98 resultados para macro-ecology
Resumo:
This paper investigates the potential improvement in signal reliability for outdoor short-range off-body communications channels at 868 MHz using the macro-diversity offered by multiple co-located base stations. In this study, ten identical hypothetical base stations were positioned equidistantly around the perimeter of a rectangle of length 6.67 m and width 3.3 m. A body worn node was placed on the central chest region of an adult male. Five scenarios, each considering different user trajectories, were then analyzed to test the efficacy of using macro-diversity when the desired link is subject to shadowing caused by the human body. A number of selection combining based macro-diversity configurations consisting of four and then ten base stations were considered. It was found that using a macro-diversity system consisting of four base stations (or equivalently signal branches), a maximum diversity gain of 22.5 dB could be obtained while implementing a 10-base station setup this figure could be improved to 25.2 dB.
Resumo:
This paper addresses the representation of landscape complexity in stated preferences research. It integrates landscape ecology and landscape economics and conducts the landscape analysis in a three-dimensional space to provide ecologically meaningful quantitative landscape indicators that are used as variables for the monetary valuation of landscape in a stated preferences study. Expected heterogeneity in taste intensity across respondents is addressed with a mixed logit model in Willingness to Pay space. Our methodology is applied to value, in monetary terms, the landscape of the Sorrento Peninsula in Italy, an area that has faced increasing pressure from urbanization affecting its traditional horticultural, herbaceous, and arboreal structure, with loss of biodiversity, and an increasing risk of landslides. We find that residents of the Sorrento Peninsula would prefer landscapes characterized by large open views and natural features. Residents also appear to dislike heterogeneous landscapes and the presence of lemon orchards and farmers' stewardship, which are associated with the current failure of protecting the traditional landscape. The outcomes suggest that the use of landscape ecology metrics in a stated preferences model may be an effective way to move forward integrated methodologies to better understand and represent landscape and its complexity.
Resumo:
The macrosystem refers to the overarching patterns that influence behavior at each level of the social ecology (Bronfenbrenner, 1977), making it a necessary component for assessing human development in contexts of political violence. This article proposes a method for systematically measuring the macrosystem in Northern Ireland that allows for a subnational analysis, multiple time units, and indicators of both low-level violence and positive relations. Articles were randomly chosen for each weekday in 2006-2011 from two prominent Northern Irish newspapers and coded according to their reflection of positive relations and political tensions between Catholics and Protestants. The newspaper data were then compared to existing macro-level measurements in Northern Ireland. We found that the newspaper data provided a more nuanced understanding of fluctuations in intergroup relations than the corresponding measures. This has practical implications for peacebuilding and advances our methods for assessing the impact of macro-level processes on individual development.
Resumo:
Fungi of the genus Aspergillus are widespread in the environment. Some Aspergillus species, most commonly Aspergillus fumigatus, may lead to a variety of allergic reactions and life-threatening systemic infections in humans. Invasive aspergillosis occurs primarily in patients with severe immunodeficiency, and has dramatically increased in recent years. There are several factors at play that contribute to aspergillosis, including both fungus and host-related factors such as strain virulence and host pulmonary structure/immune status, respectively. The environmental tenacity of Aspergilllus, its dominance in diverse microbial communities/habitats, and its ability to navigate the ecophysiological and biophysical challenges of host infection are attributable, in large part, to a robust stress-tolerance biology and exceptional capacity to generate cell-available energy. Aspects of its stress metabolism, ecology, interactions with diverse animal hosts, clinical presentations and treatment regimens have been well-studied over the past years. Here, we synthesize these findings in relation to the way in which some Aspergillus species have become successful opportunistic pathogens of human- and other animal hosts. We focus on the biophysical capabilities of Aspergillus pathogens, key aspects of their ecophysiology and the flexibility to undergo a sexual cycle or form cryptic species. Additionally, recent advances in diagnosis of the disease are discussed as well as implications in relation to questions that have yet to be resolved.
Resumo:
While child welfare practitioners in many countries are struggling to develop methods of effective family engagement, they operate within different national and cultural contexts which influence, both positively and negatively, the ability to engage with families. Increasingly, international comparisons are necessary to further understanding of the development of social work practice. This is particularly necessary because most countries utilize international frameworks (such as the United National Convention on the Rights of the Child) to provide guidance in the development of policies, programs, and interventions. Each country (and locality) struggles to advance practice to be more effective and humane. Our paper offers a comparative analysis focused on family-oriented and rights-based frameworks of different countries. Based on a review of current national policies and a review of the literature regarding family based practices, we examine similarities and differences among four countries: the United Kingdom, Sweden, the United States, and South Korea. These countries were selected because they have some similarities (advanced industrialized democracies, professional social work, formal child protection systems) but have some differences in their social welfare systems (policies, specific practices, socio-cultural context). These differences can be utilized to advance understanding regarding the promise and potential for family engagement strategies. We then discuss the utility of this comparison for theory-building in the arena of child care practice and conclude by identifying the challenges and limitations of this work.