241 research outputs found
A two-year participatory intervention project with owners to reduce lameness and limb abnormalities in working horses in Jaipur, India
Participatory methods are increasingly used in international human development, but scientific evaluation of their efficacy versus a control group is rare. Working horses support families in impoverished communities. Lameness and limb abnormalities are highly prevalent in these animals and a cause for welfare concern. We aimed to stimulate and evaluate improvements in lameness and limb abnormalities in horses whose owners took part in a 2-year participatory intervention project to reduce lameness (PI) versus a control group (C) in Jaipur, India.In total, 439 owners of 862 horses participated in the study. PI group owners from 21 communities were encouraged to meet regularly to discuss management and work practices influencing lameness and poor welfare and to track their own progress in improving these. Lameness examinations (41 parameters) were conducted at the start of the study (Baseline), and after 1 year and 2 years. Results were compared with control horses from a further 21 communities outside the intervention. Of the 149 horses assessed on all three occasions, PI horses showed significantly (P<0.05) greater improvement than C horses in 20 parameters, most notably overall lameness score, measures of sole pain and range of movement on limb flexion. Control horses showed slight but significantly greater improvements in four parameters, including frog quality in fore and hindlimbs.This participatory intervention succeeded in improving lameness and some limb abnormalities in working horses, by encouraging changes in management and work practices which were feasible within ownersβ socioeconomic and environmental constraints. Demonstration of the potentially sustainable improvements achieved here should encourage further development of participatory intervention approaches to benefit humans and animals in other contexts
Modeling magnetospheric fields in the Jupiter system
The various processes which generate magnetic fields within the Jupiter
system are exemplary for a large class of similar processes occurring at other
planets in the solar system, but also around extrasolar planets. Jupiter's
large internal dynamo magnetic field generates a gigantic magnetosphere, which
is strongly rotational driven and possesses large plasma sources located deeply
within the magnetosphere. The combination of the latter two effects is the
primary reason for Jupiter's main auroral ovals. Jupiter's moon Ganymede is the
only known moon with an intrinsic dynamo magnetic field, which generates a
mini-magnetosphere located within Jupiter's larger magnetosphere including two
auroral ovals. Ganymede's magnetosphere is qualitatively different compared to
the one from Jupiter. It possesses no bow shock but develops Alfv\'en wings
similar to most of the extrasolar planets which orbit their host stars within
0.1 AU. New numerical models of Jupiter's and Ganymede's magnetospheres
presented here provide quantitative insight into the processes that maintain
these magnetospheres. Jupiter's magnetospheric field is approximately
time-periodic at the locations of Jupiter's moons and induces secondary
magnetic fields in electrically conductive layers such as subsurface oceans. In
the case of Ganymede, these secondary magnetic fields influence the oscillation
of the location of its auroral ovals. Based on dedicated Hubble Space Telescope
observations, an analysis of the amplitudes of the auroral oscillations
provides evidence that Ganymede harbors a subsurface ocean. Callisto in
contrast does not possess a mini-magnetosphere, but still shows a perturbed
magnetic field environment. Callisto's ionosphere and atmospheric UV emission
is different compared to the other Galilean satellites as it is primarily been
generated by solar photons compared to magnetospheric electrons.Comment: Chapter for Book: Planetary Magnetis
Recommended from our members
Twenty-first-century climate impacts from a declining Arctic sea ice cover
A steady decline in Arctic sea ice has been observed over recent decades. General circulation models predict further decreases under increasing greenhouse gas scenarios. Sea ice plays an important role in the climate system in that it influences ocean-to-atmosphere fluxes, surface albedo, and ocean buoyancy. The aim of this study is to isolate the climate impacts of a declining Arctic sea ice cover during the current century. The Hadley Centre Atmospheric Model (HadAM3) is forced with observed sea ice from 1980 to 2000 (obtained from satellite passive microwave radiometer data derived with the Bootstrap algorithm) and predicted sea ice reductions until 2100 under one moderate scenario and one severe scenario of ice decline, with a climatological SST field and increasing SSTs. Significant warming of the Arctic occurs during the twenty-first century (mean increase of between 1.6Β° and 3.9Β°C), with positive anomalies of up to 22Β°C locally. The majority of this is over ocean and limited to high latitudes, in contrast to recent observations of Northern Hemisphere warming. When a climatological SST field is used, statistically significant impacts on climate are only seen in winter, despite prescribing sea ice reductions in all months. When correspondingly increasing SSTs are incorporated, changes in climate are seen in both winter and summer, although the impacts in summer are much smaller. Alterations in atmospheric circulation and precipitation patterns are more widespread than temperature, extending down to midlatitude storm tracks. Results suggest that areas of Arctic land ice may even undergo net accumulation due to increased precipitation that results from loss of sea ice. Intensification of storm tracks implies that parts of Europe may experience higher precipitation rates
