85 research outputs found

    Spatial distribution of bivalves in relation to environmental conditions (middle Danube catchment, Hungary)

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    The spatial distribution of bivalves in relation to environmental conditions was studied along a second- and third order stream – medium-sized river (River Ipoly) – large river (River Danube) continuum in the Hungarian Danube River system. Quantitative samples were collected four times in 2007 and a total of 1662 specimens, belonging to 22 bivalve species were identified. Among these species, two are endangered (Pseudanodonta complanata, Unio crassus) and five are invasive (Dreissena polymorpha, D. rostriformis bugensis, Corbicula fluminea, C. fluminalis, Anodonta woodiana) in Hungary. The higher density presented by Pisidium subtruncatum, P. supinum, P. henslowanum and C. fluminea suggests that these species may have a key role in this ecosystem. Three different faunal groups were distinguished but no significant temporal change was detected. The lowest density and diversity with two species (P. casertanum and P. personatum) occurred in streams. The highest density and diversity was found in the River Ipoly, in the side arms of the Danube and in the main arm of the Danube with sand and silt substrate, being dominated by P. subtruncatum and P. henslowanum. Moderate density and species richness were observed in the main arm of the Danube with pebble and stone substrate, being dominated by C. fluminea and S. rivicola. Ten environmental variables were found to have significant influence on the distribution of bivalves, the strongest explanatory factors being substrate types, current velocity and sedimentological characteristics.The project was financially supported by the Hungarian Scientific Research Fund under the contract No. OTKA T/046180. Special thanks to the DanubeIpoly National Park for the help in field work.info:eu-repo/semantics/publishedVersio

    All-sky search for long-duration gravitational wave transients with initial LIGO

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    We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4×10-5 and 9.4×10-4 Mpc-3 yr-1 at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves. © 2016 American Physical Society

    All-sky search for long-duration gravitational wave transients with initial LIGO

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    We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4×10-5 and 9.4×10-4 Mpc-3 yr-1 at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves. © 2016 American Physical Society

    Experimental progress in positronium laser physics

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    GW190814: gravitational waves from the coalescence of a 23 solar mass black hole with a 2.6 solar mass compact object

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    We report the observation of a compact binary coalescence involving a 22.2–24.3 Me black hole and a compact object with a mass of 2.50–2.67 Me (all measurements quoted at the 90% credible level). The gravitational-wave signal, GW190814, was observed during LIGO’s and Virgo’s third observing run on 2019 August 14 at 21:10:39 UTC and has a signal-to-noise ratio of 25 in the three-detector network. The source was localized to 18.5 deg2 at a distance of - + 241 45 41 Mpc; no electromagnetic counterpart has been confirmed to date. The source has the most unequal mass ratio yet measured with gravitational waves, - + 0.112 0.009 0.008, and its secondary component is either the lightest black hole or the heaviest neutron star ever discovered in a double compact-object system. The dimensionless spin of the primary black hole is tightly constrained to �0.07. Tests of general relativity reveal no measurable deviations from the theory, and its prediction of higher-multipole emission is confirmed at high confidence. We estimate a merger rate density of 1–23 Gpc−3 yr−1 for the new class of binary coalescence sources that GW190814 represents. Astrophysical models predict that binaries with mass ratios similar to this event can form through several channels, but are unlikely to have formed in globular clusters. However, the combination of mass ratio, component masses, and the inferred merger rate for this event challenges all current models of the formation and mass distribution of compact-object binaries

    Ocular Toxicity of Experimental Intravitreal Vitamin E

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    Supplementary Material for: Parathyroid Hormone, Fibroblast Growth Factor 23, and Parameters of Phosphate Reabsorption

