598 research outputs found

    Observations on the Kalliapseudid Tanaidacea (Crustacea: Malacostraca: Peracarida) from the Northwestern Atlantic, with an Illustrated Key to the Species

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    New information for the kalliapseudid Tanaidacea occurring in the northwestern Atlantic is presented and discussed, including data on range extensions and new depth ranges for 4 species. The taxa studied came from the shelf and coastal waters of the southeastern United States, Puerto Rico and Trinidad. The occurrence of Mesokalliapseudes bahamensis Sieg is extended from the Bahamas and Belize to the coastal waters of East and Gulf coasts (South Carolina to West Florida). The range of Psammokalliapseudes granulosus Brum is expanded northward into the eastern Gulf of Mexico and new locality records for this species are established for Tobago and Puerto Rico. Mesokalliapseudes brasiliensis (Băcescu), previously known from the southwestern Atlantic off Brazil, is reported from the coastal waters off Trinidad. The range of Tanapseudes gutui Hansknecht, Heard, and Bamber is expanded northward into the eastern Gulf of Mexico. New depth ranges are established for Alokalliapseudes macsweenyi (Drumm) (82 m), M. bahamensis (52 m), P. granulosus (53 m), and T. gutui (82 m). An offshore form of A. macsweenyi occurs at depths ranging from 10-82 m on the inner and mid continental shelf off the west coast of Florida (Gulf of Mexico); it differs from the coastal form by the shape and dentition of the male and female chelipeds. Synonymies, diagnoses, life history remarks, and an illustrated key to the seven kalliapseudid species known from the NW Atlantic are presented

    The effect of high [K(+)]o on spontaneous Ca(2+) waves in freshly isolated interstitial cells of Cajal from the rabbit urethra.

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    Interstitial cells of Cajal (ICC) act as putative pacemaker cells in the rabbit urethra. Pacemaker activity in ICC results from spontaneous global Ca(2+) waves that can be increased in frequency by raising external [K(+)]. The purpose of this study was to elucidate the mechanism of this response. Intracellular [Ca(2+)] was measured in fluo-4-loaded smooth muscle cells (SMCs) and ICC using a Nipkow spinning disk confocal microscope. Increasing [K(+)]o to 60 mmol/L caused an increase in [Ca(2+)]i accompanied by contraction in SMCs. Raising [K(+)]o did not cause contraction in ICC, but the frequency of firing of spontaneous calcium waves increased. Reducing [Ca(2+)]o to 0 mmol/L abolished the response in both cell types. Nifedipine of 1 μmol/L blocked the response of SMC to high [K(+)]o, but did not affect the increase in firing in ICC. This latter effect was blocked by 30 μmol/L NiCl2 but not by the T-type Ca(2+) channel blocker mibefradil (300 nmol/L). However, inhibition of Ca(2+) influx via reverse-mode sodium/calcium exchange (NCX) using either 1 μmol/L SEA0400 or 5 μmol/L KB-R7943 did block the effect of high [K(+)]o on ICC. These data suggest that high K(+) solution increases the frequency of calcium waves in ICC by increasing Ca(2+) influx through reverse-mode NCX

    Active peer-mentored learning can improve student understanding of physiological concepts in an undergraduate journal club

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    One of the most ubiquitous active learning modalities in the biological sciences at third level is the journal club. Journal club can promote several beneficial learning outcomes for students such as gaining critical reading skills to evaluate the scientific literature, improving scientific literacy, serving as an introduction to new concepts and techniques and improving communication skills. However, it can be difficult for instructors who facilitate journal club to gauge student audiences' understanding of topics being related by presenters. At the University of Nevada, Reno School of Medicine, international life sciences undergraduate students enrolled in our research program undergo a 12-month placement in selected research laboratories within the medical school in order to develop an understanding of basic medical scientific research and physiological concepts. As such, an integral component of this program is participation in regular journal club sessions which we had assumed helped students to develop such an understanding. However as we had never empirically assessed if this was the case or not, the aim of the current study was to determine if student understanding could be improved by complementing the standard journal club with peer-mentored workshop presentations. Data from this case study suggest that by allowing students to undergo peer-mentored learning in conjunction with journal club, student understanding of physiological concepts, as well as student confidence in presenting and communication, increases

    The Aeolus project : science outreach through art

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    With a general decline in people’s choosing to pursue science and engineering degrees there has never been a greater need to raise the awareness of lesser known fields such as acoustics. Given this context, a large-scale public engagement project, the ‘Aeolus project’, was created to raise awareness of acoustics science through a major collaboration between an acclaimed artist and acoustics researchers. It centred on touring the large singing sculpture Aeolus during 2011/12, though the project also included an extensive outreach programme of talks, exhibitions, community workshops and resources for schools. Described here are the motivations behind the project and the artwork itself, the ways in which scientists and an artist collaborated, and the public engagement activities designed as part of the project. Evaluation results suggest that the project achieved its goal of inspiring interest in the discipline of acoustics through the exploration of an otherworldly work of art

