902 research outputs found
An Equine Herpesvirus Type 1 (EHV-1) Expressing VP2 and VP5 of Serotype 8 Bluetongue Virus (BTV-8) Induces Protection in a Murine Infection Model
Bluetongue virus (BTV) can infect most species of domestic and wild ruminants causing substantial morbidity and mortality and, consequently, high economic losses. In 2006, an epizootic of BTV serotype 8 (BTV-8) started in northern Europe that caused significant disease in cattle and sheep before comprehensive vaccination was introduced two years later. Here, we evaluate the potential of equine herpesvirus type 1 (EHV-1), an alphaherpesvirus, as a novel vectored DIVA (differentiating infected from vaccinated animals) vaccine expressing VP2 of BTV-8 alone or in combination with VP5. The EHV-1 recombinant viruses stably expressed the transgenes and grew with kinetics that were identical to those of parental virus in vitro. After immunization of mice, a BTV-8-specific neutralizing antibody response was elicited. In a challenge experiment using a lethal dose of BTV-8, 100% of interferon-receptor-deficient (IFNAR−/−) mice vaccinated with the recombinant EHV-1 carrying both VP2 and VP5, but not VP2 alone, survived. VP7 was not included in the vectored vaccines and was successfully used as a DIVA marker. In summary, we show that EHV-1 expressing BTV-8 VP2 and VP5 is capable of eliciting a protective immune response that is distinguishable from that after infection and as such may be an alternative for BTV vaccination strategies in which DIVA compatibility is of importance
The Phyre2 web portal for protein modeling, prediction and analysis
Phyre2 is a suite of tools available on the web to predict and analyze protein structure, function and mutations. The focus of Phyre2 is to provide biologists with a simple and intuitive interface to state-of-the-art protein bioinformatics tools. Phyre2 replaces Phyre, the original version of the server for which we previously published a paper in Nature Protocols. In this updated protocol, we describe Phyre2, which uses advanced remote homology detection methods to build 3D models, predict ligand binding sites and analyze the effect of amino acid variants (e.g., nonsynonymous SNPs (nsSNPs)) for a user's protein sequence. Users are guided through results by a simple interface at a level of detail they determine. This protocol will guide users from submitting a protein sequence to interpreting the secondary and tertiary structure of their models, their domain composition and model quality. A range of additional available tools is described to find a protein structure in a genome, to submit large number of sequences at once and to automatically run weekly searches for proteins that are difficult to model. The server is available at http://www.sbg.bio.ic.ac.uk/phyre2. A typical structure prediction will be returned between 30 min and 2 h after submission
Discrimination of low missing energy look-alikes at the LHC
The problem of discriminating possible scenarios of TeV scale new physics
with large missing energy signature at the Large Hadron Collider (LHC) has
received some attention in the recent past. We consider the complementary, and
yet unexplored, case of theories predicting much softer missing energy spectra.
As there is enough scope for such models to fake each other by having similar
final states at the LHC, we have outlined a systematic method based on a
combination of different kinematic features which can be used to distinguish
among different possibilities. These features often trace back to the
underlying mass spectrum and the spins of the new particles present in these
models. As examples of "low missing energy look-alikes", we consider
Supersymmetry with R-parity violation, Universal Extra Dimensions with both
KK-parity conserved and KK-parity violated and the Littlest Higgs model with
T-parity violated by the Wess-Zumino-Witten anomaly term. Through detailed
Monte Carlo analysis of the four and higher lepton final states predicted by
these models, we show that the models in their minimal forms may be
distinguished at the LHC, while non-minimal variations can always leave scope
for further confusion. We find that, for strongly interacting new particle
mass-scale ~600 GeV (1 TeV), the simplest versions of the different theories
can be discriminated at the LHC running at sqrt{s}=14 TeV within an integrated
luminosity of 5 (30) fb^{-1}.Comment: 40 pages, 10 figures; v2: Further discussions, analysis and one
figure added, ordering of certain sections changed, minor modifications in
the abstract, version as published in JHE
(De)Constructing a Natural and Flavorful Supersymmetric Standard Model
Using the framework of deconstruction, we construct simple, weakly-coupled
supersymmetric models that explain the Standard Model flavor hierarchy and
produce a flavorful soft spectrum compatible with precision limits. Electroweak
symmetry breaking is fully natural; the mu-term is dynamically generated with
no B mu-problem and the Higgs mass is easily raised above LEP limits without
reliance on large radiative corrections. These models possess the distinctive
spectrum of superpartners characteristic of "effective supersymmetry": the
third generation superpartners tend to be light, while the rest of the scalars
are heavy.Comment: 36 pages, 4 figures ; v2: references added, expanded discussion of
FCNC
Adenoviruses in Lymphocytes of the Human Gastro-Intestinal Tract