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    <b><i>Background:</i></b> The serum phosphorus concentration ([P]<sub>s</sub>) is the sum of E<sub>P</sub>/C<sub>cr</sub> and TR<sub>P</sub>/C<sub>cr</sub>, where C<sub>cr</sub> is creatinine clearance and E<sub>P</sub> and TR<sub>P</sub> are rates of excretion and reabsorption of phosphate. In chronic kidney disease (CKD), parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) mediate reduction of TR<sub>P</sub>/C<sub>cr</sub>, and [PTH] and [FGF23] are linear functions of E<sub>P</sub>/C<sub>cr</sub>. If controls and patients with CKD are considered together, TR<sub>P</sub>/C<sub>cr</sub> is a hyperbolic function of E<sub>P</sub>/C<sub>cr</sub>. Given these observations, we hypothesized that hyperbolas would describe relationships of phosphate reabsorption to [PTH] and [FGF23]. <b><i>Methods:</i></b> We studied 30 patients and 28 controls with mean eGFR of 29.5 and 86.0 mL/min/1.73 m<sup>2</sup>, respectively. All analyses combined both subsets. We measured fasting [PTH] 1–84 and intact [FGF23], and determined contemporaneous E<sub>P</sub>/C<sub>cr</sub>, TR<sub>P</sub>/C<sub>cr</sub>, fractional excretion of phosphorus (FE<sub>P</sub>), and phosphate tubular maximum per volume of filtrate (Tm<sub>P</sub>/GFR). We examined linear regressions of TR<sub>P</sub>/C<sub>cr</sub> and Tm<sub>P</sub>/GFR on 100/[PTH] and 100/[FGF23]; from linear equations we derived hyperbolic equations relating reabsorptive parameters to hormone concentrations. <b><i>Results:</i></b> TR<sub>P</sub>/C<sub>cr</sub> and Tm<sub>P</sub>/GFR were linear functions of 100/[PTH] and 100/[FGF23] and hyperbolic functions of [PTH] and [FGF23]. TR<sub>P</sub>/C<sub>cr</sub> and Tm<sub>P</sub>/GFR fell minimally over the ranges of E<sub>P</sub>/C<sub>cr</sub>, [PTH], and [FGF23] seen in CKD. FE<sub>P</sub> rose with E<sub>P</sub>/C<sub>cr</sub> despite stable phosphate reabsorption. <b><i>Conclusions:</i></b> Hyperbolas describe relationships of TR<sub>P</sub>/C<sub>cr</sub> and Tm<sub>P</sub>/GFR to [PTH] and [FGF23] if subjects with normal and reduced GFR are analyzed together. Although FE<sub>P</sub> rises with [PTH] and [FGF23] as GFR falls, the simultaneous increments do not signify hormonally mediated reductions in phosphate reabsorption

    Understanding Singapore's dynamic parrot trade ecosystem

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    Singapore is prominent in the global trade of pet birds, primarily parrots. This includes its role as a key international transit hub, and also its growing domestic market, including for threatened species. There is a need to understand the trade beyond volumes and flows, including consumer knowledge, preferences and behaviours, and interactions with vendors, hobbyist groups and supporting industries. We used three methods to examine this: (1) a questionnaire with stakeholders (including parrot owners, hobbyist group members, breeders and supporting industry professionals), about the motivations for parrot ownership and interest in sustainable trade, (2) semi-structured interviews with key informants about trade dynamics, and (3) a review of online hobbyist groups. Based on our findings, we provide an initial mapping of the country's parrot trade ecosystem. Fifty-one per cent of respondents claimed to be a member of a parrot hobbyist group and 64% agreed their participation in such groups had encouraged them to purchase more parrots. The majority (71%) of parrot owners reported a preference for captive-bred rather than wild-caught parrots, and 72% were concerned about the illegal hunting of parrots for commercial trade. Most were willing to pay more (70%) and wait longer (73%) to procure a sustainably sourced parrot. Our approach presents the wildlife trade as a complex social phenomenon, with multiple physical and online channels, regulatory challenges, social networks, and evolving consumer preferences. We also document the pivotal role of hobbyist groups and their untapped potential to leverage these networks to improve sustainable trade
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