3,339 research outputs found

    A Multivariate Craniometric Analysis of Secular Change and Variation Among Recent North American Populations

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    This study presents an investigation of secular trends in craniometric variation among Afro-American and Euro-American North American populations from 1750 to the present. An additional analysis of collection specific cranial variation between two prominent anatomical collections is also undertaken. Both investigations address the question of crania variation in reference to the proper application of craniometric analysis to medico-legal identiciation of racial affiliation in forensic anthropology. The craniometric data include individual historic specimens and cemetery populations from Canada, Philadelphia and New Orleans. Anatomical specimens are collected from the Hamann-Todd and R. J. Terry collections, and recent forensic cases are obtained from forensic laboratories across the nation. Predicated on the idea that secular change in cranial size and shape contribute to the differentiation between temporally different crania series, it is suggested that temporally earlier cranial series are less appropriate as calibration samples for the identification of contemporary U.S. populations. Analyses were performed on eighty crania variables to document temporal differences among racial and ethnic groups, and to explore patterns of variation related to gender within each group. Group differences were examined by multivariate analysis of variance and temporal differences were investigated using multivariate analysis of covariance and canonical correlation. Specificity of collection association was examined by canonical discriminant analysis. The multivariate analysis of cranial variation revealed similar temporal trends in size and shape between Afro-American female and male crania, while Euro-American gender differed somewhat in their direction of change. Temporal trends and collection specificity are both statistically significant. Collections are suggested to reflect ethnic differences, particularly within the Euro-American group. It is found that significant temporal changes among Afro-American and Euro-American cranial series and ethnic specificity of individual skeletal collections can render problematic the application of earlier cranial series to the identification of recent forensic cases. An alternative to present calibration standards for forensic identification of crania is offered. Two additional cranial series of Hispanic-American males and American Indian of both sexes were added to the sample to define a four group calibration sample. Calibration standards were calculated using discriminant analysis for the separation of racial or ethnic groups. Four, three and two group discriminant function were calculated for a suple of post 1900 crania to conclude the analysis

    Unsupervised Learning of Semantic Audio Representations

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    Even in the absence of any explicit semantic annotation, vast collections of audio recordings provide valuable information for learning the categorical structure of sounds. We consider several class-agnostic semantic constraints that apply to unlabeled nonspeech audio: (i) noise and translations in time do not change the underlying sound category, (ii) a mixture of two sound events inherits the categories of the constituents, and (iii) the categories of events in close temporal proximity are likely to be the same or related. Without labels to ground them, these constraints are incompatible with classification loss functions. However, they may still be leveraged to identify geometric inequalities needed for triplet loss-based training of convolutional neural networks. The result is low-dimensional embeddings of the input spectrograms that recover 41% and 84% of the performance of their fully-supervised counterparts when applied to downstream query-by-example sound retrieval and sound event classification tasks, respectively. Moreover, in limited-supervision settings, our unsupervised embeddings double the state-of-the-art classification performance.Comment: Submitted to ICASSP 201

    Numerical study of plasmon properties in the SU(2)-Higgs model

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    Using the (effective) classical approximation, we compute numerically time-dependent correlation functions in the SU(2)-Higgs model around the electroweak phase transition, for mHmWm_H \approx m_W. The parameters of the classical model have been determined previously by the dimensional reduction relations for time-independent correlators. The HH and WW correlation functions correspond to gauge invariant fields. They show damped oscillatory behavior from which we extract frequencies \om and damping rates \gm. In the Higgs phase the damping rates have roughly the values obtained in analytic calculations in the quantum theory. In the plasma phase (where analytic estimates for gauge invariant fields are not available), the damping rate associated with HH is an order of magnitude larger than in the Higgs phase, while the WW correlator appears to be overdamped, with a small rate. The frequency \om_H shows a clear dip at the transition. The results are approximately independent of the lattice spacing, but this appears to be compatible with the lattice spacing dependence expected from perturbation theory.Comment: 27 pages, latex, 13 figures. Improved presentation, data unchanged. New is the conclusion that the apparent lattice spacing independence of the `plasmon' frequency is compatible with the divergencies expected from perturbation theory. (Version resubmitted to NPB on 17 July 1997.

