483 research outputs found

    The U.S. market for imported wildlife not listed in the CITES multilateral treaty

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    Published December 2022The international wildlife trade presents severe conservation and environmental security risks, yet no international regulatory framework exists to monitor the trade of species not listed in the appendices of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). We explored the composition and dynamics of internationally regulated versus nonregulated trade, with a focus on importations of wild-caught terrestrial vertebrates entering the United States from 2009 to 2018. We used 10 years of species-level trade records of the numbers of live, wild-caught animals imported to the United States and data on International Union for the Conservation of Nature (IUCN) estimates of extinction risk to determine whether there were differences in the diversity, abundance, and risk to extinction among imports of CITES-listed versus unlisted species. We found 3.6 times the number of unlisted species in U.S. imports compared with CITESlisted species (1366 vs. 378 species). The CITES-listed species were more likely to face reported conservation threats relative to unlisted species (71.7% vs. 27.5%). However, 376 unlisted species faced conversation threats, 297 species had unknown population trends, and 139 species were without an evaluation by the IUCN. Unlisted species appearing for the first time in records were imported 5.5 times more often relative to CITES-listed species. Unlisted reptiles had the largest rate of entry, averaging 53 unique species appearing in imports for the first time per year. Overall trade quantities were approximately 11 times larger for imports of unlisted species relative to imports of CITES-listed species. Countries that were top exporters of CITES-listed species were mostly different from exporters of unlisted species. Because of the vulnerabilities of unlisted, traded species entering the United States and increasing global demand, we strongly recommend governments adapt their policies to monitor and report on the trade of all wildlife.Freyja Watters, Oliver Stringham, Chris R. Shepherd, Phillip Casse

    Formation of black-hole X-ray binaries in globular clusters

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    Inspired by the recent identification of the first candidate BH-WD X-ray binaries, where the compact accretors may be stellar-mass black hole candidates in extragalactic globular clusters, we explore how such binaries could be formed in a dynamical environment. We provide analyses of the formation rates via well known formation channels like binary exchange and physical collisions and propose that the only possibility to form BH-WD binaries is via coupling these usual formation channels with subsequent hardening and/or triple formation. Indeed, we find that the most important mechanism to make a BH-WD X-ray binary from an initially dynamically formed BH-WD binary is triple induced mass transfer via the Kozai mechanism. Even using the most optimistic estimates for the formation rates, we cannot match the observationally inferred production rates if black holes undergo significant evaporation from the cluster or form a completely detached subcluster of black holes. We estimate that at least 1% of all formed black holes, or presumably 10% of the black holes present in the core now, must be involved in interactions with the rest of the core stellar population.Comment: 10 pages, 2 figures, submitted to Ap

    Eight gamma-ray pulsars discovered in blind frequency searches of Fermi LAT data

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    We report the discovery of eight gamma-ray pulsars in blind frequency searches using the LAT, onboard the Fermi Gamma-ray Space Telescope. Five of the eight pulsars are young (tau_c10^36 erg/s), and located within the Galactic plane (|b|<3 deg). The remaining three are older, less energetic, and located off the plane. Five pulsars are associated with sources included in the LAT bright gamma-ray source list, but only one, PSR J1413-6205, is clearly associated with an EGRET source. PSR J1023-5746 has the smallest characteristic age (tau_c=4.6 kyr) and is the most energetic (Edot=1.1E37 erg/s) of all gamma-ray pulsars discovered so far in blind searches. PSRs J1957+5033 and J2055+25 have the largest characteristic ages (tau_c~1 Myr) and are the least energetic (Edot~5E33 erg/s) of the newly-discovered pulsars. We present the timing models, light curves, and detailed spectral parameters of the new pulsars. We used recent XMM observations to identify the counterpart of PSR J2055+25 as XMMU J205549.4+253959. In addition, publicly available archival Chandra X-ray data allowed us to identify the likely counterpart of PSR J1023-5746 as a faint, highly absorbed source, CXOU J102302.8-574606. The large X-ray absorption indicates that this could be among the most distant gamma-ray pulsars detected so far. PSR J1023-5746 is positionally coincident with the TeV source HESS J1023-575, located near the young stellar cluster Westerlund 2, while PSR J1954+2836 is coincident with a 4.3 sigma excess reported by Milagro at a median energy of 35 TeV. Deep radio follow-up observations of the eight pulsars resulted in no detections of pulsations and upper limits comparable to the faintest known radio pulsars, indicating that these can be included among the growing population of radio-quiet pulsars in our Galaxy being uncovered by the LAT, and currently numbering more than 20.Comment: Submitted to Ap

    Emergency and critical care services in Tanzania: a survey of ten hospitals.

