2,266 research outputs found

    Noncontact measurement of emotional and physiological changes in heart rate from a webcam

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    Heart rate, measured in beats per minute (BPM), can be used as an index of an individual's physiological state. Each time the heart beats, blood is expelled and travels through the body. This blood flow can be detected in the face using a standard webcam that is able to pick up subtle changes in color that cannot be seen by the naked eye. Due to the light absorption spectrum of blood, we are able to detect differences in the amount of light absorbed by the blood traveling just below the skin (i.e., photoplethysmography). By modulating emotional and physiological stress -- i.e., viewing arousing images and sitting vs. standing, respectively -- to elicit changes in heart rate, we explored the feasibility of using a webcam as a psychophysiological measurement of autonomic activity. We found a high level of agreement between established physiological measures, electrocardiogram (ECG), and blood pulse oximetry, and heart rate estimates obtained from the webcam. We thus suggest webcams can be used as a non-invasive and readily available method for measuring psychophysiological changes, easily integrated into existing stimulus presentation software and hardware setups

    Noncontact measurement of emotional and physiological changes in heart rate from a webcam

    Get PDF
    Heart rate, measured in beats per minute (BPM), can be used as an index of an individual's physiological state. Each time the heart beats, blood is expelled and travels through the body. This blood flow can be detected in the face using a standard webcam that is able to pick up subtle changes in color that cannot be seen by the naked eye. Due to the light absorption spectrum of blood, we are able to detect differences in the amount of light absorbed by the blood traveling just below the skin (i.e., photoplethysmography). By modulating emotional and physiological stress -- i.e., viewing arousing images and sitting vs. standing, respectively -- to elicit changes in heart rate, we explored the feasibility of using a webcam as a psychophysiological measurement of autonomic activity. We found a high level of agreement between established physiological measures, electrocardiogram (ECG), and blood pulse oximetry, and heart rate estimates obtained from the webcam. We thus suggest webcams can be used as a non-invasive and readily available method for measuring psychophysiological changes, easily integrated into existing stimulus presentation software and hardware setups

    A Hard X-ray Study of the Normal Star-Forming Galaxy M83 with NuSTAR

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    We present results from sensitive, multi-epoch NuSTAR observations of the late-type star-forming galaxy M83 (d=4.6 Mpc), which is the first investigation to spatially resolve the hard (E>10 keV) X-ray emission of this galaxy. The nuclear region and ~ 20 off-nuclear point sources, including a previously discovered ultraluminous X-ray (ULX) source, are detected in our NuSTAR observations. The X-ray hardnesses and luminosities of the majority of the point sources are consistent with hard X-ray sources resolved in the starburst galaxy NGC 253. We infer that the hard X-ray emission is most likely dominated by intermediate accretion state black hole binaries and neutron star low-mass X-ray binaries (Z-sources). We construct the X-ray binary luminosity function (XLF) in the NuSTAR band for an extragalactic environment for the first time. The M83 XLF has a steeper XLF than the X-ray binary XLF in NGC 253, consistent with previous measurements by Chandra at softer X-ray energies. The NuSTAR integrated galaxy spectrum of M83 drops quickly above 10 keV, which is also seen in the starburst galaxies NGC253, NGC 3310 and NGC 3256. The NuSTAR observations constrain any AGN to be either highly obscured or to have an extremely low luminosity of ∼<_{\sim}^<1038^{38} erg/s (10-30 keV), implying it is emitting at a very low Eddington ratio. An X-ray point source consistent with the location of the nuclear star cluster with an X-ray luminosity of a few times 1038^{38} erg/s may be a low-luminosity AGN but is more consistent with being an X-ray binary.Comment: Accepted for publication in ApJ (25 pages, 17 figures

    Assessment of the impacts of GABA and AChE targeting pesticides on freshwater invertebrate family richness in English rivers

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    Globally, riverine system biodiversity is threatened by a range of stressors, spanning pollution, sedimentation, alterations to water flow, and climate change. Pesticides have been associated with population level impacts on freshwater invertebrates for acute high-level exposures, but far less is known about the chronic impact of episodic exposure to specific classes of pesticides or their mixtures. Here we employed the use of the UK Environment Agency's monitoring datasets over 40 years (covering years 1980 to 2019) to assess the impacts of AChE (acetylcholinesterase) and GABA (gamma-aminobutyric acid) receptor targeting pesticides on invertebrate family richness at English river sites. Concentrations of AChE and GABA pesticides toxic to freshwater invertebrates occurred (measured) across 18 of the 66 river sites assessed. For one of the three river sites (all found in the Midlands region of England) where data recorded over the past 40 years were sufficient for robust modelling studies, both AChE and GABA pesticides associated with invertebrate family richness. Here, where AChE total pesticide concentrations were classified as high, 46 of 64 invertebrate families were absent, and where GABA total pesticide concentration were classified as high, 16 of 64 invertebrate families were absent. Using a combination of field evidence and laboratory toxicity thresholds for population relevant endpoints we identify families of invertebrates most at risk in the selected English rivers to AChE and GABA pesticides. We, furthermore, provide strong evidence that the absence of the invertebrate family Polycentropodidae (caddisfly) from one field site is due to exposure effects to AChE pesticides

    Entertainment (mis)education: The framing of organ donation in entertainment television

