132 research outputs found
Aromatic moieties in meteorites: relics of interstellar grain processes?
The carbonaceous chondrite meteorites contain a record of the formation of the solar system, part of which is present within organic matter. This organic matter is predominantly aromatic, and its sources remain controversial. The δ13C values for individual free and macromolecular aromatic moieties from Cold Bokkeveld and Murchison suggest that these units originate from radiation-induced ``circle'' reactions involving simultaneous bond synthesis and cracking. Large carbon isotope fractionations and a deuterium enrichment for these entities suggest that these reactions occurred in a dense interstellar cloud. The juxtaposition of the synthesis and cracking products implies that the reactions occurred in a restricting medium, the most likely candidate for which is the icy organic mantles of interstellar grains. In contrast, the δ13C record in aromatic moieties from Orgueil is mostly obscured, possibly due to the increased levels of parent body aqueous alteration experienced by this meteorite. These novel observations are consistent with the interstellar-parent body hypothesis, where the final form of meteoritic organic matter results from the transfiguration of interstellar organic precursors by aqueous reactions on the meteorite parent body
The significance of opthalmologic evaluation in the early diagnosis of inborn errors of metabolism: the Cretan experience
BACKGROUND: The Inborn Errors of Metabolism (IEM) are far from the rare systemic diseases that mainly affect the neural tissue. There are very few written reports on ocular findings in subjects with IEM, thus it was interesting to study the frequency of ocular findings in the studied population and explore their contribution to the early diagnosis of IEM. METHODS: Our study involved the evaluation of IEM suspected cases, which had been identified in a rural population in Crete, Greece. Over a period of 3 years, 125 patients, who fulfilled the inclusion criteria of this study, were examined. Analytical physical examination, detailed laboratory investigation as well as a thorough ocular examination were made. RESULTS: A diagnosis of IEM was established in 23 of the 125 patients (18.4%). Ten (43.5%) of the diagnosed IEM had ocular findings, while 8 of them (34.8%) had findings which were specific for the diagnosed diseases. One patient diagnosed with glycogenosis type 1b presented a rare finding. Of the 102 non-diagnosed patients, 53 (51.96 %) presented various ophthalmic findings, some of which could be related to a metabolic disease and therefore may be very helpful in the future. CONCLUSIONS: The ocular investigation can be extremely useful for raising the suspicion and the establishment of an early diagnosis of IEM. It could also add new findings related to these diseases. The early management of the ocular symptoms can improve the quality of life to these patients
Beyond BMI for self-estimates of body size and shape: A new method for developing stimuli correctly calibrated for body composition
Accurate self-assessment of body shape and size plays a key role in the prevention, diagnosis, and treatment of both obesity and eating disorders. These chronic conditions cause significant health problems, reduced quality of life, and represent a major problem for health services. Variation in body shape depends on two aspects of composition: adiposity and muscularity. However, most self-assessment tools are unidimensional. They depict variation in adiposity only, typically quantified by the body mass index. This can lead to substantial, and clinically meaningful, errors in estimates of body shape and size. To solve this problem, we detail a method of creating biometrically valid body stimuli. We obtained high-resolution 3D body shape scans and composition measures from 397 volunteers (aged 18–45 years) and produced a statistical mapping between the two. This allowed us to create 3D computer-generated models of bodies, correctly calibrated for body composition (i.e., muscularity and adiposity). We show how these stimuli, whose shape changes are based on change in composition in two dimensions, can be used to match the body size and shape participants believe themselves to have, to the stimulus they see. We also show how multivariate multiple regression can be used to model shape change predicted by these 2D outcomes, so that participants’ choices can be explained by their measured body composition together with other psychometric variables. Together, this approach should substantially improve the accuracy and precision with which self-assessments of body size and shape can be made in obese individuals and those suffering from eating disorders
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Milk and dairy consumption and risk of cardiovascular diseases and all-cause mortality: dose-response meta-analysis of prospective cohort studies
With a growing number of prospective cohort studies, an updated dose-response meta-analysis of milk and dairy products with all-cause mortality, coronary heart disease (CHD) or cardiovascular disease (CVD) have been conducted. PubMed, Embase and Scopus were searched for articles published up to September 2016. Random-effect meta-analyses with summarised dose-response data were performed for total (high-fat/low-fat) dairy, milk, fermented dairy, cheese and yogurt. Non-linear associations were investigated using the spine models and heterogeneity by subgroup analyses. A total of 29 cohort studies were available for meta-analysis, with 938,465 participants and 93,158 mortality, 28,419 CHD and 25,416 CVD cases. No associations were found for total (high-fat/low-fat) dairy, and milk with the health outcomes of mortality, CHD or CVD. Inverse associations were found between total fermented dairy (included sour milk products, cheese or yogurt; per 20 g/day) with mortality (RR 0.98, 95% CI 0.97-0.99; I2 = 94.4%) and CVD risk (RR 0.98, 95% CI 0.97-0.99; I2 = 87.5%). Further analyses of individual fermented dairy of cheese and yogurt showed cheese to have a 2% lower risk of CVD (RR 0.98, 95% CI 0.95-1.00; I2 = 82.6%) per 10 g/day, but not yogurt. All of these marginally inverse associations of totally fermented dairy and cheese were attenuated in sensitivity analyses by removing one large Swedish study. This meta-analysis combining data from 29 prospective cohort studies demonstrated neutral associations between dairy products and cardiovascular and all-cause mortality. For future studies it is important to investigate in more detail how dairy products can be replaced by other foods
Fatores de risco cardiovascular e consumo alimentar em cadetes da Academia da Força Aérea Brasileira
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