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BackgroundActivity 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.MethodsSystematic 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.ResultsAll 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.ConclusionsThis 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.

Antibiotic prophylaxis after basilar skull fractures remains controversial. Previous studies have not clearly delineated the utility of prophylactic antibiotics in this setting. We undertook this study to determine if antibiotic prophylaxis after basilar skull fractures prevented meningitis. We performed a formal systematic review of previously published studies after a computerized search with use of the MEDLINE data base (1970-1996). Fourteen studies were identified, and 12 studies met the criteria for inclusion. Study design and quality were assessed by two independent investigators with use of a predetermined protocol. A total of 1,241 patients with basilar skull fractures were included; 719 patients received antibiotics, and 522 patients did not receive antibiotics. Overall results suggest that antibiotic prophylaxis did not prevent meningitis among patients with basilar skull fractures (odds ratio [OR] = 1.15; 95% confidence interval [CI] = 0.68-1.94; P = .678). Patients with basilar skull fractures and cerebrospinal fluid leakage were analyzed separately (OR = 1.34; 95% CI = 0.75-2.41; P = .358), as were children (OR = 1.04; 95% CI = 0.07-14.90; P = 1.000). Antibiotic prophylaxis after basilar skull fractures does not appear to decrease the risk of meningitis.

We computationally demonstrate the one-photon phase control of retinal isomerization under conditions of low laser intensity. The calculations, utilizing the multiconfigurational time dependent Hartree method, include coupling between the two modes that are active in isomerization and the background molecular vibrational environment. Noting previously unsuccessful computations highlights the significance of this result.