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    Researchers and practitioners who have sought to understand public reluctance to donating organs in spite of favorable attitudes toward organ donation have long thought that belief in myths about donation contribute to the problem. How these myths emerged and more important, why they have persisted in spite of national education campaigns is not clear. In the absence of direct personal experience with organ donation or transplantation, we believe that most people receive their information about donation through the media. In this study, we identify all entertainment television shows with organ donation storylines or subplots broadcast on ABC, NBC, CBS, and FOX from [2004][2005]. Frame analysis reveals 2 competing metaframes: the moral corruption of the powerful and organ donors are good people. In addition to the metaframes, 4 secondary frames, and 6 tertiary frames are identified. Organ donation is framed in mostly negative terms, with a few notable exceptions. Recommendations for how to address negative framing of organ donation in the media are offered. Choosing what frame phenomena are to be placed in may do more to determine their meaning than lengthy discussions of the facts of or arguments toward them

    The Precursors and Products of Justice Climates: Group Leader Antecedents and Employee Attitudinal Consequences

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    Drawing on the organizational justice, organizational climate, leadership and personality, and social comparison theory literatures, we develop hypotheses about the effects of leader personality on the development of three types of justice climates (e.g., procedural, interpersonal, and informational), and the moderating effects of these climates on individual level justice- attitude relationships. Largely consistent with the theoretically-derived hypotheses, the results showed that leader (a) agreeableness was positively related to procedural, interpersonal and informational justice climates, (b) conscientiousness was positively related to a procedural justice climate, and (c) neuroticism was negatively related to all three types of justice climates. Further, consistent with social comparison theory, multilevel data analyses revealed that the relationship between individual justice perceptions and job attitudes (e.g., job satisfaction, commitment) was moderated by justice climate such that the relationships were stronger when justice climate was high

    Efficient Foreign Gene Expression in Epstein-Barr Virus-Transformed Human B-Cells

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    Epstein-Barr virus (EBV) is a herpesvirus that transforms B-cells (B-LCL) and has undergone intense scrutiny owing to its association with Burkitt's lymphoma, nasopharyngeal carcinoma, and immunoblastic lymphomas. B-LCL have also proven useful in the study of human immunology. We describe a novel system for inducing efficient foreign gene expression in B-LCL using biotinylated adenovirus as an endosome-disrupting agent. Plasmid DNA is coupled to the exterior of viral particles by streptavidin-polylysine chimeric proteins. Up to 67% of B-LCL may be induced to express foreign genes in vitro in transient expression systems, and gene expression lasts for at least 17 days. We have expressed firefly luciferase, β-galactosidase (β-gal), chloramphenicol acetyltransferase, HIV gag, and env genes, as well as infectious HIV, and the EBV-specific BZLF gene in B-LCL with this system. In vivo delivery of a β-gal reporter gene to B-LCL was documented in a SCID mouse model. Potential applications include study of genetic regulation of EBV infection and transformation events, study of potential gene therapies for EBV-related B-cell tumors, and production of antigen-presenting cells for use in immunologic assays. Because of the high percentage of cells transformed and the length of foreign gene expression, the possibility of examining foreign gene expression in transient assays, without selection for clonal populations, exists

    The 0.3-30 keV Spectra of Powerful Starburst Galaxies: NuSTAR and Chandra Observations of NGC 3256 and NGC 3310

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    We present nearly simultaneous Chandra and NuSTAR observations of two actively star-forming galaxies within 50 Mpc: NGC 3256 and NGC 3310. Both galaxies are significantly detected by both Chandra and NuSTAR, which together provide the first-ever spectra of these two galaxies spanning 0.3–30 keV. The X-ray emission from both galaxies is spatially resolved by Chandra; we find that hot gas dominates the E 1–3 keV. The NuSTAR galaxy-wide spectra of both galaxies follow steep power-law distributions with Γ ≈ 2.6 at E > 5–7 keV. Using new and archival Chandra data, we search for signatures of heavily obscured or low luminosity active galactic nuclei (AGNs). We find that both NGC 3256 and NGC 3310 have X-ray detected sources coincident with nuclear regions; however, the steep NuSTAR spectra of both galaxies restricts these sources to be either low luminosity AGNs (L_(2−10 keV)/L_(Edd) 10^(−5)) or non-AGNs in nature (e.g., ULXs or crowded X-ray sources that reach L_(2−10 keV) ~ 10^(40) erg s^(−1) cannot be ruled out). Combining our constraints on the 0.3–30 keV spectra of NGC 3256 and NGC 3310 with equivalent measurements for nearby star-forming galaxies M83 and NGC 253, we analyze the star formation rate (SFR) normalized spectra of these starburst galaxies. The spectra of all four galaxies show sharply declining power-law slopes at energies above 3–6 keV primarily due to ULX populations. Our observations therefore constrain the average spectral shape of galaxy-wide populations of luminous accreting binaries (i.e., ULXs). Interestingly, despite a completely different galaxy sample selection, emphasizing here a range of SFRs and stellar masses, these properties are similar to those of super-Eddington accreting ULXs that have been studied individually in a targeted NuSTAR ULX program. We also find that NGC 3310 exhibits a factor of ≈3–10 elevation of X-ray emission over the other star-forming galaxies due to a corresponding overabundance of ULXs. We argue that the excess of ULXs in NGC 3310 is most likely explained by the relatively low metallicity of the young stellar population in this galaxy, a property that is expected to produce an excess of luminous X-ray binaries for a given SFR
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