1,924 research outputs found
The POKEMON Speckle Survey of Nearby M dwarfs. I. New Discoveries
M dwarfs are favorable targets for exoplanet detection with current
instrumentation, but stellar companions can induce false positives and inhibit
planet characterization. Knowledge of stellar companions is also critical to
our understanding of how binary stars form and evolve. We have therefore
conducted a survey of stellar companions around nearby M dwarfs, and here we
present our new discoveries. Using the DSSI speckle imager at the 4.3-meter
Lowell Discovery Telescope, and the similar NESSI instrument at the 3.5-meter
WIYN telescope, we carried out a volume-limited survey of M-dwarf multiplicity
to 15 parsecs, with a special emphasis on including the later M dwarfs that
were overlooked in previous surveys. Additional brighter targets at larger
distances were included for a total sample size of 1070 M dwarfs. Observations
of these 1070 targets revealed 26 new companions; 22 of these systems were
previously thought to be single. If all new discoveries are confirmed, then the
number of known multiples in the sample will increase by 7.6%. Using our
observed properties, as well as the parallaxes and 2MASS K magnitudes for these
objects, we calculate the projected separation, and estimate the mass ratio and
component spectral types, for these systems. We report the discovery of a new
M-dwarf companion to the white dwarf Wolf 672 A, which hosts a known M-dwarf
companion as well, making the system trinary. We also examine the possibility
that the new companion to 2MASS J13092185-2330350 is a brown dwarf. Finally, we
discuss initial insights from the POKEMON survey.Comment: 23 pages, 6 figures, 5 table
DNA hypomethylation during MSC chondrogenesis occurs predominantly at enhancer regions
Regulation of transcription occurs in a cell type specific manner orchestrated by epigenetic mechanisms including DNA methylation. Methylation changes may also play a key role in lineage specification during stem cell differentiation. To further our understanding of epigenetic regulation in chondrocytes we characterised the DNA methylation changes during chondrogenesis of mesenchymal stem cells (MSCs) by Infinium 450 K methylation array. Significant DNA hypomethylation was identified during chondrogenic differentiation including changes at many key cartilage gene loci. Integration with chondrogenesis gene expression data revealed an enrichment of significant CpGs in upregulated genes, while characterisation of significant CpG loci indicated their predominant localisation to enhancer regions. Comparison with methylation profiles of other tissues, including healthy and diseased adult cartilage, identified chondrocyte-specific regions of hypomethylation and the overlap with differentially methylated CpGs in osteoarthritis. Taken together we have associated DNA methylation levels with the chondrocyte phenotype. The consequences of which has potential to improve cartilage generation for tissue engineering purposes and also to provide context for observed methylation changes in cartilage diseases such as osteoarthritis
Geographic Variation in Pneumonia and Influenza in Long-Term Care Facilities:A National Study
There is large county-level geographic variation in pneumonia and influenza hospitalizations among short-stay and long-stay long-term care facility residents in the United States. Long-term care facilities in counties in the Southern and Midwestern regions had the highest rates of pneumonia and influenza from 2013 to 2015. Future research should identify reasons for these geographic differences
New sequestrate fungi from Guyana: Jimtrappea guyanensis gen. sp. nov., Castellanea pakaraimophila gen. sp. nov., and Costatisporus cyanescens gen. sp. nov.(Boletaceae, Boletales)
Jimtrappea guyanensis gen. sp. nov., Castellanea pakaraimophila gen. sp. nov., and Costatisporus cyanescens gen. sp. nov. are described as new to science. These sequestrate, hypogeous fungi were collected in Guyana under closed canopy tropical forests in association with ectomycorrhizal (ECM) host tree genera Dicymbe (Fabaceae subfam. Caesalpinioideae), Aldina (Fabaceae subfam. Papilionoideae), and Pakaraimaea (Dipterocarpaceae). Molecular data place these fungi in Boletaceae (Boletales, Agaricomycetes, Basidiomycota) and inform their relationships to other known epigeous and sequestrate taxa within that family. Macro- and micromorphological characters, habitat, and multi-locus DNA sequence data are provided for each new taxon. Unique morphological features and a molecular phylogenetic analysis of 185 taxa across the order Boletales justify the recognition of the three new genera
Search Engine Advertising: Channel Substitution when Pricing Ads to Context
We explore substitution patterns across advertising platforms. Using data on the advertising prices paid by lawyers for 139 Google search terms in 195 locations, we exploit a natural experiment in âambulance-chaserâ regulations across states. When lawyers cannot contact clients by mail, advertising prices per click for search engine advertisements are 5%â7% higher. Therefore, online advertising substitutes for offline advertising. This substitution toward online advertising is strongest in markets with fewer customers, suggesting that the relationship between the online and offline media is mediated by the marketers' need to target their communications.NET Institut
Advanced EFL learners' beliefs about language learning and teaching: a comparison between grammar, pronunciation, and vocabulary
This paper reports on the results of a study exploring learnersâ beliefs on the learning and teaching of English grammar, pronunciation and vocabulary at tertiary level. While the importance of learnersâ beliefs on the acquisition process is generally recognized, few studies have focussed on and compared learnersâ views on different components of the language system. A questionnaire containing semantic scale and Likert scale items probing learnersâ views on grammar, pronunciation and vocabulary was designed and completed by 117 native speakers of Dutch in Flanders, who were studying English at university. The analysis of the responses revealed that (i) vocabulary was considered to be different from grammar and pronunciation, both in the extent to which an incorrect use could lead to communication breakdown and with respect to the learnersâ language learning strategies, (ii) learners believed in the feasibility of achieving a native-like proficiency in all three components, and (iii) in-class grammar, pronunciation and vocabulary exercises were considered to be useful, even at tertiary level. The results are discussed in light of pedagogical approaches to language teaching
Runx1 deficiency protects against adverse cardiac remodeling following myocardial infarction
Background: Myocardial infarction (MI) is a leading cause of heart failure and death worldwide. Preservation of contractile function and protection against adverse changes in ventricular architecture (cardiac remodeling) are key factors to limiting progression of this condition to heart failure. Consequently, new therapeutic targets are urgently required to achieve this aim. Expression of the Runx1 transcription factor is increased in adult cardiomyocytes after MI; however, the functional role of Runx1 in the heart is unknown.
