490 research outputs found
EPIC 219388192 b - an inhabitant of the brown dwarf desert in the Ruprecht 147 open cluster
We report the discovery of EPIC 219388192 b, a transiting brown dwarf in a
5.3-day orbit around a member star of Ruprecht-147, the oldest nearby open
cluster association, which was photometrically monitored by K2 during its
Campaign 7. We combine the K2 time-series data with ground-based adaptive
optics imaging and high resolution spectroscopy to rule out false positive
scenarios and determine the main parameters of the system. EPIC 219388192 b has
a radius of =~ and mass of
=~, yielding a mean density of
~. The host star is nearly a Solar twin with
mass =~, radius
=~, effective temperature
=~K and iron abundance [Fe/H]=~dex.
Its age, spectroscopic distance, and reddening are consistent with those of
Ruprecht-147, corroborating its cluster membership. EPIC 219388192 b is the
first brown dwarf with precise determinations of mass, radius and age, and
serves as benchmark for evolutionary models in the sub-stellar regime.Comment: 13 pages, 11 figures, 4 tables, submitted to AAS Journal
Effect of physical activity, social support, and skills training on late-life emotional health: a systematic literature review and implications for public health research
Purpose: Given that emotional health is a critical component of healthy aging, we undertook a systematic literature review to assess whether current interventions can positively affect older adults’ emotional health.
Methods: A national panel of health services and mental health researchers guided the review. Eligibility criteria included community-dwelling older adult (aged ≥ 50 years) samples, reproducible interventions, and emotional health outcomes, which included multiple domains and both positive (well-being) and illness-related (anxiety) dimensions. This review focused on three types of interventions – physical activity, social support, and skills training – given their public health significance and large number of studies identified. Panel members evaluated the strength of evidence (quality and effectiveness).
Results: In all, 292 articles met inclusion criteria. These included 83 exercise/physical activity, 25 social support, and 40 skills training interventions. For evidence rating, these 148 interventions were categorized into 64 pairings by intervention type and emotional health outcome, e.g., strength training targeting loneliness or social support to address mood. 83% of these pairings were rated at least fair quality. Expert panelists found sufficient evidence of effectiveness only for skills training interventions with health outcomes of decreasing anxiety and improving quality of life and self-efficacy. Due to limitations in reviewed studies, many intervention–outcome pairings yielded insufficient evidence.
Conclusion: Skills training interventions improved several aspects of emotional health in community-dwelling older adults, while the effects for other outcomes and interventions lacked clear evidence. We discuss the implications and challenges in moving forward in this important area
Transplantation of Human Embryonic Stem Cell-Derived Retinal Pigment Epithelial Cells in Macular Degeneration
PURPOSE: Transplantation of human embryonic stem cell (hESC)-derived retinal pigment epithelial (RPE) cells offers the potential for benefit in macular degeneration. Previous trials have reported improved visual acuity (VA), but lacked detailed analysis of retinal structure and function in the treated area. DESIGN: Phase 1/2 open-label dose-escalation trial to evaluate safety and potential efficacy (clinicaltrials.gov identifier, NCT01469832). PARTICIPANTS: Twelve participants with advanced Stargardt disease (STGD1), the most common cause of macular degeneration in children and young adults. METHODS: Subretinal transplantation of up to 200 000 hESC-derived RPE cells with systemic immunosuppressive therapy for 13 weeks. MAIN OUTCOME MEASURES: The primary end points were the safety and tolerability of hESC-derived RPE cell administration. We also investigated evidence of the survival of transplanted cells and measured retinal structure and function using microperimetry and spectral-domain OCT. RESULTS: Focal areas of subretinal hyperpigmentation developed in all participants in a dose-dependent manner in the recipient retina and persisted after withdrawal of systemic immunosuppression. We found no evidence of uncontrolled proliferation or inflammatory responses. Borderline improvements in best-corrected VA in 4 participants either were unsustained or were matched by a similar improvement in the untreated contralateral eye. Microperimetry demonstrated no evidence of benefit at 12 months in the 12 participants. In one instance at the highest dose, localized retinal thinning and reduced sensitivity in the area of hyperpigmentation suggested the potential for harm. Participant-reported quality of life using the 25-item National Eye Institute Visual Function Questionnaire indicated no significant change. CONCLUSIONS: Subretinal hyperpigmentation is consistent with the survival of viable transplanted hESC-derived RPE cells, but may reflect released pigment in their absence. The findings demonstrate the value of detailed analysis of spatial correlation of retinal structure and function in determining with appropriate sensitivity the impact of cell transplantation and suggest that intervention in early stage of disease should be approached with caution. Given the slow rate of progressive degeneration at this advanced stage of disease, any protection against further deterioration may be evident only after a more extended period of observation
