One Person, Many Votes: Divided Majority and Information Aggregation

In elections, majority divisions pave the way to focal manipulations and coordination failures, which can lead to the victory of the wrong candidate. This paper shows how this flaw can be addressed if voter preferences over candidates are sensitive to information. We consider two potential sources of divisions: majority voters may have similar preferences but opposite information about the candidates, or opposite preferences. We show that when information is the source of majority divisions, Approval Voting features a unique equilibrium with full information and coordination equivalence. That is, it produces the same outcome as if both information and coordination problems could be resolved. Other electoral systems, such as Plurality and Two-Round elections, do not satisfy this equivalence. The second source of division is opposite preferences. Whenever the fraction of voters with such preferences is not too large, Approval Voting still satisfies full information and coordination equivalence.

Multi-level, Multi-stage and Stochastic Optimization Models for Energy Conservation in Buildings for Federal, State and Local Agencies

Energy Conservation Measure (ECM) project selection is made difficult given real-world constraints, limited resources to implement savings retrofits, various suppliers in the market and project financing alternatives. Many of these energy efficient retrofit projects should be viewed as a series of investments with annual returns for these traditionally risk-averse agencies. Given a list of ECMs available, federal, state and local agencies must determine how to implement projects at lowest costs. The most common methods of implementation planning are suboptimal relative to cost. Federal, state and local agencies can obtain greater returns on their energy conservation investment over traditional methods, regardless of the implementing organization. This dissertation outlines several approaches to improve the traditional energy conservations models. Any public buildings in regions with similar energy conservation goals in the United States or internationally can also benefit greatly from this research. Additionally, many private owners of buildings are under mandates to conserve energy e.g., Local Law 85 of the New York City Energy Conservation Code requires any building, public or private, to meet the most current energy code for any alteration or renovation. Thus, both public and private stakeholders can benefit from this research. The research in this dissertation advances and presents models that decision-makers can use to optimize the selection of ECM projects with respect to the total cost of implementation. A practical application of a two-level mathematical program with equilibrium constraints (MPEC) improves the current best practice for agencies concerned with making the most cost-effective selection leveraging energy services companies or utilities. The two-level model maximizes savings to the agency and profit to the energy services companies (Chapter 2). An additional model presented leverages a single congressional appropriation to implement ECM projects (Chapter 3). Returns from implemented ECM projects are used to fund additional ECM projects. In these cases, fluctuations in energy costs and uncertainty in the estimated savings severely influence ECM project selection and the amount of the appropriation requested. A risk aversion method proposed imposes a minimum on the number of “of projects completed in each stage. A comparative method using Conditional Value at Risk is analyzed. Time consistency was addressed in this chapter. This work demonstrates how a risk-based, stochastic, multi-stage model with binary decision variables at each stage provides a much more accurate estimate for planning than the agency’s traditional approach and deterministic models. Finally, in Chapter 4, a rolling-horizon model allows for subadditivity and superadditivity of the energy savings to simulate interactive effects between ECM projects. The approach makes use of inequalities (McCormick, 1976) to re-express constraints that involve the product of binary variables with an exact linearization (related to the convex hull of those constraints). This model additionally shows the benefits of learning between stages while remaining consistent with the single congressional appropriations framework.

Bayesian analysis of a mastitis control plan to investigate the influence of veterinary prior beliefs on clinical interpretation

The fundamental objective for health research is to determine whether changes should be made to clinical decisions. Decisions made by veterinary surgeons in the light of new research evidence are known to be influenced by their prior beliefs, especially their initial opinions about the plausibility of possible results. In this paper, clinical trial results for a bovine mastitis control plan were evaluated within a Bayesian context, to incorporate a community of prior distributions that represented a spectrum of clinical prior beliefs. The aim was to quantify the effect of veterinary surgeons’ initial viewpoints on the interpretation of the trial results. A Bayesian analysis was conducted using Markov chain Monte Carlo procedures. Stochastic models included a financial cost attributed to a change in clinical mastitis following implementation of the control plan. Prior distributions were incorporated that covered a realistic range of possible clinical viewpoints, including scepticism, enthusiasm and uncertainty. Posterior distributions revealed important differences in the financial gain that clinicians with different starting viewpoints would anticipate from the mastitis control plan, given the actual research results. For example, a severe sceptic would ascribe a probability of 0.50 for a return of <£5 per cow in an average herd that implemented the plan, whereas an enthusiast would ascribe this probability for a return of >£20 per cow. Simulations using increased trial sizes indicated that if the original study was four times as large, an initial sceptic would be more convinced about the efficacy of the control plan but would still anticipate less financial return than an initial enthusiast would anticipate after the original study. In conclusion, it is possible to estimate how clinicians’ prior beliefs influence their interpretation of research evidence. Further research on the extent to which different interpretations of evidence result in changes to clinical practice would be worthwhile.