Objective: Persistent adenoviral shedding in stools is known to occur past convalescence following acute adenoviral infections. We wished to establish the frequency with which adenoviruses may colonize the gut in normal human subjects. Methods: The presence of adenoviral DNA in intestinal specimens obtained at surgery or autopsy was tested using a nested PCR method. The amplified adenoviral DNA sequences were compared to each other and to known adenoviral species. Lamina propria lymphocytes (LPLs) were isolated from the specimens and the adenoviral copy numbers in the CD4+ and CD8+ fractions were determined by quantitative PCR. Adenoviral gene expression was tested by amplification of adenoviral mRNA. Results: Intestinal tissue from 21 of 58 donors and LPLs from 21 of 24 donors were positive for the presence of adenoviral DNA. The majority of the sequences could be assigned to adenoviral species E, although species B and C sequences were also common. Multiple sequences were often present in the same sample. Forty-one non-identical sequences were identified from 39 different tissue donors. Quantitative PCR for adenoviral DNA in CD4+ and CD8+ fractions of LPLs showed adenoviral DNA to be present in both cell types and ranged from a few hundred to several million copies per million cells on average. Active adenoviral gene expression as evidenced by the presence of adenoviral messenger RNA in intestinal lymphocytes was demonstrated in 9 of the 11 donors tested
Two-Particle-Self-Consistent Approach for the Hubbard Model
Even at weak to intermediate coupling, the Hubbard model poses a formidable
challenge. In two dimensions in particular, standard methods such as the Random
Phase Approximation are no longer valid since they predict a finite temperature
antiferromagnetic phase transition prohibited by the Mermin-Wagner theorem. The
Two-Particle-Self-Consistent (TPSC) approach satisfies that theorem as well as
particle conservation, the Pauli principle, the local moment and local charge
sum rules. The self-energy formula does not assume a Migdal theorem. There is
consistency between one- and two-particle quantities. Internal accuracy checks
allow one to test the limits of validity of TPSC. Here I present a pedagogical
review of TPSC along with a short summary of existing results and two case
studies: a) the opening of a pseudogap in two dimensions when the correlation
length is larger than the thermal de Broglie wavelength, and b) the conditions
for the appearance of d-wave superconductivity in the two-dimensional Hubbard
model.Comment: Chapter in "Theoretical methods for Strongly Correlated Systems",
Edited by A. Avella and F. Mancini, Springer Verlag, (2011) 55 pages.
Misprint in Eq.(23) corrected (thanks D. Bergeron
DNA deaminases: AIDing hormones in immunity and cancer
It is well established that hormones can cause cancer, much less known is how they induce this change in our somatic cells. This review highlights the recent finding that estrogen can exert its DNA-damaging potential by directly activating DNA deaminases. This recently discovered class of proteins deaminate cytosine to uracil in DNA, and are essential enzymes in the immune system. The enhanced production of a given DNA deaminase, induced by estrogen, can lead not only to a more active immune response, but also to an increase in mutations and oncogenic translocations. Identifying the direct molecular link between estrogen and a mutation event provides us with new targets for studying and possibly inhibiting the pathological side-effects of estrogen
Service engagement in interventions for street-connected children and young people: a summary of evidence supplementing a recent Cochrane–Campbell review
Abstract
Background This paper builds on a Cochrane–Campbell systematic review of interventions that reduce harms and promote reintegration in street-connected children and young people focusing on intervention outcomes. The aim of the present analysis is to explore questions raised in the systematic review over the potential role of service engagement in mediating outcomes of relevant interventions.
Objective The paper summarises engagement-related findings from quantitative intervention evaluations with street-connected populations of children and young people, as reported by study authors. It seeks to contribute to theoretical and methodological understandings of service engagement with street-connected youth populations and to highlight gaps in current knowledge.
Methods Drawing on the original search for the Cochrane–Campbell review, we rescreened search results in our database and included quantitative findings if relevant to our current research questions, regardless of study design. Additionally, we sought new study publications from authors whose work was included in the original systematic review. The discussion explores relevant data from five studies included in the original systematic review, ten studies excluded from the review, and two studies published after the completion of the review.
Results The measures of service engagement in the included studies focused on treatment attendance, ‘level of engagement’, and service satisfaction. Evidence on the impact of service engagement on other outcomes in interventions for street-connected children and young people was limited. Available data on the predictors and impact of service engagement were mixed and appear not to provide robust support for common hypotheses in the relevant context
Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015
SummaryBackground The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors—the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6–58·8) of global deaths and 41·2% (39·8–42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Funding Bill & Melinda Gates Foundation
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