbia, is the third interwoven strand in refining the chronology of the tell. This now joins models for the whole sequence based on the archive of early excavations, and for the last two known horizons at the top of the settlement mound, investigated in recent decades. In the new deep sounding, Vinča culture occupation from the 52nd century cal BC is slightly later than in the main sequence, probably reflecting the horizontal extension of the tell as it began to grow. The last dated occupation falls in the late 47th–early 46th century cal BC, slightly earlier than in the main sequence, but the top of the profile is affected by the slippage that caused the new excavations. Formal estimates are given for the succession and varying durations of burnt and unburnt houses, and indicate a period in the first part of the 5th millennium without house burning. Overall, the combined results from the three interwoven strands serve to produce a radically enhanced understanding of the temporality of the tell, which builds on, rather than supplants, previous research. We knew previously that Vinča-Belo Brdo was very long-lived, but now we can time that history with much greater precision. We can assert with much greater confidence that its vertical buildup was steady and largely uninterrupted. We have begun, from the work on the top of the tell and in the new deep sounding, to grasp better the fluctuations in house durations from generation to generation, and can now contrast the relative fortunes of unburnt and burnt houses. We can say much more about the timing and tempo of the ending of the tell, and about the possible circumstances in which that took place

    The chronology of Glastonbury Lake Village

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    The Glastonbury Lake Village in Somerset, UK, is made up of 90 mounds comprising 40 roundhouses. Excavations between 1892 and 1907 revealed Iron Age structural and material remains unparalleled in Western Europe. The settlement's exact chronology, however, has remained uncertain. Here, the authors present a programme of radiocarbon and dendrochronological dating and chronological modelling on samples from recent excavations. The results indicate that the site was founded in the early second century cal BC, with the last structures being built just over a century later. This new, robust chronology can be used to date a wide range of associated material culture, and complements chronologies established for other Iron Age sites

    The end of the world, or just 'goodbye to all that'? Contextualising the red deer heap from Links of Noltland, Westray, within late 3rd-millennium cal BC Orkney

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    As part of a major international research project, The Times of Their Lives, a programme of radiocarbon dating and Bayesian modelling was undertaken to refine the chronology of activities in one small but important part of the extensive Late Neolithic and Bronze Age settlement on Links of Noltland on the island of Westray, Orkney. The selected area (Trench D) is well known for having produced, next to a wall, the remains of a heap of at least 15 red deer carcasses, on top of which had been placed a large cod, a gannet’s wing along with part of a greater black-backed gull, and a pair of large antlers. This remarkable deposit had been preceded by, and was followed by, periods of cultivation and the deposition of domestic refuse. Refined date estimates have been produced, based on 18 radiocarbon determinations obtained from 16 samples from Trench D (including nine newly obtained dates, three from individual deer in the heap). These clarify when, during this long sequence of activities, the deer were heaped up: probably in the 22nd century cal bc, around the same time as Beaker pottery was deposited elsewhere on the Links. This allows comparison between the dated activities in this part of the site with activity elsewhere on the Links and also with other episodes of deer deposition in 3rd-millennium cal bc Orkney. It encourages exploration of the possible reasons for what appears to be a remarkable act of structured deposition. The significance of an earlier, much larger scale deposit featuring cattle remains at Ness of Brodgar is discussed in exploring the nature of Orcadian society and practices during the second half of the 3rd millennium cal bc
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