234 research outputs found
Evolution of the magnetic excitations in NaOsO through its metal-insulator transition
The temperature dependence of the excitation spectrum in NaOsO
through its metal-to-insulator transition (MIT) at 410 K has been investigated
using resonant inelastic X-ray scattering (RIXS) at the Os L edge.
High resolution ( 56 meV) measurements show that the
well-defined, low energy magnons in the insulating state weaken and dampen upon
approaching the metallic state. Concomitantly, a broad continuum of excitations
develops which is well described by the magnetic fluctuations of a nearly
antiferromagnetic Fermi liquid. By revealing the continuous evolution of the
magnetic quasiparticle spectrum as it changes its character from itinerant to
localized, our results provide unprecedented insight into the nature of the MIT
in NaOsO.Comment: Accepted in Physical Review Letters, part of a joint submission to
Physical Review B. Supersedes arXiv:1707.0555
Near and Mid-IR Photometry of the Pleiades, and a New List of Substellar Candidate Members
We make use of new near and mid-IR photometry of the Pleiades cluster in
order to help identify proposed cluster members. We also use the new photometry
with previously published photometry to define the single-star main sequence
locus at the age of the Pleiades in a variety of color-magnitude planes.
The new near and mid-IR photometry extend effectively two magnitudes deeper
than the 2MASS All-Sky Point Source catalog, and hence allow us to select a new
set of candidate very low mass and sub-stellar mass members of the Pleiades in
the central square degree of the cluster. We identify 42 new candidate members
fainter than Ks =14 (corresponding to 0.1 Mo). These candidate members should
eventually allow a better estimate of the cluster mass function to be made down
to of order 0.04 solar masses.
We also use new IRAC data, in particular the images obtained at 8 um, in
order to comment briefly on interstellar dust in and near the Pleiades. We
confirm, as expected, that -- with one exception -- a sample of low mass stars
recently identified as having 24 um excesses due to debris disks do not have
significant excesses at IRAC wavelengths. However, evidence is also presented
that several of the Pleiades high mass stars are found to be impacting with
local condensations of the molecular cloud that is passing through the Pleiades
at the current epoch.Comment: Accepted to ApJS; data tables and embedded-figure version available
at http://spider.ipac.caltech.edu/staff/stauffer/pleiades07
Epidemiological Characteristics of Foot and Ankle Injuries in 2 Professional Ballet Companies: A 3-Season Cohort Study of 588 Medical Attention Injuries and 255 Time-Loss Injuries.
The foot and ankle are often reported as the most common sites of injury in professional ballet dancers; however, epidemiological research focusing on foot and ankle injuries in isolation and investigating specific diagnoses is limited. To investigate the incidence rate, severity, burden, and mechanisms of foot and ankle injuries that (1) required visiting a medical team (medical attention foot and ankle injuries; MA-FAIs) and (2) prevented a dancer from fully participating in all dance-related activities for at least 24 hours after the injury (time-loss foot and ankle injuries; TL-FAIs) in 2 professional ballet companies. Descriptive epidemiological study. Foot and ankle injury data across 3 seasons (2016-2017 to 2018-2019) were extracted from the medical databases of 2 professional ballet companies. Injury-incidence rate (per dancer-season), severity, and burden were calculated and reported with reference to the mechanism of injury. A total of 588 MA-FAIs and 255 TL-FAIs were observed across 455 dancer-seasons. The incidence rates of MA-FAIs and TL-FAIs were significantly higher in women (1.20 MA-FAIs and 0.55 TL-FAIs per dancer-season) than in men (0.83 MA-FAIs and 0.35 TL-FAIs per dancer-season) (MA-FAIs, = .002; TL-FAIs, = .008). The highest incidence rates for any specific injury pathology were ankle impingement syndrome and synovitis for MA-FAIs (women 0.27 and men 0.25 MA-FAIs per dancer-season) and ankle sprain for TL-FAIs (women 0.15 and men 0.08 TL-FAIs per dancer-season). work and jumping actions in women and jumping actions in men were the most common mechanisms of injury. The primary mechanism of injury of ankle sprains was jumping activities, but the primary mechanisms of ankle synovitis and impingement in women were related to dancing . The results of this study highlight the importance of further investigation of injury prevention strategies targeting work and jumping actions in ballet dancers. Further research for injury prevention and rehabilitation strategies targeting posterior ankle impingement syndromes and ankle sprains are warranted. [Abstract copyright: © The Author(s) 2023.
