1,204 research outputs found
Prospects for improved branching fractions
The experimental uncertainty on the branching fraction \b(\Lambda_c \to p
K^- \pi^+) = (5.0 \pm 1.3)% has not decreased since 1998, despite a much
larger data sample. Uncertainty in this quantity dominates that in many other
quantities, including branching fractions of to other modes,
branching fractions of -flavored baryons, and fragmentation fractions of
charmed and bottom quarks. Here we advocate a lattice QCD calculation of the
form factors in (the case
is simpler as the mass of the lepton can be neglected). Such a calculation
would yield an absolute prediction for the rate for . When combined with the lifetime, it could provide
a calibration for an improved set of branching fractions as long as
the accuracy exceeds about 25%.Comment: 8 pages, 2 figures, version to be published in Phys.\ Rev.\
SeekDeep: single-base resolution de novo clustering for amplicon deep sequencing
PCR amplicon deep sequencing continues to transform the investigation of genetic diversity in viral, bacterial, and eukaryotic populations. In eukaryotic populations such as Plasmodium falciparum infections, it is important to discriminate sequences differing by a single nucleotide polymorphism. In bacterial populations, single-base resolution can provide improved resolution towards species and strains. Here, we introduce the SeekDeep suite built around the qluster algorithm, which is capable of accurately building de novo clusters representing true, biological local haplotypes differing by just a single base. It outperforms current software, particularly at low frequencies and at low input read depths, whether resolving single-base differences or traditional OTUs. SeekDeep is open source and works with all major sequencing technologies, making it broadly useful in a wide variety of applications of amplicon deep sequencing to extract accurate and maximal biologic information
Cool Jupiters greatly outnumber their toasty siblings : Occurrence rates from the Anglo-Australian Planet Search
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©2019 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.Our understanding of planetary systems different to our own has grown dramatically in the past 30 yr. However, our efforts to ascertain the degree to which the Solar system is abnormal or unique have been hindered by the observational biases inherent to the methods that have yielded the greatest exoplanet hauls. On the basis of such surveys, one might consider our planetary system highly unusual - but the reality is that we are only now beginning to uncover the true picture. In this work, we use the full 18-yr archive of data from the Anglo-Australian Planet Search to examine the abundance of 'cool Jupiters' - analogues to the Solar system's giant planets, Jupiter and Saturn. We find that such planets are intrinsically far more common through the cosmos than their siblings, the hot Jupiters.We find that the occurrence rate of such 'cool Jupiters' is 6.73 +2.09 -1.13 per cent, almost an order of magnitude higher than the occurrence of hot Jupiters (at 0.84 +0.70 -0.20 per cent). We also find that the occurrence rate of giant planets is essentially constant beyond orbital distances of ~1 au. Our results reinforce the importance of legacy radial velocity surveys for the understanding of the Solar system's place in the cosmos.Peer reviewe
Elliptic integral evaluations of Bessel moments
We record what is known about the closed forms for various Bessel function
moments arising in quantum field theory, condensed matter theory and other
parts of mathematical physics. More generally, we develop formulae for
integrals of products of six or fewer Bessel functions. In consequence, we are
able to discover and prove closed forms for with integers and , obtaining new results
for the even moments and . We also derive new closed forms
for the odd moments with and for with , relating the latter to Green functions on
hexagonal, diamond and cubic lattices. We conjecture the values of
, make substantial progress on the evaluation of ,
and and report more limited progress regarding
, and . In the process, we obtain 8
conjectural evaluations, each of which has been checked to 1200 decimal places.
One of these lies deep in 4- dimensional quantum field theory and two are
probably provable by delicate combinatorics. There remains a hard core of five
conjectures whose proofs would be most instructive, to mathematicians and
physicists alike.Comment: 51 pages, 1 Postscript figure, uses amsmath.sty, added reference
Road Salt in Maine: An Assessment of Practices, Impacts and Safety
This report presents the results from a research project by a team from the University of Maine, in cooperation with the Maine Department of Transportation (MaineDOT), that examines the use of road salt in Maine for winter travel safety. It summarizes winter maintenance practices, changing winter weather patterns, environmental impacts and costs, and winter road safety
Habitat Selection of White-tailed Deer Fawns and their Dams in the Northern Great Plains
Habitat availability can affect important life-history traits such as survival; however, little information exists on how microhabitat characteristics found at parturition sites selected by dams and bed sites selected by their offspring differ fromthe surrounding area and from each other. Therefore, we assessed how vegetation affected maternal parturition and offspring bed site selection for white-tailed deer (Odocoileus virginianus) in the Northern Great Plains. Dams selected for sites with decreased vegetation height, potentially improving their visibility, which may increase their ability to escape approaching predators. Conversely, there was no variation between vegetative characteristics at neonate bed sites and their associated random sites, indicating grasslands provide adequate concealment for neonates. Dams possess the ability to flee from approaching predators, thus increasing the importance of visibility while giving birth. Conversely, neonates depend on fear bradycardia as their main antipredator defense, so concealment is more important. Our results suggest that vegetation structure is an important characteristic to white-tailed deer as habitat needs vary between adults and neonates
Online mindfulness stress intervention for family carers of children and adults with intellectual disabilities : feasibility randomized controlled trial
Objectives: Family carers of people with intellectual disabilities (ID) are twice as likely as other carers to experience stress and mental ill-health, but research exploring interventions is sparse. Online mindfulness may provide an accessible, cost-effective resource. The addition of guided telephone support could help to tailor an existing intervention for this population. A feasibility randomized controlled trial (RCT) was conducted to inform the development of a definitive RCT.
