108 research outputs found

    The Carnegie Supernova Project. I. Third Photometry Data Release of Low-redshift Type Ia Supernovae and Other White Dwarf Explosions

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    We present final natural-system optical (ugriBV) and near-infrared (YJH) photometry of 134 supernovae (SNe) with probable white dwarf progenitors that were observed in 2004-2009 as part of the first stage of the Carnegie Supernova Project (CSP-I). The sample consists of 123 Type Ia SNe, 5 Type Iax SNe, 2 super-Chandrasekhar SN candidates, 2 Type Ia SNe interacting with circumstellar matter, and 2 SN 2006bt-like events. The redshifts of the objects range from to 0.0835; the median redshift is 0.0241. For 120 (90%) of these SNe, near-infrared photometry was obtained. Average optical extinction coefficients and color terms are derived and demonstrated to be stable during the five CSP-I observing campaigns. Measurements of the CSP-I near-infrared bandpasses are also described, and near-infrared color terms are estimated through synthetic photometry of stellar atmosphere models. Optical and near-infrared magnitudes of local sequences of tertiary standard stars for each supernova are given, and a new calibration of Y-band magnitudes of the Persson et al. standards in the CSP-I natural system is presented.Fil: Krisciunas, Kevin. Texas A&M University; Estados UnidosFil: Contreras, Carlos. University Aarhus; Dinamarca. Las Campanas Observatory; ChileFil: Burns, Christopher R.. Las Campanas Observatory; ChileFil: Phillips, M. M.. Las Campanas Observatory; ChileFil: Stritzinger, Maximilian D.. Las Campanas Observatory; Chile. University Aarhus; DinamarcaFil: Morrell, Nidia Irene. Las Campanas Observatory; ChileFil: Hamuy, Mario. Universidad de Chile; ChileFil: Anais, Jorge. Las Campanas Observatory; ChileFil: Boldt, Luis. Las Campanas Observatory; ChileFil: Busta, Luis. Las Campanas Observatory; ChileFil: Campillay, Abdo. Las Campanas Observatory; ChileFil: Castellón, Sergio. Las Campanas Observatory; ChileFil: Folatelli, Gaston. Las Campanas Observatory; Chile. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Freedman, Wendy L.. University of Chicago; Estados UnidosFil: González, Consuelo. Las Campanas Observatory; ChileFil: Hsiao, Eric Y.. Florida State University; Estados Unidos. University Aarhus; Dinamarca. Las Campanas Observatory; ChileFil: Krzeminski, Wojtek. Las Campanas Observatory; ChileFil: Persson, Sven Eric. Carnegie Observatories;Fil: Roth, Miguel. Gmto Corporation; Chile. Las Campanas Observatory; ChileFil: Salgado, Francisco. Leiden Observatory Research Institute; . Las Campanas Observatory; ChileFil: Serón, Jacqueline. Las Campanas Observatory; Chile. Cerro Tololo Inter American Observatory; ChileFil: Suntzeff, Nicholas B.. Texas A&M University; Estados UnidosFil: Torres, Simón. Soar Telescope; Chile. Las Campanas Observatory; ChileFil: Filippenko, Alexei V.. University of California at Berkeley; Estados UnidosFil: Li, Weidong. University of California at Berkeley; Estados UnidosFil: Madore, Barry F.. Jet Propulsion Laboratory, California Institute Of Technology; . Las Campanas Observatory; ChileFil: DePoy, D.L.. Texas A&M University; Estados UnidosFil: Marshall, Jennifer L.. Texas A&M University; Estados UnidosFil: Rheault, Jean Philippe. Texas A&M University; Estados UnidosFil: Villanueva, Steven. Texas A&M University; Estados Unidos. Ohio State University; Estados Unido

