Seroprevalence against bovine leukaemia virus in dairy cattle in Bolivia

This study determined seroprevalence against bovine leukaemia virus and investigated the risk factors with the seropositivity of the virus in dairy cattle in Bolivia. Ninety-eight farms in five different provinces in Santa Cruz Department were visited to study 1823 dairy cattle. Questionnaire interviews, blood sampling and inspection of skin were performed at each study farm. Individual-cattle sera were analysed using the agarose gel immunodiffusion (AGID) diagnostic method for the detection of antibody against bovine leukaemia virus. The overall percentage of test positive against bovine leukaemia virus was 29% (95% confidence interval: 27-31%). One percent of the study dairy cattle had the subcutaneous lesions. There were statistical differences for percentage of test positive against bovine leukaemia virus in dairy cattle between provinces (p<0.001). The seropositivity in relation to the existence of subcutaneous lesions indicated statistical significance (p = 0.023). Knowledge of the provincial difference of seropositivity against bovine leukaemia virus in dairy cattle would be used to determine the resource allocation for preventive measures in the study area. In the preventive measures, serological tests against bovine leukaemia virus for the cattle with subcutaneous lesions, which would be a potential indicator of the infection of bovine leukaemia, should be prioritised.Facultad de Ciencias Veterinaria

Seroprevalence against bovine leukaemia virus in dairy cattle in Bolivia

This study determined seroprevalence against bovine leukaemia virus and investigated the risk factors with the seropositivity of the virus in dairy cattle in Bolivia. Ninety-eight farms in five different provinces in Santa Cruz Department were visited to study 1823 dairy cattle. Questionnaire interviews, blood sampling and inspection of skin were performed at each study farm. Individual-cattle sera were analysed using the agarose gel immunodiffusion (AGID) diagnostic method for the detection of antibody against bovine leukaemia virus. The overall percentage of test positive against bovine leukaemia virus was 29% (95% confidence interval: 27-31%). One percent of the study dairy cattle had the subcutaneous lesions. There were statistical differences for percentage of test positive against bovine leukaemia virus in dairy cattle between provinces (p<0.001). The seropositivity in relation to the existence of subcutaneous lesions indicated statistical significance (p = 0.023). Knowledge of the provincial difference of seropositivity against bovine leukaemia virus in dairy cattle would be used to determine the resource allocation for preventive measures in the study area. In the preventive measures, serological tests against bovine leukaemia virus for the cattle with subcutaneous lesions, which would be a potential indicator of the infection of bovine leukaemia, should be prioritised.Facultad de Ciencias Veterinaria

Seroprevalence against bovine leukaemia virus in dairy cattle in Bolivia

This study determined seroprevalence against bovine leukaemia virus and investigated the risk factors with the seropositivity of the virus in dairy cattle in Bolivia. Ninety-eight farms in five different provinces in Santa Cruz Department were visited to study 1823 dairy cattle. Questionnaire interviews, blood sampling and inspection of skin were performed at each study farm. Individual-cattle sera were analysed using the agarose gel immunodiffusion (AGID) diagnostic method for the detection of antibody against bovine leukaemia virus. The overall percentage of test positive against bovine leukaemia virus was 29% (95% confidence interval: 27-31%). One percent of the study dairy cattle had the subcutaneous lesions. There were statistical differences for percentage of test positive against bovine leukaemia virus in dairy cattle between provinces (p<0.001). The seropositivity in relation to the existence of subcutaneous lesions indicated statistical significance (p = 0.023). Knowledge of the provincial difference of seropositivity against bovine leukaemia virus in dairy cattle would be used to determine the resource allocation for preventive measures in the study area. In the preventive measures, serological tests against bovine leukaemia virus for the cattle with subcutaneous lesions, which would be a potential indicator of the infection of bovine leukaemia, should be prioritised.Facultad de Ciencias Veterinaria

Serological survey of enzootic bovine leukemia in the principal province of the of dairy zone of the department of Santa Cruz, Bolivia

