172 research outputs found

    Contextual anomaly detection in crowded surveillance scenes

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    AbstractThis work addresses the problem of detecting human behavioural anomalies in crowded surveillance environments. We focus in particular on the problem of detecting subtle anomalies in a behaviourally heterogeneous surveillance scene. To reach this goal we implement a novel unsupervised context-aware process. We propose and evaluate a method of utilising social context and scene context to improve behaviour analysis. We find that in a crowded scene the application of Mutual Information based social context permits the ability to prevent self-justifying groups and propagate anomalies in a social network, granting a greater anomaly detection capability. Scene context uniformly improves the detection of anomalies in both datasets. The strength of our contextual features is demonstrated by the detection of subtly abnormal behaviours, which otherwise remain indistinguishable from normal behaviour

    The Effect of Self-Evaluation on Musical Achievement, Attentiveness, and Attitudes of Elementary School Instrumental Students.

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    The purpose of this study was to examine the effect of self-evaluation by beginning wind instrumental students of defined musical and behavioral objectives. Specific areas in which effects were studied included attitude, physical playing fundamentals, and musical/technical skill development. Attitudes examined included students\u27 attitude toward (a) school, (b) band, (c) instrument, (d) practice, (e) band director, and (f) self. Behavioral/musical objectives examined included (a) tone; pitch; rhythm notes (technical accuracy); and playing position (posture, embouchure, hand position); and (b) practiced at home. . Before initiation of the study, all students completed an attitude questionnaire and played excerpts from their class work. Performances of group and individual playing were recorded, numbered, and randomized for subsequent analysis. Following pretest administration students in the experimental group were instructed in the use of self-evaluation forms, and began the self-evaluation phase of this study. The control group proceeded as usual while the experimental group used self-evaluation forms each day. Videotaping of both groups was done each day. Pre and postexperimental tests were conducted concerning attitude, individual, and group performance. Analysis of video data indicated higher percentages of on-task in the experimental group in every category. Comparison of pre and postexperimental attitude test data revealed different trends between control and experimental groups. Control group scores remained somewhat static while some experimental group scores indicated significant gains. Analysis of preexperimental performance scores indicated that the control group scored significantly higher in areas of pitch and technique than did the experimental group. Analysis of postexperimental performance scores indicated no significant difference between groups. Considered with preexperimental differences in performance, it seems logical to conclude that the experimental group made greater progress in performance areas than the control group. Difference scores pre to post tended to substantiate the above findings. Findings of this study indicate that use of some form of self-evaluation may increase learning and enhance attitudes of students involved in wind instrumental classes. Additional investigation would help to verify the conclusions of this work and possibly lead to more effective instruments for student self-evaluation

    V838 Monocerotis: A Geometric Distance from Hubble Space Telescope Polarimetric Imaging of its Light Echo

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    Following the outburst of the unusual variable star V838 Monocerotis in 2002, a spectacular light echo appeared. A light echo provides the possibility of direct geometric distance determination, because it should contain a ring of highly linearly polarized light at a linear radius of ct, where t is the time since the outburst. We present imaging polarimetry of the V838 Mon light echo, obtained in 2002 and 2005 with the Advanced Camera for Surveys onboard the Hubble Space Telescope, which confirms the presence of the highly polarized ring. Based on detailed modeling that takes into account the outburst light curve, the paraboloidal echo geometry, and the physics of dust scattering and polarization, we find a distance of 6.1+-0.6 kpc. The error is dominated by the systematic uncertainty in the scattering angle of maximum linear polarization, taken to be theta_{max}=90^o +- 5^o. The polarimetric distance agrees remarkably well with a distance of 6.2+-1.5 kpc obtained from the entirely independent method of main-sequence fitting to a sparse star cluster associated with V838 Mon. At this distance, V838 Mon at maximum light had M_V\simeq-9.8, making it temporarily one of the most luminous stars in the Local Group. Our validation of the polarimetric method offers promise for measurement of extragalactic distances using supernova light echoes.Comment: 43 pages, 17 figures, 3 tables; accepted for publication in the Astronomical Journal. Version with high-quality figures available at http://www.stsci.edu/~bond/v838monpolariz.pd

    Challenges and Facilitating Factors in Accessing Administrative Data for Research: Insights from the Children's Health Profile and Trajectory Initiative in NB and PEI

