A sua necessidade e importância na prevenção da criminalidade

A necessidade de que haja um Sistema de Investigação Criminal (SIC) coeso na Polícia Nacional de São Tomé e Príncipe (PNSTP) é o culminar de uma resposta mais acertada/eficaz, capaz de fazer frente a estas transformações (a globalização e a alteração do mundo criminológico, isto é, os seus modus operandi) que se tem presenciado atualmente, não só ao nível internacional como também ao nível nacional. Neste contexto é essencial a implementação de uma política eficaz para que a PNSTP adquira, de facto, verdadeiras competências e capacidades de investigação. No âmbito deste estudo pretende-se identificar, se o modelo de investigação criminal existente em Portugal é adequado para a realidade santomense e desenvolver um modelo para São Tomé e Príncipe. O estudo realizado revela que há necessidade de implementação de um modelo de investigação criminal em STP, que assente numa política de partilha de competência de investigação criminal com a Polícia de Investigação Criminal (PIC), sem prejuízo à investigação de crimes reservados a esta última. Conclui-se que o modelo existente em Portugal serve para ser implementado em STP.The need for the existence of a strong Criminal Investigation System in São Tomé and Principe’s National Police is the summit of a more assertive/effective response, capable of facing this transformations (globalization and the modification of the criminal world, this is, it’s modi operandi) that are seen nowadays, not only in an international level but also in the national level. In this context it is of substance the implementation of a effective policy so that STPNP acquires, in fact, real competences and capabilities for criminal investigation. In this study we aim to identify, if the criminal investigation model which exists in Portugal is adequate for the São Tomé and Principe’s reality and to develop a model for São Tomé and Principe and, consequently, for the STPNP through the creation of a Criminal Investigation System. The study reveals that there is the need to implement a criminal investigation model in STP which stands on a policy of shared criminal investigation competences with the Criminal Investigation Police, without prejudice regarding the investigation which are reserved to the latter. It is concluded that the model which exists in Portugal is suitable for implementation in STP

Compactness and asymptotic behavior in nonautonomous linear parabolic equations with unbounded coefficients in Rd\R^d

We consider a class of second order linear nonautonomous parabolic equations in R^d with time periodic unbounded coefficients. We give sufficient conditions for the evolution operator G(t,s) be compact in C_b(R^d) for t>s, and describe the asymptotic behavior of G(t,s)f as t-s goes to infinity in terms of a family of measures mu_s, s in R, solution of the associated Fokker-Planck equation

Modulation of urban atmospheric electric field measurements with the wind direction in Lisbon (Portugal)

Atmospheric electric field measurements (potential gradient, PG) were retrieved in the urban environment of the city of Lisbon (Portugal). The measurements were performed with a Benndorf electrograph at the Portela Meteorological station in the suburbs of the city (NE from the centre). The period of 1980 to 1990 is considered here. According to wind direction, different content and types of ions and aerosols arrive at the measurement site causing significant variations to the PG. To the south there are significant pollution sources while to the north such sources are scarcer . The Iberian Peninsula is found east of the station and the Atlantic Ocean covers the western sector, Wind directions are divided in four sectors: i) NW: 270º ≤ θ ≤ 360º; ii) NE: 0 ≤ θ ≤ 90º; iii) SE: 90 ≤ θ ≤ 180º; iv) SW: 180º ≤ θ ≤ 270º. Analysis of weekly cycle, caused by anthropogenic pollution related with urban activity, was undertaken for each wind sector. NW sector has been shown to be less affected by this cycle, which is attributed to the effect of marine air. The daily variation of NE sector for weekends reveals a similar behaviour to the Carnegie curve, which corresponds to a clean air daily variation of PG, following universal time, independent of measurement site

New insight into the relation between star formation activity and dust content in galaxies

(Abridged) We assemble a sample of 3258 low-redshift galaxies from the SDSS DR6 with complementary photometric observations by GALEX, 2MASS and IRAS at far-ultraviolet and infrared wavelengths. We use a recent, simple but physically motivated model to interpret the observed spectral energy distributions of the galaxies in this sample in terms of statistical constraints on physical parameters describing the star formation history and dust content. The focus on a subsample of 1658 galaxies with highest S/N observations enables us to investigate most clearly several strong correlations between various derived physical properties of galaxies. We find that the typical dust mass of a star-forming correlates remarkably well with the star formation rate (SFR). We also find that the dust-to-stellar mass ratio, the ratio of dust mass to star formation rate and the fraction of dust luminosity contributed by the diffuse interstellar medium all correlate strongly with specific SFR. A comparison with recent models of chemical and dust evolution of galaxies suggests that these correlations could arise, at least in part, from an evolutionary sequence. As galaxies form stars, their ISM becomes enriched in dust, while the drop in gas supply makes the specific SFR decrease. Interestingly, as a result, a young, actively star-forming galaxy with low dust-to-gas ratio may still be highly dusty because it contains large amounts of interstellar gas. This may be important for the interpretation of the infrared emission from young, gas-rich star-forming galaxies at high redshift. Our study provides a useful local reference for future statistical studies of the star formation and dust properties of galaxies at high redshifts.Comment: 15 pages, 10 figures, accepted for publication in MNRAS. Full-resolution figures available from http://users.physics.uoc.gr/~dacunha/paper_dacunha.pd

