162 research outputs found

    Vaccine use in Canadian cow-calf herds and opportunities for improvement

    Get PDF
    Vaccinations are one of the most impactful tools available to cow-calf producers to control within herd disease and later, in feedlots. While vaccine use has been studied across Canada, inconsistent and variable regional data makes analysis and interpretation difficult. The objective of this study was to describe vaccination protocols and factors associated with vaccine use in Canadian cow-calf herds and define associations between vaccine use and productivity outcomes. Surveys describing vaccine use in 2020 were collected from 131 cow-calf herds (40 eastern, 91 western), recruited through a national beef cattle surveillance program. Ninety-two percent of cows and replacement heifers, and 72% of bulls were vaccinated with Infectious Bovine Rhinotracheitis (IBR), Bovine Viral Diarrhea Virus (BVDV), Parainfluenza3 Virus (PI3), and Bovine Respiratory Syncytial Virus (BRSV). At least half of cows and bulls were vaccinated for clostridial pathogens and cows and heifers for viral calf scours. Clostridial vaccines were significantly more likely to be used in western Canada compared to eastern Canada. While 92% of producers vaccinated suckling calves against IBR/BRSV/PI3, only 47% provided a second vaccine prior to weaning; 78% of calves were also vaccinated at least once for BVDV before weaning. Producers who vaccinated calves against IBR/BRSV/PI3 before 3 months of age provided a second dose prior to weaning more often than producers who administer the first IBR/BRSV/PI3 vaccine later. Vaccine use has increased across Canada, particularly in calves, prior to weaning. Relative to label recommendations for annual vaccination, clostridial vaccines were generally underutilized in cows and bulls, and by producers in eastern Canada as compared to western Canada. Opportunities also exist to improve adherence to label recommendations for the booster dose of scours vaccine when used in bred replacement heifers. Protocols including product choices, the timing and boosting of respiratory vaccines in nursing calves vary widely across herds. Use of intranasal vaccines in neonatal calves less than 2 weeks old has increased in western Canada compared to previous reports. There is a need to better understand how timing of vaccination in nursing calves contributes to effectiveness, for respiratory disease in nursing and weaned calves

    Precision scans of the pixel cell response of double sided 3D pixel detectors to pion and x-ray beams

    Get PDF
    hree-dimensional (3D) silicon sensors offer potential advantages over standard planar sensors for radiation hardness in future high energy physics experiments and reduced charge-sharing for X-ray applications, but may introduce inefficiencies due to the columnar electrodes. These inefficiencies are probed by studying variations in response across a unit pixel cell in a 55μm pitch double-sided 3D pixel sensor bump bonded to TimePix and Medipix2 readout ASICs. Two complementary characterisation techniques are discussed: the first uses a custom built telescope and a 120GeV pion beam from the Super Proton Synchrotron (SPS) at CERN; the second employs a novel technique to illuminate the sensor with a micro-focused synchrotron X-ray beam at the Diamond Light Source, UK. For a pion beam incident perpendicular to the sensor plane an overall pixel efficiency of 93.0±0.5% is measured. After a 10o rotation of the device the effect of the columnar region becomes negligible and the overall efficiency rises to 99.8±0.5%. The double-sided 3D sensor shows significantly reduced charge sharing to neighbouring pixels compared to the planar device. The charge sharing results obtained from the X-ray beam study of the 3D sensor are shown to agree with a simple simulation in which charge diffusion is neglected. The devices tested are found to be compatible with having a region in which no charge is collected centred on the electrode columns and of radius 7.6±0.6μm. Charge collection above and below the columnar electrodes in the double-sided 3D sensor is observed

    Anionic lipid nanoparticles preferentially deliver mRNA to the hepatic reticuloendothelial system

    Get PDF
    Lipid nanoparticles (LNPs) are the leading nonviral technologies for the delivery of exogenous RNA to target cells in vivo. As systemic delivery platforms, these technologies are exemplified by Onpattro, an approved LNP-based RNA interference therapy, administered intravenously and targeted to parenchymal liver cells. The discovery of systemically administered LNP technologies capable of preferential RNA delivery beyond hepatocytes has, however, proven more challenging. Here, preceded by comprehensive mechanistic understanding of in vivo nanoparticle biodistribution and bodily clearance, an LNP-based messenger RNA (mRNA) delivery platform is rationally designed to preferentially target the hepatic reticuloendothelial system (RES). Evaluated in embryonic zebrafish, validated in mice, and directly compared to LNP-mRNA systems based on the lipid composition of Onpattro, RES-targeted LNPs significantly enhance mRNA expression both globally within the liver and specifically within hepatic RES cell types. Hepatic RES targeting requires just a single lipid change within the formulation of Onpattro to switch LNP surface charge from neutral to anionic. This technology not only provides new opportunities to treat liver-specific and systemic diseases in which RES cell types play a key role but, more importantly, exemplifies that rational design of advanced RNA therapies must be preceded by a robust understanding of the dominant nano-biointeractions involved.Supramolecular & Biomaterials Chemistr

