3,878 research outputs found

    Conservation status of New Zealand freshwater invertebrates, 2013

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    The conservation status of 644 freshwater invertebrate taxa, across five Phyla, 28 Orders and 75 Families, was assessed using the New Zealand Threat Classification System (NZTCS) criteria. Forty-six species were ranked Nationally Critical, 11 Nationally Endangered and 16 Nationally Vulnerable. One hundred and seventy-two taxa were listed as Data Deficient. A full list is presented, along with summaries and brief notes on the most important changes. This list replaces all previous NZTCS lists for freshwater invertebrates

    Research and Rhetorical Purpose: Using Genre Analysis to Understand Source Use in Technical and Professional Writing

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    This chapter describes a pilot study of student research-based writing in a technical and professional writing course designed for college-level juniors and seniors across the curriculum; fifteen analytical research papers are coded based on the rhetorical move John Swales (1990) calls reference to previous research to increase our understanding of how students use sources to introduce, support, or compare/ contrast ideas and previous research. Student papers in this study overwhelmingly used sources to support main ideas, occasionally used sources to introduce ideas, often in the form of topic sentences, but rarely used sources to compare/ contrast ideas. The frequency of support instances and the infrequency of compare/ contrast instances may suggest students had difficulty using sources to position their research, whereas they had no trouble using source excerpts to support main ideas in their writing. Local impacts of this study included several discussions among instructors about the purpose of the analytical-report assignment in our technical and professional writing course as well as suggestions for pedagogical intervention and ongoing programmatic assessment as a result of the pilot study

    Optimizing Pulsar Timing Arrays to Maximize Gravitational Wave Single Source Detection: a First Cut

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    Pulsar Timing Arrays (PTAs) use high accuracy timing of a collection of low timing noise pulsars to search for gravitational waves in the microhertz to nanohertz frequency band. The sensitivity of such a PTA depends on (a) the direction of the gravitational wave source, (b) the timing accuracy of the pulsars in the array and (c) how the available observing time is allocated among those pulsars. Here, we present a simple way to calculate the sensitivity of the PTA as a function of direction of a single GW source, based only on the location and root-mean-square residual of the pulsars in the array. We use this calculation to suggest future strategies for the current North American Nanohertz Observatory for Gravitational Waves (NANOGrav) PTA in its goal of detecting single GW sources. We also investigate the affects of an additional pulsar on the array sensitivity, with the goal of suggesting where PTA pulsar searches might be best directed. We demonstrate that, in the case of single GW sources, if we are interested in maximizing the volume of space to which PTAs are sensitive, there exists a slight advantage to finding a new pulsar near where the array is already most sensitive. Further, the study suggests that more observing time should be dedicated to the already low noise pulsars in order to have the greatest positive effect on the PTA sensitivity. We have made a web-based sensitivity mapping tool available at http://gwastro.psu.edu/ptasm.Comment: 14 pages, 3 figures, accepted by Ap

    Facial Expression Discrimination in Adults Experiencing Posttraumatic Stress Symptoms

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    The present study examined the impact of posttraumatic stress symptoms (PTSS) on adultsā€™ ability to discriminate between various facial expressions of emotions. Additionally, the study examined whether individuals reporting PTSS exhibited an attentional bias toward threat-related facial expressions of emotions. The research design was a 2 (expression intensity) x 3 (emotional pairing) x 2 (PTSS group) mixed-model factorial design. Participants for the study were 89 undergraduates recruited from psychology courses at Western Kentucky University. Participants completed the Traumatic Stress Schedule to assess for prior exposure to traumatic events. A median split was used to divide the sample into two groups (i.e., low and high PTSS). Additionally, participants also completed a demographics questionnaire, the Impact of Events Scale-Revised, the Center for Epidemiological Studies Depression Scale, and the Depression Anxiety Stress Scales to assess for possible covariates. Then, participants completed the discrimination of facial expressions task and the dot probe position task. Results indicate that individuals experiencing high levels of PTSS have difficulty discriminating between threatening and non-threatening facial expressions of emotions; additionally, these individualsā€™ difficulty is exacerbated by comorbid levels of anxiety symptoms. Furthermore, results suggests these individuals focus attention on threatening facial expressions while avoiding expressions that may activate memories associated with the prior trauma. These findings have significant clinical implications, as clinicians could focus treatment on correcting these difficulties which should help promote more beneficial social interactions for these individuals experiencing high levels of PTSS. Additionally, these behavioral measures could be used to assess the effectiveness of treatment. Effective treatment should help alleviate these difficulties, which could be measured by improved performance on the discrimination of facial expressions task and the dot probe position task from baseline to post-treatment