SARS-CoV-2 viability on sports equipment is limited, and dependent on material composition
OBJECTIVES
The control of the COVID-19 pandemic in the UK has necessitated restrictions on amateur and professional sports due to the perceived infection risk to competitors, via direct person to person transmission, or possibly via the surfaces of sports equipment. The sharing of sports equipment such as tennis balls was therefore banned by some sport’s governing bodies. We sought to investigate the potential of sporting equipment as transmission vectors of SARS-CoV-2.
Methods
Ten different types of sporting equipment, including balls from common sports, were inoculated with 40μl droplets containing clinically relevant concentrations of live SARS-CoV-2 virus. Materials were then swabbed at time points relevant to sports (1, 5, 15, 30, 90 minutes). The amount of live SARS-CoV-2 recovered at each time point was enumerated using viral plaque assays, and viral decay and half-life was estimated through fitting linear models to log transformed data from each material.
RESULTS
At one minute, SARS-CoV-2 virus was recovered in only seven of the ten types of equipment with the low dose inoculum, one at five minutes and none at 15 minutes. Retrievable virus dropped significantly for all materials tested using the high dose inoculum with mean recovery of virus falling to 0.74% at 1 minute, 0.39% at 15 minutes and 0.003% at 90 minutes. Viral recovery, predicted decay, and half-life varied between materials with porous surfaces limiting virus transmission.
CONCLUSIONS
This study shows that there is an exponential reduction in SARS-CoV-2 recoverable from a range of sports equipment after a short time period, and virus is less transferrable from materials such as a tennis ball, red cricket ball and cricket glove. Given this rapid loss of viral load and the fact that transmission requires a significant inoculum to be transferred from equipment to the mucous membranes of another individual it seems unlikely that sports equipment is a major cause for transmission of SARS-CoV-2. These findings have important policy implications in the context of the pandemic and may promote other infection control measures in sports to reduce the risk of SARS-CoV-2 transmission and urge sports equipment manufacturers to identify surfaces that may or may not be likely to retain transferable virus
Acoustics and oceanographic observations collected during the QPE Experiment by Research Vessels OR1, OR2 and OR3 in the East China Sea in the Summer of 2009
This document describes data, sensors, and other useful information pertaining to the ONR sponsored
QPE field program to quantify, predict and exploit uncertainty in observations and prediction of sound
propagation. This experiment was a joint operation between Taiwanese and U.S. researchers to
measure and assess uncertainty of predictions of acoustic transmission loss and ambient noise, and to
observe the physical oceanography and geology that are necessary to improve their predictability. This
work was performed over the continental shelf and slope northeast of Taiwan at two sites: one that was
a relatively flat, homogeneous shelf region and a more complex geological site just shoreward of the
shelfbreak that was influenced by the proximity of the Kuroshio Current. Environmental moorings
and ADCP moorings were deployed and a shipboard SeaSoar vehicle was used to measure
environmental spatial structure. In addition, multiple bottom moored receivers and a horizontal
hydrophone array were deployed to sample transmission loss from a mobile source and ambient noise.
The acoustic sensors, environmental sensors, shipboard resources, and experiment design, and their
data, are presented and described in this technical report.Funding was provided by the Office of Naval Research under Contract No. N00014-08-1-076
Fish oil administration in older adults: is there potential for adverse events? A systematic review of the literature
ackground: Omega-3 (n-3) fatty acid supplementation is becoming increasingly popular. However given its
antithrombotic properties the potential for severe adverse events (SAE) such as bleeding has safety implications,
particularly in an older adult population. A systematic review of randomized control trials (RCT) was conducted to
explore the potential for SAE and non-severe adverse events (non-SAE) associated with n-3 supplementation in
older adults.
Methods: A comprehensive search strategy using Medline and a variety of other electronic sources was conducted.
Studies investigating the oral administration of n-3 fish oil containing eicosapentaenoic acid (EPA), docosahexaenoic
acid (DHA) or both against a placebo were sourced. The primary outcome of interest included reported SAE
associated with n-3 supplementation. Chi-square analyses were conducted on the pooled aggregate of AEs.
Results: Of the 398 citations initially retrieved, a total of 10 studies involving 994 older adults aged ≥60 years were
included in the review. Daily fish oil doses ranged from 0.03 g to 1.86 g EPA and/or DHA with study durations
ranging from 6 to 52 weeks. No SAE were reported and there were no significant differences in the total AE rate
between groups (n-3 intervention group: 53/540; 9.8%; placebo group: 28/454; 6.2%; p= 0.07). Non-SAE relating to
gastrointestinal (GI) disturbances were the most commonly reported however there was no significant increase in
the proportion of GI disturbances reported in participants randomized to the n-3 intervention (n-3 intervention
group: 42/540 (7.8%); placebo group: 24/454 (5.3%); p= 0.18).
