410 research outputs found

    Spectroscopy of Stellar-Like Objects Contained in the Second Byurakan Survey. I

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    The results of spectroscopic observations of 363 star-like objects from the Second Byurakan Survey (SBS) are reported. This SBS's subsample has proven to be a rich source of newly identified quasars, Seyfert type galaxies, degenerate stars and hot subdwarfs. In the subsample here studied, we identified 35 new QSOs, 142 White Dwarfs (WDs) the majority of which, 114 are of DA type, 55 subdwarfs (29 of which are sdB-type stars), 10 HBB, 16 NHB, 54 G-type and 25 F-type stars, two objects with composite spectra, four Cataclismic Variables (CV), two peculiar emission line stars, 17 objects with continuous spectra, as well as one planetary nebula. Among the 35 QSOs we have found two Broad Absorption Line (BAL) QSOs, namely SBS 1423+500 and SBS 1435+500A. Magnitudes, redshifts, and slit spectra for all QSOs, also some typical spectra of the peculiar stars are presented. We estimate the minimum surface density of bright QSOs in redshift range 0.3<z<2.2 to be 0.05 per sq. deg. for B<17.0 and 0.10 per sq. deg. for B<17.5.Comment: 22 pages, 3 tables, 4 figures, PASP in pres

    Building better Sex Robots: Lessons from Feminist Pornography

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    How should we react to the development of sexbot technology? Taking their cue from anti-porn feminism, several academic critics lament the development of sexbot technology, arguing that it objectifies and subordinates women, is likely to promote misogynistic attitudes toward sex, and may need to be banned or restricted. In this chapter I argue for an alternative response. Taking my cue from the sex positive ‘feminist porn’ movement, I argue that the best response to the development of ‘bad’ sexbots is to make better ones. This will require changes to the content, process and context of sexbot development. Doing so will acknowledge the valuable role that technology can play in human sexuality, and allow us to challenge gendered norms and assumptions about male and female sexual desire. This will not be a panacea to the social problems that could arise from sexbot development, but it offers a more realistic and hopeful vision for the future of this technology in a pluralistic and progressive society

    The JCMT Gould Belt Survey: A First Look at the Auriga–California Molecular Cloud with SCUBA-2

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    We present 850 and 450 μm observations of the dense regions within the Auriga–California molecular cloud using SCUBA-2 as part of the JCMT Gould Belt Legacy Survey to identify candidate protostellar objects, measure the masses of their circumstellar material (disk and envelope), and compare the star formation to that in the Orion A molecular cloud. We identify 59 candidate protostars based on the presence of compact submillimeter emission, complementing these observations with existing Herschel/SPIRE maps. Of our candidate protostars, 24 are associated with young stellar objects (YSOs) in the Spitzer and Herschel/PACS catalogs of 166 and 60 YSOs, respectively (177 unique), confirming their protostellar nature. The remaining 35 candidate protostars are in regions, particularly around LkHα 101, where the background cloud emission is too bright to verify or rule out the presence of the compact 70 μm emission that is expected for a protostellar source. We keep these candidate protostars in our sample but note that they may indeed be prestellar in nature. Our observations are sensitive to the high end of the mass distribution in Auriga–Cal. We find that the disparity between the richness of infrared star-forming objects in Orion A and the sparsity in Auriga–Cal extends to the submillimeter, suggesting that the relative star formation rates have not varied over the Class II lifetime and that Auriga–Cal will maintain a lower star formation efficiency