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    Introduction Administrative health data (AHD) are typically not analyzed to produce evidence on the effectiveness and limitations of primary prevention programs and strategies. The value of AHD for answering research questions is generally recognized, but the challenges in accessing and using these data for research are not always know and documented. Objectives and Approach To identify and advise on the facilitating factors and challenges of accessing select AHD in New Brunswick (NB) and Prince Edward Island (PEI) for the purpose of creating an intra-provincial Child Health Profile (CHP) and population-based birth cohort database, using existing AHD not been previously linked. This research is a cross-jurisdictional collaboration between NB and PEI with an integrated knowledge translation (iKT) approach that adheres to each province’s unique data policies, data procedures, and data governance. The collaboration involves people in various roles: provincial government managers, policy-makers, data custodians, health practitioners, citizens, community organizations, in addition to academic researchers. Results Access to select AHD required considerable preparation, cross province coordination, and ongoing discussions over many months. Key facilitators were the NB Institute for Research, Data and Training, a newly established data repository that holds provincial AHD in NB, and the provincial health authority in PEI. In NB, the existence of well-documented protocols and support from designated personnel (including trained data analysts) were assets facilitating data access through the data repository. In PEI, REB approval was obtained more rapidly but challenges occurred in subsequent stages of data access directly through the health authority. This research supports the empowerment of stakeholders such as Public Health and researchers who are trying to leverage ‘big data’ resources to address research and practice questions regarding children’s health. Conclusion/Implications Accessing AHD for the project was facilitated by the existence of well-documented protocols and other specialized resources that help streamline the process of data sharing while ensuring data privacy and security. Continued relationship-building among stakeholders is needed to facilitate and maximize the use of existing AHD in NB and PEI

    A proposal for a coordinated effort for the determination of brainwide neuroanatomical connectivity in model organisms at a mesoscopic scale

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    In this era of complete genomes, our knowledge of neuroanatomical circuitry remains surprisingly sparse. Such knowledge is however critical both for basic and clinical research into brain function. Here we advocate for a concerted effort to fill this gap, through systematic, experimental mapping of neural circuits at a mesoscopic scale of resolution suitable for comprehensive, brain-wide coverage, using injections of tracers or viral vectors. We detail the scientific and medical rationale and briefly review existing knowledge and experimental techniques. We define a set of desiderata, including brain-wide coverage; validated and extensible experimental techniques suitable for standardization and automation; centralized, open access data repository; compatibility with existing resources, and tractability with current informatics technology. We discuss a hypothetical but tractable plan for mouse, additional efforts for the macaque, and technique development for human. We estimate that the mouse connectivity project could be completed within five years with a comparatively modest budget.Comment: 41 page

    The Hubble Constant

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    I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. There are two broad categories of measurements. The first uses individual astrophysical objects which have some property that allows their intrinsic luminosity or size to be determined, or allows the determination of their distance by geometric means. The second category comprises the use of all-sky cosmic microwave background, or correlations between large samples of galaxies, to determine information about the geometry of the Universe and hence the Hubble constant, typically in a combination with other cosmological parameters. Many, but not all, object-based measurements give H0H_0 values of around 72-74km/s/Mpc , with typical errors of 2-3km/s/Mpc. This is in mild discrepancy with CMB-based measurements, in particular those from the Planck satellite, which give values of 67-68km/s/Mpc and typical errors of 1-2km/s/Mpc. The size of the remaining systematics indicate that accuracy rather than precision is the remaining problem in a good determination of the Hubble constant. Whether a discrepancy exists, and whether new physics is needed to resolve it, depends on details of the systematics of the object-based methods, and also on the assumptions about other cosmological parameters and which datasets are combined in the case of the all-sky methods.Comment: Extensively revised and updated since the 2007 version: accepted by Living Reviews in Relativity as a major (2014) update of LRR 10, 4, 200