    PLoS One

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    Diffusion MRI is extensively used to investigate changes in white matter microstructure. However, diffusion measures within white matter tissue can be affected by partial volume effects due to cerebrospinal fluid and white matter hyperintensities, especially in the aging brain. In previous aging studies, the cingulum bundle that plays a central role in the architecture of the brain networks supporting cognitive functions has been associated with cognitive deficits. However, most of these studies did not consider the partial volume effects on diffusion measures. The aim of this study was to evaluate the effect of free water elimination on diffusion measures of the cingulum in a group of 68 healthy elderly individuals. We first determined the effect of free water elimination on conventional DTI measures and then examined the effect of free water elimination on verbal fluency performance over 12 years. The cingulum bundle was reconstructed with a tractography pipeline including a white matter hyperintensities mask to limit the negative impact of hyperintensities on fiber tracking algorithms. We observed that free water elimination increased the ability of conventional DTI measures to detect associations between tissue diffusion measures of the cingulum and changes in verbal fluency in older individuals. Moreover, free water content and mean diffusivity measured along the cingulum were independently associated with changes in verbal fluency. This suggests that both tissue modifications and an increase in interstitial isotropic water would contribute to cognitive decline. These observations reinforce the importance of using free water elimination when studying brain aging and indicate that free water itself could be a relevant marker for age-related cingulum white matter modifications and cognitive decline

    Attraction and repulsion of mobile wild organisms to finfish and shellfish aquaculture: a review

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    Knowledge of aquaculture–environment interactions is essential for the development of a sustainable aquaculture industry and efficient marine spatial planning. The effects of fish and shellfish farming on sessile wild populations, particularly infauna, have been studied intensively. Mobile fauna, including crustaceans, fish, birds and marine mammals, also interact with aquaculture operations, but the interactions are more complex and these animals may be attracted to (attraction) or show an aversion to (repulsion) farm operations with various degrees of effects. This review outlines the main mechanisms and effects of attraction and repulsion of wild animals to/from marine finfish cage and bivalve aquaculture, with a focus on effects on fisheries-related species. Effects considered in this review include those related to the provision of physical structure (farm infrastructure acting as fish aggregating devices (FADs) or artificial reefs (ARs), the provision of food (e.g. farmed animals, waste feed and faeces, fouling organisms associated with farm structures) and some farm activities (e.g. boating, cleaning). The reviews show that the distribution of mobile organisms associated with farming structures varies over various spatial (vertical and horizontal) and temporal scales (season, feeding time, day/night period). Attraction/repulsion mechanisms have a variety of direct and indirect effects on wild organisms at the level of individuals and populations and may have implication for the management of fisheries species and the ecosystem in the context of marine spatial planning. This review revealed considerable uncertainties regarding the long-term and ecosystem-wide consequences of these interactions. The use of modelling may help better understand consequences, but long-term studies are necessary to better elucidate effects

    Reproducibility of goniometric measurement of the knee in the in-hospital phase following total knee arthroplasty

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    <p>Abstract</p> <p>Background</p> <p>The objective of the present study was to assess interobserver reproducibility (in terms of reliability and agreement) of active and passive measurements of knee RoM using a long arm goniometer, performed by trained physical therapists in a clinical setting in total knee arthroplasty patients, within the first four days after surgery.</p> <p>Methods</p> <p>Test-retest analysis</p> <p>Setting: University hospital departments of orthopaedics and physical therapy</p> <p>Participants: Two experienced physical therapists assessed 30 patients, three days after total knee arthroplasty.</p> <p>Main outcome measure: RoM measurement using a long-arm (50 cm) goniometer</p> <p>Agreement was calculated as the mean difference between observers ± 95% CI of this mean difference. The intraclass correlation coefficient (ICC) was calculated as a measure of reliability, based on two-way random effects analysis of variance.</p> <p>Results</p> <p>The lowest level of agreement was that for measurement of passive flexion with the patient in supine position (mean difference 1.4°; limits of agreement 16.2° to 19° for the difference between the two observers. The highest levels of agreement were found for measurement of passive flexion with the patient in sitting position and for measurement of passive extension (mean difference 2.7°; limits of agreement -6.7 to 12.1 and mean difference 2.2°; limits of agreement -6.2 to 10.6 degrees, respectively). The ability to differentiate between subjects ranged from 0.62 for measurement of passive extension to 0.89 for measurements of active flexion (ICC values).</p> <p>Conclusion</p> <p>Interobserver agreement for flexion as well as extension was only fair. When two different observers assess the same patients in the acute phase after total knee arthroplasty using a long arm goniometer, differences in RoM of less than eight degrees cannot be distinguished from measurement error. Reliability was found to be acceptable for comparison on group level, but poor for individual comparisons over time.</p

    Tractography passes the test: Results from the diffusion-simulated connectivity (disco) challenge.