Methods: Sixty participants were randomized to complete Be Mindful (a brief online mindfulness intervention) either with or without additional Peer Mentor support. Feasibility of recruitment, retention, intervention adherence, and acceptability of study design were examined. Preliminary analyses were undertaken on participant-reported outcomes pre- and post-intervention. Eighteen semi-structured interviews were conducted as a process evaluation.
Results: Feasibility outcomes indicate that it would be possible to recruit and retain (88%) participants to a definitive RCT, and that the study design and intervention are acceptable. The addition of guided telephone support was not burdensome; indeed, it was additionally motivating. Telephone support can be delivered with high fidelity, but this is inconsistent and requires further piloting. Preliminary comparison data indicate small, but non-significant, improvements for participants receiving guided telephone support relative to those who did not over time.
Conclusions: It is feasible to deliver online mindfulness with additional telephone guided support to family carers of people with ID, and this may lead to small benefits over receiving online mindfulness alone. A definitive RCT can be planned to examine the effectiveness and cost-effectiveness of this intervention
Defining adherence to therapeutic exercise for musculoskeletal pain : a systematic review
Objective
To establish the meaning of the term ‘adherence’ (including conceptual and measurement definitions) in the context of therapeutic exercise (TE) for musculoskeletal (MSK) pain.
Design
Systematic review using a search strategy including terms for: adherence, TE and MSK pain. Identified studies were independently screened for inclusion by two researchers. Two independent researchers extracted data on: study type; MSK pain population; type of TE used; definitions, parameters, measurement methods and values of adherence.
Data sources
Seven electronic databases were searched from inception to December 2016.
Eligibility criteria
Any study type featuring TE for adults with MSK pain and containing a definition of adherence, or a description of how adherence was measured.
Results
459 studies were identified and 86 were included in the review. Most were prospective cohort studies and featured back and/or neck pain. Strengthening and stretching were the most common types of TE. A clearly identifiable definition of adherence was provided in 40% of the studies, with 12% using the same definition. Exercise frequency was the most commonly measured parameter of adherence, with self-report logs the most common measurement method. The most common value range used to determine satisfactory adherence was 80%–99% of the recommended exercise dose.
Conclusion
No single definition of adherence to TE was apparent. We found no definition of adherence that specifically related to TE for MSK pain or described the dimensions of TE that should be measured. We recommend conceptualising adherence to TE for MSK pain from the perspective of all relevant stakeholders
Serological Survey and Pathogen Exposure of Adult Female White-tailed Deer in the Western Dakotas
Establishing baseline values for pathogen exposure and nutritional indices is necessary to monitor population health. However, little is known about white-tailed deer (Odocoileus virginianus) pathogen exposure and nutritional condition in the Northern Great Plains. Our objective was to assess pathogen exposure and establish nutritional indices for female white-tailed deer in Dunn and Grant counties, North Dakota and Perkins County, South Dakota. During 2014, we collected blood serum from 150 adult female white-tailed deer. Pathogens with the highest antibody prevalence included West Nile Virus (WNV; 85%), epizootic hemorrhagic disease (48%), and malignant catarrhal fever (32%). Serum values for creatine kinase, globulin, glucose, potassium, and lactate dehydrogenase in all three study areas were higher than reference ranges while sodium was low in Grant County relative to Dunn and Perkins counties. We speculate that high exposure of WNV and high potassium values combined with low sodium values may affect neonate survival in Grant County. However, regional differences in pathogen exposure, their connection to serum values, and their potential interactive effects on survival are not well understood
Detection of Planetary and Stellar Companions to Neighboring Stars via a Combination of Radial Velocity and Direct Imaging Techniques
13 pages, 6 figures, 4 tables, accepted for publication in the Astronomical Journal (submitted 25 Feb 2019; accepted 28 April 2019). Machine readable tables and Posteriors from the RadVel fits are available here: http://stephenkane.net/rvfits.tarThe sensitivities of radial velocity (RV) surveys for exoplanet detection are extending to increasingly longer orbital periods, where companions with periods of several years are now being regularly discovered. Companions with orbital periods that exceed the duration of the survey manifest in the data as an incomplete orbit or linear trend, a feature that can either present as the sole detectable companion to the host star, or as an additional signal overlain on the signatures of previously discovered companion(s). A diagnostic that can confirm or constrain scenarios in which the trend is caused by an unseen stellar rather than planetary companion is the use of high-contrast imaging observations. Here, we present RV data from the Anglo-Australian Planet Search (AAPS) for 20 stars that show evidence of orbiting companions. Of these, six companions have resolved orbits, with three that lie in the planetary regime. Two of these (HD 92987b and HD 221420b) are new discoveries. Follow-up observations using the Differential Speckle Survey Instrument (DSSI) on the Gemini South telescope revealed that 5 of the 20 monitored companions are likely stellar in nature. We use the sensitivity of the AAPS and DSSI data to place constraints on the mass of the companions for the remaining systems. Our analysis shows that a planetary-mass companion provides the most likely self-consistent explanation of the data for many of the remaining systems.Peer reviewedFinal Accepted Versio
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