Conclusions: The potential for AEs appear mild-moderate at worst and are unlikely to be of clinical significance. The
use of n-3 fatty acids and the potential for SAE should however be further researched to investigate whether this
evidence is consistent at higher doses and in other populations. These results also highlight that well-documented data
outlining the potential for SAE following n-3 supplementation are limited nor adequately reported to draw definitive
conclusions concerning the safety associated with n-3 supplementation. A more rigorous and systematic approach for
monitoring and recording AE data in clinical settings that involve n-3 supplementation is required.The authors would like to acknowledge funding
provided for the ongoing ATLANTIC randomized controlled trial supported
by the National Health and Medical Research Council (NHMRC), Australia
Supplementation of diet with krill oil protects against experimental rheumatoid arthritis
<p>Abstract</p> <p>Background</p> <p>Although the efficacy of standard fish oil has been the subject of research in arthritis, the effect of krill oil in this disease has yet to be investigated. The objective of the present study was to evaluate a standardised preparation of krill oil and fish oil in an animal model for arthritis.</p> <p>Methods</p> <p>Collagen-induced arthritis susceptible DBA/1 mice were provided <it>ad libitum </it>access to a control diet or diets supplemented with either krill oil or fish oil throughout the study. There were 14 mice in each of the 3 treatment groups. The level of EPA + DHA was 0.44 g/100 g in the krill oil diet and 0.47 g/100 g in the fish oil diet. Severity of arthritis was determined using a clinical scoring system. Arthritis joints were analysed by histopathology and graded. Serum samples were obtained at the end of the study and the levels of IL-1α, IL-1β, IL-7, IL-10, IL-12p70, IL-13, IL-15, IL-17 and TGF-β were determined by a Luminex™ assay system.</p> <p>Results</p> <p>Consumption of krill oil and supplemented diet significantly reduced the arthritis scores and hind paw swelling when compared to a control diet not supplemented with EPA and DHA. However, the arthritis score during the late phase of the study was only significantly reduced after krill oil administration. Furthermore, mice fed the krill oil diet demonstrated lower infiltration of inflammatory cells into the joint and synovial layer hyperplasia, when compared to control. Inclusion of fish oil and krill oil in the diets led to a significant reduction in hyperplasia and total histology score. Krill oil did not modulate the levels of serum cytokines whereas consumption of fish oil increased the levels of IL-1α and IL-13.</p> <p>Conclusions</p> <p>The study suggests that krill oil may be a useful intervention strategy against the clinical and histopathological signs of inflammatory arthritis.</p
Flaxseed, olive and fish oil influence plasmatic lipids, lymphocyte migration and morphometry of the intestinal of Wistar rats
Intra-Organ Variation in Age-Related Mutation Accumulation in the Mouse
Using a transgenic mouse model harboring chromosomally integrated lacZ mutational target genes, we previously demonstrated that mutations accumulate with age much more rapidly in the small intestine than in the brain. Here it is shown that in the small intestine point mutations preferentially accumulate in epithelial cells of the mucosa scraped off the underlying serosa. The mucosal cells are the differentiated villus cells that have undergone multiple cell divisions. A smaller age-related increase, also involving genome rearrangements, was observed in the serosa, which consists mainly of the remaining crypts and non-dividing smooth muscle cells. In the brain we observed an accumulation of only point mutations in no other areas than hypothalamus and hippocampus. To directly test for cell division as the determining factor in the generation of point mutations we compared mutation induction between mitotically active and quiescent embryonic fibroblasts from the same lacZ mice, treated with either UV (a point mutagen) or hydrogen peroxide (a clastogen). The results indicate that while point mutations are highly replication-dependent, genome rearrangements are as easily induced in non-dividing cells as in mitotically active ones. This strongly suggests that the point mutations found to have accumulated in the mucosal part of the small intestine are the consequence of replication errors. The same is likely true for point mutations accumulating in hippocampus and hypothalamus of the brain since neurogenesis in these two areas continues throughout life. The observed intra-organ variation in mutation susceptibility as well as the variation in replication dependency of different types of mutations indicates the need to not only extend observations made on whole organs to their sub-structures but also take the type of mutations and mitotic activity of the cells into consideration. This should help elucidating the impact of genome instability and its consequences on aging and disease
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