A medida e as escalas de avaliação da saúde das populações neonatais e pediátricas : estudo de simulação de Monte Carlo com variáveis ordinais

A investigação na área da saúde e a utilização dos seus resultados tem funcionado como base para a melhoria da qualidade de cuidados, exigindo dos profissionais de saúde conhecimentos na área específica onde desempenham funções, conhecimentos em metodologia de investigação que incluam as técnicas de observação, técnicas de recolha e análise de dados, para mais facilmente serem leitores capacitados dos resultados da investigação. Os profissionais de saúde são observadores privilegiados das respostas humanas à saúde e à doença, podendo contribuir para o desenvolvimento e bem-estar dos indivíduos muitas vezes em situações de grande vulnerabilidade. Em saúde infantil e pediatria o enfoque está nos cuidados centrados na família privilegiando-se o desenvolvimento harmonioso da criança e jovem, valorizando os resultados mensuráveis em saúde que permitam determinar a eficácia das intervenções e a qualidade de saúde e de vida. No contexto pediátrico realçamos as práticas baseadas na evidência, a importância atribuída à pesquisa e à aplicação dos resultados da investigação nas práticas clínicas, assim como o desenvolvimento de instrumentos de mensuração padronizados, nomeadamente as escalas de avaliação, de ampla utilização clínica, que facilitam a apreciação e avaliação do desenvolvimento e da saúde das crianças e jovens e resultem em ganhos em saúde. A observação de forma sistematizada das populações neonatais e pediátricas com escalas de avaliação tem vindo a aumentar, o que tem permitido um maior equilíbrio na avaliação das crianças e também uma observação baseada na teoria e nos resultados da investigação. Alguns destes aspetos serviram de base ao desenvolvimento deste trabalho que pretende dar resposta a 3 objetivos fundamentais. Para dar resposta ao primeiro objetivo, “Identificar na literatura científica, os testes estatísticos mais frequentemente utilizados pelos investigadores da área da saúde infantil e pediatria quando usam escalas de avaliação” foi feita uma revisão sistemática da literatura, que tinha como objetivo analisar artigos científicos cujos instrumentos de recolha de dados fossem escalas de avaliação, na área da saúde da criança e jovem, desenvolvidas com variáveis ordinais, e identificar os testes estatísticos aplicados com estas variáveis. A análise exploratória dos artigos permitiu-nos verificar que os investigadores utilizam diferentes instrumentos com diferentes formatos de medida ordinal (com 3, 4, 5, 7, 10 pontos) e tanto aplicam testes paramétricos como não paramétricos, ou os dois em simultâneo, com este tipo de variáveis, seja qual for a dimensão da amostra. A descrição da metodologia nem sempre explicita se são cumpridas as assunções dos testes. Os artigos consultados nem sempre fazem referência à distribuição de frequência das variáveis (simetria/assimetria) nem à magnitude das correlações entre os itens. A leitura desta bibliografia serviu de suporte à elaboração de dois artigos, um de revisão sistemática da literatura e outro de reflexão teórica. Apesar de terem sido encontradas algumas respostas às dúvidas com que os investigadores e os profissionais, que trabalham com estes instrumentos, se deparam, verifica-se a necessidade de desenvolver estudos de simulação que confirmem algumas situações reais e alguma teoria já existente, e trabalhem outros aspetos nos quais se possam enquadrar os cenários reais de forma a facilitar a tomada de decisão dos investigadores e clínicos que utilizam escalas de avaliação. Para dar resposta ao segundo objetivo “Comparar a performance, em termos de potência e probabilidade de erro de tipo I, das 4 estatísticas da MANOVA paramétrica com 2 estatísticas da MANOVA não paramétrica quando se utilizam variáveis ordinais correlacionadas, geradas aleatoriamente”, desenvolvemos um estudo de simulação, através do Método de Monte Carlo, efetuado no Software R. O delineamento do estudo de simulação incluiu um vetor com 3 variáveis dependentes, uma variável independente (fator com três grupos), escalas de avaliação com um formato de medida com 3, 4, 5, e 7 pontos, diferentes probabilidades marginais (p1 para distribuição simétrica, p2 para distribuição assimétrica positiva, p3 para distribuição assimétrica negativa e p4 para distribuição uniforme) em cada um dos três grupos, correlações de baixa, média e elevada magnitude (r=0.10, r=0.40, r=0.70, respetivamente), e seis dimensões de amostras (n=30, 60, 90, 120, 240, 300). A análise dos resultados permitiu dizer que a maior raiz de Roy foi a estatística que apresentou estimativas de probabilidade de erro de tipo I e de potência de teste mais elevadas. A potência dos testes apresenta comportamentos diferentes, dependendo da distribuição de frequência da resposta aos itens, da magnitude das correlações entre itens, da dimensão da amostra e do formato de medida da escala. Tendo por base a distribuição de frequência, considerámos três situações distintas: a primeira (com probabilidades marginais p1,p1,p4 e p4,p4,p1) em que as estimativas da potência eram muito baixas, nos diferentes cenários; a segunda situação (com probabilidades marginais p2,p3,p4; p1,p2,p3 e p2,p2,p3) em que a magnitude das potências é elevada, nas amostras com dimensão superior ou igual a 60 observações e nas escalas com 3, 4,5 pontos e potências de magnitude menos elevada nas escalas com 7 pontos, mas com a mesma ma magnitude nas amostras com dimensão igual a 120 observações, seja qual for o cenário; a terceira situação (com probabilidades marginais p1,p1,p2; p1,p2,p4; p2,p2,p1; p4,p4,p2 e p2,p2,p4) em que quanto maiores, a intensidade das correlações entre itens e o número de pontos da escala, e menor a dimensão das amostras, menor a potência dos testes, sendo o lambda de Wilks aplicado às ordens mais potente do que todas as outra s estatísticas da MANOVA, com valores imediatamente a seguir à maior raiz de Roy. No entanto, a magnitude das potências dos testes paramétricos e não paramétricos assemelha-se nas amostras com dimensão superior a 90 observações (com correlações de baixa e média magnitude), entre as variáveis dependentes nas escalas com 3, 4 e 5 pontos; e superiores a 240 observações, para correlações de baixa intensidade, nas escalas com 7 pontos. No estudo de simulação e tendo por base a distribuição de frequência, concluímos que na primeira situação de simulação e para os diferentes cenários, as potências são de baixa magnitude devido ao facto de a MANOVA não detetar diferenças entre grupos pela sua similaridade. Na segunda situação de simulação e para os diferentes cenários, a magnitude das potências é elevada em todos os cenários cuja dimensão da amostra seja superior a 60 observações, pelo que é possível aplicar testes paramétricos. Na terceira situação de simulação, e para os diferentes cenários quanto menor a dimensão da amostra e mais elevada a intensidade das correlações e o número de pontos da escala, menor a potência dos testes, sendo a magnitude das potências mais elevadas no teste de Wilks aplicado às ordens, seguido do traço de Pillai aplicado às ordens. No entanto, a magnitude das potências dos testes paramétricos e não paramétricos assemelha-se nas amostras com maior dimensão e correlações de baixa e média magnitude. Para dar resposta ao terceiro objetivo “Enquadrar os resultados da aplicação da MANOVA paramétrica e da MANOVA não paramétrica a dados reais provenientes de escalas de avaliação com um formato de medida com 3, 4, 5 e 7 pontos, nos resultados do estudo de simulação estatística” utilizaram-se dados reais que emergiram da observação de recém-nascidos com a escala de avaliação das competências para a alimentação oral, Early Feeding Skills (EFS), o risco de lesões da pele, com a Neonatal Skin Risk Assessment Scale (NSRAS), e a avaliação da independência funcional em crianças e jovens com espinha bífida, com a Functional Independence Measure (FIM). Para fazer a análise destas escalas foram realizadas 4 aplicações práticas que se enquadrassem nos cenários do estudo de simulação. A idade, o peso, e o nível de lesão medular foram as variáveis independentes escolhidas para selecionar os grupos, sendo os recém-nascidos agrupados por “classes de idade gestacional” e por “classes de peso” as crianças e jovens com espinha bífida por “classes etárias” e “níveis de lesão medular”. Verificou-se um bom enquadramento dos resultados com dados reais no estudo de simulação.