    Stellar Population Models and Individual Element Abundances I: Sensitivity of Stellar Evolution Models

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    Integrated light from distant galaxies is often compared to stellar population models via the equivalent widths of spectral features--spectral indices--whose strengths rely on the abundances of one or more elements. Such comparisons hinge not only on the overall metal abundance but also on relative abundances. Studies have examined the influence of individual elements on synthetic spectra but little has been done to address similar issues in the stellar evolution models that underlie most stellar population models. Stellar evolution models will primarily be influenced by changes in opacities. In order to explore this issue in detail, twelve sets of stellar evolution tracks and isochrones have been created at constant heavy element mass fraction Z that self-consistently account for varying heavy element mixtures. These sets include scaled-solar, alpha-enhanced, and individual cases where the elements C, N, O, Ne, Mg, Si, S, Ca, Ti, and Fe have been enhanced above their scaled-solar values. The variations that arise between scaled-solar and the other cases are examined with respect to the H-R diagram and main sequence lifetimes.Comment: 33 pages, 13 figures, accepted to Ap

    Aspergillus nidulans ArfB Plays a Role in Endocytosis and Polarized Growth

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    Filamentous fungi undergo polarized growth throughout most of their life cycles. The Spitzenkƶrper is an apical organelle composed primarily of vesicles that is unique to filamentous fungi and is likely to act as a vesicle supply center for tip growth. Vesicle assembly and trafficking are therefore important for hyphal growth. ADP ribosylation factors (Arfs), a group of small GTPase proteins, play an important role in nucleating vesicle assembly. Little is known about the role of Arfs in filamentous hyphal growth. We found that Aspergillus nidulans is predicted to encode six Arf family proteins. Analysis of protein sequence alignments suggests that A. nidulans ArfB shares similarity with ARF6 of Homo sapiens and Arf3p of Saccharomyces cerevisiae. An arfB null allele (arfB disrupted by a transposon [arfB::Tn]) was characterized by extended isotropic growth of germinating conidia followed by cell lysis or multiple, random germ tube emergence, consistent with a failure to establish polarity. The mutant germ tubes and hyphae that do form initially meander abnormally off of the axis of polarity and frequently exhibit dichotomous branching at cell apices, consistent with a defect in polarity maintenance. FM4-64 staining of the arfB::Tn strain revealed that another phenotypic characteristic seen for arfB::Tn is a reduction and delay in endocytosis. ArfB is myristoylated at its N terminus. Green fluorescent protein-tagged ArfB (ArfB::GFP) localizes to the plasma membrane and endomembranes and mutation (ArfB(G2A)::GFP) of the N-terminal myristoylation motif disperses the protein to the cytoplasm rather than to the membranes. These results demonstrate that ArfB functions in endocytosis to play important roles in polarity establishment during isotropic growth and polarity maintenance during hyphal extension

    Iterative focused screening with biological fingerprints identifies selective Asc-1 inhibitors distinct from traditional high throughput screening

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    N-methyl-d-aspartate receptors (NMDARs) mediate glutamatergic signaling that is critical to cognitive processes in the central nervous system, and NMDAR hypofunction is thought to contribute to cognitive impairment observed in both schizophrenia and Alzheimerā€™s disease. One approach to enhance the function of NMDAR is to increase the concentration of an NMDAR coagonist, such as glycine or d-serine, in the synaptic cleft. Inhibition of alanineā€“serineā€“cysteine transporter-1 (Asc-1), the primary transporter of d-serine, is attractive because the transporter is localized to neurons in brain regions critical to cognitive function, including the hippocampus and cortical layers III and IV, and is colocalized with d-serine and NMDARs. To identify novel Asc-1 inhibitors, two different screening approaches were performed with whole-cell amino acid uptake in heterologous cells stably expressing human Asc-1: (1) a high-throughput screen (HTS) of 3 M compounds measuring 35S l-cysteine uptake into cells attached to scintillation proximity assay beads in a 1536 well format and (2) an iterative focused screen (IFS) of a 45ā€Æ000 compound diversity set using a 3H d-serine uptake assay with a liquid scintillation plate reader in a 384 well format. Critically important for both screening approaches was the implementation of counter screens to remove nonspecific inhibitors of radioactive amino acid uptake. Furthermore, a 15ā€Æ000 compound expansion step incorporating both on- and off-target data into chemical and biological fingerprint-based models for selection of additional hits enabled the identification of novel Asc-1-selective chemical matter from the IFS that was not identified in the full-collection HTS

