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

UBER: Innovation or déja vu? CEPS Commentary, 25 February 2015

The emergence of the controversial car service Uber has provoked a wide and heated discussion among economists specialising in the services sector in recent months. This Commentary explores the most salient questions being raised in the debate: Does Uber really offer a new service? And does it represent true innovation? The authors argue that there are some very interesting innovative elements associated with Uber, but those related to the specific industrial relations model might prove to be prejudiced against drivers

Estimation of Mediterranean forest attributes by the application of k-NN procedures to multitemporal Landsat ETM+ images

Routinely, applications of nonparametric estimation methods to satellite data for assisting the creation of forest inventories in Northern European countries are stimulating interest in the possible extension of these methods to more complex Mediterranean areas. This is the subject of the current work, which presents an experiment based on the integration of remotely sensed images and sample field measurements aimed at producing forest attribute maps in central Italy. Testing was carried out in an area where 370 geocoded field plots, sampled on a singlestage cluster design, were collected to characterize wood and non-wood forest attributes. These ground data served to apply various k-Nearest Neighbour (k- NN) estimation procedures to multitemporal Landsat 7 ETM+ images in order to map major forest attributes (basal area and simulated leaf area index, LAI). More specifically, the investigation focused on evaluating the effects of using satellite images from different periods of the growing season and spectral metrics of increasing complexity. The results achieved by the examined methods are finally discussed in order to provide guidelines for possible operational utilization.L'articolo è disponibile sul sito dell'editore http://www.tandf.co.uk/journals

K-NN FOREST: a software for the non-parametric prediction and mapping of environmental variables by the k-Nearest Neighbors algorithm

In the last decades researchers investigated the possibility of extending the information collected in sampling units during a field survey to wider geographical areas through the use of remotely sensed images. One of the most widely adopted approaches is based on the non-parametric k-Nearest Neighbors (k-NN) algorithm. This contribution describes the software K-NN FOREST we developed to provide a complete tool for the implementation of the k-NN technique to generate spatially explicit estimations (maps) of a response variable acquired in the field by sampling units through the use of remotely sensed data or other ancillary variables. K-NN FOREST is designed to guide the user through a graphic user interface in the different phases of the process. K-NN FOREST is freely available for download and it is designed to run under Windows environment in conjunction with the GIS software IDRISI

Evaluating the effects of environmental changes on the gross primary production of italian forests

A ten-year data-set descriptive of Italian forest gross primary production (GPP) has been recently constructed by the application of Modified C-Fix, a parametric model driven by remote sensing and ancillary data. That data-set is currently being used to develop multivariate regression models which link the inter-year GPP variations of five forest types (white fir, beech, chestnut, deciduous and evergreen oaks) to seasonal values of temperature and precipitation. The five models obtained, which explain from 52% to 88% of the interyear GPP variability, are then applied to predict the effects of expected environmental changes (+2 °C and increased CO2 concentration). The results show a variable response of forest GPP to the simulated climate change, depending on the main ecosystem features. In contrast, the effects of increasing CO2 concentration are always positive and similar to those given by a combination of the two environmental factors. These findings are analyzed with reference to previous studies on the subject, particularly concerning Mediterranean environments. The analysis confirms the plausibility of the scenarios obtained, which can cast light on the important issue of forest carbon pool variations under expected global changes

Effect of Intergalactic Medium on the Observability of Lyman Alpha Emitters during Cosmic Reionization

We perform a systematic study of how the inhomogeneities in the Inter-Galactic Medium (IGM) affect the observability of Lyman Alpha Emitters (LAEs) around the Epoch of Reionization. We focus on the IGM close to the galaxies as the detailed ionization distribution and velocity fields of this region could significantly influence the scattering of Ly-alpha photons off neutral H atoms as they traverse the IGM after escaping from the galaxy. We simulate the surface brightness (SB) maps and spectra of more than 100 LAEs at z=7.7 as seen by an observer at z=0. To achieve this, we extract the source properties of galaxies and their surrounding IGM from cosmological simulations of box sizes 5-30 Mpc/h and follow the coupled radiative transfer of ionizing and Ly-alpha radiation through the IGM using CRASH-alpha. We find that the simulated SB profiles are extended and their detailed structure is affected by inhomogeneities in the IGM, especially at high neutral fractions. The detectability of LAEs and the fraction of the flux observed depend heavily on the shape of the SB profile and the SB threshold (SB_th) of the observational campaign. Only ultradeep observations (e.g. SB_th ~ 10^-23 ergs/s/cm^2/arcsec^2) would be able to obtain the true underlying mass-luminosity relation and luminosity functions of LAEs. The details of our results depend on whether Ly-alpha photons are significantly shifted in the galaxy to longer wavelengths, the mean ionization fraction in the IGM and the clustering of ionizing sources. These effects can lead to an easier escape of Ly-alpha photons with less scattering in the IGM and a concentrated SB profile similar to the one of a point source. Finally, we show that the SB profiles are steeper at high ionization fraction for the same LAE sample which can potentially be observed from the stacked profile of a large number of LAEs.Comment: 22 pages, 23 figures, 2 tables, Accepted by MNRAS. Minor change

Progettazione e valutazione di un percorso educativo personalizzato per la promozione dell'attivita' fisica tra gli studenti universitari

La pratica di un adeguato livello di attivita' fisica rappresenta un comportamento molto importante per il mantenimento ed il miglioramento della salute della persone. Anche per questo motivo, l’educazione fisica e’ presente nei curricula scolastici da livello globale, con lo scopo di aiutare i giovani a valorizzare l’importanza di uno stile di vita attivo. Ciononostante, nel passaggio dalla scuola all’universita’ si registra un calo nei livelli di attivita’ fisica praticata. A questo fenomeno, si va a sommare la presenza di giovani che presentano profili di inattivita’ gia’ durante il periodo scolastico, e che sono maggiormente a rischio di sedentarieta’ anche durante gli anni universitari. Puo’ risultare quindi utile, al fine del miglioramento della salute e del benessere degli studenti universitari, implementare degli interventi di promozione dell’attivita’ fisica. La presente tesi descrive un percorso di progettazione e di valutazione di un programma educativo per promuovere tra gli studenti universitari l'adozione e il mantenimento di uno stile di vita attivo. Il fine e’ quello di poter fornire un valido progetto per la creazione di un servizio di promozione dell’attivita’ fisica offerto dall’universita’ agli studenti. La tesi si compone di tre parti principali, correlate tra loro, ma che costituiscono anche ricerche in parte indipendenti: 1) Una revisione sistematica della letteratura riguardante i trial controllati che hanno valutato degli interventi di promozione del’attivita’ fisica tra gli studenti universitari. In questa parte della tesi verra’ analizzata criticamente la letteratura del settore, alla ricerca di strategie progettuali ed operative che abbiano dimostrato di riuscire a promuovere l’attivita’ fisica tra gli studenti universitari. 2) Un sondaggio esplorativo tra gli studenti dell'Universita’ di Padova. Il sondaggio e’ stato effettuato per indagare il fenomeno dell’inattività fisica tra gli studenti dell’Universita’ di Padova, ed analizzare le principali barriere percepite dagli studenti nei confronti dell’attivita’ fisica. 3) La progettazione e la valutazione, tramite uno studio pilota, di un percorso educativo personalizzato per la promozione dell’attivita’ fisica tra gli studenti universitari. La progettazione del percorso educativo e’ preceduta da una presentazione del quadro teorico - antropologico e pedagogico - di riferimento