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

Physical activity and mental health in women with polycystic ovary syndrome.

Physical activity is prescribed as a component of primary management for Polycystic Ovary Syndrome (PCOS). This study investigates the association between physical activity and mental health as well as the exercise barriers, motivators and support providers for younger women with and without PCOS to assist in physical activity uptake and prescription for these women

Pyrethroids and Nectar Toxins Have Subtle Effects on the Motor Function, Grooming and Wing Fanning Behaviour of Honeybees (Apis mellifera)

Sodium channels, found ubiquitously in animal muscle cells and neurons, are one of the main target sites of many naturally-occurring, insecticidal plant compounds and agricultural pesticides. Pyrethroids, derived from compounds found only in the Asteraceae, are particularly toxic to insects and have been successfully used as pesticides including on flowering crops that are visited by pollinators. Pyrethrins, from which they were derived, occur naturally in the nectar of some flowering plant species. We know relatively little about how such compounds—i.e., compounds that target sodium channels—influence pollinators at low or sub-lethal doses. Here, we exposed individual adult forager honeybees to several compounds that bind to sodium channels to identify whether these compounds affect motor function. Using an assay previously developed to identify the effect of drugs and toxins on individual bees, we investigated how acute exposure to 10 ng doses (1 ppm) of the pyrethroid insecticides (cyfluthrin, tau-fluvalinate, allethrin and permethrin) and the nectar toxins (aconitine and grayanotoxin I) affected honeybee locomotion, grooming and wing fanning behaviour. Bees exposed to these compounds spent more time upside down and fanning their wings. They also had longer bouts of standing still. Bees exposed to the nectar toxin, aconitine, and the pyrethroid, allethrin, also spent less time grooming their antennae. We also found that the concentration of the nectar toxin, grayanotoxin I (GTX), fed to bees affected the time spent upside down (i.e., failure to perform the righting reflex). Our data show that low doses of pyrethroids and other nectar toxins that target sodium channels mainly influence motor function through their effect on the righting reflex of adult worker honeybees

Ribavirin Enhances IFN-α Signalling and MxA Expression: A Novel Immune Modulation Mechanism during Treatment of HCV

The nucleoside analogue Ribavirin significantly increases patient response to IFN-α treatment of HCV, by directly inhibiting viral replication. Recent studies indicate that Ribavirin also regulates immunity and we propose that Ribavirin enhances specific interferon sensitive gene (ISG) expression by amplifying the IFN-α-JAK/STAT pathway. We found that IFN-α-induced STAT1 and STAT3 phosphorylation was increased in hepatocytes co-treated with Ribavirin and IFN-α, compared to IFN-α alone. Ribavirin specifically enhanced IFN-α induced mRNA and protein of the anti-viral mediator MxA, which co-localised with HCV core protein. These novel findings indicate for the first time that Ribavirin, in addition to its viral incorporation, also enhances IFN-α-JAK/STAT signalling, leading to a novel MxA-mediated immuno-modulatory mechanism that may enhance IFN-α anti-viral activity against HCV

A controlled study of team-based learning for undergraduate clinical neurology education

<p>Abstract</p> <p>Background</p> <p>Team-based learning (TBL), a new active learning method, has not been reported for neurology education. We aimed to determine if TBL was more effective than passive learning (PL) in improving knowledge outcomes in two key neurology topics - neurological localization and neurological emergencies.</p> <p>Methods</p> <p>We conducted a modified crossover study during a nine-week internal medicine posting involving 49 third-year medical undergraduates, using TBL as the active intervention, compared against self-reading as a PL control, for teaching the two topics. Primary outcome was the mean percentage change in test scores immediately after (post-test 1) and 48 hours after TBL (post-test 2), compared to a baseline pre-test. Student engagement was the secondary outcome.</p> <p>Results</p> <p>Mean percentage change in scores was greater in the TBL versus the PL group in post-test 1 (8.8% vs 4.3%, p = 0.023) and post-test 2 (11.4% vs 3.4%, p = 0.001). After adjustment for gender and second year examination grades, mean percentage change in scores remained greater in the TBL versus the PL group for post-test 1 (10.3% vs 5.8%, mean difference 4.5%,95% CI 0.7 - 8.3%, p = 0.021) and post-test 2 (13.0% vs 4.9%, mean difference 8.1%,95% CI 3.7 - 12.5%, p = 0.001), indicating further score improvement 48 hours post-TBL. Academically weaker students, identified by poorer examination grades, showed a greater increase in scores with TBL versus strong students (p < 0.02). Measures of engagement were high in the TBL group, suggesting that continued improvements in scores 48 hours post-TBL may result from self-directed learning.</p> <p>Conclusions</p> <p>Compared to PL, TBL showed greater improvement in knowledge scores, with continued improvement up to 48 hours later. This effect is larger in academically weaker students. TBL is an effective method for improving knowledge in neurological localization and neurological emergencies in undergraduates.</p

