508 research outputs found
Axion-like-particle search with high-intensity lasers
We study ALP-photon-conversion within strong inhomogeneous electromagnetic
fields as provided by contemporary high-intensity laser systems. We observe
that probe photons traversing the focal spot of a superposition of Gaussian
beams of a single high-intensity laser at fundamental and frequency-doubled
mode can experience a frequency shift due to their intermittent propagation as
axion-like-particles. This process is strongly peaked for resonant masses on
the order of the involved laser frequencies. Purely laser-based experiments in
optical setups are sensitive to ALPs in the mass range and can
thus complement ALP searches at dipole magnets.Comment: 25 pages, 2 figure
Smear plus Detect-TB for a sensitive diagnosis of pulmonary tuberculosis: a cost-effectiveness analysis in an incarcerated population
Background: Prison conditions can favor the spread of tuberculosis (TB). This study aimed to evaluate in a Brazilian prison: the performance and accuracy of smear, culture and Detect-TB; performance of smear plus culture and smear plus Detect-TB, according to different TB prevalence rates; and the cost-effectiveness of these procedures for pulmonary tuberculosis (PTB) diagnosis. Methods: This paper describes a cost-effectiveness study. A decision analytic model was developed to estimate the costs and cost-effectiveness of five routine diagnostic procedures for diagnosis of PTB using sputum specimens: a) Smear alone, b) Culture alone, c) Detect-TB alone, d) Smear plus culture and e) Smear plus Detect-TB. The cost-effectiveness ratio of costs were evaluated per correctly diagnosed TB case and all procedures costs were attributed based on the procedure costs adopted by the Brazilian Public Health System. Results: A total of 294 spontaneous sputum specimens from patients suspected of having TB were analyzed. The sensibility and specificity were calculated to be 47% and 100% for smear; 93% and 100%, for culture; 74% and 95%, for Detect-TB; 96% and 100%, for smear plus culture; and 86% and 95%, for smear plus Detect-TB. The negative and positive predictive values for smear plus Detect-TB, according to different TB prevalence rates, ranged from 83 to 99% and 48 to 96%, respectively. In a cost-effectiveness analysis, smear was both less costly and less effective than the other strategies. Culture and smear plus culture were more effective but more costly than the other strategies. Smear plus Detect-TB was the most cost-effective method. Conclusions: The Detect-TB evinced to be sensitive and effective for the PTB diagnosis when applied with smear microscopy. Diagnostic methods should be improved to increase TB case detection. To support rational decisions about the implementation of such techniques, cost-effectiveness studies are essential, including in prisons, which are known for health care assessment problems
On the experimental intradiscal pressure measurement techniques : a review
Series : Mechanisms and machine science, ISSN 2211-0984, vol. 24The intradiscal pressure has been essential for prevent the spinal complaints by forming a basis for clinical advice to promote the correct sitting postures. As a consequence, it is evident the need of an accurate method for measure the intradiscal pressure, to better understand the disc response to hydorstatic pressure fluctuations. Numerous reviews regarding disc mechanics are available, including intradiscal pressure benchmarks; however, an analysis on the techniques of intradiscal pressure measurement is needed. Therefore, this review will remain focused on the methodologies adopted for measure the intradiscal pressure in several conditions: for different daily activities, under external loads and for values where occurs annulus fibrosus disruption. The importance of the intradiscal pressure on disc function will be discussed as well as the some guidelines for design new measurement techniques will be defined
Accelerated apoptotic death and <i>in vivo</i> turnover of erythrocytes in mice lacking functional mitogen- and stress-activated kinase MSK1/2
The mitogen- and stress-activated kinase MSK1/2 plays a decisive role in
apoptosis. In analogy to apoptosis of nucleated cells, suicidal erythrocyte
death called eryptosis is characterized by cell shrinkage and cell membrane
scrambling leading to phosphatidylserine (PS) externalization. Here, we
explored whether MSK1/2 participates in the regulation of eryptosis. To this
end, erythrocytes were isolated from mice lacking functional MSK1/2 (msk−/−)
and corresponding wild-type mice (msk+/+). Blood count, hematocrit, hemoglobin
concentration and mean erythrocyte volume were similar in both msk−/− and
msk+/+ mice, but reticulocyte count was significantly increased in msk−/−
mice. Cell membrane PS exposure was similar in untreated msk−/− and msk+/+
erythrocytes, but was enhanced by pathophysiological cell stressors ex vivo
such as hyperosmotic shock or energy depletion to significantly higher levels
in msk−/− erythrocytes than in msk+/+ erythrocytes. Cell shrinkage following
hyperosmotic shock and energy depletion, as well as hemolysis following
decrease of extracellular osmolarity was more pronounced in msk−/−
erythrocytes. The in vivo clearance of autologously-infused CFSE-labeled
erythrocytes from circulating blood was faster in msk−/− mice. The spleens
from msk−/− mice contained a significantly greater number of PS-exposing
erythrocytes than spleens from msk+/+ mice. The present observations point to
accelerated eryptosis and subsequent clearance of erythrocytes leading to
enhanced erythrocyte turnover in MSK1/2-deficient mice
Transmission of Plasmodium vivax in South-Western Uganda: Report of Three Cases in Pregnant Women
Plasmodium vivax is considered to be rare in the predominantly Duffy negative populations of Sub-Saharan Africa, as this red blood cell surface antigen is essential for invasion by the parasite. However, despite only very few reports of molecularly confirmed P. vivax from tropical Africa, serological evidence indicated that 13% of the persons sampled in Congo had been exposed to P. vivax. We identified P. vivax by microscopy in 8 smears from Ugandan pregnant women who had been enrolled in a longitudinal study of malaria in pregnancy. A nested polymerase chain reaction (PCR) protocol was used to detect and identify the Plasmodium parasites present. PCR analysis confirmed the presence of P. vivax for three of the women and analysis of all available samples from these women revealed clinically silent chronic low-grade vivax infections for two of them. The parasites in one woman carried pyrimethamine resistance-associated double non-synonymous mutations in the P. vivax dihydrofolate reductase gene. The three women found infected with P. vivax were Duffy positive as were nine of 68 women randomly selected from the cohort. The data presented from these three case reports is consistent with stable transmission of malaria in a predominantly Duffy negative African population. Given the substantial morbidity associated with vivax infection in non-African endemic areas, it will be important to investigate whether the distribution and prevalence of P. vivax have been underestimated in Sub-Saharan Africa. This is particularly important in the context of the drive to eliminate malaria and its morbidity
The genomes of two key bumblebee species with primitive eusocial organization
Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation
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