Promoting physical activity among university students: a systematic review of controlled trials

Objective: University study is often accompanied by a decline in physical activity (PA) levels but can offer the opportunity to promote a lifelong active lifestyle. This review aims to summarize controlled trials of interventions promoting PA among uni- versity students, describing the quality of the evidence, effective strategies, and deficiencies in the interventions employed, to provide directions for future research and for practical implementations. Data Source: PubMed, PsychINFO, Cochrane Library, Education Source, and SPORTDiscus. Study Inclusion Criteria: Randomized or nonrandomized controlled trial, describing an intervention to promote PA in uni- versity students, where PA was one of the outcomes and results were published in English. Data Extraction: Country, study design, participants\u2019 inclusion criteria, participation rate and characteristics, randomization, blinding, theoretical framework, intervention characteristics, participant retention rate and withdrawal reasons, measures employed, data analysis, PA results, and findings regarding PA correlates. Data Synthesis: Data were synthetized considering study characteristics, strategies used, and outcomes. Results: Two thousand five hundred eighty-five articles were identified. Twenty-seven studies met the inclusion criteria. Sixteen studies reported an increase in PA levels. Conclusion: Physical Activity promotion interventions should address a range of behavioral determinants. Personalized approaches and PA sessions should be considered in future studies. The high risk of bias of many studies (mainly due to attrition and poor reporting) and missing information about intervention components limit the strength of conclusions about the most effective strategies and the evidence of effectiveness, highlighting the need for further high-quality studies

Room-temperature air-stable spin transport in bathocuproine-based spin valves

Organic semiconductors, characterized by weak spin-scattering mechanisms, are attractive materials for those spintronic applications in which the spin information needs to be retained for long times. Prototypical spin-valve devices employing organic interlayers sandwiched between ferromagnetic materials possess a figure of merit (magnetoresistance (MR)) comparable to their fully inorganic counterparts. However, these results are a matter of debate as the conductivity of the devices does not show the expected temperature dependence. Here we show spin valves with an interlayer of bathocuproine in which the transport takes place unambiguously through the organic layer and where the electron spin coherence is maintained over large distances (>60 nm) at room temperature. Additionally, the devices show excellent air stability, with MR values almost unaltered after 70 days of storage under ambient conditions, making bathocuproine an interesting material for future spintronic applications.Fil: Sun, Xiangnan. CIC nanoGUNE; EspañaFil: Gobbi, Marco. Université de Strasbourg; Francia. CIC nanoGUNE; EspañaFil: Bedoya Pinto, Amilcar. CIC nanoGUNE; EspañaFil: Txoperena, Oihana. CIC nanoGUNE; EspañaFil: Golmar, Federico. CIC nanoGUNE; España. Instituto Nacional de Tecnología Industrial; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Llopis, Roger. CIC nanoGUNE; EspañaFil: Chuvilin, Andrey. CIC nanoGUNE; España. Fundación Vasca para la Ciencia; EspañaFil: Casanova, Félix. CIC nanoGUNE; España. Fundación Vasca para la Ciencia; EspañaFil: Hueso, Luis E.. CIC nanoGUNE; España. Fundación Vasca para la Ciencia; Españ

How reliable are Hanle measurements in metals in a three-terminal geometry?

We test the validity of Hanle measurements in three-terminal devices by using aluminum (Al) and gold (Au). The obtained Hanle and inverted Hanle-like curves show an anomalous behavior. First, we measure Hanle signals 8 orders of magnitude larger than those predicted by standard theory. Second, the temperature and voltage dependences of the signal do not match with the tunneling spin polarization of the ferromagnetic contact. Finally, the spin relaxation times obtained with this method are independent of the choice of the metallic channel. These results are not compatible with spin accumulation in the metal. Furthermore, a scaling of the Hanle signal with the interface resistance of the devices suggests that the measured signal is originated in the tunnel junction.Comment: 9 pages, 5 figure

Randomized controlled clinical trials in orthopedics: difficulties and limitations

Os ensaios clínicos controlados e randomizados (ECCR) são considerados o padrão ouro da medicina baseada em evidências na atualidade, sendo importantes para direcionar a conduta médica através de observações científicas consistentes. Passos como seleção dos pacientes, randomização e cegamento são fundamentais na realização de um ECCR e apresentam algumas dificuldades extras nos ensaios que envolvem procedimentos cirúrgicos, como é comum na Ortopedia. O objetivo deste artigo é destacar e discutir algumas dificuldades e eventuais limitações dos ECCR na área cirúrgica.Randomized controlled clinical trials (RCTs) are considered to be the gold standard for evidence-based medicine nowadays, and are important for directing medical practice through consistent scientific observations. Steps such as patient selection, randomization and blinding are fundamental for conducting an RCT, but some additional difficulties are presented in trials that involve surgical procedures, as in common in orthopedics. The aim of this article was to highlight and discuss some difficulties and possible limitations on RCTs within the field of surgery

A cationic tetrapyrrole inhibits toxic activities of the cellular prion protein

Prion diseases are rare neurodegenerative conditions associated with the conformational conversion of the cellular prion protein (PrPC) into PrPSc, a self-replicating isoform (prion) that accumulates in the central nervous system of affected individuals. The structure of PrPSc is poorly defined, and likely to be heterogeneous, as suggested by the existence of different prion strains. The latter represents a relevant problem for therapy in prion diseases, as some potent anti-prion compounds have shown strain-specificity. Designing therapeutics that target PrPC may provide an opportunity to overcome these problems. PrPC ligands may theoretically inhibit the replication of multiple prion strains, by acting on the common substrate of any prion replication reaction. Here, we characterized the properties of a cationic tetrapyrrole [Fe(III)-TMPyP], which was previously shown to bind PrPC, and inhibit the replication of a mouse prion strain. We report that the compound is active against multiple prion strains in vitro and in cells. Interestingly, we also find that Fe(III)-TMPyP inhibits several PrPC-related toxic activities, including the channel-forming ability of a PrP mutant, and the PrPC-dependent synaptotoxicity of amyloid-beta (A beta) oligomers, which are associated with Alzheimer's Disease. These results demonstrate that molecules binding to PrPC may produce a dual effect of blocking prion replication and inhibiting PrPC-mediated toxicity

Increasing pattern recognition accuracy for chemical sensing by evolutionary based drift compensation

Artificial olfaction systems, which mimic human olfaction by using arrays of gas chemical sensors combined with pattern recognition methods, represent a potentially low-cost tool in many areas of industry such as perfumery, food and drink production, clinical diagnosis, health and safety, environmental monitoring and process control. However, successful applications of these systems are still largely limited to specialized laboratories. Sensor drift, i.e., the lack of a sensor's stability over time, still limits real in dustrial setups. This paper presents and discusses an evolutionary based adaptive drift-correction method designed to work with state-of-the-art classification systems. The proposed approach exploits a cutting-edge evolutionary strategy to iteratively tweak the coefficients of a linear transformation which can transparently correct raw sensors' measures thus mitigating the negative effects of the drift. The method learns the optimal correction strategy without the use of models or other hypotheses on the behavior of the physical chemical sensors