6,722 research outputs found
Percutaneous transhepatic cholangiography rather than ultrasound as a screening test for postoperative biliary complications in liver transplant patients.
Conflict between International Treaties: failing to mitigate the effects of introduced marine species.
Humans have changed the face of the earth - we have intentionally altered the locations of species in order to achieve food and economic security (eg, aquaculture of the freshwater fish Tilapia and the marine algae Kappaphycus) while also appealing to our cultural and aesthetic values (eg, the introduction of gorse to New Zealand and Australia). We have accidentally spread pathogens and diseases beyond their natural ranges1 and we have improved our technologies (such as shipping) to such an extent that we can transit our planet in shorter and shorter timeframes.
All of these activities have occurred over many hundreds of years and have led in one way or another, to an increasing number of species being introduced beyond their natural ranges. Such introductions are now considered one of the top five threats to native biological diversity.
This paper examines how humans have impacted upon the marine environment through the introduction of species beyond their native ranges. Introduced species impact upon native biodiversity, spread diseases and pathogens, and have had economic and social impacts in their ‘new’ ecosystems. Because of the range and extent of introduced species impacts, numerous methods to mitigate the effects of
introduced species have been developed and implemented. Within this paper we will examine how two international legal instruments, the Convention on Biological Diversity, 1992 (CBD) and the World Trade Organization’s General Agreement on Tariffs and Trade 1994 (GATT), in particular its associated Agreement on the Application of Sanitary and Phytosanitary Measures (SPS), deal with introduced species. In this context, the paper focuses on the potential for conflict that may arise with the application of these international legal instruments, thus causing a failure to
effectively mitigate for the effects of introduced species
Revisiting the relativistic ejection event in XTE J1550-564 during the 1998 outburst
We revisit the discovery outburst of the X-ray transient XTE J1550−564 during which relativistic jets were observed in 1998 September, and review the radio images obtained with the Australian Long Baseline Array, and light curves obtained with the Molonglo Observatory Synthesis Telescope and the Australia Telescope Compact Array. Based on Hi spectra, we constrain the source distance to between 3.3 and 4.9 kpc. The radio images, taken some 2 d apart, show the evolution of an ejection event. The apparent separation velocity of the two outermost ejecta is at least 1.3c and may be as large as 1.9c; when relativistic effects are taken into account, the inferred true velocity is ≥ 0.8c. The flux densities appear to peak simultaneously during the outburst, with a rather flat (although still optically thin) spectral index of −0.2
An ecological role for assortative mating under infection?
ReviewThis is the final version of the article. Available from Springer Verlag via the DOI in this record.Wildlife diseases are emerging at a higher rate than ever before meaning that understanding their potential impacts is essential, especially for those species and populations that may already be of conservation concern. The link between population genetic structure and the resistance of populations to disease is well understood: high genetic diversity allows populations to better cope with environmental changes, including the outbreak of novel diseases. Perhaps following this common wisdom, numerous empirical and theoretical studies have investigated the link between disease and disassortative mating patterns, which can increase genetic diversity. Few however have looked at the possible link between disease and the establishment of assortative mating patterns. Given that assortative mating can reduce genetic variation within a population thus reducing the adaptive potential and long-term viability of populations, we suggest that this link deserves greater attention, particularly in those species already threatened by a lack of genetic diversity. Here, we summarise the potential broad scale genetic implications of assortative mating patterns and outline how infection by pathogens or parasites might bring them about. We include a review of the empirical literature pertaining to disease-induced assortative mating. We also suggest future directions and methodological improvements that could advance our understanding of how the link between disease and mating patterns influences genetic variation and long-term population viability.Funding was provided by Marie Curie Fellowship and NERC PhD Studentship
The comprehensive cohort model in a pilot trial in orthopaedic trauma
Background: The primary aim of this study was to provide an estimate of effect size for the functional outcome of
operative versus non-operative treatment for patients with an acute rupture of the Achilles tendon using
accelerated rehabilitation for both groups of patients. The secondary aim was to assess the use of a
comprehensive cohort research design (i.e. a parallel patient-preference group alongside a randomised group) in
improving the accuracy of this estimate within an orthopaedic trauma setting.
Methods: Pragmatic randomised controlled trial and comprehensive cohort study within a level 1 trauma centre.
Twenty randomised participants (10 operative and 10 non-operative) and 29 preference participants (3 operative
and 26 non-operative). The ge range was 22-72 years and 37 of the 52 patients were men. All participants had an
acute rupture of their Achilles tendon and no other injuries. All of the patients in the operative group had a simple
end-to-end repair of the tendon with no augmentation. Both groups then followed the same eight-week
immediate weight-bearing rehabilitation programme using an off-the-shelf orthotic. The disability rating index (DRI;
primary outcome), EQ-5D, Achilles Total Rupture Score and complications were assessed ed at two weeks, six
weeks, three months, six months and nine months after initial injury.
Results: At nine months, there was no significant difference in DRI between patients randomised to operative or
non-operative management. There was no difference in DRI between the randomised group and the parallel
patient preference group. The use of a comprehensive cohort of patients did not provide useful additional
information as to the treatment effect size because the majority of patients chose non-operative management.