    CYTOSTATIC EFFECT OF CYCLOPHOSPHAMIDE ON BONE MARROW IN SHEEP

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    Abstract Hofirek B., J. Drabek: Cytostatic Effect of Cyclophosphamide on Bone Marrow in Sheep. Acta vet. Brno 49, 1980: 217-222. Cyclophosphamide (25 mg. kg -1) at a concentration of 2 % was administered intravenously to Merino sheep. A cytologic picture of bone marrow prior to and 22 days post administration was followed. Following the administration of the cytostatics a short-term and temporary depression in hemopoiesis was observed, the red component of bone marrow being more affected. In the white component only more mature cells (neutrophil metamyelocytes and stab granulocytes) were decreased in number. In both bone marrow components the short-term depression lasting 2-4 days was followed by an increase both in erythro-and myelopoiesis, persisting throughout anemia or leukopenia in peripheral blood. It was found that the administration of cyclophosphamide at this dose does not induce permanent effects in bone marrow which preserves its full regeneration ability. This conclusion is also confi med by the modification of peripheral blood picture and by the course of experiment when no disturbance in clinical condition of sheep appeared. Sheep, cytostatics, cyclophosphamide, blood, bone marrow. Considering the development of sheep breeding and the increase of their stock, the intensive technology of their rearing, facilitating high productivity, is important for Czechoslovakia. One of the problems to be solved is the replacement of tiresome labour connected with mechanical wool shearing. Moreover, the problem is aggravated by a persisting lack of skilled clippers. Possibilities are, therefore, sought in the rationalization of this labourious task, particularly by using the chemicals with cytostatic effects affecting also the hair follicles. Cytostatics are known to influence all cells of a living organism and it is, therefore, necessary to examine possible negative effects upon the sheep health condition. One of the chemicals considered is cyclophosphamide. Dolnick et aI. (1969) was one of the first who studied the possibility of chemical release of fleece; he proved that the dose of 30 mg. kg -1 was not toxic for sheep. When studying the side effects of cyclophosphamide the changes of some hematologic or biochemical values of blood were followed. Ziegler et aI. (1972) demonstrated that after intraruminal administration of 30 mg kg :&quot; significant leukopenia occurred at 8th day, reaching half the normal value, and lasting till the 27th day. Almost no effect was observed on erythrocytes and hemoglobin. Skalka et aI. (1972) applying a dose of 20 mg.kg-! removed the fleece during 14th -21st day following the cyclophosphamide administration. They also examined its effect upon the blood picture of experimental sheep. The decrease of leukocyte count was found to be most striking whereas the hemoglobin and hematocrit values decreased only on the 3rd-5th day, other hematologic and biochemical values (transaminases GOT, GPT, total protein, bilirubin, glucose, P, Mg, Cu and Fe) not showing significant change

    The JCMT Gould Belt Survey: Evidence for radiative heating in Serpens MWC 297 and its influence on local star formation

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    We present SCUBA-2 450micron and 850micron observations of the Serpens MWC 297 region, part of the JCMT Gould Belt Survey of nearby star-forming regions. Simulations suggest that radiative feedback influences the star-formation process and we investigate observational evidence for this by constructing temperature maps. Maps are derived from the ratio of SCUBA-2 fluxes and a two component model of the JCMT beam for a fixed dust opacity spectral index of beta = 1.8. Within 40 of the B1.5Ve Herbig star MWC 297, the submillimetre fluxes are contaminated by free-free emission with a spectral index of 1.03+-0.02, consistent with an ultra-compact HII region and polar winds/jets. Contamination accounts for 73+-5 per cent and 82+-4 per cent of peak flux at 450micron and 850micron respectively. The residual thermal disk of the star is almost undetectable at these wavelengths. Young Stellar Objects are confirmed where SCUBA-2 850micron clumps identified by the fellwalker algorithm coincide with Spitzer Gould Belt Survey detections. We identify 23 objects and use Tbol to classify nine YSOs with masses 0.09 to 5.1 Msun. We find two Class 0, one Class 0/I, three Class I and three Class II sources. The mean temperature is 15+-2K for the nine YSOs and 32+-4K for the 14 starless clumps. We observe a starless clump with an abnormally high mean temperature of 46+-2K and conclude that it is radiatively heated by the star MWC 297. Jeans stability provides evidence that radiative heating by the star MWC 297 may be suppressing clump collapse.Comment: 24 pages, 13 figures, 7 table

    Diving behavior of the Emperor Penguin, Aptenodytes forsteri

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    Numerical Simulations of Void Linkage in Model Materials using a Nonlocal Ductile Damage Approximation

