4,356 research outputs found

    Finding the Most Uniform Changes in Vowel Polygon Caused by Psychological Stress

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    Using vowel polygons, exactly their parameters, is chosen as the criterion for achievement of differences between normal state of speaker and relevant speech under real psychological stress. All results were experimentally obtained by created software for vowel polygon analysis applied on ExamStress database. Selected 6 methods based on cross-correlation of different features were classified by the coefficient of variation and for each individual vowel polygon, the efficiency coefficient marking the most significant and uniform differences between stressed and normal speech were calculated. As the best method for observing generated differences resulted method considered mean of cross correlation values received for difference area value with vector length and angle parameter couples. Generally, best results for stress detection are achieved by vowel triangles created by /i/-/o/-/u/ and /a/-/i/-/o/ vowel triangles in formant planes containing the fifth formant F5 combined with other formants

    The Optical Gravitational Lensing Experiment. Variable Stars in Globular Clusters - IV. Fields 104A-E in 47 Tuc

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    Five fields located close to the center of the globular cluster NGC 104=47 Tuc were surveyed in a search for variable stars. We present V-band light curves for 42 variables. This sample includes 13 RR Lyr stars -- 12 of them belong to the Small Magellanic Cloud (SMC) and 1 is a background object from the galactic halo. Twelve eclipsing binaries were identified -- 9 contact systems and 3 detached/semi-detached systems. Seven eclipsing binaries are located in the blue straggler region on the cluster color-magnitude diagram (CMD) and four binaries can be considered main-sequence systems. One binary is probably a member of the SMC. Eight contact binaries are likely members of the cluster and one is most probably a foreground star. We show that for the surveyed region of 47 Tuc, the relative frequency of contact binaries is very low as compared with other recently surveyed globular clusters. The sample of identified variables also includes 15 red variables with periods ranging from about 2 days to several weeks. A large fraction of these 15 variables probably belong to the SMC but a few stars are likely to be red giants in 47 Tuc. VI photometry for about 50 000 stars from the cluster fields was obtained as a by product of our survey.Comment: Latex file, l-aa style, 10 pages, 7 ps figures included. Submitted to A&A. Figure 8 available from ftp://sirius.astrouw.edu.pl/pub/jka/47Tuc/fig8.ps.

    Open your eyes: recognizing the signs and symptoms of human trafficking

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    Human trafficking is both a human rights violation and a major public health concern. Trafficking in persons, prevalent both domestically and internationally, is a form of modern-day slavery. Although there are different typse of human trafficking, the most prevalent is the recruitment of girls and boys to be used in sex trafficking. This form of human trafficking uses force, violence, fraud, and coercion to control the victims and keep them from from contacting law enforcement or seeking help. Knowledge and awareness of signs and symptoms of human trafficking are crucial for doctor of nursing practice-family nurse practitioners (DNP-FNP), as they are likely to interact with victims while they are still in captivity. Through a literature review, this scholarly project defines human trafficking, increases awareness of human trafficking, examines signs and symptoms of human trafficking, describes common health problems, and finally discusses how the DNP-FNP can assist the victim in the clinical setting

    The Host Galaxy of GRB 060505: Host ISM Properties

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    We investigate the ISM environment of GRB 060505. Using optical emission-line diagnostic ratios, we compare the ISM properties of the GRB 060505 host region with the hosts of unambiguous long- and short-duration GRBs. We show that the metallicity, ionization state, and star formation rate of the GRB 060505 environment are more consistent with short-duration GRBs than with long-duration GRBs. We compare the metallicity and star formation rates of the GRB 060505 region with four other star-forming regions within the GRB 060505 host galaxy. We find no significant change in metallicity or star formation rate between the GRB 060505 region and the other four host regions. Our results are consistent with a compact-object-merger progenitor for GRB 060505.Comment: 7 pages, two figures; accepted for publication in ApJ

