2,238 research outputs found

    Transformation between Australian datums using a modified transverse Mercator projection

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    The introduction of the Geocentric Datum of Australia (GDA94) in the year 2000 will undoubtedly require the transformation of a large amount of coordinate data in Australia. This paper presents a modified transverse Mercator (MTM) map-projection such that the latitude and longitude on one datum are projected so that they closely agree with the transverse Mercator easting and northing on another datum. This approach will allow the introduction of the GDA94 whilst preserving Australian Map Grid (AMG) coordinates. Conversely, the MTM projection can be used to transform coordinates directly from the Australian Geodetic Datum (AGD) to the new Map Grid of Australia (MGA94). In order to test these two approaches, MTM parameters have been computed from 82 co-located GDA94/MGA94 and AGD98/AMG84 coordinates that comprise the Western Australian STATEFIX geodetic network. When using the national seven- and three-parameter datum transformations, the maximum differences between observed and transformed coordinates are 2.04m and 2.21m, respectively. When using the transformation by MTM projection, the projected coordinates agree with the observed coordinates to less than 2.04m

    Nitrous oxide emission from a range of land uses across Europe

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    International audienceThe results of a literature study examining quantitative estimates of N2O emission rates are presented for a range of land-uses across Europe. The analysis shows that the highest N2O emission rates are for agricultural lands compared to forests and grasslands. The main factors regulating these rates are available mineral nitrogen, soil temperature, soil water content and the available labile organic compounds. These controls operate across different time-scales, all must exceed a certain threshold for N2O emission to occur. The results support the need for an emission factor function of land-use and climate within models describing nitrogen dynamics in catchments. This would allow the assessment of the net N2O emission within catchments in terms of current levels and potential changes associated with climate variability, climate change and land use change. Keywords: nitrous oxide, soil water content, inorganic N, soil temperature, ecosystems, land-use management, soil typ

    Confirmation of a Four-Factor Structure of the Schizotypal Personality Questionnaire among Undergraduate Students

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    Objective Although several exploratory and confirmatory factor analyses have supported the initially proposed factor structure of the Schizotypal Personality Questionnaire (SPQ) in which its nine subscales are grouped into cognitive-perceptual, interpersonal, and disorganized domains, others have revealed different latent structures. This study determined the best-fitting factor structure from among five models that have been proposed in the literature, as well as five additional hierarchically related models. Method Undergraduate college students (n=825) completed the SPQ as well as the Perceptual Aberration Scale (PAS) and the Revised Social Anhedonia Scale (SAS). Confirmatory factor analyses involving the nine SPQ subscales were conducted using the Linear Structural Relations Program (LISREL 8.72). Results The best fitting model was a previously described 4-factor model including cognitiveperceptual, paranoid, negative, and disorganized domains. Correlations between the derived SPQ domains and the PAS score ranged r=.26–.39, and correlations between the SPQ domains and the SAS ranged r=.07–.41. Conclusions The present findings support a 4-factor model over the standard 3-factor model that is typically used to derive SPQ subscale scores. The four derived domains are minimally to moderately correlated with other measures of psychosis-proneness

    An examination of the factorial structure of the Schizotypal Personality Questionnaire–Brief (SPQ-B) among undergraduate students

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    Cognitive-perceptual, interpersonal, and disorganized subscales of the Schizotypal Personality Questionnaire–Brief (SPQ-B), reflecting the three commonly used subscales of the full-version SPQ, have been used in a number of studies. However, the factorial validity of SPQB subscales remains to be clarified. Utilizing data from 825 undergraduate students, confirmatory factor analyses involving the 22 items of the SPQ-B were conducted. A significant χ2 difference test favored the 3-factor over the 1-factor model and fit indices for the 3-factor model were generally satisfactory. However, several of the items may index more than one of the hypothesized factors, so the item-factor separation is not sharp. Thus, more research is needed on the factorial validity of the increasingly used SPQ-B subscales

    Spectropolarimetric measurements of hidden broad lines in nearby megamaser galaxies: a lack of clear evidence for a correlation between black hole masses and virial products

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    High-accuracy black hole (BH) masses require excellent spatial resolution that is only achievable for galaxies within ~100 Mpc using present-day technology. At larger distances, BH masses are often estimated with single-epoch scaling relations for active galactic nuclei. This method requires only luminosity and the velocity dispersion of the broad line region (BLR) to calculate a virial product, and an additional virial factor, ff, to determine BH mass. The accuracy of these single-epoch masses, however, is unknown, and there are few empirical constraints on the variance of ff between objects. We attempt to calibrate single-epoch BH masses using spectropolarimetric measurements of nine megamaser galaxies from which we measure the velocity distribution of the BLR. We do not find strong evidence for a correlation between the virial products used for single-epoch masses and dynamical mass, both for the megamaser sample alone and when combined with dynamical masses from reverberation mapping modeling. Furthermore, we find evidence that the virial parameter ff varies between objects, but we do not find strong evidence for a correlation with other observable parameters such as luminosity or broad line width. Although we cannot definitively rule out the existence of any correlation between dynamical mass and virial product, we find tension between allowed ff values for masers and those widely used in the literature. We conclude that the single-epoch method requires further investigation if it is to be used successfully to infer BH masses.Comment: 27 pages, 16 figures, resubmitted to ApJ after incorporating reviewer's comments. Corrected Figure 8, main results do not chang