    Peanut Can Be Used as a Reference Allergen for Hazard Characterization in Food Allergen Risk Management: A Rapid Evidence Assessment and Meta-Analysis

    Get PDF
    Regional and national legislation mandates the disclosure of “priority” allergens when present as an ingredient in foods, but this does not extend to the unintended presence of allergens due to shared production facilities. This has resulted in a proliferation of precautionary allergen (“may contain”) labels (PAL) that are frequently ignored by food-allergic consumers. Attempts have been made to improve allergen risk management to better inform the use of PAL, but a lack of consensus has led to variety of regulatory approaches and nonuniformity in the use of PAL by food businesses. One potential solution would be to establish internationally agreed “reference doses,” below which no PAL would be needed. However, if reference doses are to be used to inform the need for PAL, then it is essential to characterize the hazard associated with these low-level exposures. For peanut, there are now published data relating to over 3000 double-blind, placebo-controlled challenges in allergic individuals, but a similar level of evidence is lacking for other priority allergens. We present the results of a rapid evidence assessment and meta-analysis for the risk of anaphylaxis to a low-level allergen exposure for priority allergens. On the basis of this analysis, we propose that peanut can and should be considered an exemplar allergen for the hazard characterization at a low-level allergen exposure. Resumen: La legislación regional y nacional exige la divulgación de alérgenos "prioritarios" cuando están presentes como ingrediente en los alimentos, pero esto no se extiende a la presencia involuntaria de alérgenos debido a instalaciones de producción compartidas. Esto ha dado lugar a una proliferación de etiquetas de precaución para alérgenos ("pueden contener") (PAL) que los consumidores alérgicos a los alimentos suelen ignorar. Se han hecho intentos para mejorar la gestión del riesgo de alérgenos para informar mejor el uso de PAL, pero la falta de consenso ha llevado a una variedad de enfoques regulatorios y a la falta de uniformidad en el uso de PAL por parte de las empresas alimentarias. Una posible solución sería establecer “dosis de referencia” acordadas internacionalmente, por debajo de las cuales no se necesitaría PAL. Sin embargo, si se van a utilizar dosis de referencia para informar la necesidad de PAL, entonces es esencial caracterizar el peligro asociado con estas exposiciones de bajo nivel. Para el maní, ahora hay datos publicados relacionados con más de 3000 desafíos doble ciego controlados por placebo en individuos alérgicos, pero falta un nivel similar de evidencia para otros alérgenos prioritarios. Presentamos los resultados de una evaluación rápida de la evidencia y un metanálisis del riesgo deanafilaxia a una exposición a alérgenos de bajo nivel para alérgenos prioritarios. Sobre la base de este análisis, proponemos que el cacahuete puede y debe considerarse un alérgeno ejemplar para la caracterización del peligro en una exposición a un alérgeno de bajo nivel.Instituto de Investigación de Tecnología de AlimentosFil: Turner, Paul J. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Patel, Nandinee. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Ballmer-Weber, Barbara K. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Ballmer-Weber, Barbara K. Clínica de Dermatología y Alergología. Kantonsspital; Suiza.Fil: Baumert, Joe L. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Blom, W. Marty. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Brooke-Taylor, Simon. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Brough, Helen. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Brough, Helen. King's College London. Departamento de Alergia Pediátrica; Reino Unido.Fil: Campbell, Dianne E. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Campbell, Dianne E. Tecnologías DBV. Montrouge; Francia.Fil: Chen, Hongbing. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Chinthrajah, R. Sharon. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Crevel, René W.R. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Dubois, Anthony E.J. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Ebisawa, Motohiro. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Elizur, Arnon. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Elizur, Arnon. Universidad de Tel Aviv. Facultad de Medicina Sackler. Departamento de Pediatría; Israel.Fil: Gerdts, Jennifer D. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Gowland, M. Hazel. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Houben, Geert F. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Hourihane, Jonathan O.B. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Knulst, André C. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: La Vieille, Sébastien. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: López, María Cristina. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Mills, E.N. Clare. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Polenta, Gustavo Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Tecnología de Alimentos; Argentina.Fil: Polenta, Gustavo Alberto. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Purington, Natasha. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Said, María. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Sampson, Hugh A. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Sampson, Hugh A. Escuela de Medicina Icahn. División de Alergia e Inmunología Pediátricasen. Nueva York. Estados Unidos de América.Fil: Schnadt, Sabine. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Södergren, Eva. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Södergren, Eva. ThermoFisher Scientific; Suecia.Fil: Taylor, Stephen L. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Remington, Benjamin C. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Remington, Benjamin C. Grupo BV. Consultoría Remington; Holanda