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    While there is a need for good quality care for patients with serious reversible disease in all countries in the world, Emergency and Critical Care tends to be one of the weakest parts of health systems in low-income countries. We assessed the structure and availability of resources for Emergency and Critical Care in Tanzania in order to identify the priorities for improving care in this neglected specialty. Ten hospitals in four regions of Tanzania were assessed using a structured data collection tool. Quality was evaluated with standards developed from the literature and expert opinion. Important deficits were identified in infrastructure, routines and training. Only 30% of the hospitals had an emergency room for adult and paediatric patients. None of the seven district and regional hospitals had a triage area or intensive care unit for adults. Only 40% of the hospitals had formal systems for adult triage and in less than one third were critically ill patients seen by clinicians more than once daily. In 80% of the hospitals there were no staff trained in adult triage or critical care. In contrast, a majority of equipment and drugs necessary for emergency and critical care were available in the hospitals (median 90% and 100% respectively. The referral/private hospitals tended to have a greater overall availability of resources (median 89.7%) than district/regional hospitals (median 70.6). Many of the structures necessary for Emergency and Critical Care are lacking in hospitals in Tanzania. Particular weaknesses are infrastructure, routines and training, whereas the availability of drugs and equipment is generally good. Policies to improve hospital systems for the care of emergency and critically ill patients should be prioritised

    An unusual cause of granulomatous disease

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    BACKGROUND: Chronic granulomatous disease (CGD) is an inherited disorder of phagocytic cells caused by an inability to generate active microbicidal oxygen species required kill certain types of fungi and bacteria. This leads to recurrent life-threatening bacterial and fungal infections with tissue granuloma formation. CASE PRESENTATION: We describe a case of X-linked Chronic granulomatous disease (CGD) diagnosed in an 18-year-old male. He initially presented with granulomatous disease mimicking sarcoidosis and was treated with corticosteroids. He subsequently developed Burkholderia cepacia complex pneumonia and further investigation confirmed a diagnosis of CGD. CONCLUSION: Milder phenotypes of CGD are now being recognised. CGD should be considered in patients of any age with granulomatous diseases, especially if there is a history of recurrent or atypical infection

    PSR J1907+0602: A Radio-Faint Gamma-Ray Pulsar Powering a Bright TeV Pulsar Wind Nebula

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    We present multiwavelength studies of the 106.6 ms gamma-ray pulsar PSR J1907+06 near the TeV source MGRO J1908+06. Timing observations with Fermi result in a precise position determination for the pulsar of R.A. = 19h07m547(2), decl. = +06:02:16(2) placing the pulsar firmly within the TeV source extent, suggesting the TeV source is the pulsar wind nebula of PSR J1907+0602. Pulsed gamma-ray emission is clearly visible at energies from 100 MeV to above 10 GeV. The phase-averaged power-law index in the energy range E > 0.1 GeV is = 1.76 \pm 0.05 with an exponential cutoff energy E_{c} = 3.6 \pm 0.5 GeV. We present the energy-dependent gamma-ray pulsed light curve as well as limits on off-pulse emission associated with the TeV source. We also report the detection of very faint (flux density of ~3.4 microJy) radio pulsations with the Arecibo telescope at 1.5 GHz having a dispersion measure DM = 82.1 \pm 1.1 cm^{-3}pc. This indicates a distance of 3.2 \pm 0.6 kpc and a pseudo-luminosity of L_{1400} ~ 0.035 mJy kpc^2. A Chandra ACIS observation revealed an absorbed, possibly extended, compact <(4 arcsec) X-ray source with significant non-thermal emission at R.A. = 19h07m54.76, decl. = +06:02:14.6 with a flux of 2.3^{+0.6}_{-1.4} X 10^{-14} erg cm^{-2} s^{-1}. From archival ASCA observations, we place upper limits on any arcminute scale 2--10 keV X-ray emission of ~ 1 X 10^{-13} erg cm^{-2} s^{-1}. The implied distance to the pulsar is compatible with that of the supernova remnant G40.5-0.5, located on the far side of the TeV nebula from PSR J1907+0602, and the S74 molecular cloud on the nearer side which we discuss as potential birth sites