The RS Oph outburst of 2021 monitored in X-rays with NICER
The 2021 outburst of the symbiotic recurrent nova RS Oph was monitored with
the Neutron Star Interior Composition Explorer Mission (NICER) in the 0.2-12
keV range from day one after the optical maximum, until day 88, producing an
unprecedented, detailed view of the outburst development. The X-ray flux
preceding the supersoft X-ray phase peaked almost 5 days after optical maximum
and originated only in shocked ejecta for 21 to 25 days. The emission was
thermal; in the first 5 days only a non-collisional-ionization equilibrium
model fits the spectrum, and a transition to equilibrium occurred between days
6 and 12. The ratio of peak X-rays flux measured in the NICER range to that
measured with Fermi in the 60 MeV-500 GeV range was about 0.1, and the ratio to
the peak flux measured with H.E.S.S. in the 250 GeV-2.5 TeV range was about
100. The central supersoft X-ray source (SSS), namely the shell hydrogen
burning white dwarf (WD), became visible in the fourth week, initially with
short flares. A huge increase in flux occurred on day 41, but the SSS flux
remained variable. A quasi-periodic oscillation every ~35 s was always observed
during the SSS phase, with variations in amplitude and a period drift that
appeared to decrease in the end. The SSS has characteristics of a WD of mass >1
M(solar). Thermonuclear burning switched off shortly after day 75, earlier than
in 2006 outburst. We discuss implications for the nova physics.Comment: Accepted for publication in the Astrophysical Journa
Biomarker-guided antibiotic stewardship in suspected ventilator-associated pneumonia (VAPrapid2) : a randomised controlled trial and process evaluation
Background
Ventilator-associated pneumonia is the most common intensive care unit (ICU)-acquired infection, yet accurate diagnosis remains difficult, leading to overuse of antibiotics. Low concentrations of IL-1Ξ² and IL-8 in bronchoalveolar lavage fluid have been validated as effective markers for exclusion of ventilator-associated pneumonia. The VAPrapid2 trial aimed to determine whether measurement of bronchoalveolar lavage fluid IL-1Ξ² and IL-8 could effectively and safely improve antibiotic stewardship in patients with clinically suspected ventilator-associated pneumonia.
Methods
VAPrapid2 was a multicentre, randomised controlled trial in patients admitted to 24 ICUs from 17 National Health Service hospital trusts across England, Scotland, and Northern Ireland. Patients were screened for eligibility and included if they were 18 years or older, intubated and mechanically ventilated for at least 48 h, and had suspected ventilator-associated pneumonia. Patients were randomly assigned (1:1) to biomarker-guided recommendation on antibiotics (intervention group) or routine use of antibiotics (control group) using a web-based randomisation service hosted by Newcastle Clinical Trials Unit. Patients were randomised using randomly permuted blocks of size four and six and stratified by site, with allocation concealment. Clinicians were masked to patient assignment for an initial period until biomarker results were reported. Bronchoalveolar lavage was done in all patients, with concentrations of IL-1Ξ² and IL-8 rapidly determined in bronchoalveolar lavage fluid from patients randomised to the biomarker-based antibiotic recommendation group. If concentrations were below a previously validated cutoff, clinicians were advised that ventilator-associated pneumonia was unlikely and to consider discontinuing antibiotics. Patients in the routine use of antibiotics group received antibiotics according to usual practice at sites. Microbiology was done on bronchoalveolar lavage fluid from all patients and ventilator-associated pneumonia was confirmed by at least 104 colony forming units per mL of bronchoalveolar lavage fluid. The primary outcome was the distribution of antibiotic-free days in the 7 days following bronchoalveolar lavage. Data were analysed on an intention-to-treat basis, with an additional per-protocol analysis that excluded patients randomly assigned to the intervention group who defaulted to routine use of antibiotics because of failure to return an adequate biomarker result. An embedded process evaluation assessed factors influencing trial adoption, recruitment, and decision making. This study is registered with ISRCTN, ISRCTN65937227, and ClinicalTrials.gov, NCT01972425.