    Interstellar-medium mapping in M82 through light echoes around supernova 2014J

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    We present multiple-epoch measurements of the size and surface brightness of the light echoes from supernova (SN) 2014J in the nearby starburst galaxy M82. Hubble Space Telescope (HST) ACS/WFC images were taken ~277 and ~416 days after B-band maximum in the filters F475W, F606W, and F775W. Observations with HST WFC3/UVIS images at epochs ~216 and ~365 days are included for a more complete analysis. The images reveal the temporal evolution of at least two major light-echo components. The first one exhibits a filled ring structure with position-angle-dependent intensity. This radially extended, diffuse echo indicates the presence of an inhomogeneous interstellar dust cloud ranging from ~100 to ~500 pc in the foreground of the SN. The second echo component appears as an unresolved luminous quarter-circle arc centered on the SN. The wavelength dependence of scattering measured in different dust components suggests that the dust producing the luminous arc favors smaller grain sizes, while that causing the diffuse light echo may have sizes similar to those of the Milky Way dust. Smaller grains can produce an optical depth consistent with that along the supernova-Earth line of sight measured by previous studies around maximum light. Therefore, it is possible that the dust slab from which the luminous arc arises is also responsible for most of the extinction toward SN 2014J. The optical depths determined from the Milky Way-like dust in the scattering matters are lower than the optical depth produced by the dust slab

    Partner in fat metabolism: role of KLFs in fat burning and reproductive behavior

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    The abnormalities caused by excess fat accumulation can result in pathological conditions which are linked to several interrelated diseases, such as cardiovascular disease and obesity. This set of conditions, known as metabolic syndrome, is a global pandemic of enormous medical, economic, and social concern affecting a significant portion of the world’s population. Although genetics, physiology and environmental components play a major role in the onset of disease caused by excessive fat accumulation, little is known about how or to what extent each of these factors contributes to it. The worm, Caenorhabditis elegans offers an opportunity to study disease related to metabolic disorder in a developmental system that provides anatomical and genomic simplicity relative to the vertebrate animals and is an excellent eukaryotic genetic model which enable us to answer the questions concerning fat accumulation which remain unresolved. The stored triglycerides (TG) provide the primary source of energy during periods of food deficiency. In nature, lipid stored as TGs are hydrolyzed into fatty acids which are broken down through β-oxidation to yield acetyl-CoA. Our recent study suggests that a member of C. elegans Krüppel-like factor, klf-3 regulates lipid metabolism by promoting FA β-oxidation and in parallel may contribute in normal reproduction and fecundity. Genetic and epigenetic factors that influence this pathway may have considerable impact on fat related diseases in human. Increasing number of studies suggest the role of mammalian KLFs in adipogenesis. This functional conservation should guide our further effort to explore C. elegans as a legitimate model system for studying the role of KLFs in many pathway components of lipid metabolism

    Apolipoprotein A-II Influences Apolipoprotein E-Linked Cardiovascular Disease Risk in Women with High Levels of HDL Cholesterol and C-Reactive Protein

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    Background: In a previous report by our group, high levels of apolipoprotein E (apoE) were demonstrated to be associated with risk of incident cardiovascular disease in women with high levels of C-reactive protein (CRP) in the setting of both low (designated as HR1 subjects) and high (designated as HR2 subjects) levels of high-density lipoprotein cholesterol (HDL-C). To assess whether apolipoprotein A-II (apoA-II) plays a role in apoE-associated risk in the two female groups. Methodology/Principal: Outcome event mapping, a graphical data exploratory tool; Cox proportional hazards multivariable regression; and curve-fitting modeling were used to examine apoA-II influence on apoE-associated risk focusing on HDL particles with apolipoprotein A-I (apoA-I) without apoA-II (LpA-I) and HDL particles with both apoA-I and apoA-II (LpA-I:A-II). Results of outcome mappings as a function of apoE levels and the ratio of apoA-II to apoA-I revealed within each of the two populations, a high-risk subgroup characterized in each situation by high levels of apoE and additionally: in HR1, by a low value of the apoA-II/apoA-I ratio; and in HR2, by a moderate value of the apoA-II/apoA-I ratio. Furthermore, derived estimates of LpA-I and LpA-I:A-II levels revealed for high-risk versus remaining subjects: in HR1, higher levels of LpA-I and lower levels of LpA-I:A-II; and in HR2 the reverse, lower levels of LpA-I and higher levels of LpA-I:A-II. Results of multivariable risk modeling as a function of LpA-I and LpA-I:A-II (dichotomized as highest quartile versus combined three lower quartiles) revealed association of risk only for high levels of LpA-I:A-II in the HR2 subgroup (hazard ratio 5.31, 95% CI 1.12-25.17, p = 0.036). Furthermore, high LpA-I: A-II levels interacted with high apoE levels in establishing subgroup risk. Conclusions/Significance: We conclude that apoA-II plays a significant role in apoE-associated risk of incident CVD in women with high levels of HDL-C and CRP
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