    Fermi LAT observations of the Geminga pulsar

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    We report on the \textit{Fermi}-LAT observations of the Geminga pulsar, the second brightest non-variable GeV source in the γ\gamma-ray sky and the first example of a radio-quiet γ\gamma-ray pulsar. The observations cover one year, from the launch of the FermiFermi satellite through 2009 June 15. A data sample of over 60,000 photons enabled us to build a timing solution based solely on γ\gamma rays. Timing analysis shows two prominent peaks, separated by Δϕ\Delta \phi = 0.497 ±\pm 0.004 in phase, which narrow with increasing energy. Pulsed γ\gamma rays are observed beyond 18 GeV, precluding emission below 2.7 stellar radii because of magnetic absorption. The phase-averaged spectrum was fitted with a power law with exponential cut-off of spectral index Γ\Gamma = (1.30 ±\pm 0.01 ±\pm 0.04), cut-off energy E0E_{0} = (2.46 ±\pm 0.04 ±\pm 0.17) GeV and an integral photon flux above 0.1 GeV of (4.14 ±\pm 0.02 ±\pm 0.32) ×\times 106^{-6} cm2^{-2} s1^{-1}. The first uncertainties are statistical and the second are systematic. The phase-resolved spectroscopy shows a clear evolution of the spectral parameters, with the spectral index reaching a minimum value just before the leading peak and the cut-off energy having maxima around the peaks. Phase-resolved spectroscopy reveals that pulsar emission is present at all rotational phases. The spectral shape, broad pulse profile, and maximum photon energy favor the outer magnetospheric emission scenarios.Comment: 32 pages, 12 figures, 3 tables. Accepted for publication in The Astrophysical Journal. Corresponding authors: Denis Dumora ([email protected]), Fabio Gargano ([email protected]), Massimiliano Razzano ([email protected]

    Fermi Large Area Telescope Observations of the Crab Pulsar and Nebula

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    We report on gamma-ray observations of the Crab Pulsar and Nebula using 8 months of survey data with the Fermi Large Area Telescope (LAT). The high quality light curve obtained using the ephemeris provided by the Nancay and Jodrell Bank radio telescopes shows two main peaks stable in phase with energy. The first gamma-ray peak leads the radio main pulse by (281 \pm 12 \pm 21) mus, giving new constraints on the production site of non-thermal emission in pulsar magnetospheres. The improved sensitivity and the unprecedented statistics afforded by the LAT enable precise measurement of the Crab Pulsar spectral parameters: cut-off energy at E_c = (5.8 \pm 0.5 \pm 1.2) GeV, spectral index of Gamma = (1.97 \pm 0.02 \pm 0.06) and integral photon flux above 100 MeV of (2.09 \pm 0.03 \pm 0.18) x 10^{-6} cm^{-2} s^{-1}. The first errors represent the statistical error on the fit parameters, while the second ones are the systematic uncertainties. Pulsed gamma-ray photons are observed up to ~ 20 GeV which precludes emission near the stellar surface, below altitudes of around 4 to 5 stellar radii in phase intervals encompassing the two main peaks. The spectrum of the nebula in the energy range 100 MeV - 300 GeV is well described by the sum of two power-laws of indices Gamma_{sync} = (3.99 \pm 0.12 \pm 0.08) and Gamma_{IC} = (1.64 \pm 0.05 \pm 0.07), corresponding to the falling edge of the synchrotron and the rising edge of the inverse Compton components, respectively. This latter, which links up naturally with the spectral data points of Cherenkov experiments, is well reproduced via inverse Compton scattering from standard Magnetohydrodynamics (MHD) nebula models, and does not require any additional radiation mechanism.Comment: 17 pages, 9 figures, Accepted for publications in Astrophysical Journa

    Fermi Large Area Telescope observations of PSR J1836+5925

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    The discovery of the gamma-ray pulsar PSR J1836+5925, powering the formerly unidentified EGRET source 3EG J1835+5918, was one of the early accomplishments of the Fermi Large Area Telescope (LAT). Sitting 25 degrees off the Galactic plane, PSR J1836+5925 is a 173 ms pulsar with a characteristic age of 1.8 million years, a spindown luminosity of 1.1×1034\times10^{34} erg s1^{-1}, and a large off-peak emission component, making it quite unusual among the known gamma-ray pulsar population. We present an analysis of one year of LAT data, including an updated timing solution, detailed spectral results and a long-term light curve showing no indication of variability. No evidence for a surrounding pulsar wind nebula is seen and the spectral characteristics of the off-peak emission indicate it is likely magnetospheric. Analysis of recent XMM observations of the X-ray counterpart yields a detailed characterization of its spectrum, which, like Geminga, is consistent with that of a neutron star showing evidence for both magnetospheric and thermal emission.Comment: Accepted to Astrophysical Journa
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