Findings
Between Nov 6, 2013, and Sept 13, 2016, 360 patients were screened for inclusion in the study. 146 patients were ineligible, leaving 214 who were recruited to the study. Four patients were excluded before randomisation, meaning that 210 patients were randomly assigned to biomarker-guided recommendation on antibiotics (n=104) or routine use of antibiotics (n=106). One patient in the biomarker-guided recommendation group was withdrawn by the clinical team before bronchoscopy and so was excluded from the intention-to-treat analysis. We found no significant difference in the primary outcome of the distribution of antibiotic-free days in the 7 days following bronchoalveolar lavage in the intention-to-treat analysis (p=0Β·58). Bronchoalveolar lavage was associated with a small and transient increase in oxygen requirements. Established prescribing practices, reluctance for bronchoalveolar lavage, and dependence on a chain of trial-related procedures emerged as factors that impaired trial processes
Large-scale magnetic topologies of mid-M dwarfs
We present in this paper the first results of a spectropolarimetric analysis
of a small sample (~ 20) of active stars ranging from spectral type M0 to M8,
which are either fully-convective or possess a very small radiative core. This
study aims at providing new constraints on dynamo processes in fully-convective
stars.
The present paper focuses on 5 stars of spectral type ~M4, i.e. with masses
close to the full convection threshold (~ 0.35 Msun), and with short rotational
periods. Tomographic imaging techniques allow us to reconstruct the surface
magnetic topologies from the rotationally modulated time-series of circularly
polarised profiles. We fnd that all stars host mainly axisymmetric large-scale
poloidal fields. Three stars were observed at two different epochs separated by
~1 yr; we find the magnetic topologies to be globally stable on this timescale.
We also provide an accurate estimation of the rotational period of all stars,
thus allowing us to start studying how rotation impacts the large-scale
magnetic field.Comment: 17 pages, 14 figures, accepted for publication in MNRA
Energy or information? The role of seed availability for reproductive decisions in edible dormice
The edible dormouse is a specialized seed predator which is highly adapted to the fluctuations of food availability caused by mast seeding of beech and oak trees. Dormice produce young just in time with maximum food availability, and can completely skip reproduction in years with a lack of seeding. Because their decision to reproduce or not in any particular year is made long before the ripe seeds are available, it seems that dormice can anticipate the upcoming mast situation. We tested the hypothesis that the presence of high caloric food in spring affects their reproductive decision. Therefore, we supplementary fed dormice in a field experiment from spring to early summer with sunflower seeds, which also contain a high amount of energy. Supplemental feeding caused significant increases in the proportion of reproducing females and reproductively active males. These results suggest that edible dormice may use the occurrence of an energy rich food resource to predict the autumnal mast situation. Further, our data indicate that the decision to reproduce was not the result of an increased body mass due to the consumption of surplus food, but that sufficient seed abundance acts as an environmental signal to which dormice adjust their reproduction
A Neuromedin U Receptor Acts with the Sensory System to Modulate Food Type-Dependent Effects on C. elegans Lifespan
Different food types modulate worm lifespan and involve the neuropeptide receptor NMUR-1, which acts with the sensory neurons in a bacterial lipopolysaccaharide structure-dependent manner
On the Origin and Spread of the Scab Disease of Apple: Out of Central Asia
Background Venturia inaequalis is an ascomycete fungus responsible for apple scab, a disease that has invaded almost all apple growing regions worldwide, with the corresponding adverse effects on apple production. Monitoring and predicting the effectiveness of intervention strategies require knowledge of the origin, introduction pathways, and population biology of pathogen populations. Analysis of the variation of genetic markers using the inferential framework of population genetics offers the potential to retrieve this information. Methodology/Principal Findings Here, we present a population genetic analysis of microsatellite variation in 1,273 strains of V. inaequalis representing 28 orchard samples from seven regions in five continents. Analysis of molecular variance revealed that most of the variation (88%) was distributed within localities, which is consistent with extensive historical migrations of the fungus among and within regions. Despite this shallow population structure, clustering analyses partitioned the data set into separate groups corresponding roughly to geography, indicating that each region hosts a distinct population of the fungus. Comparison of the levels of variability among populations, along with coalescent analyses of migration models and estimates of genetic distances, was consistent with a scenario in which the fungus emerged in Central Asia, where apple was domesticated, before its introduction into Europe and, more recently, into other continents