2,023 research outputs found

    Morphing of Triangular Meshes in Shape Space

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    We present a novel approach to morph between two isometric poses of the same non-rigid object given as triangular meshes. We model the morphs as linear interpolations in a suitable shape space S\mathcal{S}. For triangulated 3D polygons, we prove that interpolating linearly in this shape space corresponds to the most isometric morph in R3\mathbb{R}^3. We then extend this shape space to arbitrary triangulations in 3D using a heuristic approach and show the practical use of the approach using experiments. Furthermore, we discuss a modified shape space that is useful for isometric skeleton morphing. All of the newly presented approaches solve the morphing problem without the need to solve a minimization problem.Comment: Improved experimental result

    Pathways to Meteoritic Glycine and Methylamine

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    Glycine and methylamine are meteoritic water-soluble organic compounds that provide insights into the processes that occurred before, during, and after the formation of the Solar System. Both glycine and methylamine and many of their potential synthetic precursors have been studied in astrophysical environments via observations, laboratory experiments, and modeling. Despite these studies, the synthetic mechanisms for their formation leading to their occurrence in meteorites remain poorly understood. Typical 13C-isotopic values (13C) of meteoritic glycine and methylamine are 13C-enriched relative to their terrestrial counterparts; thus, analyses of their stable carbon isotopic compositions (13C/12C) may be used not only to assess terrestrial contamination in meteorites but also to provide information about their synthetic routes inside the parent body. Here, we examine potential synthetic routes of glycine and methylamine from a common set of precursors present in carbonaceous chondrite meteorites, using data from laboratory analyses of the well-studied CM2 Murchison meteorite. Several synthetic mechanisms for the origins of glycine and methylamine found in carbonaceous chondrites may be possible, and the prevalence of these mechanisms will largely depend on (a) the molecular abundance of the precursor molecules and (b) the levels of processing (aqueous and thermal) that occurred inside the parent body. In this work, we also aim to contextualize the current knowledge about gas-phase reactions and irradiated ice grain chemistry for the synthesis of these species through parent body processes. Our evaluation of various mechanisms for the origins of meteoritic glycine and methylamine from simple species shows what work is still needed to evaluate both the abundances and isotopic compositions of simpler precursor molecules from carbonaceous chondrites as well as the effects of parent body processes on those abundances and isotopic compositions. The analyses presented here combined with the indicated measurements will aid a better interpretation of quantitative analysis of reaction rates, molecular stability, and distribution of organic products from laboratory simulations of interstellar ices, astronomical observations, and theoretical modeling

    The merger rate of massive galaxies

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    We calculate the projected two point correlation function for samples of luminous and massive galaxies in the COMBO-17 photometric redshift survey, focusing particularly on the amplitude of the correlation function at small projected radii and exploring the constraints such measurements can place on the galaxy merger rate. For nearly volume-limited samples with 0.4<z<0.8, we find that 4+/-1% of luminous M_B<-20 galaxies are in close physical pairs (with real space separation of <30 proper kpc). The corresponding fraction for massive galaxies with M_*>2.5e10 M_sun is 5+/-1%. Incorporating close pair fractions from the literature, the 2dFGRS and the SDSS, we find a fairly rapid evolution of the merger fraction of massive galaxies between z=0.8 and the present day. Assuming that the major merger timescale is of order the dynamical timescale for close massive galaxy pairs, we tentatively infer that ~50% (70%) of all galaxies with present-day masses M_*>5e10 M_sun (remnants of mergers between galaxies with M_*>2.5e10 M_sun) have undergone a major merger since z=0.8(1): major mergers between massive galaxies are a significant driver of galaxy evolution over the last eight billion years.Comment: ApJ, in press. 8 pages, 3 figures. Expanded discussion section with explicit discussion of merger fraction vs. close pair fraction. Change of typical close pair timescale results in increased inferred merger rat

    Brood patch and sex-ratio observations indicate breeding provenance and timing in New Zealand storm petrel (Fregetta maoriana)

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    We used measurements of brood patch and moult status to estimate the breeding phenology of New Zealand Storm-Petrel, using birds caught at sea within the Hauraki Gulf Marine Park near Auckland, New Zealand. Birds caught October–January had completely downy brood patches, whereas birds caught February–April had bare brood patches with an observed male bias in the February sex-ratio, consistent with a female pre-laying exodus typical of petrels and with the existence of an unknown colony in the region. No birds captured exhibited primary moult, which is known to occur in storm-petrels during their non-breeding season. Our data support the conclusion that the New Zealand storm-petrel breeds during January–June in northern New Zealand and that field surveys for the species on offshore islands in this region during this period are warrante

    Discovery of the Narrow-Line Seyfert 1 galaxy Mkn 335 in an historical low X-ray flux state