    CNN Architectures for Large-Scale Audio Classification

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    Convolutional Neural Networks (CNNs) have proven very effective in image classification and show promise for audio. We use various CNN architectures to classify the soundtracks of a dataset of 70M training videos (5.24 million hours) with 30,871 video-level labels. We examine fully connected Deep Neural Networks (DNNs), AlexNet [1], VGG [2], Inception [3], and ResNet [4]. We investigate varying the size of both training set and label vocabulary, finding that analogs of the CNNs used in image classification do well on our audio classification task, and larger training and label sets help up to a point. A model using embeddings from these classifiers does much better than raw features on the Audio Set [5] Acoustic Event Detection (AED) classification task.Comment: Accepted for publication at ICASSP 2017 Changes: Added definitions of mAP, AUC, and d-prime. Updated mAP/AUC/d-prime numbers for Audio Set based on changes of latest Audio Set revision. Changed wording to fit 4 page limit with new addition

    Development and assessment of postcranial sex estimation methods for a Guatemalan population

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    This study tests whether postcranial sex estimation methods generated from Hispanic, and mainly Mexican samples, can be successfully applied to other increasingly common migrant populations from Central America. We use a sample of postcranial data from a modern (1980s) Guatemalan Maya sample (n = 219). Results indicate a decrease in classification accuracies for previously established univariate methods when applied to the Guatemalan study sample, specifically for males whose accuracies ranged from 30 to 84%. This bias toward inaccuracies for Guatemalan males is associated with the smaller skeletal sizes for the Guatemalan sample as compared to the samples used in the tested sex estimation methods. In contrast, the tested multivariate discriminant function classification yielded less sex bias and improved classification accuracies ranging from 82 to 89%. Our results highlight which of the tested univariate and multivariate methods reach acceptable levels for accuracy for sex estimation of cases where the region of origin may include Guatemala

    Compartmentalisation and localisation of the translation initiation factor (eIF) 4F complex in normally growing fibroblasts

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    Previous observations of association of mRNAs and ribosomes with subcellular structures highlight the importance of localised translation. However, little is known regarding associations between eukaryotic translation initiation factors and cellular structures within the cytoplasm of normally growing cells. We have used detergent-based cellular fractionation coupled with immunofluorescence microscopy to investigate the subcellular localisation in NIH3T3 fibroblasts of the initiation factors involved in recruitment of mRNA for translation, focussing on eIF4E, the mRNA cap-binding protein, the scaffold protein eIF4GI and poly(A) binding protein (PABP). We find that these proteins exist mainly in a soluble cytosolic pool, with only a subfraction tightly associated with cellular structures. However, this "associated" fraction was enriched in active "eIF4F" complexes (eIF4E.eIF4G.eIF4A.PABP). Immunofluorescence analysis reveals both a diffuse and a perinuclear distribution of eIF4G, with the perinuclear staining pattern similar to that of the endoplasmic reticulum. eIF4E also shows both a diffuse staining pattern and a tighter perinuclear stain, partly coincident with vimentin intermediate filaments. All three proteins localise to the lamellipodia of migrating cells in close proximity to ribosomes, microtubules, microfilaments and focal adhesions, with eIF4G and eIF4E at the periphery showing a similar staining pattern to the focal adhesion protein vinculin

    Maximizing geographical efficiency : An analysis of the configuration of Colorado’s trauma system

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    ACKNOWLEDGEMENT The data used for this study were supplied by the Health Facilities and Emergency Medical Services Division of the Colorado Department of Public Health and Environment, which specifically disclaims responsibility for any analyses, interpretations, or conclusions it has not provided. The data used for this study were supplied by the Health Facilities and Emergency Medical Services Division of the Colorado Department of Public Health and Environment, which specifically disclaims responsibility for any analyses, interpretations, or conclusions it has not provided.Peer reviewedPostprin

    The universality class of the electroweak theory

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    We study the universality class and critical properties of the electroweak theory at finite temperature. Such critical behaviour is found near the endpoint m_H=m_{H,c} of the line of first order electroweak phase transitions in a wide class of theories, including the Standard Model (SM) and a part of the parameter space of the Minimal Sypersymmetric Standard Model (MSSM). We find that the location of the endpoint corresponds to the Higgs mass m_{H,c} = 72(2) GeV in the SM with sin^2 theta_W = 0, and m_{H,c} < 80 GeV with sin^2 theta_W = 0.23. As experimentally m_H > 88 GeV, there is no electroweak phase transition in the SM. We compute the corresponding critical indices and provide strong evidence that the phase transitions near the endpoint fall into the three dimensional Ising universality class.Comment: 35 pages, 15 figure
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