Coupled human and natural system dynamics as key to the sustainability of Lake Victoria's ecosystem services

East Africa’s Lake Victoria provides resources and services to millions of people on the lake’s shores and abroad. In particular, the lake’s fisheries are an important source of protein, employment, and international economic connections for the whole region. Nonetheless, stock dynamics are poorly understood and currently unpredictable. Furthermore, fishery dynamics are intricately connected to other supporting services of the lake as well as to lakeshore societies and economies. Much research has been carried out piecemeal on different aspects of Lake Victoria’s system; e.g., societies, biodiversity, fisheries, and eutrophication. However, to disentangle drivers and dynamics of change in this complex system, we need to put these pieces together and analyze the system as a whole. We did so by first building a qualitative model of the lake’s social-ecological system. We then investigated the model system through a qualitative loop analysis, and finally examined effects of changes on the system state and structure. The model and its contextual analysis allowed us to investigate system-wide chain reactions resulting from disturbances. Importantly, we built a tool that can be used to analyze the cascading effects of management options and establish the requirements for their success. We found that high connectedness of the system at the exploitation level, through fisheries having multiple target stocks, can increase the stocks’ vulnerability to exploitation but reduce society’s vulnerability to variability in individual stocks. We describe how there are multiple pathways to any change in the system, which makes it difficult to identify the root cause of changes but also broadens the management toolkit. Also, we illustrate how nutrient enrichment is not a self-regulating process, and that explicit management is necessary to halt or reverse eutrophication. This model is simple and usable to assess system-wide effects of management policies, and can serve as a paving stone for future quantitative analyses of system dynamics at local scales.

Farm resilience in organic and nonorganic cocoa farming systems in Alto Beni, Bolivia

Cocoa production in Alto Beni, Bolivia, is a major source of income and is severely affected by climate change impacts and other stress factors. Resilient farming systems are, thus, important for local families. This study compares indicators for social–ecological resilience in 30 organic and 22 nonorganic cocoa farms of Alto Beni. Organic farms had a higher tree and crop diversity, higher yields and incomes, more social connectedness, and participated in more courses on cocoa cultivation. Resilience was enhanced by local farmers’ organizations, providing organic certification and supporting diversified agroforestry with seedlings and extension, going beyond basic organic certification requirements.

"Teens talk healthy weight": A video technology project

Purpose. The purpose of this study was to investigate the impact of a motivational weight management DVD on knowledge of obesity related diseases, readiness, motivation, and self-efficacy to lose weight, connectedness to their care provider, and patients return to clinic. Design. A randomized control trial was conducted in which 40 overweight/obese adolescents and their parents/caregivers were randomly assigned to standard care alone or standard care plus DVD. Subjects completed a set of pre- and post-questionnaire measures. A group of 22 patients was also formed as a historical control group in order to account for the potential effect of extra attention given to subjects prospectively enrolled. Methods. The adolescents and their parent/caregiver were placed into a patient room. Consent was obtained and a set of written pre-questionnaires were given to both the parent and the adolescent. Standard care was provided to all patients by the Registered Dietitian and physician; the DVD was shown in addition to standard care among the intervention group. A set of post-questionnaires were given and compensation was provided. Analysis. Groups were compared to determine equivalence at baseline. Analysis of covariance was used to evaluate changes over time, while controlling for pre-test scores and race/ethnicity. Results. Parents who viewed the DVD experienced greater changes in correct knowledge as compared to parents who did not view the DVD. Conclusion. Our study found only one substantial benefit of the DVD beyond standard clinical practices. This is an important area for change as it increased awareness of obesity as a serious disease and has future clinical implications.^

A look at parent-adolescent processes and adolescent sexual intentions among urban, minority, middle school youth

