1,335 research outputs found

    Late Quaternary Relative Sea-Level Change on the West Coast of Newfoundland

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    Two revised relative sea-level (RSL) curves are presented for the Port au Choix to Daniel’s Harbour area of the Great Northern Peninsula, northwestern Newfoundland. Both curves are similar, showing continuous emergence of 120-140 m between 14 700 cal BP and present. The half-life of exponential curves fit to the RSL data is 1400 years and the rate of emergence varies from ~2.3 m per century prior to 10 000 cal BP to ~0.13 m per century since 5000 cal BP. The curves fit a general pattern of RSL history along the west coast of Newfoundland, where there is a southward transition from solely emergence to emergence followed by submergence. Isostatic depression curves are generated for four RSL records spanning the west coast. Almost double the crustal depression is recorded to the northwest, reflecting the greater glacioisostatic loading by the Laurentide Ice Sheet over southern Labrador and QuĂ©bec compared to a smaller loading centre by a regional ice complex over Newfoundland. Only the St. George’s Bay RSL record in the southwest appears to show evidence for a proglacial forebulge, when at 6000 cal BP an isostatic ridge of 4 m amplitude begins to collapse.Deux courbes du niveau marin relatif (NMR) sont prĂ©sentĂ©es pour la rĂ©gion allant de Port-au-Choix Ă  Daniel’s Harbour sur la Grande PĂ©ninsule Nord, au nord-ouest de Terre-Neuve. Les deux courbes sont semblables, montrant une Ă©mergence continue de 120 Ă  140 m entre 14 700 cal BP et l’actuel. La demi-vie des courbes exponentielles ajustĂ©es au NMR est de 1400 ans, et le taux d’émergence varie de ~2.3 m par siĂšcle avant 10 000 cal BP Ă  ~0.13 m par siĂšcle depuis 5000 cal BP. Les courbes s’ajustent au modĂšle gĂ©nĂ©ral de l’histoire du NMR de la cĂŽte ouest de Terre-Neuve, oĂč il existe une transition d’émergence seule Ă  une Ă©mergence suivie d’une submergence, en allant vers le sud. Des courbes de dĂ©pressions isostatiques prĂ©liminaires sont gĂ©nĂ©rĂ©es pour quatre chronologies du NMR couvrant la cĂŽte ouest. Presque le double de la dĂ©pression de la croĂ»te est enregistrĂ© au nord-ouest, reflĂ©tant la charge glacio-isostatique plus grande de l’Inlandsis Laurentidien sur le sud du Labrador et du QuĂ©bec comparĂ©e Ă  la charge plus faible du complexe glaciaire rĂ©gional localisĂ© sur Terre-Neuve. Seules les donnĂ©es du NMR de St. George’s Bay, au sud-ouest, semble dĂ©montrer l’affaissement du bourrelet pĂ©riphĂ©rique lorsqu’une vague isostatique de 4 m d’amplitude commence Ă  s’effondrer vers 6000 cal BP

    The BTC40 Survey for Quasars at 4.8 < z < 6

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    The BTC40 Survey for high-redshift quasars is a multicolor search using images obtained with the Big Throughput Camera (BTC) on the CTIO 4-m telescope in V, I, and z filters to search for quasars at redshifts of 4.8 < z < 6. The survey covers 40 sq. deg. in B, V, & I and 36 sq. deg. in z. Limiting magnitudes (3 sigma) reach to V = 24.6, I = 22.9 and z = 22.9. We used the (V-I) vs. (I-z) two-color diagram to select high-redshift quasar candidates from the objects classified as point sources in the imaging data. Follow-up spectroscopy with the AAT and CTIO 4-m telescopes of candidates having I < 21.5 has yielded two quasars with redshifts of z = 4.6 and z = 4.8 as well as four emission line galaxies with z = 0.6. Fainter candidates have been identified down to I = 22 for future spectroscopy on 8-m class telescopes.Comment: 27 pages, 8 figures; Accepted for publication in the Astronomical Journa

    Simulation of greenhouse gases following land-use change to bioenergy crops using the ECOSSE model : a comparison between site measurements and model predictions

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    This work contributes to the ELUM (Ecosystem Land Use Modelling & Soil Carbon GHG Flux Trial) project, which was commissioned and funded by the Energy Technologies Institute (ETI). We acknowledge the E-OBS data set from the EU-FP6 project ENSEMBLES (http://ensembles-eu.metoffice.com) and the data providers in the ECA&D project (http://www.ecad.eu).Peer reviewedPublisher PD

    Catena-[triaquabis(ÎŒ2-1,4-bis(diphenylphosphoryl)butane)nitrato-Îș2O-praseodymium(III) nitrate monohydrate methanol solvate