    Report on Sea Lice Epidemiology and Management in Ireland with Particular Reference to Potential Interactions with Wild Salmon (Salmo salar) and Freshwater Pearl Mussel (Margaritifera margaritifera) Populations

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    In 2009 two Non-Governmental organizations (NGOs) submitted a legal complaint (Anon. 2009 a) against Ireland to the EU Commission (EU Pilot Case 764/09/ENV1). The substance of the complaint was that Ireland was failing to comply with the Habitats Directive and the Environmental Impact Assessment Directive in three named fisheries; the Delphi (Bundorragha River), the Newport Fishery (Newport River) and the Ballynahinch Fishery (Ballynahinch River). The complainants also cited a failure to protect both the salmon (Salmo salar) and the freshwater pearl mussel (Margaritifera margaritifera). In responding to the complaint a detailed scientific investigation was undertaken. Long term research and specifically commissioned studies were accessed and their data drawn on to ensure a comprehensive and accurate response based on the best available scientific data and information. This report sets out this information, together with the associated studies and data which formed the basis of the scientific response to the complaint. The complaint was closed in favour of the State on the 11th of October 2012.Funder: Marine Institut

    Determining the Electronic Confinement of a Subsurface Metallic State

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    Dopant profiles in semiconductors are important for understanding nanoscale electronics. Highly conductive and extremely confined phosphorus doping profiles in silicon, known as Si:P δ-layers, are of particular interest for quantum computer applications, yet a quantitative measure of their electronic profile has been lacking. Using resonantly enhanced photoemission spectroscopy, we reveal the real-space breadth of the Si:P δ-layer occupied states and gain a rare view into the nature of the confined orbitals. We find that the occupied valley-split states of the δ-layer, the so-called 1Γ and 2Γ, are exceptionally confined with an electronic profile of a mere 0.40 to 0.52 nm at full width at half-maximum, a result that is in excellent agreement with density functional theory calculations. Furthermore, the bulk-like Si 3pz orbital from which the occupied states are derived is sufficiently confined to lose most of its pz-like character, explaining the strikingly large valley splitting observed for the 1Γ and 2Γ states

    Notes on a paper of Mess

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    These notes are a companion to the article "Lorentz spacetimes of constant curvature" by Geoffrey Mess, which was first written in 1990 but never published. Mess' paper will appear together with these notes in a forthcoming issue of Geometriae Dedicata.Comment: 26 page

    The SMILE Soft X-ray Imager (SXI) CCD design and development

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    SMILE, the Solar wind Magnetosphere Ionosphere Link Explorer, is a joint science mission between the European Space Agency and the Chinese Academy of Sciences. The spacecraft will be uniquely equipped to study the interaction between the Earth’s magnetosphere-ionosphere system and the solar wind on a global scale. SMILE’s instruments will explore this science through imaging of the solar wind charge exchange soft X-ray emission from the dayside magnetosheath, simultaneous imaging of the UV northern aurora and in-situ monitoring of the solar wind and magnetosheath plasma and magnetic field conditions. The Soft X-ray Imager (SXI) is the instrument being designed to observe X-ray photons emitted by the solar wind charge exchange process at photon energies between 200 eV and 2000 eV. X-rays will be collected using a focal plane array of two custom-designed CCDs, each consisting of 18 µm square pixels in a 4510 by 4510 array. SMILE will be placed in a highly elliptical polar orbit, passing in and out of the Earth’s radiation belts every 48 hours. Radiation damage accumulated in the CCDs during the mission’s nominal 3-year lifetime will degrade their performance (such as through decreases in charge transfer efficiency), negatively impacting the instrument’s ability to detect low energy X-rays incident on the regions of the CCD image area furthest from the detector outputs. The design of the SMILE-SXI CCDs is presented here, including features and operating methods for mitigating the effects of radiation damage and expected end of life CCD performance. Measurements with a PLATO device that has not been designed for soft X-ray signal levels indicate a temperature-dependent transfer efficiency performance varying between 5 × 10−5 and 9 × 10−4 at expected End of Life for 5.9 keV photons, giving an initial set of measurements from which to extrapolate the performance of the SXI CCDs

    Dirichlet fundamental domains and complex-projective varieties

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    We prove that for every finitely-presented group G there exists a 2-dimensional irreducible complex-projective variety W with the fundamental group G, so that all singularities of W are normal crossings and Whitney umbrellas.Comment: 1 figur

    Not just for romance: applications of speed dating in social work education

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    In this article we address how a contemporary adaptation of the \u27speed dating\u27 model was used for educational purposes with two cohorts of social work students. We outline the dimensions of \u27speed dating\u27 as a contemporary social phenomenon, then address how this model relates specifically to groupwork process, and can be used to facilitate social work student learning. The curriculum for two classroom group activities using the \u27speed dating\u27 model are outlined, the first to develop university level study skills, the second for debriefing field placement learning experiences. Finally we examine why the \u27speed dating\u27 metaphor was successful in provoking a playful yet constructively creative space for students to engage in groupwork process.<br /
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