Background. The United States continues to have the highest rates in teenage pregnancy among industrialized nations and approximately 46% of high school students engaged in sex by the time they graduated. Various family adolescent processes (family connectedness, perceived parental beliefs about sex, parent-child communication about sex) have been linked to adolescent sexual behavior. However, the association between family adolescent and adolescent sexual intentions has not often been studied in middle school minority youth.^ Methods. Research hypotheses were tested using a secondary data analysis from a HIV, STI, and pregnancy prevention program for urban middle school students.^ Results. At baseline, 77% of students reported low intentions to engage in vaginal or oral sex within a year and 87% reported they would use a condom if having sex within the next 3 months. After adjusting for gender, age, and race/ethnicity, family connectedness and perceived parental beliefs about sex were significantly associated with vaginal and oral sex intentions. Only perceived parental beliefs was associated with condom use intentions. ^ Conclusions. Family adolescent processes appear to be associated with adolescents’ intentions regarding sex and condom use. Early interventions are needed that take into account the importance of healthy, supportive parent-adolescent relationships and encourage parents to share their beliefs about sex to adolescents before the onset of sexual activity. ^

Topological invariance and spatial scaling of surface roughness in two highly eroded zones of Mexico: a comparative study

The Fractal Image Informatics toolbox (Oleschko et al., 2008 a; Torres-Argüelles et al., 2010) was applied to extract, classify and model the topological structure and dynamics of surface roughness in two highly eroded catchments of Mexico. Both areas are affected by gully erosion (Sidorchuk, 2005) and characterized by avalanche-like matter transport. Five contrasting morphological patterns were distinguished across the slope of the bare eroded surface of Faeozem (Queretaro State) while only one (apparently independent on the slope) roughness pattern was documented for Andosol (Michoacan State). We called these patterns ?the roughness clusters? and compared them in terms of metrizability, continuity, compactness, topological connectedness (global and local) and invariance, separability, and degree of ramification (Weyl, 1937). All mentioned topological measurands were correlated with the variance, skewness and kurtosis of the gray-level distribution of digital images. The morphology0 spatial dynamics of roughness clusters was measured and mapped with high precision in terms of fractal descriptors. The Hurst exponent was especially suitable to distinguish between the structure of ?turtle shell? and ?ramification? patterns (sediment producing zone A of the slope); as well as ?honeycomb? (sediment transport zone B) and ?dinosaur steps? and ?corals? (sediment deposition zone C) roughness clusters. Some other structural attributes of studied patterns were also statistically different and correlated with the variance, skewness and kurtosis of gray distribution of multiscale digital images. The scale invariance of classified roughness patterns was documented inside the range of five image resolutions. We conjectured that the geometrization of erosion patterns in terms of roughness clustering might benefit the most semi-quantitative models developed for erosion and sediment yield assessments (de Vente and Poesen, 2005).

Disparate connectivity for structural and functional networks is revealed when physical location of the connected nodes is considered

Macroscopic brain networks have been widely described with the manifold of metrics available using graph theory. However, most analyses do not incorporate information about the physical position of network nodes. Here, we provide a multimodal macroscopic network characterization while considering the physical positions of nodes. To do so, we examined anatomical and functional macroscopic brain networks in a sample of twenty healthy subjects. Anatomical networks are obtained with a graph based tractography algorithm from diffusion-weighted magnetic resonance images (DW-MRI). Anatomical con- nections identified via DW-MRI provided probabilistic constraints for determining the connectedness of 90 dif- ferent brain areas. Functional networks are derived from temporal linear correlations between blood-oxygenation level-dependent signals derived from the same brain areas. Rentian Scaling analysis, a technique adapted from very- large-scale integration circuits analyses, shows that func- tional networks are more random and less optimized than the anatomical networks. We also provide a new metric that allows quantifying the global connectivity arrange- ments for both structural and functional networks. While the functional networks show a higher contribution of inter-hemispheric connections, the anatomical networks highest connections are identified in a dorsal?ventral arrangement. These results indicate that anatomical and functional networks present different connectivity organi- zations that can only be identified when the physical locations of the nodes are included in the analysis.