    Schizotypy and Nicotine, Alcohol, and Cannabis Use in a Non-Psychiatric Sample

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    Schizotypy is a multidimensional personality construct that is characterized by perceptual abnormalities, social withdrawal, mild suspiciousness, and odd thinking patterns. This study examined the relationship between four dimensions of self-reported schizotypy and substance use involving nicotine, alcohol, and cannabis, in undergraduate students. Results showed that higher levels of disorganized schizotypy, or odd thinking and behavior, were associated with greater indices of use of all three substances. Furthermore, higher cognitive-perceptual schizotypy was selectively associated with cannabis use. Results confirm findings of recent research that has discovered associations among schizotypy and substance use, highlighting links between behavioral traits and use of nicotine, alcohol, and cannabis. This study is one of the first to examine a wide range of schizotypy domains, and to show selective effects of the disorganized domain of schizotypy

    J-band variability of M dwarfs in the WFCAM Transit Survey

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    We present an analysis of the photometric variability of M dwarfs in the Wide Field Camera (WFCAM) Transit Survey. Although periodic light-curve variability in low mass stars is generally dominated by photospheric star spot activity, M dwarf variability in the J band has not been as thoroughly investigated as at visible wavelengths. Spectral type estimates for a sample of over 200 000 objects are made using spectral type-colour relations, and over 9600 dwarfs (J 0.2 mag flaring event from an M4V star in our sample.Peer reviewe

    Inelastic Proton Scattering to M_1 States in 12-C, 24-Mg, and 28-Si at 62 MeV

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    This work was supported by National Science Foundation Grants PHY 76-84033A01, PHY 78-22774, and Indiana Universit

    Developing implementation research capacity: longitudinal evaluation of the King's College London Implementation Science Masterclass, 2014-2019.

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    BACKGROUND: Despite an increasing number of training opportunities in implementation science becoming available, the demand for training amongst researchers and practitioners is unmet. To address this training shortfall, we developed the King's College London 'Implementation Science Masterclass' (ISM), an innovative 2-day programme (and currently the largest of its kind in Europe), developed and delivered by an international faculty of implementation experts. METHODS: This paper describes the ISM and provides delegates' quantitative and qualitative evaluations (gathered through a survey at the end of the ISM) and faculty reflections over the period it has been running (2014-2019). RESULTS: Across the 6-year evaluation, a total of 501 delegates have attended the ISM, with numbers increasing yearly from 40 (in 2014) to 147 (in 2019). Delegates represent a diversity of backgrounds and 29 countries from across the world. The overall response rate for the delegate survey was 64.5% (323/501). Annually, the ISM has been rated 'highly' in terms of delegates' overall impression (92%), clear and relevant learning objectives (90% and 94%, respectively), the course duration (85%), pace (86%) and academic level 87%), and the support provided on the day (92%). Seventy-one percent of delegates reported the ISM would have an impact on how they approached their future work. Qualitative feedback revealed key strengths include the opportunities to meet with an international and diverse pool of experts and individuals working in the field, the interactive nature of the workshops and training sessions, and the breadth of topics and contexts covered. CONCLUSIONS: Yearly, the UK ISM has grown, both in size and in its international reach. Rated consistently favourably by delegates, the ISM helps to tackle current training demands from all those interested in learning and building their skills in implementation science. Evaluation of the ISM will continue to be an annual iterative process, reflective of changes in the evidence base and delegates changing needs as the field evolves

    Anomalous interactions in confined charge-stabilized colloid

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    Charge-stabilized colloidal spheres dispersed in weak 1:1 electrolytes are supposed to repel each other. Consequently, experimental evidence for anomalous long-ranged like-charged attractions induced by geometric confinement inspired a burst of activity. This has largely subsided because of nagging doubts regarding the experiments' reliability and interpretation. We describe a new class of thermodynamically self-consistent colloidal interaction measurements that confirm the appearance of pairwise attractions among colloidal spheres confined by one or two bounding walls. In addition to supporting previous claims for this as-yet unexplained effect, these measurements also cast new light on its mechanism.Comment: 8 pages, 5 figures, RevTeX4. Conference proceedings for CODEF-04, Colloidal Dispersions in External Fields, March 29 - April 1, 200
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