1,236 research outputs found

    Infection of swine ex vivo tissues with avian viruses including H7N9 and correlation with glycomic analysis

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    OBJECTIVES: Swine have been regarded as intermediate hosts in the spread of influenza from birds to humans but studies of the sialylated glycans that comprise their respiratory tract have not been extensively studied in the past. This study analyzed the sialylated N-glycan and O-glycan profile of swine trachea and lung and correlated this with ex-vivo infection of swine explants with avian influenza viruses. SAMPLE: Lungs and tracheal samples were obtained from normal farm and laboratory raised swine and used for ex vivo infection as well as mass spectrometric analysis. Infection of the ex vivo tissues used high pathogenic and low pathogenic avian viruses including the novel H7N9 virus that emerged in China in early 2013. MAIN OUTCOME MEASURES: Assessment of successful replication was determined by TCID50 as well as virus immunohistochemistry. The N-glycan and O-glycan profiles were measured by MALDI-TOF and sialylated linkages were determined by sialidase treatment. Lectin binding histochemistry was also performed on formalin fixed tissue samples with positive binding detected by chromogen staining. RESULTS: The swine respiratory tract glycans differed from the human respiratory tact glycans in two main areas. There was a greater abundance of Gal-α-Gal linkages resulting in a relative decrease in sialylated glycans. The swine respiratory tract also had a greater proportion of glycans containing Neu5Gc and Siaα2-6 glycans than the human respiratory tract. Infection with avian viruses was confined primarily to lung bronchioles rather than trachea and parenchyma. CONCLUSIONS: In contrast to previous studies we found that there was not as much expression of Siaα2-3 glycans on the surface of the trachea. Infection of Siaα2-3 binding avian viruses was restricted to the lower respiratory tract bronchioles. This finding may diminish the ability of the swine to act as an intermediary in the transmission of avian viruses to humans.published_or_final_versio

    Capture the fracture: a best practice framework and global campaign to break the fragility fracture cycle

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    Summary The International Osteoporosis Foundation (IOF) Capture the Fracture Campaign aims to support implementation of Fracture Liaison Services (FLS) throughout the world. Introduction FLS have been shown to close the ubiquitous secondary fracture prevention care gap, ensuring that fragility fracture sufferers receive appropriate assessment and intervention to reduce future fracture risk. Methods Capture the Fracture has developed internationally endorsed standards for best practice, will facilitate change at the national level to drive adoption of FLS and increase awareness of the challenges and opportunities presented by secondary fracture prevention to key stakeholders. The Best Practice Framework (BPF) sets an international benchmark for FLS, which defines essential and aspirational elements of service delivery. Results The BPF has been reviewed by leading experts from many countries and subject to beta-testing to ensure that it is internationally relevant and fit-for-purpose. The BPF will also serve as a measurement tool for IOF to award ‘Capture the Fracture Best Practice Recognition’ to celebrate successful FLS worldwide and drive service development in areas of unmet need. The Capture the Fracture website will provide a suite of resources related to FLS and secondary fracture prevention, which will be updated as new materials become available. A mentoring programme will enable those in the early stages of development of FLS to learn from colleagues elsewhere that have achieved Best Practice Recognition. A grant programme is in development to aid clinical systems which require financial assistance to establish FLS in their localities. Conclusion Nearly half a billion people will reach retirement age during the next 20 years. IOF has developed Capture the Fracture because this is the single most important thing that can be done to directly improve patient care, of both women and men, and reduce the spiralling fracture-related care costs worldwide.</p

    Towards Optimal and Expressive Kernelization for d-Hitting Set

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    d-Hitting Set is the NP-hard problem of selecting at most k vertices of a hypergraph so that each hyperedge, all of which have cardinality at most d, contains at least one selected vertex. The applications of d-Hitting Set are, for example, fault diagnosis, automatic program verification, and the noise-minimizing assignment of frequencies to radio transmitters. We show a linear-time algorithm that transforms an instance of d-Hitting Set into an equivalent instance comprising at most O(k^d) hyperedges and vertices. In terms of parameterized complexity, this is a problem kernel. Our kernelization algorithm is based on speeding up the well-known approach of finding and shrinking sunflowers in hypergraphs, which yields problem kernels with structural properties that we condense into the concept of expressive kernelization. We conduct experiments to show that our kernelization algorithm can kernelize instances with more than 10^7 hyperedges in less than five minutes. Finally, we show that the number of vertices in the problem kernel can be further reduced to O(k^{d-1}) with additional O(k^{1.5 d}) processing time by nontrivially combining the sunflower technique with d-Hitting Set problem kernels due to Abu-Khzam and Moser.Comment: This version gives corrected experimental results, adds additional figures, and more formally defines "expressive kernelization

