990 resultados para worldwide
Resumo:
We discuss the on-going worldwide activity to develop forward looking standards for quantum key distribution (QKD) in the European Telecommunications Standards Institute (ETSI) QKD industry specification group (ISG). The long term goal is to develop a certification methodology that bridges the gap between theoretical proofs and practical implementations with imperfect devices. Current efforts are focused on the handling of side channels and characterization of the most relevant components.
Resumo:
Multi-junction solar cells are widely used in high-concentration photovoltaic systems (HCPV) attaining the highest efficiencies in photovoltaic energy generation. This technology is more dependent on the spectral variations of the impinging Direct Normal Irradiance (DNI) than conventional photovoltaics based on silicon solar cells and consequently demands a deeper knowledge of the solar resource characteristics. This article explores the capabilities of spectral indexes, namely, spectral matching ratios (SMR), to spectrally characterize the annual irradiation reaching a particular location on the Earth and to provide the necessary information for the spectral optimization of a MJ solar cell in that location as a starting point for CPV module spectral tuning. Additionally, the relationship between such indexes and the atmosphere parameters, such as the aerosol optical depth (AOD), precipitable water (PW), and air mass (AM), is discussed using radiative transfer models such as SMARTS to generate the spectrally-resolved DNI. The network of ground-based sun and sky-scanning radiometers AERONET (AErosol RObotic NETwork) is exploited to obtain the atmosphere parameters for a selected bunch of 34 sites worldwide. Finally, the SMR indexes are obtained for every location, and a comparative analysis is carried out for four architectures of triple junction solar cells, covering both lattice match and metamorphic technologies. The differences found among cell technologies are much less significant than among locations.
Resumo:
World poverty is a global issue and a development issue. Poverty reduction and women's empowerment are deeply connected to regional stability and long lasting peace. Nations will continue to be plagued by poverty, and top-down government agency aid programs to date have been unsuccessful. Encouraging news resides in innovative microfinance initiatives that alleviate poverty and impact millions of impoverished people around the globe. Microfinance organizations provide small loans, primarily to women otherwise excluded from the formal banking sector, for entrepreneurial endeavors. Myriad social, educational, and health programs accompany microfinance loan services. It is a powerful poverty-fighting tool with socioeconomic benefits. Evidence suggests that while imperfect, microfinance goals and successes are inspiring given the paucity of realistic alternatives in today's global development arena.
Resumo:
OBJECTIVES: To describe the recommendations and interventions addressing violence against women (VAW) in vulnerable women (disabled, pregnant, ethnic minority, immigrant and older women) in key documents and laws enacted in different countries. METHODS: Content analysis of key documents for the development of VAW policies and laws: The United Nations Handbook for Legislation on Violence Against Women Advance Version, the Model of Laws and Policies on Intrafamiliar Violence Against Women of the Pan-American Health Organization and Recommendation No. R(2002)5 of the Committee of Ministers of the European Council. The content of the 62 VAW laws was also analyzed. RESULTS: Key documents demonstrate the importance of eliminating any obstacle facing disabled, pregnant, immigrant, ethnic minority or older women when accessing VAW services. Only 12 laws mention one or more of these groups of vulnerable women. Pregnant, disabled and ethnic minority women are the groups most often mentioned. In these laws, references to punitive measures, action plans and specific strategies to guarantee access to VAW resources are the most common interventions. CONCLUSION: Decisive interventions addressing the specific needs of disabled, pregnant, immigrant, ethnic minority and older women are needed in order to achieve a broader equity approach in VAW legislation.
Resumo:
Participation trends in 6-hour ultra-marathons held word-wide were investigated to gain basic demographic data on 6-hour ultra-marathoners and where these races took place. Participation trends and the association between nationality and race performance were investigated in all 6-hour races held worldwide between 1991 and 2010. Participation increased linearly in both women and men across years. The annual number of finishes was significantly higher in men than in women (P=0.013). The male-to-female ratio remained stable at ~4 since 1991. Runners in age group 45-49 years showed the largest increase in participation for both men (800 participants in 18 years) and women (208 participants in 16 years). Europe attracted most of the runners from other continents (166 runners), more than all other continents combined (55 runners). European runners also showed the best top ten performances (73±3 km for women and 77±11 km for men), while African (with 65±9 km for men) and South American (54±4 km for women and 65±2 km for men) runners showed the weakest. To summarize, participation in 6-hour ultra-marathons increased across years. Most of the development took place in Europe and in athletes in the age group 45-49 years. Europe also attracted the most diverse field of athletes with runners from all other continents. European runners accounted for the most runners and achieved the best top ten performances.
Resumo:
When closely related species co-occur in sympatry, they face a significant challenge. They must adapt to the same local conditions in their shared environment, which favours the convergent evolution of traits, while simultaneously minimizing the costs of competition for shared resources that typically favours the divergent evolution of traits. Here, we use a comparative sister lineage approach to test how most species have responded to these conflicting selection pressures in sympatry, focusing on a key ecological trait: the bill morphology of birds. If similar bill morphologies incur fitness costs due to species interactions, then we predicted that the bill morphologies of closely related species would differ more in sympatry compared with allopatry. Alternatively, if similar bill morphologies incur fitness benefits due to local adaptation, then we predicted that the bill morphologies would be more similar in sympatry compared with allopatry. We used museum specimens to measure five aspects of bill (maxilla) morphology – depth, length, width, side shape, and bottom shape – in diverse bird species from around the world to test our alternative hypotheses. We found support for both divergent evolution and convergent evolution (or trait retention) in one ecological trait: closely related sympatric species diverged in bill depth, but converged in side shape. These patterns of bill evolution were influenced by the genetic distance between closely related sister taxa and the geographic distance between allopatric lineages. Overall, our results highlight species interactions as an important mechanism for the evolution of some (bill depth), but not all (bill shape), aspects of bill morphology in closely related species in sympatry, and provide strong support for the bill as a key ecological trait that can adapt in different ways to the conflicting challenges of sympatry.