154 research outputs found
Evidence for the strangeness-changing weak decay
Using a collision data sample corresponding to an integrated luminosity
of 3.0~fb, collected by the LHCb detector, we present the first search
for the strangeness-changing weak decay . No
hadron decay of this type has been seen before. A signal for this decay,
corresponding to a significance of 3.2 standard deviations, is reported. The
relative rate is measured to be
, where and
are the and fragmentation
fractions, and is the branching
fraction. Assuming is bounded between 0.1 and
0.3, the branching fraction would lie
in the range from to .Comment: 7 pages, 2 figures, All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-047.htm
Experience of taking care of children exposed to HIV: a trajectory of expectations
OBJETIVO: conhecer a experiência do cuidador/mãe em relação ao cuidado para com a criança exposta ao vÃrus da imunodeficiência humana por transmissão vertical, na trajetória pós-natal. MÉTODO: pesquisa qualitativa, que utilizou o Interacionismo Simbólico como referencial teórico. Foram realizadas entrevistas com 39 cuidadores de crianças expostas ao vÃrus da imunodeficiência humana e em seguimento em um serviço especializado. Os dados foram analisados pela análise de conteúdo indutiva. RESULTADOS: apreenderam-se quatro categorias que reportam à experiência solitária de manuseio da terapia antirretroviral da criança, no que se refere principalmente à ausência ou incompletude de informações recebidas; estar atento aos cuidados, que incluem o uso da profilaxia para pneumonia, vacinas e outros restritos à interação mãe/criança; querer omitir a presença do vÃrus da imunodeficiência humana pelo medo do preconceito e olhar o futuro e temer a doença. CONCLUSÃO: a presença do vÃrus da imunodeficiência humana e a ameaça dessa infecção na criança são capazes de gerar apreensão e tantos outros sentimentos como medo, culpa e ansiedade no cuidador. Os profissionais de saúde precisam trabalhar conjuntamente com a mãe para o enfrentamento das demandas e sofrimentos. Assim, o tratamento para evitar a transmissão vertical será eficiente e a mãe, juntamente à criança, viverá essa trajetória com apoio, apesar da apreensão pelo resultado.OBJETIVO: conocer la experiencia del cuidador/madre en relación al cuidado de niño expuesto al VIH por transmisión vertical en la trayectoria posnatal. MÉTODO: investigación cualitativa, que utilizó el Interaccionismo Simbólico como referencial teórico. Fueron realizadas entrevistas con 39 cuidadores de niños expuestos al VIH y que eran acompañados en un servicio especializado. Los datos fueron analizados por el análisis de contenido inductivo. RESULTADOS: se encontraron cuatro categorÃas que informan sobre la experiencia solitaria de la administración de la terapia antirretroviral del niño, en lo que se refiere principalmente a: la ausencia o a informaciones incompletas recibidas; al estar atento a los cuidados, que incluyen el uso de la profilaxis para neumonÃa, vacunas y otros restringidos a la interacción madre-niño; al querer omitir la presencia del VIH por miedo al prejuicio; y al mirar al futuro y temer a la enfermedad. CONCLUSIÓN: la presencia del VIH y la amenaza de infectar al niño son capaces de generar preocupación y varios otros sentimientos en el cuidador, como miedo, culpa y ansiedad. Los profesionales de la salud precisan trabajar conjuntamente con la madre para el enfrentamiento de las demandas y sufrimientos. AsÃ, el tratamiento para evitar la transmisión vertical será eficiente y la madre con el niño vivirán esa trayectoria con apoyo, a pesar de la preocupación por el resultado.'OBJECTIVE: to learn about the experience of caregivers/mothers providing care to infants exposed to HIV through vertical transmission. METHODS: this qualitative study used Symbolic Interactionism as the theoretical framework. A total of 39 caregivers of children exposed to HIV in follow-up at a specialized service were interviewed. Data were analyzed through inductive content analysis. RESULTS: four categories were identified that report on the lonely experience of handling the child's antiretroviral therapy, mainly due to a lack of information or incomplete information; being attentive to required care, such as the use of prophylaxis for pneumonia, vaccines, and other practices restricted to the mother-child interaction; the desire to omit the HIV out of fear of prejudice and fear of the disease, considering future prospects. CONCLUSION: the HIV and the threat this infection may affect the child cause apprehension and feelings such as fear, guilt and anxiety in the caregivers. Healthcare workers need to work together with mothers so they are able to cope with demands and distress. Only then will the treatment to avoid vertical transmission be efficient and will mother and child be supported during the process, despite apprehension with the outcome
Measurements of long-range near-side angular correlations in TeV proton-lead collisions in the forward region
Two-particle angular correlations are studied in proton-lead collisions at a
nucleon-nucleon centre-of-mass energy of TeV, collected
with the LHCb detector at the LHC. The analysis is based on data recorded in
two beam configurations, in which either the direction of the proton or that of
the lead ion is analysed. The correlations are measured in the laboratory
system as a function of relative pseudorapidity, , and relative
azimuthal angle, , for events in different classes of event
activity and for different bins of particle transverse momentum. In
high-activity events a long-range correlation on the near side, , is observed in the pseudorapidity range . This
measurement of long-range correlations on the near side in proton-lead
collisions extends previous observations into the forward region up to
. The correlation increases with growing event activity and is found
to be more pronounced in the direction of the lead beam. However, the
correlation in the direction of the lead and proton beams are found to be
compatible when comparing events with similar absolute activity in the
direction analysed.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-040.htm
Study of the production of and hadrons in collisions and first measurement of the branching fraction
The product of the () differential production
cross-section and the branching fraction of the decay () is
measured as a function of the beauty hadron transverse momentum, ,
and rapidity, . The kinematic region of the measurements is and . The measurements use a data sample
corresponding to an integrated luminosity of collected by the
LHCb detector in collisions at centre-of-mass energies in 2011 and in 2012. Based on previous LHCb
results of the fragmentation fraction ratio, , the
branching fraction of the decay is
measured to be \begin{equation*} \mathcal{B}(\Lambda_b^0\rightarrow J/\psi
pK^-)= (3.17\pm0.04\pm0.07\pm0.34^{+0.45}_{-0.28})\times10^{-4},
\end{equation*} where the first uncertainty is statistical, the second is
systematic, the third is due to the uncertainty on the branching fraction of
the decay , and the
fourth is due to the knowledge of . The sum of the
asymmetries in the production and decay between and
is also measured as a function of and .