The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe
The preponderance of matter over antimatter in the early Universe, the
dynamics of the supernova bursts that produced the heavy elements necessary for
life and whether protons eventually decay --- these mysteries at the forefront
of particle physics and astrophysics are key to understanding the early
evolution of our Universe, its current state and its eventual fate. The
Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed
plan for a world-class experiment dedicated to addressing these questions. LBNE
is conceived around three central components: (1) a new, high-intensity
neutrino source generated from a megawatt-class proton accelerator at Fermi
National Accelerator Laboratory, (2) a near neutrino detector just downstream
of the source, and (3) a massive liquid argon time-projection chamber deployed
as a far detector deep underground at the Sanford Underground Research
Facility. This facility, located at the site of the former Homestake Mine in
Lead, South Dakota, is approximately 1,300 km from the neutrino source at
Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino
charge-parity symmetry violation and mass ordering effects. This ambitious yet
cost-effective design incorporates scalability and flexibility and can
accommodate a variety of upgrades and contributions. With its exceptional
combination of experimental configuration, technical capabilities, and
potential for transformative discoveries, LBNE promises to be a vital facility
for the field of particle physics worldwide, providing physicists from around
the globe with opportunities to collaborate in a twenty to thirty year program
of exciting science. In this document we provide a comprehensive overview of
LBNE's scientific objectives, its place in the landscape of neutrino physics
worldwide, the technologies it will incorporate and the capabilities it will
possess.Comment: Major update of previous version. This is the reference document for
LBNE science program and current status. Chapters 1, 3, and 9 provide a
comprehensive overview of LBNE's scientific objectives, its place in the
landscape of neutrino physics worldwide, the technologies it will incorporate
and the capabilities it will possess. 288 pages, 116 figure
Impact of Cultural Tourism Upon Urban Economies: An Econometric Exercise
In recent years, interest in tourism has spread rapidly throughout many small and medium European cities, which previously have not necessarily considered themselves as tourist destinations. Tourism is increasingly seen as a potential lever towards high economic growth, measured both in terms of income and employment. In the present Working Paper we report the analysis on the economic impact undertaken in the framework of the PICTURE Project, showing the results of a novel econometric exercise to statistically assess the impacts of cultural tourism upon European municipalities. More precisely the analysis aims at estimating the effects of tourism specialisation on local income and prices. The Working Paper is built as follows. Section 1 presents and discusses secondary data about tourism facts and figures, including the economic impact of tourism upon European economies, with a focus on cultural tourism. An extensive review of literature, which identifies the main categories of impacts and the currently available methodologies to assess them, is undertaken. Section 2 focuses on the state of the art. Section 3 describes the database built for the analysis, sources and variables. In order to visually represent the spatial variability of the main parameters, a series of thematic maps at NUTS 3 level(Maps of European tourism), using GIS (Geographical Information System) are also included in the Working Paper. Section 4 shows the results of the econometric analysis of European panel data for the estimation of the effects of tourism specialisation on both local incomes and prices. Section 5 concludes
Phylogeography of Sardinian Cave Salamanders (Genus Hydromantes) Is Mainly Determined by Geomorphology