Anaesthetic Impairment of Immune Function Is Mediated via GABAA Receptors

GABA(A) receptors are members of the Cys-loop family of neurotransmitter receptors, proteins which are responsible for fast synaptic transmission, and are the site of action of wide range of drugs. Recent work has shown that Cys-loop receptors are present on immune cells, but their physiological roles and the effects of drugs that modify their function in the innate immune system are currently unclear. We are interested in how and why anaesthetics increase infections in intensive care patients; a serious problem as more than 50% of patients with severe sepsis will die. As many anaesthetics act via GABA(A) receptors, the aim of this study was to determine if these receptors are present on immune cells, and could play a role in immunocompromising patients.We demonstrate, using RT-PCR, that monocytes express GABA(A) receptors constructed of α1, α4, β2, γ1 and/or δ subunits. Whole cell patch clamp electrophysiological studies show that GABA can activate these receptors, resulting in the opening of a chloride-selective channel; activation is inhibited by the GABA(A) receptor antagonists bicuculline and picrotoxin, but not enhanced by the positive modulator diazepam. The anaesthetic drugs propofol and thiopental, which can act via GABA(A) receptors, impaired monocyte function in classic immunological chemotaxis and phagocytosis assays, an effect reversed by bicuculline and picrotoxin.Our results show that functional GABA(A) receptors are present on monocytes with properties similar to CNS GABA(A) receptors. The functional data provide a possible explanation as to why chronic propofol and thiopental administration can increase the risk of infection in critically ill patients: their action on GABA(A) receptors inhibits normal monocyte behaviour. The data also suggest a potential solution: monocyte GABA(A) receptors are insensitive to diazepam, thus the use of benzodiazepines as an alternative anesthetising agent may be advantageous where infection is a life threatening problem

Functional illness in primary care: dysfunction versus disease

<p>Abstract</p> <p>Background</p> <p>The Biopsychosocial Model aims to integrate the biological, psychological and social components of illness, but integration is difficult in practice, particularly when patients consult with medically unexplained physical symptoms or functional illness.</p> <p>Discussion</p> <p>This Biopsychosocial Model was developed from General Systems Theory, which describes nature as a dynamic order of interacting parts and processes, from molecular to societal. Despite such conceptual progress, the biological, psychological, social and spiritual components of illness are seldom managed as an integrated whole in conventional medical practice. This is because the biomedical model can be easier to use, clinicians often have difficulty relinquishing a disease-centred approach to diagnosis, and either dismiss illness when pathology has been excluded, or explain all undifferentiated illness in terms of psychosocial factors. By contrast, traditional and complementary treatment systems describe reversible functional disturbances, and appear better at integrating the different components of illness. Conventional medicine retains the advantage of scientific method and an expanding evidence base, but needs to more effectively integrate psychosocial factors into assessment and management, notably of 'functional' illness. As an aid to integration, pathology characterised by structural change in tissues and organs is contrasted with dysfunction arising from disordered physiology or psychology that may occur independent of pathological change.</p> <p>Summary</p> <p>We propose a classification of illness that includes orthogonal dimensions of pathology and dysfunction to support a broadly based clinical approach to patients; adoption of which may lead to fewer inappropriate investigations and secondary care referrals and greater use of cognitive behavioural techniques, particularly when managing functional illness.</p

Seasonality in Human Zoonotic Enteric Diseases: A Systematic Review

BACKGROUND: Although seasonality is a defining characteristic of many infectious diseases, few studies have described and compared seasonal patterns across diseases globally, impeding our understanding of putative mechanisms. Here, we review seasonal patterns across five enteric zoonotic diseases: campylobacteriosis, salmonellosis, vero-cytotoxigenic Escherichia coli (VTEC), cryptosporidiosis and giardiasis in the context of two primary drivers of seasonality: (i) environmental effects on pathogen occurrence and pathogen-host associations and (ii) population characteristics/behaviour. METHODOLOGY/PRINCIPAL FINDINGS: We systematically reviewed published literature from 1960-2010, resulting in the review of 86 studies across the five diseases. The Gini coefficient compared temporal variations in incidence across diseases and the monthly seasonality index characterised timing of seasonal peaks. Consistent seasonal patterns across transnational boundaries, albeit with regional variations was observed. The bacterial diseases all had a distinct summer peak, with identical Gini values for campylobacteriosis and salmonellosis (0.22) and a higher index for VTEC (Gini  0.36). Cryptosporidiosis displayed a bi-modal peak with spring and summer highs and the most marked temporal variation (Gini = 0.39). Giardiasis showed a relatively small summer increase and was the least variable (Gini = 0.18). CONCLUSIONS/SIGNIFICANCE: Seasonal variation in enteric zoonotic diseases is ubiquitous, with regional variations highlighting complex environment-pathogen-host interactions. Results suggest that proximal environmental influences and host population dynamics, together with distal, longer-term climatic variability could have important direct and indirect consequences for future enteric disease risk. Additional understanding of the concerted influence of these factors on disease patterns may improve assessment and prediction of enteric disease burden in temperate, developed countries

Mechanisms of metastasis

Metastasis is an enormously complex process that remains to be a major problem in the management of cancer. The fact that cancer patients might develop metastasis after years or even decades from diagnosis of the primary tumor makes the metastatic process even more complex. Over the years many hypotheses were developed to try to explain the inefficiency of the metastatic process, but none of these theories completely explains the current biological and clinical observations. In this review we summarize some of the proposed models that were developed in attempt to understand the mechanisms of tumor dissemination and colonization as well as metastatic progression