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    Estimating structural connectivity from diffusion-weighted magnetic resonance imaging is a challenging task, partly due to the presence of false-positive connections and the misestimation of connection weights. Building on previous efforts, the MICCAI-CDMRI Diffusion-Simulated Connectivity (DiSCo) challenge was carried out to evaluate state-of-the-art connectivity methods using novel large-scale numerical phantoms. The diffusion signal for the phantoms was obtained from Monte Carlo simulations. The results of the challenge suggest that methods selected by the 14 teams participating in the challenge can provide high correlations between estimated and ground-truth connectivity weights, in complex numerical environments. Additionally, the methods used by the participating teams were able to accurately identify the binary connectivity of the numerical dataset. However, specific false positive and false negative connections were consistently estimated across all methods. Although the challenge dataset doesn't capture the complexity of a real brain, it provided unique data with known macrostructure and microstructure ground-truth properties to facilitate the development of connectivity estimation methods

    Implementation strategies for knowledge products in primary healthcare: A systematic review of systematic reviews

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    BACKGROUND: The underuse or overuse of knowledge products leads to waste in healthcare, and primary care is no exception. OBJECTIVE: We aimed to characterize which knowledge products are frequently implemented, the implementation strategies used in primary care, and the implementation outcomes that are measured. METHODS: We performed a systematic review of systematic reviews (SR) using the Cochrane systematic approach to include eligible SR. The inclusion criteria were: any primary care contexts; healthcare professionals and patients; any EPOC implementation strategies of specified knowledge products; any comparator; and any implementation outcomes based on the Proctor framework. We searched the Medline, EMBASE, CINAHL, Ovid PsycINFO, Web of Science, and Cochrane Library databases from their inception to October 2019, without any restriction. We searched the references of the included SR. Pairs of reviewers independently performed selection, data extraction and methodological quality assessment with AMSTAR 2. Data extraction was informed by EPOC taxonomy for implementation strategies and the Proctor framework for implementation outcomes. We performed a descriptive analysis and summarized the results using a narrative synthesis. RESULTS: Of the 11,101 records identified, 81 SR were included. Forty-seven SR involved healthcare professionals alone. Fifteen SR were of high or moderate methodological quality. Most of them addressed one type of knowledge product (56/81), common clinical practice guidelines (26/56) or management, and behavioural or pharmacological health interventions (24/56). Mixed strategies were used for implementation (67/81), predominantly educational-based (meetings in 60/81, materials distribution in 59/81, and academic detailing in 45/81), reminder (53/81) and audit and feedback (40/81) strategies. Education meetings (P=.13) and academic detailing (P=.11) seem to be more used when the population is composed of Healthcare professionals alone. The improvement of the adoption of knowledge products was the most commonly measured outcome (72/81). The evidence level was reported in 10/81 SR on 62 outcomes (including 48 improvement of adoption), of which 16 outcomes were of moderate or high level. CONCLUSIONS: Clinical practice guidelines and management, behavioural or pharmacological health interventions are the most commonly implemented knowledge products through the mixed use of educational, reminders and audit and feedback strategies. There is need for a strong methodology for the SR of RCTs to explore their effectiveness and the whole cascade of implementation outcomes. CLINICALTRIAL: Not applicable

    Tractography dissection variability: What happens when 42 groups dissect 14 white matter bundles on the same dataset?