with the expansion of apple growing. Across the novel range, levels of variability pointed to multiple introductions and all populations displayed signatures of significant post-introduction increases in population size. Most populations exhibited high genotypic diversity and random association of alleles across loci, indicating recombination both in native and introduced areas. Conclusions/Significance Venturia inaequalis is a model of invasive phytopathogenic fungus that has now reached the ultimate stage of the invasion process with a broad geographic distribution and well-established populations displaying high genetic variability, regular sexual reproduction, and demographic expansion.Contexte Venturia inaequalis est un champignon ascomycete responsable de la tavelure du pommier, une maladie qui a envahi presque toutes les rΓ©gions du monde oΓΉ le pommier est cultivΓ© posant ainsi de graves problΓ¨mes en production. PrΓ©venir et enrayer efficacement la rΓ©ussite dβun tel succΓ¨s invasif nΓ©cessite des connaissances approfondies sur lβorigine, les voies dβintroduction, la biologie et la gΓ©nΓ©tique de ces populations invasives. En utilisant le potentiel dβinfΓ©rence de la gΓ©nΓ©tique des populations, lβanalyse de la variation de marqueurs gΓ©nΓ©tiques offre la possibilitΓ© dβaccΓ©der Γ ces informations. MΓ©thodologie et Principaux rΓ©sultats Ici nous prΓ©sentons lβanalyse de donnΓ©es microsatellites obtenues pour 1273 souches de V. inaequalis provenant de 28 vergers prΓ©levΓ©es dans 7 rΓ©gions sur les 5 continents. Lβanalyse de la variance molΓ©culaire rΓ©vΓ¨le que 88% de la variation se retrouve dans les vergers Γ©chantillonnΓ©s, ce qui est compatible avec dβimportantes migrations historiques du champignon entre et Γ lβintΓ©rieur mΓͺme des rΓ©gions. MalgrΓ© cette trΓ¨s faible structuration des populations, les diffΓ©rentes analyses de clustering mettent en Γ©vidence un partage des populations en groupes sΓ©parΓ©s correspondant Γ leur origine gΓ©ographique, montrant ainsi que chaque rΓ©gion hΓ©berge une population distincte du champignon. Ensemble, les rΓ©sultats obtenus sur la comparaison du niveau de variabilitΓ© entre populations, les analyses de coalescence et les modΓ¨les de migration testΓ©s plaident en faveur dβun scΓ©nario dans lequel le champignon aurait Γ©mergΓ© dβAsie Centrale, oΓΉ le pommier a Γ©tΓ© domestiquΓ©, avant dβΓͺtre introduit en Europe puis plus rΓ©cemment dans les autres continents suite Γ lβexpansion de la culture du pommier. Les niveaux de variabilitΓ© indiquent que ces territoires ont subi des introductions multiples et que les populations portent toutes des signatures rΓ©vΓ©lant de fortes expansions dΓ©mographiques aprΓ¨s leur introduction. Enfin, la forte diversitΓ© gΓ©notypique des populations et lβassociation alΓ©atoire des allΓ¨les entre loci suggΓ¨rent que le champignon prΓ©sente une reproduction sexuΓ©e rΓ©guliΓ¨re Γ la fois dans les rΓ©gions oΓΉ il a Γ©tΓ© introduit et dans sa rΓ©gion native. Conclusion et PortΓ©e. Venturia inaequalis est un modΓ¨le de champignons phytopathogΓ¨ne invasif qui a maintenant atteint le stade ultime du processus invasif, cβest Γ dire une trΓ¨s large distribution gΓ©ographique par des populations bien Γ©tablies montrant une grande diversitΓ© gΓ©nΓ©tique, une reproduction sexuΓ©e rΓ©guliΓ¨re et une histoire dβexpansion dΓ©mographique
Plasmodium knowlesi: Reservoir Hosts and Tracking the Emergence in Humans and Macaques
Plasmodium knowlesi, a malaria parasite originally thought to be restricted to macaques in Southeast Asia, has recently been recognized as a significant cause of human malaria. Unlike the benign and morphologically similar P. malariae, these parasites can lead to fatal infections. Malaria parasites, including P. knowlesi, have not yet been detected in macaques of the Kapit Division of Malaysian Borneo, where the majority of human knowlesi malaria cases have been reported. In order to extend our understanding of the epidemiology and evolutionary history of P. knowlesi, we examined 108 wild macaques for malaria parasites and sequenced the circumsporozoite protein (csp) gene and mitochondrial (mt) DNA of P. knowlesi isolates derived from macaques and humans. We detected five species of Plasmodium (P. knowlesi, P. inui, P. cynomolgi, P. fieldi and P. coatneyi) in the long-tailed and pig-tailed macaques, and an extremely high prevalence of P. inui and P. knowlesi. Macaques had a higher number of P. knowlesi genotypes per infection than humans, and some diverse alleles of the P. knowlesi csp gene and certain mtDNA haplotypes were shared between both hosts. Analyses of DNA sequence data indicate that there are no mtDNA lineages associated exclusively with either host. Furthermore, our analyses of the mtDNA data reveal that P. knowlesi is derived from an ancestral parasite population that existed prior to human settlement in Southeast Asia, and underwent significant population expansion approximately 30,000β40,000 years ago. Our results indicate that human infections with P. knowlesi are not newly emergent in Southeast Asia and that knowlesi malaria is primarily a zoonosis with wild macaques as the reservoir hosts. However, ongoing ecological changes resulting from deforestation, with an associated increase in the human population, could enable this pathogenic species of Plasmodium to switch to humans as the preferred host
- β¦