165 research outputs found

    Trace Element Analysis of Human Tooth Enamel by LA-ICP-MS for Estimating Region of Origin

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    Tooth enamel is among the most durable substances in the human body and as such has high recoverability in forensic anthropology cases. Its crystalline hydroxyapatite matrix has a slightly variable chemical composition which incorporates biologically available trace elements. The trace elements are derived from an individual’s diet and the water he or she consumes during the period of enamel formation. As a result, trace element profiles of enamel can reflect the geology, pollution, and certain cultural dietary factors of the area in which they resided during this period. This research examines a sample of teeth with known demographic information from the Antioquia Modern Skeletal Reference Collection in Medellin, Colombia. A sample set of 75 teeth from 61 individuals born in areas throughout northwestern Colombia were analyzed using laser ablation-inductively coupled plasma- mass spectrometry (LA-ICP-MS), a minimally destructive, semi-quantitative technique. Analysis was performed at the Center for Archaeology, Materials, and Applied Spectroscopy (CAMAS) at Idaho State University. 33 elements were analyzed in the sample. Nonparametric methods were used to assess the relationship between elemental profiles and region of origin. Sr, Mo, Ag, Ba, Eu, and Tm concentration profiles were found to vary among regional groups. Al, Ni, Cr, Mn, Co, Sr, Cd, Sb, Sm, Eu, and U were found to predict region of origin. Differences in municipality were classified with 72% accuracy, variation across the department of Antioquia was classified with 67% accuracy, and the age of the geologic substrate was classified with 67% accuracy. The results suggest that trace element analysis of permanent tooth enamel may be of some use in estimating an individual’s region of origin in forensic anthropological contexts. Further research with both larger sample sizes and more geographic variation is necessary

    Individual Channel Analysis and Design and its Application to Helicopter Flight Control

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    The publication in 1989 of the Aeronautical Design Standard (ADS)-33C (which, in 1994, was upgraded to ADS-33D) has provided a focus for helicopter flight control research, by both industrial and academic engineers. Helicopters are highly coupled, open-loop unstable systems with complex dynamics, mainly due to the main rotor, and as a consequence available mathematical models have a high degree of uncertainty. Because of these reasons, the design of control laws to enable ADS-33 Level 1 Handling Qualities requirements to be met has been thought to preclude the use of classical one-loop-at-a-time control system design techniques (the helicopter will exhibit Level 1 Handling Qualities if minimal pilot compensation is required during a flying task). The need for control laws which are robust to model uncertainty and demonstrate good decoupling has caused recent attention to be focused on so called 'modern' techniques which synthesis controllers by closing all loops simultaneously and can cater, to some degree, for performance and robustness issues. However, it can be argued that much of the physical insight that classical techniques allow is lost when using modern techniques. A recent development in classical control theory known as Individual Channel Analysis and Design (1CAD) is unique in that it explicitly captures multivariable metrics as part of the single-input single-output (SISO) analysis and design process. These multivariable metrics are known as multivariable structure functions (MSFs) and have three important uses. First they provide a robustness diagnostic which indicates when classical SISO gain and phase margins can be reliably interpreted as robustness measures of a multivariable system. Second, they are used to establish sequential (one-loop-at-a-time) design procedures which will guarantee closed-loop stability and third, they indicate attainable performance of the control system. This thesis develops the theory of ICAD to a level where it can effectively and efficiently be applied to the design of helicopter flight control laws and which will cater for meeting the requirements of ADS-33 in the design process. The development includes the extension of ICAD to cater for non-square systems and a technique to express the MSFs in state space form, thus enabling numerically reliable state space algorithms to be used for computation. The development is generic in nature and therefore can be applied to a wide range of control problems. The analysis and design of four different helicopter flight control laws is described in detail. The control laws are of low order and after extensive linear and non-linear simulation are found to satisfy Level 1 requirements over a wide flight envelope. ICAD is found to be a highly effective technique for the analysis and design of helicopter flight control laws which will meet ADS-33 Level 1 requirements

    Victims as moral beacons of humanitarianism in post-conflict societies.

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    This paper reports on interview data amongst victims of conflict and organised violence. Despite their victimhood, they evince a level of forgivingness, civility and tolerance that constructs in the very acts of atrocity that portend its demise, a form of humanitarianism which enables victims to be moral beacons in post-conflict societies that otherwise are largely devoid of any a moral or sacred canopy. Data cover victims in Sri Lanka, South Africa and Northern Ireland. The theoretical contribution of the paper is to proffer a view that humanitarianism in societies emerging out of conflict is best understood as a social practice constituted by victims' practices for tolerance and civility. This makes humanitarianism pro-social, having the potential to affect social consciousness and social understandings in post-conflict societies and to assist in the remaking of society after conflict

    Moderate-Intensity Exercise Improves Body Composition and Improves Physiological Markers of Stress in HIV-Infected Men

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    HIV/AIDS and its treatment often alter body composition and result in poorer physical functioning. The aim of this study was to determine the effects of a moderate-intensity exercise program on body composition and the hormones and cytokines associated with adverse health outcomes. HIV-infected males (N = 111) were randomized to an exercise group (EX) who completed 6 weeks of moderate-intensity exercise training, or to a nonintervention control group (CON). In pre- and postintervention, body composition was estimated via DXA, peak strength was assessed, and resting blood samples were obtained. There was a decrease in salivary cortisol at wake (P = 0.025) in the EX and a trend (P = 0.07) for a decrease 1 hour after waking. The EX had a significant increase in lean tissue mass (LTM) (P \u3c 0.001) following the intervention. Those in the EX below median body fat (20%) increased LTM (P = 0.014) only, while those above 20% decreased fat mass (P = 0.02), total fat (N = 0.009), and trunk fat (P = 0.001), while also increasing LTM (P = 0.027). Peak strength increased between 14% and 28% on all exercises in the EX group. These data indicate that 6 weeks of moderate-intensity exercise training can decrease salivary cortisol levels, improve physical performance, and improve body composition in HIV-infected men

