25 research outputs found
Astrobiological Complexity with Probabilistic Cellular Automata
Search for extraterrestrial life and intelligence constitutes one of the
major endeavors in science, but has yet been quantitatively modeled only rarely
and in a cursory and superficial fashion. We argue that probabilistic cellular
automata (PCA) represent the best quantitative framework for modeling
astrobiological history of the Milky Way and its Galactic Habitable Zone. The
relevant astrobiological parameters are to be modeled as the elements of the
input probability matrix for the PCA kernel. With the underlying simplicity of
the cellular automata constructs, this approach enables a quick analysis of
large and ambiguous input parameters' space. We perform a simple clustering
analysis of typical astrobiological histories and discuss the relevant boundary
conditions of practical importance for planning and guiding actual empirical
astrobiological and SETI projects. In addition to showing how the present
framework is adaptable to more complex situations and updated observational
databases from current and near-future space missions, we demonstrate how
numerical results could offer a cautious rationale for continuation of
practical SETI searches.Comment: 37 pages, 11 figures, 2 tables; added journal reference belo
Ultrasound-assessed perirenal fat is related to increased ophthalmic artery resistance index in HIV-1 patients
<p>Abstract</p> <p>Background</p> <p>The introduction of highly active antiretroviral therapy (HAART) has dramatically changed the prognosis of human immunodeficiency virus (HIV) infection, with a significant decline in morbidity and mortality.</p> <p>Changes in body fat distribution are a common finding in individuals with HIV infection being treated with antiretrovirals, and this condition (collectively termed lipodystrophy syndrome) is associated with depletion of subcutaneous fat, increased triglycerides and insulin resistance. Obesity, particularly visceral obesity, is associated with increased risk of cardiovascular disease. Therefore, estimating visceral fat distribution is important in identifying subjects at high risk for cardiovascular disease.</p> <p>The aim of our study was to evaluate whether perirenal fat thickness (PRFT), a parameter of central obesity, is related to ophthalmic artery resistance index (OARI), an index of occlusive carotid artery disease in HIV-1 infected patients.</p> <p>Methods</p> <p>We enrolled 88 consecutive HIV-1-infected patients receiving highly active antiretroviral therapy for more than 12 months, in a prospective cohort study. Echographically measured PRFT and OARI, as well as serum metabolic parameters, were evaluated. PRFT and OARI were measured by 3.75 MHz convex and 7.5 MHz linear probe, respectively.</p> <p>Results</p> <p>The means of PRFT and OARI in HIV-1-infected patients with visceral obesity was considerably higher than in patients without it (p < 0.0001 and p < 0.001, respectively). Using the average OARI as the dependent variable, total serum cholesterol level, HDL, triglycerides, glycemia, sex, blood pressure, age and PRFT were independent factors associated with OARI. A PRFT of 6.1 mm was the most discriminatory value for predicting an OARI > 0.74 (sensitivity 78.9%, specificity 82.8%).</p> <p>Conclusions</p> <p>Our data indicate that ultrasound assessment of PRFT may have potential as a marker of increased endothelial damage with specific involvement of the ocular vascular region in HIV-1-infected patients.</p
Development and in-flight calibration of IR2: 2-μm camera onboard Japan’s Venus orbiter, Akatsuki
EsterĂłides anabolizantes no esporte Anabolic steroids in sports
Os hormĂ´nios esterĂłides anabĂłlicos androgĂŞnicos (EAA) compreendem a testosterona e seus derivados. Eles sĂŁo produzidos nos testĂculos e no cĂłrtex adrenal, e promovem as caracterĂsticas sexuais secundárias associadas Ă masculinidade. Na medicina, os EAA sĂŁo utilizados geralmente no tratamento de sarcopenias, do hipogonadismo, do câncer de mama e da osteoporose. Nos esportes, sĂŁo utilizados para o aumento da força fĂsica e da massa muscular; entretanto, os efeitos sobre o desempenho atlĂ©tico permanecem, ainda, controversos. Os EAA podem causar diversos efeitos colaterais, como psicopatologias, câncer de prĂłstata, doença coronariana e esterilidade. Estudos epidemiolĂłgicos apontam a problemática acerca do uso de EAA, nos esportes; todavia, no Brasil nĂŁo existem publicações substanciais sobre esse tema. Esta revisĂŁo analisa esse assunto, procurando despertar a curiosidade e o interesse dos leitores para a produção cientĂfica de novos trabalhos relacionados ao tema.<br>Anabolic androgenic steroids (AAS) are hormones that include or are derivatives of testosterone. They are produced in the testicles and in the adrenal cortex. AAS promote development of sexual characteristics associated with the male sex. They are applied as a general rule in the treatment of sarcopenia, hypogonadism, breast cancer, and osteoporosis. In relation to sports, they are used to increase strength and muscle mass. Their effects on athletics performance are still controversial. AAS can cause several side-effects, such as mental disease, prostate cancer, coronary disease, and sterility. There are no epidemiologic studies regarding the use of AAS in Brazil . This review intends to deal with this matter widely and aims at stimulating curiosity and interest in order to provide new publications about this issue