    Wheat genotypic variation in dynamic fluxes of WSC components in different stem segments under drought during grain filling

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    In wheat, stem water soluble carbohydrates (WSC), composed mainly of fructans, are the major carbon sources for grain filling during periods of decreasing photosynthesis or under drought stress after anthesis. Here, in a field drought experiment, WSC levels and associated enzyme activities were followed in different stem segments (peduncle, penultimate internode, lower parts of stem, and sheath) during grain filling. The focus was on two double haploid (DH) lines, DH 307 and DH 338, derived from a Westonia/Kauz cross, two drought-tolerant wheat varieties that follow different drought adaptation strategies during grain filling. The results showed that in irrigated plants, in the period between 20 and 30 days after anthesis (DAA), 70–80% of WSC were fructans. Before and after this period, the fructan proportion varied from 10 to 60%, depending on the location along the stem. Under drought, the fructan proportion changed, depending on genotype, and developmental stages. After anthesis, stem fructans accumulation occurred mainly in the peduncle and penultimate internode until 14 DAA in both DH lines, with clear genotypic variation in subsequent fructan degradation under drought. In DH 307 a significant reduction of fructans with a concomitant increase in fructose levels occurred earlier in the lower parts of the stem and the sheath, as compared to DH 338 or other stem segments in both lines. This was associated with an earlier increase of grain weight and thousand grain weight in DH 307. Spatiotemporal analysis of fructan dynamics and enzymatic activities in fructan metabolism revealed that several types of FEHs are involved in fructan remobilization to the grain under drought

    A retrospective analysis of bilateral fractures over sixteen years: localisation and variation in treatment of second hip fractures

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    The aim of this study was the evaluation of contralateral hip fractures after a previous hip fracture. For this retrospective analysis patients were selected from the database of the LUMC, a teaching hospital in the south-west of the Netherlands. We analyzed all patients with a second fracture of a hip between 1992 and 2007. The exclusion criteria were high impact trauma and patients with diseases or medication known to have a negative effect on bone metabolism. A total of 1,604 hip fractures were identified. The possible predictive factors for the second fracture and descriptive statistics related to surgery (Hb and HT before and after the operation, total amount of intra- and postoperative blood loss, type of osteosynthesis, complications, time of death after the last fracture, time between arrival in the hospital and operation and hospital stay for both fractures) were recorded. A total of 32 second hip fractures were identified (2%) at a mean of 27.5 (SD 28.9) months after the initial hip fracture. The mean age at the first fracture was 77.2 years (SD 11.7), and 27 of 32 patients were female. Of these 32 patients (64 bilateral hip fractures), 32 fractures were intracapsular (1 femoral neck, 31 subcapital) and 32 were extracapsular fractures (6 subtrochanteric, 26 transtrochanteric). Although 24 of the 32 patients had identical first and second hip fractures, only eight out of 32 hips were treated with the same implants. There was a significant difference in Singh index between both hips at the time of the first fracture. There was also a significant difference in Singh index between the hip which was not fractured compared with its subsequent index when it was broken. All other studied patient and fracture characteristics were not significantly different. In this population the percentage of second hip fractures was relatively low compared to other studies. The choice of implants in this study shows that implants were chosen randomly. Because there is a significant difference in the Singh index during first and second hip fracture, osteoporosis medication might help reduce the incidence of second hip fractures

    Mining social mixing patterns for infectious disease models based on a two-day population survey in Belgium