    A Transdisciplinary Approach to Determining the Provenience of a Distorted, Pre-Columbian Skull Recovered in Rural Idaho

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    Transdisciplinary research involves cooperation, exchange of information, sharing of resources and integration of disciplines to achieve a common scientific goal. In this study, collaborators utilized tools and knowledge of materials science, anthropology, archaeology, geosciences and biology in an attempt to determine the provenience of skeletal remains of unknown origin. The exchange of ideas and skills along with the crossing of disciplines in this study sucessfully allowed the incorporation of expertise from many team members. This transdisciplinary approach to research provided a more comprehensive and detailed analysis than any one field alone could provide. An archaeological assessment of a human skull recovered in rural Idaho recognized cranial deformation and post-mortem application of a red pigment. A combination of scanning electron microscopy (SEM), x-ray fluorescence (XRF) and energy-dispersive x-ray spectroscopy (EDS) identified the major and trace elements present in the red post-mortem pigment as cinnabar and rare earth metals. Analysis via carbon and oxygen stable isotopes from teeth and bone to provided insight into the diet and habitat for distinct segments of the individual’s life, indicating a regional separation in early life versus late adulthood. Radiocarbon dating determined the approximate age of the skull to be between 600-700 years old and a forensic mtDNA assessmentcategorized a mitochondrial haplogroup for the remains as originating from the East African or Arabian Peninsula

    Rapid identification of human muscle disease with fibre optic Raman spectroscopy

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    The diagnosis of muscle disorders (“myopathies”) can be challenging and new biomarkers of disease are required to enhance clinical practice and research. Despite advances in areas such as imaging and genomic medicine, muscle biopsy remains an important but time-consuming investigation. Raman spectroscopy is a vibrational spectroscopy application that could provide a rapid analysis of muscle tissue, as it requires no sample preparation and is simple to perform. Here, we investigated the feasibility of using a miniaturised, portable fibre optic Raman system for the rapid identification of muscle disease. Samples were assessed from 27 patients with a final clinico-pathological diagnosis of a myopathy and 17 patients in whom investigations and clinical follow-up excluded myopathy. Multivariate classification techniques achieved accuracies ranging between 71–77%. To explore the potential of Raman spectroscopy to identify different myopathies, patients were subdivided into mitochondrial and non-mitochondrial myopathy groups. Classification accuracies were between 74–89%. Observed spectral changes were related to changes in protein structure. These data indicate fibre optic Raman spectroscopy is a promising technique for the rapid identification of muscle disease that could provide real time diagnostic information. The application of fibre optic Raman technology raises the prospect of in vivo bedside testing for muscle diseases which would significantly streamline the diagnostic pathway of these disorders

    "That's the world standard": a critical ethnography of "Universal" knowledge

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    This paper analyzes how knowledge is reproduced as "universal" in contemporary higher education and how this production of universality influences the application of knowledge. Using a case study of clinical psychology, it describes the results of over two years of ethnographic fieldwork in a university and professional settings in Singapore with short comparative field studies in Australia and the Netherlands. The results provide critical insights into the cultural effects and knowledge contestations within transnational higher education

    Impoundments facilitate a biological invasion: Dispersal and establishment of non-native armoured catfish Loricariichthys platymetopon (IsbrĂĽckler & Nijssen, 1979) in a neotropical river.

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    Where dam construction eliminates natural barriers to fish movement between previously disconnected catchments then this presents an opportunity for the movement of species between previously discrete assemblages. Here, the movement of a non-native armoured catfish, Loricariichthys platymetopon, is detailed from its natural range in the lower Paraná River basin, Brazil, into its invasive range in the upper basin following construction of the Itaipu Dam. Its upstream dispersal into a major tributary, the Paranapanema River, is outlined, with focus on its establishment within hydroelectric dams. This case study thus provides further evidence of how river regulation can increase opportunities for biological invasions

    A comparative analysis reveals weak relationships between ecological factors and beta diversity of stream insect metacommunities at two spatial levels.

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    The hypotheses that beta diversity should increase with decreasing latitude and increase with spatial extent of a region have rarely been tested based on a comparative analysis of multiple datasets, and no such study has focused on stream insects. We first assessed how well variability in beta diversity of stream insect metacommunities is predicted by insect group, latitude, spatial extent, altitudinal range, and dataset properties across multiple drainage basins throughout the world. Second, we assessed the relative roles of environmental and spatial factors in driving variation in assemblage composition within each drainage basin. Our analyses were based on a dataset of 95 stream insect metacommunities from 31 drainage basins distributed around the world. We used dissimilarity-based indices to quantify beta diversity for each metacommunity and, subsequently, regressed beta diversity on insect group, latitude, spatial extent, altitudinal range, and dataset properties (e.g., number of sites and percentage of presences). Within each metacommunity, we used a combination of spatial eigenfunction analyses and partial redundancy analysis to partition variation in assemblage structure into environmental, shared, spatial, and unexplained fractions. We found that dataset properties were more important predictors of beta diversity than ecological and geographical factors across multiple drainage basins. In the within-basin analyses, environmental and spatial variables were generally poor predictors of variation in assemblage composition. Our results revealed deviation from general biodiversity patterns because beta diversity did not show the expected decreasing trend with latitude. Our results also call for reconsideration of just how predictable stream assemblages are along ecological gradients, with implications for environmental assessment and conservation decisions. Our findings may also be applicable to other dynamic systems where predictability is low
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