Con el objetivo de investigar la seroprevalencia de Leucosis Enzoótica Bovina (LEB) en la cuenca lechera del departamento de Santa Cruz - Bolivia, se procesaron 1769 sueros de bovinos hembras, mayores de dos años, de diferentes razas existentes en la región, durante los meses de Abril a Septiembre 2009, pertenecientes a 94 unidades productivas (tambos) distribuidas en cinco provincias del departamento (Andrés Ibáñez, Warnes, Ichilo Obispo Santistevan y Sara). La técnica serológica utilizada fue inmunodifusión en gel de agar. Los resultados se interpretaron de acuerdo a las variables: provincia, raza y edad. Los datos fueron analizados mediante la prueba de x2 y Fisher. Sobre el total de animales muestrea- dos, 492 de las muestras fueron positivos, lo cual representa una prevalencia del 27,81%. La mayor seroprevalencia fue encontrada en las provincia Obispo Santistevan (52,50%) y Warnes (38,44%), observándose diferencias significativas (p0.05). No se encontraron diferencias significativas de seroprevalencia asociadas a las variables raza y edad (p>0.05). Ningún animal se evidenció sintomatología clínica compatible con la enfermedad.During the months of April to September 2009, 1769 serum samples from cows over two years old, from different races belonging to 94 productive units in five provinces of the department (Andrés Ibáñez, Warnes, Ichilo Obispo Santistevan and Sara) were processed in order to investigate the seroprevalence of Enzootic Bovine Leukosis (EBL) in the milk basin of the department of Santa Cruz - Bolivia. The serological technique used in this study was agar gel immunodiffusion. The results were interpreted according to the variables: province, race and age. The data were analyzed by x2 and Fisher test. Over all animals sampled, 492 samples were positive to ELB, representing a prevalence of 27,81%. The higher prevalence was found in the provinces of Obispo Santistevan (52,50%) and Warnes (38,44%), showing significan! differences (p 0.05).There were no significant differences in seroprevalence associated with race and age variables (p > 0.05). No animals showed clinical symptoms compatible with the disease.Facultad de Ciencias Veterinaria

Serological survey of enzootic bovine leukemia in the principal province of the of dairy zone of the department of Santa Cruz, Bolivia

Con el objetivo de investigar la seroprevalencia de Leucosis Enzoótica Bovina (LEB) en la cuenca lechera del departamento de Santa Cruz - Bolivia, se procesaron 1769 sueros de bovinos hembras, mayores de dos años, de diferentes razas existentes en la región, durante los meses de Abril a Septiembre 2009, pertenecientes a 94 unidades productivas (tambos) distribuidas en cinco provincias del departamento (Andrés Ibáñez, Warnes, Ichilo Obispo Santistevan y Sara). La técnica serológica utilizada fue inmunodifusión en gel de agar. Los resultados se interpretaron de acuerdo a las variables: provincia, raza y edad. Los datos fueron analizados mediante la prueba de x2 y Fisher. Sobre el total de animales muestrea- dos, 492 de las muestras fueron positivos, lo cual representa una prevalencia del 27,81%. La mayor seroprevalencia fue encontrada en las provincia Obispo Santistevan (52,50%) y Warnes (38,44%), observándose diferencias significativas (p0.05). No se encontraron diferencias significativas de seroprevalencia asociadas a las variables raza y edad (p>0.05). Ningún animal se evidenció sintomatología clínica compatible con la enfermedad.During the months of April to September 2009, 1769 serum samples from cows over two years old, from different races belonging to 94 productive units in five provinces of the department (Andrés Ibáñez, Warnes, Ichilo Obispo Santistevan and Sara) were processed in order to investigate the seroprevalence of Enzootic Bovine Leukosis (EBL) in the milk basin of the department of Santa Cruz - Bolivia. The serological technique used in this study was agar gel immunodiffusion. The results were interpreted according to the variables: province, race and age. The data were analyzed by x2 and Fisher test. Over all animals sampled, 492 samples were positive to ELB, representing a prevalence of 27,81%. The higher prevalence was found in the provinces of Obispo Santistevan (52,50%) and Warnes (38,44%), showing significan! differences (p 0.05).There were no significant differences in seroprevalence associated with race and age variables (p > 0.05). No animals showed clinical symptoms compatible with the disease.Facultad de Ciencias Veterinaria