The previously published branching fraction of , relative to that of , is updated.
The branching fractions of are determined.Comment: 29 pages, 19figures. All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-032.htm
Search for the rare decays and
A search for the rare decay of a or meson into the final
state is performed, using data collected by the LHCb experiment
in collisions at and TeV, corresponding to an integrated
luminosity of 3 fb. The observed number of signal candidates is
consistent with a background-only hypothesis. Branching fraction values larger
than for the decay mode are
excluded at 90% confidence level. For the decay
mode, branching fraction values larger than are excluded at
90% confidence level, this is the first branching fraction limit for this
decay.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-044.htm
Nocturia, Sleep-Disordered Breathing, and Cardiovascular Morbidity in a Community-Based Cohort
Background: Nocturia has been independently associated with cardiovascular morbidity and all-cause mortality, but such studies did not adjust for sleep-disordered breathing (SDB), which may have mediated such a relationship. Our aims were to determine whether an association between nocturia and cardiovascular morbidity exists that is independent of SDB. We also determined whether nocturia is independently associated with SDB. Methodology/Principal Findings: In order to accomplish these aims we performed a cross-sectional analysis of the Sleep Heart Health Study that contained information regarding SDB, nocturia, and cardiovascular morbidity in a middle-age to elderly community-based population. In 6342 participants (age 63±11 [SD] years, 53% women), after adjusting for known confounders such as age, body mass index, diuretic use, diabetes mellitus, alpha-blocker use, nocturia was independently associated with SDB (measured as Apnea Hypopnea index >15 per hour; OR 1.3; 95%CI, 1.2-1.5). After adjusting for SDB and other known confounders, nocturia was independently associated with prevalent hypertension (OR 1.23; 95%CI 1.08-1.40; P = 0.002), cardiovascular disease (OR 1.26; 95%CI 1.05-1.52; P = 0.02) and stroke (OR 1.62; 95%CI 1.14-2.30; P = 0.007). Moreover, nocturia was also associated with adverse objective alterations of sleep as measured by polysomnography and self-reported excessive daytime sleepiness (P<0.05). Conclusions/Significance: Nocturia is independently associated with sleep-disordered breathing. After adjusting for SDB, there remained an association between nocturia and cardiovascular morbidity. Such results support screening for SDB in patients with nocturia, but the mechanisms underlying the relationship between nocturia and cardiovascular morbidity requires further study. MeSH terms: Nocturia, sleep-disordered breathing, obstructive sleep apnea, sleep apnea, polysomnography, hypertension
Potential geographic distribution of Hantavirus reservoirs in Brazil
Hantavirus cardiopulmonary syndrome is an emerging zoonosis in Brazil. Human infections occur via inhalation of aerosolized viral particles from excreta of infected wild rodents. Necromys lasiurus and Oligoryzomys nigripes appear to be the main reservoirs of hantavirus in the Atlantic Forest and Cerrado biomes. We estimated and compared ecological niches of the two rodent species, and analyzed environmental factors influencing their occurrence, to understand the geography of hantavirus transmission. N. lasiurus showed a wide potential distribution in Brazil, in the Cerrado, Caatinga, and Atlantic Forest biomes. Highest climate suitability for O. nigripes was observed along the Brazilian Atlantic coast. Maximum temperature in the warmest months and annual precipitation were the variables that most influence the distributions of N. lasiurus and O. nigripes, respectively. Models based on occurrences of infected rodents estimated a broader area of risk for hantavirus transmission in southeastern and southern Brazil, coinciding with the distribution of human cases of hantavirus cardiopulmonary syndrome. We found no demonstrable environmental differences among occurrence sites for the rodents and for human cases of hantavirus. However, areas of northern and northeastern Brazil are also apparently suitable for the two species, without broad coincidence with human cases. Modeling of niches and distributions of rodent reservoirs indicates potential for transmission of hantavirus across virtually all of Brazil outside the Amazon Basin
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