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    <p>Abstract</p> <p>Background</p> <p>Until recently, mathematical models of person to person infectious diseases transmission had to make assumptions on transmissions enabled by personal contacts by estimating the so-called WAIFW-matrix. In order to better inform such estimates, a population based contact survey has been carried out in Belgium over the period March-May 2006. In contrast to other European surveys conducted simultaneously, each respondent recorded contacts over two days. Special attention was given to holiday periods, and respondents with large numbers of professional contacts.</p> <p>Methods</p> <p>Participants kept a paper diary with information on their contacts over two different days. A contact was defined as a two-way conversation of at least three words in each others proximity. The contact information included the age of the contact, gender, location, duration, frequency, and whether or not touching was involved.</p> <p>For data analysis, we used association rules and classification trees. Weighted generalized estimating equations were used to analyze contact frequency while accounting for the correlation between contacts reported on the two different days.</p> <p>A contact surface, expressing the average number of contacts between persons of different ages was obtained by a bivariate smoothing approach and the relation to the so-called next-generation matrix was established.</p> <p>Results</p> <p>People mostly mixed with people of similar age, or with their offspring, their parents and their grandparents. By imputing professional contacts, the average number of daily contacts increased from 11.84 to 15.70. The number of reported contacts depended heavily on the household size, class size for children and number of professional contacts for adults. Adults living with children had on average 2 daily contacts more than adults living without children. In the holiday period, the daily contact frequency for children and adolescents decreased with about 19% while a similar observation is made for adults in the weekend. These findings can be used to estimate the impact of school closure.</p> <p>Conclusion</p> <p>We conducted a diary based contact survey in Belgium to gain insights in social interactions relevant to the spread of infectious diseases. The resulting contact patterns are useful to improve estimating crucial parameters for infectious disease transmission models.</p

    Polarizations of J/psi and psi(2S) Mesons Produced in ppbar Collisions at 1.96 TeV

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    We have measured the polarizations of \jpsi and \psiprime mesons as functions of their transverse momentum \pt when they are produced promptly in the rapidity range ∣y∣<0.6|y|<0.6 with \pt \geq 5 \pgev. The analysis is performed using a data sample with an integrated luminosity of about 800 \ipb collected by the CDF II detector. For both vector mesons, we find that the polarizations become increasingly longitudinal as \pt increases from 5 to 30 \pgev. These results are compared to the predictions of nonrelativistic quantum chromodynamics and other contemporary models. The effective polarizations of \jpsi and \psiprime mesons from BB-hadron decays are also reported.Comment: 8 pages, 7 figures, published in Physical Review Letter

    Observation and Mass Measurement of the Baryon Ξb−\Xi^-_b

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    We report the observation and measurement of the mass of the bottom, strange baryon Ξb−\Xi^-_b through the decay chain Ξb−→J/ψΞ−\Xi^-_b \to J/\psi \Xi^-, where J/ψ→μ+μ−J/\psi \to \mu^+ \mu^-, Ξ−→Λπ−\Xi^- \to \Lambda \pi^-, and Λ→pπ−\Lambda \to p \pi^-. Evidence for observation is based on a signal whose probability of arising from the estimated background is 6.6 x 10^{-15}, or 7.7 Gaussian standard deviations. The Ξb−\Xi^-_b mass is measured to be 5792.9±2.55792.9\pm 2.5 (stat.) ±1.7\pm 1.7 (syst.) MeV/c2c^2.Comment: Minor text changes for the second version. Accepted by Phys. Rev. Let

    Precise measurement of the top quark mass in the lepton+jets topology at CDF II

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    We present a measurement of the mass of the top quark from proton-antiproton collisions recorded at the CDF experiment in Run II of the Fermilab Tevatron. We analyze events from the single lepton plus jets final state (ttˉ→W+bW−bˉ→lνbqqˉ′bˉt\bar t\to W^+bW^-\bar b\to l\nu b q \bar q'\bar b). The top quark mass is extracted using a direct calculation of the probability density that each event corresponds to the ttˉt\bar t final state. The probability is a function of both the mass of the top quark and the energy scale of the calorimeter jets, which is constrained {\it in situ} by the hadronic WW boson mass. Using 167 events observed in 955 pb−1^{{-}1} of integrated luminosity, we achieve the single most precise measurement of the top quark mass, 170.8 ±\pm 2.2 (stat.) ±\pm 1.4 (syst.) GeV/c2c^2.Comment: accepted by Phys. Rev. Let
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