Relatório de missão ESAPP a Moçambique: Seminário ALS em Meluco (projecto E502) e seguimento do Estabelecimento do Programa (projecto E206): 16 de julho a 11 de agosto de 2004

Mission report.

Being Bullied: Associated Factors in Children and Adolescents 8 to 18 Years Old in 11 European Countries

OBJECTIVES. To analyze the prevalence of bullying victims among children and adolescents aged 8 to 18 years in 11 European countries and to investigate the associated sociodemographic, physical, and psychosocial factors. METHODS. Being a bullying victim was measured by using the social acceptance (bullying) scale from the Kidscreen-52, a health-related quality-of-life questionnaire administered to 16 210 children and adolescents aged 8 to 18 and their parents in postal or school-based surveys in 11 European countries. Standardized mean differences (effect size) were computed to measure the percentage of children/adolescents scoring 1 SD below the mean on the Kidscreen bullying scale. Logistic regression models were used to determine which sociodemographic, physical, and psychosocial factors were associated with being bullied. RESULTS. The percentage of children being bullied was 20.6% for the entire sample, ranging from 10.5% in Hungary to 29.6% in the United Kingdom. In almost all countries the factors most strongly associated with being bullied were younger age, having probable mental health problems, having a low score on the Kidscreen-52 moods and emotions dimensions, and poor social support. Using the grand mean for all countries as the reference category, there was an above-average likelihood of children or adolescents reporting that they had been victims of bullying in 5 countries (Austria, Netherlands, Spain, Switzerland, and the United Kingdom), and a below-average likelihood in 3 countries (France, Greece, Hungary). CONCLUSIONS. This study indicated considerable variation between countries in the prevalence of those perceiving themselves to be victims of bullying but also revealed a clear profile of those likely to be bullied. The study also suggests that the Kidscreen bullying scale could be useful in identifying potential bullying victims.

Energy Efficient Multimedia Communications in IEEE 802.11 Networks

During the last decade wireless mobile communications have progressively become part of the people’s daily lives, leading users to expect to be “alwaysbest-connected” to the Internet, regardless of their location or time of day. This is indeed motivated by the fact that wireless access networks are increasingly ubiquitous, through different types of service providers, together with an outburst of thoroughly portable devices, namely laptops, tablets, mobile phones, among others. The “anytime and anywhere” connectivity criterion raises new challenges regarding the devices’ battery lifetime management, as energy becomes the most noteworthy restriction of the end-users’ satisfaction. This wireless access context has also stimulated the development of novel multimedia applications with high network demands, although lacking in energy-aware design. Therefore, the relationship between energy consumption and the quality of the multimedia applications perceived by end-users should be carefully investigated. This dissertation addresses energy-efficient multimedia communications in the IEEE 802.11 standard, which is the most widely used wireless access technology. It advances the literature by proposing a unique empirical assessment methodology and new power-saving algorithms, always bearing in mind the end-users’ feedback and evaluating quality perception. The new EViTEQ framework proposed in this thesis, for measuring video transmission quality and energy consumption simultaneously, in an integrated way, reveals the importance of having an empirical and high-accuracy methodology to assess the trade-off between quality and energy consumption, raised by the new end-users’ requirements. Extensive evaluations conducted with the EViTEQ framework revealed its flexibility and capability to accurately report both video transmission quality and energy consumption, as well as to be employed in rigorous investigations of network interface energy consumption patterns, regardless of the wireless access technology. Following the need to enhance the trade-off between energy consumption and application quality, this thesis proposes the Optimized Power save Algorithm for continuous Media Applications (OPAMA). By using the end-users’ feedback to establish a proper trade-off between energy consumption and application performance, OPAMA aims at enhancing the energy efficiency of end-users’ devices accessing the network through IEEE 802.11. OPAMA performance has been thoroughly analyzed within different scenarios and application types, including a simulation study and a real deployment in an Android testbed. When compared with the most popular standard power-saving mechanisms defined in the IEEE 802.11 standard, the obtained results revealed OPAMA’s capability to enhance energy efficiency, while keeping end-users’ Quality of Experience within the defined bounds. Furthermore, OPAMA was optimized to enable superior energy savings in multiple station environments, resulting in a new proposal called Enhanced Power Saving Mechanism for Multiple station Environments (OPAMA-EPS4ME). The results of this thesis highlight the relevance of having a highly accurate methodology to assess energy consumption and application quality when aiming to optimize the trade-off between energy and quality. Additionally, the obtained results based both on simulation and testbed evaluations, show clear benefits from employing userdriven power-saving techniques, such as OPAMA, instead of IEEE 802.11 standard power-saving approaches.

Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air

The stratospheric degradation of chlorofluorocarbons (CFCs) releases chlorine, which is a major contributor to the destruction of stratospheric ozone (O3). A recent study reported strong chlorine isotope fractionation during the breakdown of the most abundant CFC (CFC-12, CCl2F2, Laube et al., 2010a), similar to effects seen in nitrous oxide (N2O). Using air archives to obtain a long-term record of chlorine isotope ratios in CFCs could help to identify and quantify their sources and sinks. We analyse the three most abundant CFCs and show that CFC-11 (CCl3F) and CFC-113 (CClF2CCl2F) exhibit significant stratospheric chlorine isotope fractionation, in common with CFC-12. The apparent isotope fractionation (ϵapp) for mid- and high-latitude stratospheric samples are respectively −2.4 (0.5) and −2.3 (0.4) ‰ for CFC-11, −12.2 (1.6) and −6.8 (0.8) ‰ for CFC-12 and −3.5 (1.5) and −3.3 (1.2) ‰ for CFC-113, where the number in parentheses is the numerical value of the standard uncertainty expressed in per mil. Assuming a constant isotope composition of emissions, we calculate the expected trends in the tropospheric isotope signature of these gases based on their stratospheric 37Cl enrichment and stratosphere–troposphere exchange. We compare these projections to the long-term δ (37Cl) trends of all three CFCs, measured on background tropospheric samples from the Cape Grim air archive (Tasmania, 1978–2010) and tropospheric firn air samples from Greenland (North Greenland Eemian Ice Drilling (NEEM) site) and Antarctica (Fletcher Promontory site). From 1970 to the present day, projected trends agree with tropospheric measurements, suggesting that within analytical uncertainties, a constant average emission isotope delta (δ) is a compatible scenario. The measurement uncertainty is too high to determine whether the average emission isotope δ has been affected by changes in CFC manufacturing processes or not. Our study increases the suite of trace gases amenable to direct isotope ratio measurements in small air volumes (approximately 200 mL), using a single-detector gas chromatography–mass spectrometry (GC–MS) system.

Microbiota Promotes Chronic Pulmonary Inflammation by Enhancing IL-17A and Autoantibodies

RATIONALE Changes in the pulmonary microbiota are associated with progressive respiratory diseases including chronic obstructive pulmonary disease. Whether there is a causal relationship between these changes and disease progression remains unknown. OBJECTIVE To investigate the link between an altered microbiota and disease, we utilized a model of chronic lung inflammation in specific pathogen free (SPF) mice and mice depleted of microbiota by antibiotic treatment or devoid of a microbiota (axenic). METHODS Mice were challenged with LPS/elastase intranasally over 4 weeks, resulting in a chronically inflamed and damaged lung. The ensuing cellular infiltration, histological damage and decline in lung function were quantified. MEASUREMENTS AND MAIN RESULTS Similar to human disease, the composition of the pulmonary microbiota was altered in disease animals. We found that the microbiota richness and diversity were decreased in LPS/Elastase-treated mice, with an increased representation of the genera Pseudomonas, Lactobacillus and a reduction in Prevotella. Moreover, the microbiota was implicated in disease development as mice depleted of microbiota exhibited an improvement in lung function, reduction in airway inflammation, decrease in lymphoid neogenesis and auto-reactive antibody responses. The absence of microbial cues also markedly decreased the production of IL-17A, whilst intranasal transfer of fluid enriched with the pulmonary microbiota isolated from diseased mice enhanced IL-17A production in the lungs of antibiotic treated or axenic recipients. Finally, in mice harboring a microbiota, neutralizing IL-17A dampened inflammation and restored lung function. CONCLUSIONS Collectively, our data indicate that host-microbial cross-talk promotes inflammation and could underlie the chronicity of inflammatory lung diseases.