Segmentação de imagens pela transformada imagem-floresta com faixa de restrição geodésica

Vários métodos tradicionais de segmentação de imagens, como a transformada de watershed de marcado- res e métodos de conexidade fuzzy (Relative Fuzzy Connectedness- RFC, Iterative Relative Fuzzy Connected- ness - IRFC), podem ser implementados de modo eficiente utilizando o método em grafos da Transformada Imagem-Floresta (Image Foresting Transform - IFT). No entanto, a carência de termos de regularização de fronteira em sua formulação fazem com que a borda do objeto segmentado possa ser altamente irregular. Um modo de contornar isto é por meio do uso de restrições de forma do objeto, que favoreçam formas mais regulares, como na recente restrição de convexidade geodésica em estrela (Geodesic Star Convexity - GSC). Neste trabalho, apresentamos uma nova restrição de forma, chamada de Faixa de Restrição Geodésica (Geodesic Band Constraint - GBC), que pode ser incorporada eficientemente em uma sub-classe do fra- mework de corte em grafos generalizado (Generalized Graph Cut - GGC), que inclui métodos pela IFT. É apresentada uma prova da otimalidade do novo algoritmo em termos de um mínimo global de uma função de energia sujeita às novas restrições de borda. A faixa de restrição geodésica nos ajuda a regularizar a borda dos objetos, consequentemente melhorando a segmentação de objetos com formas mais regulares, mantendo o baixo custo computacional da IFT. A GBC pode também ser usada conjuntamente com um mapa de custos pré estabelecido, baseado em um modelo de forma, de modo a direcionar a segmentação a seguir uma dada forma desejada, com grau de liberdade de escala e demais deformações controladas por um parâmetro único. Essa nova restrição também pode ser combinada com a GSC e com as restrições de polaridade de borda sem custo adicional. O método é demonstrado em imagens naturais, sintéticas e médicas, sendo estas provenientes de tomografias computadorizadas e de ressonância magnética.

Análise da dinâmica e quantificação metabólica de imagens de medicina nuclear na modalidade PET/CT.

A presença da Medicina Nuclear como modalidade de obtenção de imagens médicas é um dos principais procedimentos utilizados hoje nos centros de saúde, tendo como grande vantagem a capacidade de analisar o comportamento metabólico do paciente, traduzindo-se em diagnósticos precoces. Entretanto, sabe-se que a quantificação em Medicina Nuclear é dificultada por diversos fatores, entre os quais estão a correção de atenuação, espalhamento, algoritmos de reconstrução e modelos assumidos. Neste contexto, o principal objetivo deste projeto foi melhorar a acurácia e a precisão na análise de imagens de PET/CT via processos realísticos e bem controlados. Para esse fim, foi proposta a elaboração de uma estrutura modular, a qual está composta por um conjunto de passos consecutivamente interligados começando com a simulação de phantoms antropomórficos 3D para posteriormente gerar as projeções realísticas PET/CT usando a plataforma GATE (com simulação de Monte Carlo), em seguida é aplicada uma etapa de reconstrução de imagens 3D, na sequência as imagens são filtradas (por meio do filtro de Anscombe/Wiener para a redução de ruído Poisson caraterístico deste tipo de imagens) e, segmentadas (baseados na teoria Fuzzy Connectedness). Uma vez definida a região de interesse (ROI) foram produzidas as Curvas de Atividade de Entrada e Resultante requeridas no processo de análise da dinâmica de compartimentos com o qual foi obtida a quantificação do metabolismo do órgão ou estrutura de estudo. Finalmente, de uma maneira semelhante imagens PET/CT reais fornecidas pelo Instituto do Coração (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP) foram analisadas. Portanto, concluiu-se que a etapa de filtragem tridimensional usando o filtro Anscombe/Wiener foi relevante e de alto impacto no processo de quantificação metabólica e em outras etapas importantes do projeto em geral.