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    Experiments on the growth and linkage of 10 μm diameter holes laser drilled in high precision patterns into Al-plates were modelled with finite elements. The simulations used geometries identical to those of the experiments and incorporated ductile damage by element removal under the control of a ductile damage indicator based on the micromechanical studies of Rice and Tracey. A regularization of the problem was achieved through an integral-type nonlocal model based on the smoothing of the rate of a damage indicator D over a characteristic length L. The simulation does not predict the experimentally observed damage acceleration either in the case where no damage is included or when only a local damage model is used. However, the full three-dimensional simulations based on the nonlocal damage methodology do predict both the failure path and the failure strain at void linkage for almost all configurations studied. For the cases considered the critical parameter controlling the local deformations at void linkage was found to be the ratio between hole diameter and hole spacing

    I will not go, I cannot go: cultural and social limitations of disaster preparedness in Asia, Africa, and Oceania

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    While much work has been invested in addressing the economic and technical basis of disaster preparedness, less effort has been directed towards understanding the cultural and social obstacles to and opportunities for disaster risk reduction. This paper presents local insights from five different national settings into the cultural and social contexts of disaster preparedness. In most cases, an early warning system was in place, but it failed to alert people to diverse environmental shocks. The research findings show that despite geographical and typological differences in these locations, the limitations of the systems were fairly similar. In Kenya, people received warnings, but from contradictory systems, whereas in the Philippines and on the island of Saipan, people did not understand the messages or take them seriously. In Bangladesh and Nepal, however, a deeper cultural and religious reasoning serves to explain disasters, and how to prevent them or find safety when they strike

    The JCMT Gould Belt Survey: constraints on prestellar core properties in Orion A North

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    This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2015 The Authors. Journal compilation © 2015 RAS. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.We employ SCUBA-2 (Submillimetre Common-User Bolometer Array 2) observations of the Orion A North molecular cloud to derive column density and temperature maps. We apply a novel, Hessian-based structural identification algorithm for detection of prestellar cores to these data, allowing for automated generation of the prestellar mass function. The resulting mass function is observed to peak at 1.39^{+0.18}_{-0.19} M⊙, indicating a star-forming efficiency lower limit of ˜14 per cent when compared with the Orion nebula Cluster initial mass function (IMF) peak. Additionally, the prestellar mass function is observed to decay with a high-mass power-law exponent α =2.53^{+0.16}_{-0.14}, indicating approximate functional similarity with the Salpeter IMF (α = 2.35). This result, when combined with the results of previous investigations suggests a regional dependence of the star-forming efficiency.Science and Technology Facilities Council of the United KingdomNational Research Council of CanadaNetherlands OrganizationCanada Foundation for InnovationCanadian Space Agenc

    The JCMT Gould Belt Survey: first results from the SCUBA-2 observations of the Ophiuchus molecular cloud and a virial analysis of its prestellar core population

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    In this paper, we present the first observations of the Ophiuchus molecular cloud performed as part of the James Clerk Maxwell Telescope (JCMT) Gould Belt Survey (GBS) with the SCUBA-2 instrument. We demonstrate methods for combining these data with previous HARP CO, Herschel, and IRAM N2H+ observations in order to accurately quantify the properties of the SCUBA-2 sources in Ophiuchus. We produce a catalogue of all of the sources found by SCUBA-2. We separate these into protostars and starless cores. We list all of the starless cores and perform a full virial analysis, including external pressure. This is the first time that external pressure has been included in this level of detail. We find that the majority of our cores are either bound or virialized. Gravitational energy and external pressure are on average of a similar order of magnitude, but with some variation from region to region. We find that cores in the Oph A region are gravitationally bound prestellar cores, while cores in the Oph C and E regions are pressure-confined. We determine that N2H+ is a good tracer of the bound material of prestellar cores, although we find some evidence for N2H+ freeze-out at the very highest core densities. We find that non-thermal linewidths decrease substantially between the gas traced by C18O and that traced by N2H+, indicating the dissipation of turbulence at higher densities. We find that the critical Bonnor-Ebert stability criterion is not a good indicator of the boundedness of our cores. We detect the pre-brown dwarf candidate Oph B-11 and find a flux density and mass consistent with previous work. We discuss regional variations in the nature of the cores and find further support for our previous hypothesis of a global evolutionary gradient across the cloud from south-west to north-east, indicating sequential star formation across the regio
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