Methods: To address this question, we have generated a novel tamoxifen-inducible cardiomyocyte-specific Runx1-deficient mouse. Mice were subjected to MI by means of coronary artery ligation. Cardiac remodeling and contractile function were assessed extensively at the whole-heart, cardiomyocyte, and molecular levels.
Results: Runx1-deficient mice were protected against adverse cardiac remodeling after MI, maintaining ventricular wall thickness and contractile function. Furthermore, these mice lacked eccentric hypertrophy, and their cardiomyocytes exhibited markedly improved calcium handling. At the mechanistic level, these effects were achieved through increased phosphorylation of phospholamban by protein kinase A and relief of sarco/endoplasmic reticulum Ca2+-ATPase inhibition. Enhanced sarco/endoplasmic reticulum Ca2+-ATPase activity in Runx1-deficient mice increased sarcoplasmic reticulum calcium content and sarcoplasmic reticulumâmediated calcium release, preserving cardiomyocyte contraction after MI.
Conclusions: Our data identified Runx1 as a novel therapeutic target with translational potential to counteract the effects of adverse cardiac remodeling, thereby improving survival and quality of life among patients with MI
Physiotherapy and occupational therapy vs no therapy in mild to moderate Parkinson disease: a randomized clinical trial
IMPORTANCE It is unclear whether physiotherapy and occupational therapy are clinically effective and cost-effective in Parkinson disease (PD).
OBJECTIVE To perform a large pragmatic randomized clinical trial to evaluate the clinical effectiveness of individualized physiotherapy and occupational therapy in PD.
DESIGN, SETTING, AND PARTICIPANTS The PD REHAB Trial was a multicenter, open-label, parallel group, controlled efficacy trial. A total of 762 patients with mild to moderate PD were recruited from 38 sites across the United Kingdom. Recruitment took place between October 2009 and June 2012, with 15 months of follow-up.
INTERVENTIONS Participants with limitations in activities of daily living (ADL) were randomized to physiotherapy and occupational therapy or no therapy.
MAIN OUTCOMES AND MEASURES The primary outcome was the Nottingham Extended Activities of Daily Living (NEADL) Scale score at 3 months after randomization. Secondary outcomes were health-related quality of life (assessed by Parkinson Disease Questionnaireâ39 and EuroQol-5D); adverse events; and caregiver quality of life. Outcomes were assessed before trial entry and then 3, 9, and 15 months after randomization.
RESULTS Of the 762 patients included in the study (mean [SD] age, 70 [9.1] years), 381 received physiotherapy and occupational therapy and 381 received no therapy. At 3 months, there was no difference between groups in NEADL total score (difference, 0.5 points; 95%CI, â0.7 to 1.7; P = .41) or Parkinson Disease Questionnaireâ39 summary index (0.007 points; 95%CI, â1.5 to 1.5; P = .99). The EuroQol-5D quotient was of borderline significance in favor of therapy (â0.03; 95%CI, â0.07 to â0.002; P = .04). The median therapist contact time was 4 visits of 58 minutes over 8 weeks. Repeated-measures analysis showed no difference in NEADL total score, but Parkinson Disease Questionnaireâ39 summary index (diverging 1.6 points per annum; 95%CI, 0.47 to 2.62; P = .005) and EuroQol-5D score (0.02; 95%CI, 0.00007 to 0.03; P = .04) showed small differences in favor of therapy. There was no difference in adverse events.
CONCLUSIONS AND RELEVANCE Physiotherapy and occupational therapy were not associated with immediate or medium-term clinically meaningful improvements in ADL or quality of life in mild to moderate PD. This evidence does not support the use of low-dose, patient-centered, goal-directed physiotherapy and occupational therapy in patients in the early stages of PD. Future research should explore the development and testing of more structured and intensive physical and occupational therapy programs in patients with all stages of PD
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