    Near-Infrared Spectroscopy of Carbon-Enhanced Metal-Poor Stars. I. A SOAR/OSIRIS Pilot Study

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    We report on an abundance analysis for a pilot study of seven Carbon-Enhanced Metal-Poor (CEMP) stars, based on medium-resolution optical and near-infrared spectroscopy. The optical spectra are used to estimate [Fe/H], [C/Fe], [N/Fe], and [Ba/Fe] for our program stars. The near-infrared spectra, obtained during a limited early science run with the new SOAR 4.1m telescope and the Ohio State Infrared Imager and Spectrograph (OSIRIS), are used to obtain estimates of [O/Fe] and 12C/13C. The chemical abundances of CEMP stars are of importance for understanding the origin of CNO in the early Galaxy, as well as for placing constraints on the operation of the astrophysical s-process in very low-metallicity Asymptotic Giant Branch (AGB) stars. This pilot study includes a few stars with previously measured [Fe/H], [C/Fe], [N/Fe],[O/Fe], 12C/13C, and [Ba/Fe], based on high-resolution optical spectra obtained with large-aperture telescopes. Our analysis demonstrates that we are able to achieve reasonably accurate determinations of these quantities for CEMP stars from moderate-resolution optical and near-infrared spectra. This opens the pathway for the study of significantly larger samples of CEMP stars in the near future. Furthermore, the ability to measure [Ba/Fe] for (at least the cooler) CEMP stars should enable one to separate stars that are likely to be associated with s-process enhancements (the CEMP-s stars) from those that do not exhibit neutron-capture enhancements (the CEMP-no stars).Comment: 27 pages, including 5 tables, 6 figures, accepted for publication in The Astronomical Journa

    In defense of the personal/impersonal distinction in moral psychology research: Cross-cultural validation of the dual process model of moral judgment

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    The dual process model of moral judgment (DPM; Greene et al., 2004) argues that such judgments are influenced by both emotion-laden intuition and controlled reasoning. These influences are associated with distinct neural circuitries and different response tendencies. After reanalyzing data from an earlier study, McGuire et al. (2009) questioned the level of support for the dual process model and asserted that the distinction between emotion evoking moral dilemmas (personal dilemmas) and those that do not trigger such intuitions (impersonal dilemmas) is spurious. Using similar reanalysis methods on data reported by Moore, Clark, and Kane (2008), we show that the personal/impersonal distinction is reliable. Furthermore, new data show that this distinction is fundamental to moral judgment across widely different cultures (U.S. and China) and supports claims made by the DPM

    Optimization of NANOGrav\u27s Time Allocation for Maximum Sensitivity to Single Sources

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    Pulsar timing arrays (PTAs) are a collection of precisely timed millisecond pulsars (MSPs) that can search for gravitational waves (GWs) in the nanohertz frequency range by observing characteristic signatures in the timing residuals. The sensitivity of a PTA depends on the direction of the propagating GW source, the timing accuracy of the pulsars, and the allocation of the available observing time. The goal of this paper is to determine the optimal time allocation strategy among the MSPs in the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) for a single source of GW under a particular set of assumptions. We consider both an isotropic distribution of sources across the sky and a specific source in the Virgo cluster. This work improves on previous efforts by modeling the effect of intrinsic spin noise for each pulsar. We find that, in general, the array is optimized by maximizing time spent on the best-timed pulsars, with sensitivity improvements typically ranging from a factor of 1.5 to 4
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