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    White matter bundle segmentation using diffusion MRI fiber tractography has become the method of choice to identify white matter fiber pathways in vivo in human brains. However, like other analyses of complex data, there is considerable variability in segmentation protocols and techniques. This can result in different reconstructions of the same intended white matter pathways, which directly affects tractography results, quantification, and interpretation. In this study, we aim to evaluate and quantify the variability that arises from different protocols for bundle segmentation. Through an open call to users of fiber tractography, including anatomists, clinicians, and algorithm developers, 42 independent teams were given processed sets of human whole-brain streamlines and asked to segment 14 white matter fascicles on six subjects. In total, we received 57 different bundle segmentation protocols, which enabled detailed volume-based and streamline-based analyses of agreement and disagreement among protocols for each fiber pathway. Results show that even when given the exact same sets of underlying streamlines, the variability across protocols for bundle segmentation is greater than all other sources of variability in the virtual dissection process, including variability within protocols and variability across subjects. In order to foster the use of tractography bundle dissection in routine clinical settings, and as a fundamental analytical tool, future endeavors must aim to resolve and reduce this heterogeneity. Although external validation is needed to verify the anatomical accuracy of bundle dissections, reducing heterogeneity is a step towards reproducible research and may be achieved through the use of standard nomenclature and definitions of white matter bundles and well-chosen constraints and decisions in the dissection process

    Global Variation of Nutritional Status in Children Undergoing Chronic Peritoneal Dialysis : A Longitudinal Study of the International Pediatric Peritoneal Dialysis Network

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    While children approaching end-stage kidney disease (ESKD) are considered at risk of uremic anorexia and underweight they are also exposed to the global obesity epidemic. We sought to investigate the variation of nutritional status in children undergoing chronic peritoneal dialysis (CPD) around the globe. The distribution and course of body mass index (BMI) standard deviation score over time was examined prospectively in 1001 children and adolescents from 35 countries starting CPD who were followed in the International Pediatric PD Network (IPPN) Registry. The overall prevalence of underweight, and overweight/obesity at start of CPD was 8.9% and 19.7%, respectively. Underweight was most prevalent in South and Southeast Asia (20%), Central Europe (16.7%) and Turkey (15.2%), whereas overweight and obesity were most common in the Middle East (40%) and the US (33%). BMI SDS at PD initiation was associated positively with current eGFR and gastrostomy feeding prior to PD start. Over the course of PD BMI SDS tended to increase on CPD in underweight and normal weight children, whereas it decreased in initially overweight patients. In infancy, mortality risk was amplified by obesity, whereas in older children mortality was markedly increased in association with underweight. Both underweight and overweight are prevalent in pediatric ESKD, with the prevalence varying across the globe. Late dialysis start is associated with underweight, while enteral feeding can lead to obesity. Nutritional abnormalities tend to attenuate with time on dialysis. Mortality risk appears increased with obesity in infants and with underweight in older children.Peer reviewe

    Clinimetric evaluation of active range of motion measures in patients with non-specific neck pain: a systematic review

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    The study is to provide a critical analysis of the research literature on clinimetric properties of instruments that can be used in daily practice to measure active cervical range of motion (ACROM) in patients with non-specific neck pain. A computerized literature search was performed in Medline, Cinahl and Embase from 1982 to January 2007. Two reviewers independently assessed the clinimetric properties of identified instruments using a criteria list. The search identified a total of 33 studies, investigating three different types of measurement instruments to determine ACROM. These instruments were: (1) different types of goniometers/inclinometers, (2) visual estimation, and (3) tape measurements. Intra- and inter-observer reliability was demonstrated for the cervical range of motion instrument (CROM), Cybex electronic digital instrument (EDI-320) and a single inclinometer. The presence of agreement was assessed for the EDI-320 and a single inclinometer. The CROM received a positive rating for construct validity. When clinical acceptability is taken into account both the CROM and the single inclinometer can be considered appropriate instruments for measuring the active range of motion in patients with non-specific neck pain in daily practice. Reliability is the aspect most frequently evaluated. Agreement, validity and responsiveness are documented less frequently
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