    BVRI Observations of the Optical Afterglow of GRB 990510

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    We present BVRIBVRI observations of the optical counterpart to the Gamma-Ray Burst (GRB) 990510 obtained with the Las Campanas 1.0-m telescope between 15 and 48 hours after the burst. The temporal analysis of the data indicates steepening decay, independent of wavelength, approaching asymptotically t−0.76±0.01t^{-0.76\pm 0.01} at early times (tâ‰Ș1day)t\ll 1 day) and t−2.40±0.02t^{-2.40\pm 0.02} at late times, with the break time at t0=1.57±0.03dayst_0=1.57\pm 0.03 days. GRB 990510 is the most rapidly fading of the well-documented GRB afterglows. It is also the first observed example of broad-band break for a GRB optical counterpart. The optical spectral energy distribution, corrected for significant Galactic reddening, is well fitted by a single power-law with Μ−0.61±0.12\nu^{-0.61\pm 0.12}. However, when the BB-band point is dropped from the fit, the power-law becomes Μ−0.46±0.08\nu^{-0.46\pm 0.08}, indicating a possible deviation from the power-law in the spectrum, either intrinsic or due to additional extinction near the source or from an intervening galaxy at z=1.62z=1.62. Broad-band break behavior broadly similar to that observed in GRB 990510 has been predicted in some jet models of GRB afterglows, thus supporting the idea that the GRB energy is beamed, at least in some cases.Comment: submitted to the ApJ Letters, 13 pages, 5 tables, 3 figures; additional data available at ftp://cfa-ftp.harvard.edu/pub/kstanek/GRB990510/ and through WWW at http://cfa-www.harvard.edu/cfa/oir/Research/GRB

    Host Galaxies of Gamma-Ray Bursts

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    Host galaxies are an excellent means of probing the natal environments that generate gamma-ray bursts (GRBs). Recent work on the host galaxies of short-duration GRBs has offered new insights into the parent stellar populations and ages of their enigmatic progenitors. Similarly, surveys of long-duration GRB (LGRB) host environments and their ISM properties have produced intriguing new results with important implications for long GRB progenitor models. These host studies are also critical in evaluating the utility of LGRBs as potential tracers of star formation and metallicity at high redshifts. I will summarize the latest research on LGRB host galaxies, and discuss the resulting impact on our understanding of these events' progenitors, energetics, and cosmological applications.Comment: 8 pages, 3 figures; to appear in Proceedings of IAU 279 "Death of Massive Stars: Supernovae and Gamma-ray Bursts

    Resolving Gamma-Ray Burst 000301C with a Gravitational Microlens

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    The afterglow of the Gamma-Ray Burst (GRB) 000301C exhibited achromatic, short time-scale variability that is difficult to reconcile with the standard relativistic shock model. We interpret the observed light curves as a microlensing event superimposed on power-law flux decays typical of afterglows. In general, a relativistic GRB shock appears on the sky as a thin ring expanding at a superluminal speed. Initially the ring is small relative to its angular separation from the lens and so its flux is magnified by a constant factor. As the ring grows and sweeps across the lens its magnification reaches a maximum. Subsequently, the flux gradually recovers its unlensed value. This behavior involves only three free parameters in its simplest formulation and was predicted theoretically by Loeb & Perna (1998). Fitting the available R-band photometric data of GRB 000301C to a simple model of the microlensing event and a broken power-law for the afterglow, we find reasonable values for all the parameters and a reduced chi^2/DOF parameter of 1.48 compared with 2.99 for the broken power-law fit alone. The peak magnification of ~2 occurred 3.8 days after the burst. The entire optical-IR data imply a width of the GRB ring of order 10% of its radius, similar to theoretical expectations. The angular resolution provided by microlensing is better than a micro-arcsecond. We infer a mass of approximately 0.5 M_Sun for a lens located half way to the source at z_s=2.04. A galaxy 2'' from GRB 000301C might be the host of the stellar lens, but current data provides only an upper-limit on its surface brightness at the GRB position.Comment: to appear in the ApJ Letters, 13 pages, 3 figures (one additional figure included); all data used for the fits available at ftp://cfa-ftp.harvard.edu/pub/kstanek/GRB000301C/ and through WWW at http://cfa-www.harvard.edu/cfa/oir/Research/GRB
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