Measurement of the ratio of branching fractions BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma)

The ratio of branching fractions of the radiative B decays B0 -> K*0 gamma and Bs0 -> phi gamma has been measured using 0.37 fb-1 of pp collisions at a centre of mass energy of sqrt(s) = 7 TeV, collected by the LHCb experiment. The value obtained is BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma) = 1.12 +/- 0.08 ^{+0.06}_{-0.04} ^{+0.09}_{-0.08}, where the first uncertainty is statistical, the second systematic and the third is associated to the ratio of fragmentation fractions fs/fd. Using the world average for BR(B0 -> K*0 gamma) = (4.33 +/- 0.15) x 10^{-5}, the branching fraction BR(Bs0 -> phi gamma) is measured to be (3.9 +/- 0.5) x 10^{-5}, which is the most precise measurement to date.Comment: 15 pages, 1 figure, 2 table

Search for CP violation in D+→K−K+π+D^{+} \to K^{-}K^{+}\pi^{+} decays

A model-independent search for direct CP violation in the Cabibbo suppressed decay $D^+ \to K^- K^+\pi^+$ in a sample of approximately 370,000 decays is carried out. The data were collected by the LHCb experiment in 2010 and correspond to an integrated luminosity of 35 pb$^{-1}$. The normalized Dalitz plot distributions for $D^+$ and $D^-$ are compared using four different binning schemes that are sensitive to different manifestations of CP violation. No evidence for CP asymmetry is found.Comment: 13 pages, 8 figures, submitted to Phys. Rev.

Opposite-side flavour tagging of B mesons at the LHCb experiment

The calibration and performance of the oppositeside flavour tagging algorithms used for the measurements of time-dependent asymmetries at the LHCb experiment are described. The algorithms have been developed using simulated events and optimized and calibrated with B + →J/ψK +, B0 →J/ψK ∗0 and B0 →D ∗− μ + νμ decay modes with 0.37 fb−1 of data collected in pp collisions at √ s = 7 TeV during the 2011 physics run. The oppositeside tagging power is determined in the B + → J/ψK + channel to be (2.10 ± 0.08 ± 0.24) %, where the first uncertainty is statistical and the second is systematic

Measurement of the CP-violating phase phi_s in the decay Bs->J/psi phi

We present a measurement of the time-dependent CP-violating asymmetry in B_s -> J/psi phi decays, using data collected with the LHCb detector at the LHC. The decay time distribution of B_s -> J/psi phi is characterized by the decay widths Gamma_H and Gamma_L of the heavy and light mass eigenstates of the B_s-B_s-bar system and by a CP-violating phase phi_s. In a sample of about 8500 B_s -> J/psi phi events isolated from 0.37 fb^-1 of pp collisions at sqrt(s)=7 TeV we measure phi_s = 0.15 +/- 0.18 (stat) +/- 0.06 (syst) rad. We also find an average B_s decay width Gamma_s == (Gamma_L + Gamma_H)/2 = 0.657 +/- 0.009 (stat) +/- 0.008 (syst) ps^-1 and a decay width difference Delta Gamma_s == Gamma_L - Gamma_H} = 0.123 +/- 0.029 (stat) +/- 0.011 (syst) ps^-1. Our measurement is insensitive to the transformation (phi_s,DeltaGamma_s --> pi - phi_s, - Delta Gamma_s.Comment: 9 pages, 3 figure

Observation of excited Lambda_b0 baryons

Using pp collision data corresponding to 1.0 fb-1 integrated luminosity collected by the LHCb detector, two narrow states are observed in the Lambda_b0pi+pi- spectrum with masses 5911.97 +- 0.12(stat) +- 0.02(syst) +- 0.66(Lambda_b0 mass) MeV/c^2 and 5919.77 +- 0.08(stat) +- 0.02(syst) +- 0.66(Lambda_b0 mass) MeV/c^2. The significances of the observations are 5.2 and 10.2 standard deviations, respectively. These states are interpreted as the orbitally-excited Lambda_b0 baryons, Lambda_b*0(5912) and Lambda_b*0(5920).Comment: Replaced by version published in Phys. Rev. Lett, modified fit with better mass resolution treatmen