Building International CSR on Solid Foundations: Location and Network Aspects of Nonmarket Environments in Europe and Non-Europe Markets. ACES Working Papers, 2011

Multinational companies' (MNCs) corporate social responsibility (CSR) programs frequently comprise a portfolio of disconnected country-level programs or, alternatively, consist of blanket corporate policies that apply in the same way across the geographies where the company operates. Yet, the international nonmarket environment in which CSR programs operate is neither a completely fragmented nor a perfectly homogeneous one. Building on the concept of stakeholder-issue-networks, we develop a model that explicitly takes into consideration the role of geography in the characterization of a firm's nonmarket environment. This allows us to develop a taxonomy of nonmarket environments on the basis of their geographic spread and their degree of cross-border connectedness. We then explore the strategic and organizational implications that different ideal types of (cross-border) nonmarket environments have for the development of international CSR policies.

The Relationship between Adolescent Social Network Structure and Perceptions of School Climate

Thesis (Ph.D.)--University of Washington, 2016-06

Being, Belonging, and Connecting: Filipino Youths' Narratives of Place(s) and Wellbeing in Hawai'i

Thesis (Ph. D.)--University of Washington, 2016-04

Utility functions on locally connected spaces

We investigate the role of local connectedness in utility theory and prove that any continuous total preorder on a locally connected separable space is continuously representable. This is a new simple criterion for the representability of continuous preferences, and is not a consequence of the standard theorems in utility theory that use conditions such as connectedness and separability, second countability, or path-connectedness. Finally we give applications to problems involving the existence of value functions in population ethics and to the problem of proving the existence of continuous utility functions in general equilibrium models with land as one of the commodities. (C) 2003 Elsevier B.V. All rights reserved.

The moderating role of individual differences in the relation between transformational/transactional leadership perceptions and organizational identification

In this study, we examined the relationship between transformational/transactional leadership perceptions and organizational identification and further explored the moderating role of individual difference variables, such as separateness-connectedness self-schema, and positive and negative affectivity. Data from 502 services employees indicated significant positive effects of transformational and transactional leadership perceptions on organizational identification. Regarding the moderating role of individual differences, our data showed that the positive relationship of transformational leadership and organizational identification was stronger for individuals of low positive affectivity as well as for employees of high negative affectivity. In addition, results indicated that transactional leadership had a stronger positive effect on organizational identification for individuals characterized by a connected self-schema. (c) 2005 Elsevier Inc. All rights reserved.

Larval dispersal reveals regional sources and sinks in the Great Barrier Reef

We analysed simulated connectivity patterns for reef fish larvae in the Cairns section of the Great Barrier Reef, and identified 2 key subregions that exhibit regional scale source–sink dynamics. The source and sink were separated latitudinally by a boundary at 16.1°S, with the source subregion lying to the north. Larval transport between the 2 subregions was predominantly unidirectional, from north to south. Only a few local populations, described here as ‘gateway reefs’, were able to transport larvae from the sink subregion to the source subregion and thus maintain the connectedness of the metapopulation. The northern subregion was able to persist without external larval supply, but when conditions were recruitment limited, the southern subregion depended on larval supply from the north to persist. The relative autonomy of the northern subregion, and its importance in sustaining the southern subregion, will influence the effectiveness of conservation efforts.

Suit keen renovator: Alternate reality design

Virtual territories and their theme parks are more akin to the physical world of real estate than they might at first appear. The trick in triggering the designer's imagination, is to find a 'nice renovator' (cottage/ house) at a low price, with loads of potential, and by doing it on the cheap to add character, and engage the imagination. Here the designer can construct changes from an imagined space. Vision is more important than how the actual place presents.This work describes a case study involving undergraduate students in the Creative Industries who needed a place to explore, so as to create their own visions and projects. The place had to inspire, trigger engagement, and their imaginations. At the same time it was important that the place did not coerce activity, or distract from the task by confusing tools with task, or architectural navigation with conceptual skills.The solution was an alternate reality.