Conclusions: Recruitment to clinical trials that compare operative and non-operative interventions is notoriously
difficult; especially within the trauma setting. Including a parallel patient preference group to create a
comprehensive cohort of patients has been suggested as a way of increasing the power of such trials. In our
study, the comprehensive cohort model doubled the number of patients involved in the study. However, a strong
preference for non-operative treatment meant that the increased number of patients did not significantly increase
the ability of the trial to detect a difference between the two interventions
Giant QCD K-factors beyond NLO
Hadronic observables in Z+jet events can be subject to large NLO corrections
at TeV scales, with K-factors that even reach values of order 50 in some cases.
We develop a method, LoopSim, by which approximate NNLO predictions can be
obtained for such observables, supplementing NLO Z+jet and NLO Z+2-jet results
with a unitarity-based approximation for missing higher loop terms. We first
test the method against known NNLO results for Drell-Yan lepton pt spectra. We
then show our approximate NNLO results for the Z+jet observables. Finally we
examine whether the LoopSim method can provide useful information even in cases
without giant K-factors, with results for observables in dijet events that can
be compared to early LHC data.Comment: 38 pages, 13 figures; v2 includes additional reference
A Self-Reference False Memory Effect in the DRM Paradigm: Evidence from Eastern and Western Samples
It is well established that processing information in relation to oneself (i.e., selfreferencing) leads to better memory for that information than processing that same information in relation to others (i.e., other-referencing). However, it is unknown whether self-referencing also leads to more false memories than other-referencing. In the current two experiments with European and East Asian samples, we presented participants the Deese-Roediger/McDermott (DRM) lists together with their own name or other people’s name (i.e., “Trump” in Experiment 1 and “Li Ming” in Experiment 2). We found consistent results across the two experiments; that is, in the self-reference condition, participants had higher true and false memory rates compared to those in the other-reference condition. Moreover, we found that selfreferencing did not exhibit superior mnemonic advantage in terms of net accuracy compared to other-referencing and neutral conditions. These findings are discussed in terms of theoretical frameworks such as spreading activation theories and the fuzzytrace theory. We propose that our results reflect the adaptive nature of memory in the sense that cognitive processes that increase mnemonic efficiency may also increase susceptibility to associative false memories
b-Initiated processes at the LHC: a reappraisal
Several key processes at the LHC in the standard model and beyond that
involve quarks, such as single-top, Higgs, and weak vector boson associated
production, can be described in QCD either in a 4-flavor or 5-flavor scheme. In
the former, quarks appear only in the final state and are typically
considered massive. In 5-flavor schemes, calculations include quarks in the
initial state, are simpler and allow the resummation of possibly large initial
state logarithms of the type into the
parton distribution function (PDF), being the typical scale of the
hard process. In this work we critically reconsider the rationale for using
5-flavor improved schemes at the LHC. Our motivation stems from the observation
that the effects of initial state logs are rarely very large in hadron
collisions: 4-flavor computations are pertubatively well behaved and a
substantial agreement between predictions in the two schemes is found. We
identify two distinct reasons that explain this behaviour, i.e., the
resummation of the initial state logarithms into the -PDF is relevant only
at large Bjorken and the possibly large ratios 's are
always accompanied by universal phase space suppression factors. Our study
paves the way to using both schemes for the same process so to exploit their
complementary advantages for different observables, such as employing a
5-flavor scheme to accurately predict the total cross section at NNLO and the
corresponding 4-flavor computation at NLO for fully exclusive studies.Comment: Fixed typo in Eq. (A.10) and few typos in Eq. (C.2) and (C.3
Social representations of HIV/AIDS in five Central European and Eastern European countries: A multidimensional analysis
Cognitive processing models of risky sexual behaviour have proliferated in the two decades since the first reporting of HIV/AIDS, but far less attention has been paid to individual and
group representations of the epidemic and the relationship between these representations and reported sexual behaviours. In this study, 494 business people and medics from Estonia, Georgia, Hungary, Poland and Russia sorted free associations around HIV/AIDS in a matrix completion task. Exploratory factor and multidimensional scaling analyses revealed two main dimensions (labelled ‘Sex’ and ‘Deadly disease’), with significant cultural and gender variations along both dimension scores. Possible explanations for these results are discussed in the light of growing concerns over the spread of the epidemic in this region
The UK's Global Health Respiratory Network: Improving respiratory health of the world's poorest through research collaborations.
Respiratory disorders are responsible for considerable morbidity, health care utilisation, societal costs and approximately one in five deaths worldwide [1-4]. Yet, despite this substantial health and societal burden – which particularly affects the world’s poorest populations and as such is a major contributor to global health inequalities – respiratory disorders have historically not received the
policy priority they warrant. For example, despite causing an estimated 1000 deaths per day, less than half of the world’s countries collect data on asthma prevalence (http://www.globalasthmareport.org/). This
is true for both communicable and non-communicable respiratory disorders, many of which are either amenable to treatment or preventable
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