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    The bidentate ligand, 1,4-bis(diphenlyphosphoryl)butane (dppbO2), was used to prepare a 1D polymeric Pr(III) complex which was characterised by single-crystal X-ray diffraction.Peer reviewe

    Resources for Teaching and Assessing the Vision and Change Biology Core Concepts

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    The Vision and Change report called for the biology community to mobilize around teaching the core concepts of biology. This essay describes a collection of resources developed by several different groups that can be used to respond to the report’s call to transform undergraduate education at both the individual course and departmental levels. First, we present two frameworks that help articulate the Vision and Change core concepts, the BioCore Guide and the Conceptual Elements (CE) Framework, which can be used in mapping the core concepts onto existing curricula and designing new curricula that teach the biology core concepts. Second, we describe how the BioCore Guide and the CE Framework can be used alongside the Partnership for Undergraduate Life Sciences Education curricular rubric as a way for departments to self-assess their teaching of the core concepts. Finally, we highlight three sets of instruments that can be used to directly assess student learning of the core concepts: the Biology Card Sorting Task, the Biology Core Concept Instruments, and the Biology—Measuring Achievement and Progression in Science instruments. Approaches to using these resources independently and synergistically are discussed

    Surrogate Markers of Cardiovascular Risk and Chronic Obstructive Pulmonary Disease: A Large Case-Controlled Study.

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    Cardiovascular disease is a common comorbidity and cause of mortality in chronic obstructive pulmonary disease. A better understanding of mechanisms of cardiovascular risk in chronic obstructive pulmonary disease patients is needed to improve clinical outcomes. We hypothesized that such patients have increased arterial stiffness, wave reflections, and subclinical atherosclerosis compared with controls and that these findings would be independent of smoking status and other confounding factors. A total of 458 patients with a diagnosis of chronic obstructive pulmonary disease and 1657 controls (43% were current or ex-smokers) with no airflow limitation were matched for age, sex, and body mass index. All individuals underwent assessments of carotid-femoral (aortic) pulse wave velocity, augmentation index, and carotid intima-media thickness. The mean age of the cohort was 67±8 years and 58% were men. Patients with chronic obstructive pulmonary disease had increased aortic pulse wave velocity (9.95±2.54 versus 9.27±2.41 m/s; P<0.001), augmentation index (28±10% versus 25±10%; P<0.001), and carotid intima-media thickness (0.83±0.19 versus 0.74±0.14 mm; P<0.001) compared with controls. Chronic obstructive pulmonary disease was associated with increased levels of each vascular biomarker independently of physiological confounders, smoking, and other cardiovascular risk factors. In this large case-controlled study, chronic obstructive pulmonary disease was associated with increased arterial stiffness, wave reflections, and subclinical atherosclerosis, independently of traditional cardiovascular risk factors. These findings suggest that the cardiovascular burden observed in this condition may be mediated through these mechanisms and supports the concept that chronic obstructive pulmonary disease is an independent risk factor for cardiovascular disease

    Overuse of medications in low- and middle-income countries: a scoping review

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    OBJECTIVE: To identify and summarize the evidence about the extent of overuse of medications in low- and middle-income countries, its drivers, consequences and potential solutions. METHODS: We conducted a scoping review by searching the databases PubMed¼, Embase¼, APA PsycINFO¼ and Global Index Medicus using a combination of MeSH terms and free text words around overuse of medications and overtreatment. We included studies in any language published before 25 October 2021 that reported on the extent of overuse, its drivers, consequences and solutions. FINDINGS: We screened 3489 unique records and included 367 studies reporting on over 5.1 million prescriptions across 80 low- and middle-income countries – with studies from 58.6% (17/29) of all low-, 62.0% (31/50) of all lower-middle- and 60.0% (33/55) of all upper-middle-income countries. Of the included studies, 307 (83.7%) reported on the extent of overuse of medications, with estimates ranging from 7.3% to 98.2% (interquartile range: 30.2–64.5). Commonly overused classes included antimicrobials, psychotropic drugs, proton pump inhibitors and antihypertensive drugs. Drivers included limited knowledge of harms of overuse, polypharmacy, poor regulation and financial influences. Consequences were patient harm and cost. Only 11.4% (42/367) of studies evaluated solutions, which included regulatory reforms, educational, deprescribing and audit–feedback initiatives. CONCLUSION: Growing evidence suggests overuse of medications is widespread within low- and middle-income countries, across multiple drug classes, with few data of solutions from randomized trials. Opportunities exist to build collaborations to rigorously develop and evaluate potential solutions to reduce overuse of medications
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