26 research outputs found

    The physical and dynamical structure of Serpens - Two very different sub-(proto)clusters

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    Context. The Serpens North cluster is a nearby low mass star forming region which is part of the Gould belt. It contains a range of young stars thought to correspond to two different bursts of star formation and provides the opportunity to study different stages of cluster formation. Aims. This work aims to study the molecular gas in the Serpens North cluster to probe the origin of the most recent burst of star formation in Serpens. Methods. Transitions of the C17O and C18O observed with the IRAM 30 m telescope and JCMT are used to study the mass and velocity structure of the region while the physical properties of the gas are derived using LTE and non-LTE analyses of the three lowest transitions of C18O. Results. The molecular emission traces the two centres of star formation which are seen in submillimetre dust continuum emission. In the ~40 NW sub-cluster the gas and dust emission trace the same structures although there is evidence of some depletion of the gas phase C18O. The gas has a very uniform temperature (~10 K) and velocity (~8.5 km s-1) throughout the region. This is in marked contrast to the SE sub-cluster. In this region the dust and the gas trace different features, with the temperature peaking between the submillimetre continuum sources, reaching up to ~14 K. The gas in this region has double peaked line profiles which reveal the presence of a second cloud in the line of sight. The submillimetre dust continuum sources predominantly appear located in the interface region between the two clouds. Conclusions. Even though they are at a similar stage of evolution, the two Serpens sub-clusters have very different characteristics. We propose that these differences are linked to the initial trigger of the collapse in the regions and suggest that a cloud-cloud collision could explain the observed properties

    Psychology as a natural science in the eighteenth century

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    Psychology considered as a natural science began as Aristotelian "physics" or "natural philosophy" of the soul. C. Wolff placed psychology under metaphysics, coordinate with cosmology. Scottish thinkers placed it within moral philosophy, but distinguished its "physical" laws from properly moral laws (for guiding conduct). Several Germans sought to establish an autonomous empirical psychology as a branch of natural science. British and French visual theorists developed mathematically precise theories of size and distance perception; they created instruments to test these theories and to measure visual phenomena such as the duration of visual impressions. These investigators typically were dualists who included mental phenomena within nature

    Genomic Relationships, Novel Loci, and Pleiotropic Mechanisms across Eight Psychiatric Disorders

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    Genetic influences on psychiatric disorders transcend diagnostic boundaries, suggesting substantial pleiotropy of contributing loci. However, the nature and mechanisms of these pleiotropic effects remain unclear. We performed analyses of 232,964 cases and 494,162 controls from genome-wide studies of anorexia nervosa, attention-deficit/hyper-activity disorder, autism spectrum disorder, bipolar disorder, major depression, obsessive-compulsive disorder, schizophrenia, and Tourette syndrome. Genetic correlation analyses revealed a meaningful structure within the eight disorders, identifying three groups of inter-related disorders. Meta-analysis across these eight disorders detected 109 loci associated with at least two psychiatric disorders, including 23 loci with pleiotropic effects on four or more disorders and 11 loci with antagonistic effects on multiple disorders. The pleiotropic loci are located within genes that show heightened expression in the brain throughout the lifespan, beginning prenatally in the second trimester, and play prominent roles in neurodevelopmental processes. These findings have important implications for psychiatric nosology, drug development, and risk prediction.Peer reviewe

    The National Early Warning Score and its subcomponents recorded within ±24 hours of emergency medical admission are poor predictors of hospital-acquired acute kidney injury

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    YesBackground: Hospital-acquired Acute Kidney Injury (H-AKI) is a common cause of avoidable morbidity and mortality. Aim: To determine if the patients’ vital signs data as defined by a National Early Warning Score (NEWS), can predict H-AKI following emergency admission to hospital. Methods: Analyses of emergency admissions to York hospital over 24-months with NEWS data. We report the area under the curve (AUC) for logistic regression models that used the index NEWS (model A0), plus age and sex (A1), plus subcomponents of NEWS (A2) and two-way interactions (A3). Likewise for maximum NEWS (models B0,B1,B2,B3). Results: 4.05% (1361/33608) of emergency admissions had H-AKI. Models using the index NEWS had the lower AUCs (0.59 to 0.68) than models using the maximum NEWS AUCs (0.75 to 0.77). The maximum NEWS model (B3) was more sensitivity than the index NEWS model (A0) (67.60% vs 19.84%) but identified twice as many cases as being at risk of H-AKI (9581 vs 4099) at a NEWS of 5. Conclusions: The index NEWS is a poor predictor of H-AKI. The maximum NEWS is a better predictor but seems unfeasible because it is only knowable in retrospect and is associated with a substantial increase in workload albeit with improved sensitivity.The Health Foundatio

    Edwin F. Ladd Papers, 1890-1966

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    First chemistry professor at North Dakota Agricultural College (now NDSU), later president of NDAC, before becoming a U.S. Senator for North Dakota

    Initial Development of a Concept Inventory to Assess Size, Scale, and Structure in Introductory Astronomy

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    Research has shown that undergraduates have problems understanding astronomical concepts, especially size, scale, and structure. One way to evaluate understanding is to use concept inventories. Therefore, the purpose of this study was to begin the development of the Size, Scale, and Structure Concept Inventory (S3CI) to assess understanding of these concepts in introductory undergraduate astronomy courses for majors and non-majors. A secondary purpose was to determine the impact of a newly developed WorldWide Telescope (WWT) enhanced lab on parallax, part of a suite of WWT enriched labs for introductory astronomy courses currently under development. We present in this paper preliminary results from the first WWT-enhanced lab on parallax. In Fall 2013, a beta version of the S3CI was piloted in an introductory astronomy course at a small private university. An item analysis was done and estimates of internal consistency reliability were determined using the Kuder-Richardson Formula #20 (KR20). The impact of the newly developed lab was also evaluated using a sub-test of six questions from the S3CI

    The Size, Scale, and Structure Concept Inventory (S3CI) for Astronomy

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    We present a concept inventory to evaluate student understanding of size, scale, and structure concepts in the astronomical context. Students harbor misconceptions regarding these concepts, and these misconceptions often persist even after instruction. Evaluation of these concepts prior to as well as after instruction can ensure misconceptions are addressed. Currently, no concept inventories focus exclusively on these geometrical ideas, so we have developed the Size, Scale and Structure Concept Inventory (S3CI). In fall 2013, we piloted a 24-item version of the S3CI in an introductory astronomy course at a small private university. We performed an item analysis and estimated the internal consistency reliability for the instrument. Based on these analyses, problematic questions were revised for a second version. We discuss the results from the pilot phase and preview our updated test in this work. A valid and reliable concept inventory has the potential to accurately evaluate undergraduates’ understanding of size, scale, and structure concepts in the astronomical context, as well as assess conceptual change after targeted instruction. Lessons learned in the evaluation of the initial version of the S3CI can guide future development of this and other astronomical concept inventories. Instructors interested in participating in the ongoing development of the S3CI should contact the authors
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