Dispersion and collapse in stochastic velocity fields on a cylinder

The dynamics of fluid particles on cylindrical manifolds is investigated. The velocity field is obtained by generalizing the isotropic Kraichnan ensemble, and is therefore Gaussian and decorrelated in time. The degree of compressibility is such that when the radius of the cylinder tends to infinity the fluid particles separate in an explosive way. Nevertheless, when the radius is finite the transition probability of the two-particle separation converges to an invariant measure. This behavior is due to the large-scale compressibility generated by the compactification of one dimension of the space

Homogenized dynamics of stochastic partial differential equations with dynamical boundary conditions

A microscopic heterogeneous system under random influence is considered. The randomness enters the system at physical boundary of small scale obstacles as well as at the interior of the physical medium. This system is modeled by a stochastic partial differential equation defined on a domain perforated with small holes (obstacles or heterogeneities), together with random dynamical boundary conditions on the boundaries of these small holes. A homogenized macroscopic model for this microscopic heterogeneous stochastic system is derived. This homogenized effective model is a new stochastic partial differential equation defined on a unified domain without small holes, with static boundary condition only. In fact, the random dynamical boundary conditions are homogenized out, but the impact of random forces on the small holes' boundaries is quantified as an extra stochastic term in the homogenized stochastic partial differential equation. Moreover, the validity of the homogenized model is justified by showing that the solutions of the microscopic model converge to those of the effective macroscopic model in probability distribution, as the size of small holes diminishes to zero.Comment: Communications in Mathematical Physics, to appear, 200

Group-based physical activity interventions for postpartum women with children aged 0–5 years old: a systematic review of randomized controlled trials

Background: It is estimated that less than one third of women (28%) worldwide, are not sufficiently active, and there is evidence indicating physical activity (PA) participation is lower during pregnancy and the postpartum period. Despite the importance of educating and encouraging postpartum women to engage in PA, existing systematic reviews have only focused on examining the impact of individually tailored PA interventions and on specific postpartum populations such as women who are inactive (i.e., do not meet PA recommendations) or women at risk of gestational diabetes mellitus or postnatal depression. This review aims to fill this gap by examining the impact of group-based PA interventions on postpartum women’s PA levels or other health behavior outcomes. Methods: A systematic literature search was conducted using four electronic databases (MEDLINE, CINAHL, EMBASE and PsychInfo) of published studies between 1st January 2000 and 31st October 2020. Studies were included if they targeted postpartum women with no current health conditions, had children aged 0–5 years, and engaged postpartum women in a group-based PA program that reported PA or other health behavior outcomes. Out of a total of 1091 articles that were initially identified, six were included. Results: Group-based PA interventions were moderately successful in changing or increasing postpartum women’s self-reported PA levels and psychological wellbeing in the first 2 years of their offspring’s life. Overall, group-based PA interventions were not successful in changing or increasing postpartum women’s objectively measured PA levels, but only one study objectively measured postpartum women’s PA levels. Narrative synthesis highlights the heterogeneity of the outcomes and methodologies used, and the low to medium risk of bias in the included studies. Conclusion: To strengthen the evidence-base for group-based PA programs with postpartum women there is an on-going need for more rigorous randomised controlled trials of appropriate length (at least 3 months in duration) with an adequate dose of group-based PA sessions per week (to meet PA guidelines), and that utilise objective measures of PA. In addition, future PA interventions for this population should include, at the very least, fidelity and process data to capture the characteristics or design features that appeal most to postpartum women

Analysis of factors influencing the ultrasonic fetal weight estimation

Objective: The aim of our study was the evaluation of sonographic fetal weight estimation taking into consideration 9 of the most important factors of influence on the precision of the estimation. Methods: We analyzed 820 singleton pregnancies from 22 to 42 weeks of gestational age. We evaluated 9 different factors that potentially influence the precision of sonographic weight estimation ( time interval between estimation and delivery, experts vs. less experienced investigator, fetal gender, gestational age, fetal weight, maternal BMI, amniotic fluid index, presentation of the fetus, location of the placenta). Finally, we compared the results of the fetal weight estimation of the fetuses with poor scanning conditions to those presenting good scanning conditions. Results: Of the 9 evaluated factors that may influence accuracy of fetal weight estimation, only a short interval between sonographic weight estimation and delivery (0-7 vs. 8-14 days) had a statistically significant impact. Conclusion: Of all known factors of influence, only a time interval of more than 7 days between estimation and delivery had a negative impact on the estimation