Detecting the factors that determine the interruption of gene flow between populations is key to understanding how speciation occurs. In this context, caves are an excellent system for studying processes of colonization, differentiation and speciation, since they represent discrete geographical units often with known geological histories. Here, we asked whether discontinuous calcareous areas and cave systems represent major barriers to gene flow within and among the five species of Sardinian cave salamanders (genus Hydromantes) and whether intraspecific genetic structure parallels geographic distance within and among caves. We generated mitochondrial cytochrome b gene sequences from 184 individuals representing 48 populations, and used a Bayesian phylogeographic approach to infer possible areas of cladogenesis for these species and reconstruct historical and current dispersal routes among distinct populations. Our results show deep genetic divergence within and among all Sardinian cave salamander species, which can mostly be attributed to the effects of mountains and discontinuities in major calcareous areas and cave systems acting as barriers to gene flow. While these salamander species can also occur outside caves, our results indicate that there is a very poor dispersal of these species between separate cave systems
Incidence and mortality rates of selected infection-related cancers in Puerto Rico and in the United States
<p>Abstract</p> <p>Background</p> <p>In 2002, 17.8% of the global cancer burden was attributable to infections. This study assessed the age-standardized incidence and mortality rates of stomach, liver, and cervical cancer in Puerto Rico (PR) for the period 1992-2003 and compared them to those of Hispanics (USH), non-Hispanic Whites (NHW), and non-Hispanic Blacks (NHB) in the United States (US).</p> <p>Methods</p> <p>Age-standardized rates [ASR(World)] were calculated based on cancer incidence and mortality data from the PR Cancer Central Registry and SEER, using the direct method and the world population as the standard. Annual percent changes (APC) were calculated using the Poisson regression model from 1992-2003.</p> <p>Results</p> <p>The incidence and mortality rates from stomach, liver and cervical cancer were lower in NHW than PR; with the exception of mortality from cervical cancer which was similar in both populations. Meanwhile, the incidence rates of stomach, liver and cervical cancers were similar between NHB and PR; except for NHB women who had a lower incidence rate of liver cancer than women in PR. NHB had a lower mortality from liver cancer than persons in PR, and similar mortality from stomach cancer.</p> <p>Conclusions</p> <p>The burden of liver, stomach, and cervical cancer in PR compares to that of USH and NHB and continues to be a public health priority. Public health efforts are necessary to further decrease the burden of cancers associated to infections in these groups, the largest minority population groups in the US. Future studies need to identify factors that may prevent infections with cancer-related agents in these populations. Strategies to increase the use of preventive strategies, such as vaccination and screening, among minority populations should also be developed.</p
The SuperCam Instrument Suite on the Mars 2020 Rover: Science Objectives and Mast-Unit Description
On the NASA 2020 rover mission to Jezero crater, the remote determination of the texture, mineralogy and chemistry of rocks is essential to quickly and thoroughly characterize an area and to optimize the selection of samples for return to Earth. As part of the Perseverance payload, SuperCam is a suite of five techniques that provide critical and complementary observations via Laser-Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman and Luminescence (TRR/L), visible and near-infrared spectroscopy (VISIR), high-resolution color imaging (RMI), and acoustic recording (MIC). SuperCam operates at remote distances, primarily 2-7 m, while providing data at sub-mm to mm scales. We report on SuperCam's science objectives in the context of the Mars 2020 mission goals and ways the different techniques can address these questions. The instrument is made up of three separate subsystems: the Mast Unit is designed and built in France; the Body Unit is provided by the United States; the calibration target holder is contributed by Spain, and the targets themselves by the entire science team. This publication focuses on the design, development, and tests of the Mast Unit; companion papers describe the other units. The goal of this work is to provide an understanding of the technical choices made, the constraints that were imposed, and ultimately the validated performance of the flight model as it leaves Earth, and it will serve as the foundation for Mars operations and future processing of the data.In France was provided by the Centre National d'Etudes Spatiales (CNES). Human resources were provided in part by the Centre National de la Recherche Scientifique (CNRS) and universities. Funding was provided in the US by NASA's Mars Exploration Program. Some funding of data analyses at Los Alamos National Laboratory (LANL) was provided by laboratory-directed research and development funds
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