3,797 research outputs found
Association between the perceived environment and physical activity among adults in Latin America: a systematic review
BACKGROUND: Activity friendly environments have been identified as promising strategies to increase physical activity levels in the population. Associations between perceived environmental attributes and physical activity in Latin America may vary from those observed in high income countries. The objective of this systematic review is to identify which perceived environmental attributes are associated with physical activity in Latin America. METHODS: Systematic literature search of articles published in English, Portuguese, and Spanish in four databases was conducted (PubMed, Virtual Health Library, EBSCO, and Web of Science). Associations with environmental attributes were analyzed separately for physical activity domains. Fifteen articles were included in the analysis. RESULTS: All studies had cross-sectional designs. The majority of associations were statistically non-significant, and only four associations were found in the unexpected direction. Leisure-time and transport-related physical activity were the domains most frequently included in the studies and had higher number of associations in the expected direction. Leisure-time physical activity showed a convincing association in the expected direction with safety during the day. Transport-related physical activity had a convincing association with presence of street lighting. CONCLUSIONS: This study shows that perceived environmental attributes and their relationship with physical activity appears to be domain, and context specific. In addition, findings from this study show inconsistencies with the information gathered from high-income countries
SYNTAX II and SYNTAX III trials: What is the take home message for surgeons?
Percutaneous coronary intervention (PCI) has evolved greatly in the last 40 years since its introduction by Andreas Grüntzig in 1977. Since then, we've observed an evolution in balloons, the development of stents, changes in stent structure, development of drug eluting stents, improvements in strut design, thickness and even their polymeric coating. Most recently we saw the rise and "fall" of bioabsorbable scaffolds for PCI. Trials with the most diverse devices for PCI and diagnostic techniques have been conducted. Two of the most recent trials were reported in the last year and deserve special attention-SYNTAX II and SYNTAX III. These trials are completely different in design but present valuable information for doctors managing coronary artery disease (CAD). Both trials take into account contemporary technology for assessing and treating CAD. The first uses so-called "state-of-the-art" PCI and compares the outcomes of that approach with the outcomes of the PCI arm of the pivotal SYNTAX trial. SYNTAX III Revolution on the other hand does not focus on clinical endpoints: it is a blinded trial that does not randomize patients but randomizes doctors ("the heart team") to make a decision on the best treatment for complex CAD. This decision was based either on multi-slice CT with physiological assessment using FFRCT or on conventional angiography. In this review we bring the most important aspects of those trials and the key messages for surgeons together; also, what the surgeon may expect in the future after the publication of these interesting concepts
Analysis Over the Accuracy of Dynamic Formulas for Predicting Ultimate Load Capacity in Deep Foundations
In Civil Engineering, particularly in Geotechnics, several empirical methods, commonly referred to as dynamic equations, have been proposed for prediction of ultimate load capacity of driven piles. However, these formulas are admitted inaccurate and, so, there is a need to evaluate the results obtained by them. In this work a comparative analysis of the values ​​obtained by five dynamic equations (Janbu, Danish, Gates, FHWA-Gates and WSDOT) with actual ultimate load capacities (obtained through pile load tests at site) is made. Errors are measured using the root mean squared error and the correlation between the equation´s results and the measured values ​​is verified. The results showed important differences between the ultimate capacities obtained from the analyzed models and the real values verified in field tests. It was also verified a superiority, in terms of lower error and greater correlation, of the WSDOT and Danish formulas. Attempts were made to improve the methods. For this, coefficients were determined that, when multiplied by the results of the formulas, promoted a reduction in error. Once again, WSDOT presented best perform in terms of correlation and error
Both cetaceans in the Brazilian Amazon show sustained, profound population declines over two decades
<div><p>Obligate river dolphins occur only in the rivers of Asia and South America, where they are increasingly subject to damaging pressures such as habitat degradation, food competition and entanglement in fishing gear as human populations expand. The Amazon basin hosts two, very different, dolphins—the boto or Amazon river dolphin (<i>Inia geoffrensis</i>) and the smaller tucuxi (<i>Sotalia fluviatilis</i>). Both species have wide geographical ranges and were once considered to be relatively abundant. Their IUCN Red List conservation status of Data Deficient (DD), due to limited information on threats, ecology, population numbers and trends, did not initially cause alarm. However, the development of dolphin hunting to provide fish bait at around the beginning of this millennium broadly coincided with the onset of a widespread perception that numbers of both species were in decline. Consequently, the need for population trend data to inform conservation advice and measures became urgent. This paper presents a 22-year time series of standardised surveys for both dolphins within the Mamirauá Reserve, Amazonas State, Brazil. Analysis of these data show that both species are in steep decline, with their populations halving every 10 years (botos) and 9 years (tucuxis) at current rates. These results are consistent with published, independent information on survival rates of botos in this area, which demonstrated a substantial drop in annual survival, commencing at around the year 2000. Mamirauá is a protected area, and is subject to fewer environmental pressures than elsewhere in the region, so there is no reason to suspect that the decline in dolphins within the Reserve is more pronounced than outside it. If South America's freshwater cetaceans are to avoid following their Asian counterparts on the path to a perilous conservation status, effective conservation measures are required immediately. Enforcement of existing fishery laws would greatly assist in achieving this.</p></div
The angular scale of homogeneity with SDSS-IV DR16 Luminous Red Galaxies
We report measurements of the angular scale of cosmic homogeneity
() using the recently released luminous red galaxy sample of the
sixteenth data release of the Sloan Digital Sky Survey (SDSS-IV LRG DR16). It
consists of a model-independent method, as we only use the celestial
coordinates of these objects to carry out such an analysis. The observational
data is divided into thin redshift bins, namely , ,
and , in order to avoid projection biases, and we estimate our
uncertainties through a bootstrap method and a suite of mock catalogues. We
find that the LRGs exhibit an angular scale of homogeneity consistent with the
predictions of the standard cosmology within the redshift interval studied.
Considering the bootstrap method, in which the measurements are obtained in a
model-independent way, we found at 1 level that deg, deg and
deg. Such results are in good
agreement with the ones obtained using mock catalogues built under the
assumption of the standard cosmological model.Comment: 13 pages, 4 figures, 3 tables. References updated; matches version
published in JCA
Union after multiple anterior cervical fusion 21 cases followed for 1-6 years
With a mean follow-up of 3 (1-6) years, we report on 21 patients who underwent
multiple level cervical fusion, using autologous iliac crest grafts. Dissectomies
were performed in 14 patients and corpectomies in another 7. Instrumentation was
used in all patients with corpectomies and in 2 patients who underwent 2-level
and 3-level dissectomies. Non-union occurred in 1 patient at 1 level. Graft
displacement requiring reoperation was observed in 2 patients with massive
corpectomies, in 1 of them as a consequence of trauma. In both patients complete
bony fusion was obtained after reoperation and no other complications were
observed. We conclude that the success rate with multiple-level fusion is
comparable to that of single-level fusion when adequate fixation is achieve
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