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    We report the discovery of the Narrow-Line Seyfert 1 galaxy Mkn 335 in an extremely low X-ray state. A comparison of Swift observations obtained in May and June/July 2007 with all previous X-ray observations between 1971 to 2006 show the AGN to have diminished in flux by a factor of more than 30, the lowest X-ray flux Mkn 335 has ever been observed in. The Swift observations show an extremely hard X-ray spectrum at energies above 2 keV. Possible interpretations include partial covering absorption or X-ray reflection from the disk. In this letter we consider the partial covering interpretation. The Swift observations can be well fit by a strong partial covering absorber with varying absorption column density N_H= 1-4 x 10^{23} cm-2 and a covering fraction f_c=0.9 - 1. When corrected for intrinsic absorption, the X-ray flux of Mkn 335 varies by only factors of 4-6. In the UV Mkn 335 shows variability in the order of 0.2 mag. We discuss the similarity of Mkn 335 with the highly variable NLS1 WPVS007, and speculate about a possible link between NLS1 galaxies and broad-absorption line quasars.Comment: ApJ Letter accepted; 8 pages, 2 figures; The new version has three more sentences in the introduction and three references added to the discussio

    Assessing costs and benefits of measures to achieve good environmental status in European regional seas: challenges, opportunities, and lessons learnt

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    The EU Marine Strategy Framework Directive (MSFD) requires Member States to assess the costs and benefits of Programmes of Measures (PoMs) put in place to ensure that European marine waters achieve Good Environmental Status by 2020. An interdisciplinary approach is needed to carry out such an assessment whereby economic analysis is used to evaluate the outputs from ecological analysis that determines the expected effects of such management measures. This paper applies and tests an existing six-step approach to assess costs and benefits of management measures with potential to support the overall goal of the MSFD and discusses a range of ecological and economic analytical tools applicable to this task. Environmental cost-benefit analyses are considered for selected PoMs in three European case studies: Baltic Sea (Finland), East Coast Marine Plan area (UK), and the Bay of Biscay (Spain). These contrasting case studies are used to investigate the application of environmental cost-benefit analysis (CBA) including the challenges, opportunities and lessons learnt from using this approach. This paper demonstrates that there are opportunities in applying the six-step environmental CBA framework presented to assess the impact of PoMs. However, given demonstrated limitations of knowledge and data availability, application of other economic techniques should also be considered (although not applied here) to complement the more formal environmental CBA approach

    NATIONAL HEALTH COVERAGE SYSTEM : PHARMACISTS AND JKN PARTICIPANT SATISFACTION IN PRIMARY HEALTH FACILITIES

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    National Health Insurance is a health protection system for participants to obtain health care benefits and protection to meet basic health needs that organized based on social insurance and equity principles. JKN in cooperation with the primary health facilities to provide comprehensive health services including pharmacy services. Pharmacist responsible for drug availability and affordability that affected by drug procurement process, drug distribution process, and drug cost claiming process.This research’s aim to determine relationship between national health insurances services to pharmacists satisfaction and to determine relationship between pharmacy services to outpatient satisfaction at primary health facilities. Data used in research are primary data that collected through questionnare and interview. The method used is purposive sampling which the data is analyzed using linear and multiple regresion and see significant value (p). The number of respondents was 40 pharmacists and 150 patients in health centers and primary clinics scattered in Sleman, Bantul, and Kota Yogyakarta. The results showed that the process of procurement and distribution of drugs have a relationship with a pharmacist satisfaction while drug costs not process claims with consecutive p 0.010, 0.002, and 0.261. Related to the satisfaction of the outpatient pharmacy services result there is a relationship of drug availability (p = 0.003), service time (p = 0.006), and get drug (p = 0.000) to the satisfaction of outpatients. The conclusion of this study is the process of procurement and distribution of drugs have a relationship with a pharmacist satisfaction. In addition, the availability of pharmacy services such as medication, a drug services, and the provision of drug information also has a significant relationship to the satisfaction of outpatients in health facilities first rate.Keywords: pharmacy services, pharmacists, patients, JK

    The Reappearance of the Transient Low Mass X-ray Binary X1658-298

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    In April 1999 the transient low mass X-ray binary X1658-298 resumed its strong and persistent X-ray emission after a 21-year interval of quiescence. We present RXTE data obtained soon after the reappearance, including four eclipses with a mean duration of 901.9 +/- 0.8 sec and ingress/egress times of 6-13 sec. Our updated ephemeris for the source indicates that the 7.1-hr orbital period of the system is decreasing with a timescale of 10^7 yr. Contemporaneous optical observations provide the first-ever lightcurve of V2134 Oph, the optical counterpart of X1658-298. The optical modulation is highly variable from night to night and exhibits a distinct, narrow eclipse feature of about 0.2 mag superposed on a gradual brightness variation with ~0.7-0.8 mag amplitude. Our data indicate that there is no significant offset between the time of mid-eclipse in the X-ray and optical and that the narrow optical eclipse feature is of the same duration as the X-ray eclipse. This implies an accretion disk structure characterized by enhanced optical emission coincident with the central X-ray emitting area.Comment: 13 pages including 4 figures and 3 tables; Accepted for publication in The Astrophysical Journa
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