8,758 research outputs found
Multiple drivers of decline in the global status of freshwater crayfish (Decapoda: Astacidea)
Rates of biodiversity loss are higher in freshwater ecosystems than in most terrestrial or marine ecosystems, making freshwater conservation a priority. However, prioritization methods are impeded by insufficient knowledge on the distribution and conservation status of freshwater taxa, particularly invertebrates. We evaluated the extinction risk of the world's 590 freshwater crayfish species using the IUCN Categories and Criteria and found 32% of all species are threatened with extinction. The level of extinction risk differed between families, with proportionally more threatened species in the Parastacidae and Astacidae than in the Cambaridae. Four described species were Extinct and 21% were assessed as Data Deficient. There was geographical variation in the dominant threats affecting the main centres of crayfish diversity. The majority of threatened US and Mexican species face threats associated with urban development, pollution, damming and water management. Conversely, the majority of Australian threatened species are affected by climate change, harvesting, agriculture and invasive species. Only a small proportion of crayfish are found within the boundaries of protected areas, suggesting that alternative means of long-term protection will be required. Our study highlights many of the significant challenges yet to come for freshwater biodiversity unless conservation planning shifts from a reactive to proactive approach
Collision of adenocarcinoma and gastrointestinal stromal tumour (GIST) in the stomach: report of a case
A 78-year-old woman was diagnosed with a proximal gastric adenocarcinoma and underwent an elective D2 total gastrectomy with splenectomy. Subsequent histopathology revealed the presence of another tumour at the gastric antrum. This was a small benign gastrointestinal stromal tumour (GIST) mixed with gastric adenocarcinoma cells similar to those of the main gastric tumour i.e. a collision tumour. The literature has only few previous reports of this very rare association. It is not known whether this synchronicity is incidental or there is a causative factor inducing the development of tumours of different histotypes in the same organ. Pathologists, oncologists and surgeons should be aware of this interesting condition
Angular analysis of B decaying into J/psi Tensor, J/psi Vector and J/psi Scalar
The analysis of B \to \jpsi K^{\star}_{2}(1430) decay mode is complicated
by the fact that close to the meson \Kstart(1430), there lie
other and resonances, and
respectively. We show how an angular analysis can be used
to isolate the contributions from the different resonances and partial waves
contributing to the final state B\to \jpsi K_X, where could be any of
the resonance , or
. For this purpose we study the time integrated
differential decay rate. We also construct a time dependent angular asymmetry
that enables a clean measurement of the mixing phase in the mode B\to
\jpsi \Kstart(1430) alone, without contributions from the decay modes
B\to\jpsi\Kstarsz(1430) or B\to\jpsi\Kstar(1410).Comment: 20 pages, 0 figure
On improving the accuracy of the M2 barotropic tides embedded in a high-resolution global ocean circulation model
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/116867/1/ocemod_ASEnKF_tides_ngodocketal_2016.pd
Ultrasound Guided Regional Anesthesia Training Simulator Using Microsoft Kinect
We present a system for the interactive simulation of ultrasound guided peripheral nerve blocks using a Microsoft Kinect®. The system performs motion tracking of both the ultrasound probe and the nerve block needle. Software generates synthetic ultrasound images from previously captured ultrasound images. Details of the software elements in the system are described. Some of the current challenges and future work in this research are discussed
Measurement of the Branching Fractions for D^0 → π^-e^+v_e and D^0 → + K^-e^+V_e and Determination of │V_(cd)/V_(cs)│^2
Measurements of the exclusive branching fractions B(D^0→π^-e^+ν_e) and B(D^0→K^-e^+ν_e), using data collected at the ψ(3770) with the Mark III detector at the SLAC e^+e^- storage ring SPEAR, are used to determine the ratio of the Kobayashi-Maskawa matrix elements │V_(cd)/V_(cs)│^2 =0.057_(-0.015)^(+0.038)±0.005
Search for the decay D^0→K^0e^+e^-
A search for the decay of the charmed meson D^0→K^0e^+e^- is presented, based on data collected at the ψ(3770) resonance with the Mark III detector at the SLAC storage ring SPEAR. No evidence for this process is found, resulting in an upper limit on the decay branching ratio of 1.7×10^(-3) at the 90% confidence level
Analysis of hadronic invariant mass spectrum in inclusive charmless semileptonic B decays
We make an analysis of the hadronic invariant mass spectrum in inclusive
charmless semileptonic B meson decays in a QCD-based approach. The decay width
is studied as a function of the invariant mass cut. We examine their
sensitivities to the parameters of the theory. The theoretical uncertainties in
the determination of from the hadronic invariant mass spectrum are
investigated. A strategy for improving the theoretical accuracy in the value of
is described.Comment: 13 pages, 5 Postscript figure
ANSI/ASHRAE/IESNA Standard 90.1-2010 Preliminary Qualitative Determination
A preliminary qualitative analysis of all addenda to American National Standards Institute (ANSI)/American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE)/Illuminating Engineering Society of North America (IESNA) Standard 90.1-2007 (Standard 90.1-2007 or 2007 edition) that were included in ANSI/ASHRAE/IESNA Standard 90.1-2010 (Standard 90.1-2010 or 2010 edition) was conducted. All 109 addenda processed by ASHRAE in the creation of Standard 90.1-2010 from Standard 90.1-2007 were evaluated by DOE for their impact on energy efficiency. DOE preliminarily determined whether that addenda would have a positive, neutral, or negative impact on overall building efficiency
Instability of the symmetric Couette-flow in a granular gas: hydrodynamic field profiles and transport
We investigate the inelastic hard disk gas sheared by two parallel bumpy
walls (Couette-flow). In our molecular dynamic simulations we found a
sensitivity to the asymmetries of the initial condition of the particle places
and velocities and an asymmetric stationary state, where the deviation from
(anti)symmetric hydrodynamic fields is stronger as the normal restitution
coefficient decreases. For the better understanding of this sensitivity we
carried out a linear stability analysis of the former kinetic theoretical
solution [Jenkins and Richman: J. Fluid. Mech. {\bf 171} (1986)] and found it
to be unstable. The effect of this asymmetry on the self-diffusion coefficient
is also discussed.Comment: 9 pages RevTeX, 14 postscript figures, sent to Phys. Rev.
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