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

    Get PDF
    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Amplification of hypercharge electromagnetic fields by a cosmological pseudoscalar

    Full text link
    If, in addition to the standard model fields, a new pseudoscalar field exists and couples to hypercharge topological number density, it can exponentially amplify hyperelectric and hypermagnetic fields in the symmetric phase of the electroweak plasma, while coherently rolling or oscillating. We present the equations describing the coupled system of a pseudoscalar field and hypercharge electromagnetic fields in the electroweak plasma at temperatures above the electroweak phase transition, discuss approximations to the equations, and their validity. We then solve the approximate equations using assorted analytical and numerical methods, and determine the parameters for which hypercharge electromagnetic fields can be exponentially amplified.Comment: 14 pages, 6 figure

    Theory of magnetically powered jets

    Full text link
    The magnetic theory for the production of jets by accreting objects is reviewed with emphasis on outstanding problem areas. An effort is made to show the connections behind the occasionally diverging nomenclature in the literature, to contrast the different points of view about basic mechanisms, and to highlight concepts for interpreting the results of numerical simulations. The role of dissipation of magnetic energy in accelerating the flow is discussed, and its importance for explaining high Lorentz factors. The collimation of jets to the observed narrow angles is discussed, including a critical discussion of the role of `hoop stress'. The transition between disk and outflow is one of the least understood parts of the magnetic theory; its role in setting the mass flux in the wind, in possible modulations of the mass flux, and the uncertainties in treating it realistically are discussed. Current views on most of these problems are still strongly influenced by the restriction to 2 dimensions (axisymmetry) in previous analytical and numerical work; 3-D effects likely to be important are suggested. An interesting problem area is the nature and origin of the strong, preferably highly ordered magnetic fields known to work best for jet production. The observational evidence for such fields and their behavior in numerical simulations is discussed. I argue that the presence or absence of such fields may well be the `second parameter' governing not only the presence of jets but also the X-ray spectra and timing behavior of X-ray binaries.Comment: 29 pages. Publication delays offered the opportunity for further corrections, an expansion of sect 4.2, and one more Fig. To appear in Belloni, T. (ed.): The Jet Paradigm - From Microquasars to Quasars, Lect. Notes Phys. 794 (2009

    Mendelian randomisation study of height and body mass index as modifiers of ovarian cancer risk in 22,588 BRCA1 and BRCA2 mutation carriers

    Get PDF
    Item does not contain fulltextBACKGROUND: Height and body mass index (BMI) are associated with higher ovarian cancer risk in the general population, but whether such associations exist among BRCA1/2 mutation carriers is unknown. METHODS: We applied a Mendelian randomisation approach to examine height/BMI with ovarian cancer risk using the Consortium of Investigators for the Modifiers of BRCA1/2 (CIMBA) data set, comprising 14,676 BRCA1 and 7912 BRCA2 mutation carriers, with 2923 ovarian cancer cases. We created a height genetic score (height-GS) using 586 height-associated variants and a BMI genetic score (BMI-GS) using 93 BMI-associated variants. Associations were assessed using weighted Cox models. RESULTS: Observed height was not associated with ovarian cancer risk (hazard ratio [HR]: 1.07 per 10-cm increase in height, 95% confidence interval [CI]: 0.94-1.23). Height-GS showed similar results (HR = 1.02, 95% CI: 0.85-1.23). Higher BMI was significantly associated with increased risk in premenopausal women with HR = 1.25 (95% CI: 1.06-1.48) and HR = 1.59 (95% CI: 1.08-2.33) per 5-kg/m(2) increase in observed and genetically determined BMI, respectively. No association was found for postmenopausal women. Interaction between menopausal status and BMI was significant (Pinteraction < 0.05). CONCLUSION: Our observation of a positive association between BMI and ovarian cancer risk in premenopausal BRCA1/2 mutation carriers is consistent with findings in the general population

    Collisional and Radiative Processes in Optically Thin Plasmas

    Get PDF
    Most of our knowledge of the physical processes in distant plasmas is obtained through measurement of the radiation they produce. Here we provide an overview of the main collisional and radiative processes and examples of diagnostics relevant to the microphysical processes in the plasma. Many analyses assume a time-steady plasma with ion populations in equilibrium with the local temperature and Maxwellian distributions of particle velocities, but these assumptions are easily violated in many cases. We consider these departures from equilibrium and possible diagnostics in detail
    corecore