A meta-analysis of trabecular bone score in fracture risk prediction and its relationship to FRAX

Trabecular bone score (TBS) is a grey-level textural index of bone microarchitecture derived from lumbar spine dual-energy X-ray absorptiometry (DXA) images. TBS is a BMD-independent predictor of fracture risk. The objective of this meta-analysis was to determine whether TBS predicted fracture risk independently of FRAX probability and to examine their combined performance by adjusting the FRAX probability for TBS. We utilized individual level data from 17,809 men and women in 14 prospective population-based cohorts. Baseline evaluation included TBS and the FRAX risk variables and outcomes during follow up (mean 6.7 years) comprised major osteoporotic fractures. The association between TBS, FRAX probabilities and the risk of fracture was examined using an extension of the Poisson regression model in each cohort and for each sex and expressed as the gradient of risk (GR; hazard ratio per 1SD change in risk variable in direction of increased risk). FRAX probabilities were adjusted for TBS using an adjustment factor derived from an independent cohort (the Manitoba Bone Density Cohort). Overall, the GR of TBS for major osteoporotic fracture was 1.44 (95% CI: 1.35-1.53) when adjusted for age and time since baseline and was similar in men and women (p > 0.10). When additionally adjusted for FRAX 10-year probability of major osteoporotic fracture, TBS remained a significant, independent predictor for fracture (GR 1.32, 95%CI: 1.24-1.41). The adjustment of FRAX probability for TBS resulted in a small increase in the GR (1.76, 95%CI: 1.65, 1.87 vs. 1.70, 95%CI: 1.60-1.81). A smaller change in GR for hip fracture was observed (FRAX hip fracture probability GR 2.25 vs. 2.22). TBS is a significant predictor of fracture risk independently of FRAX. The findings support the use of TBS as a potential adjustment for FRAX probability, though the impact of the adjustment remains to be determined in the context of clinical assessment guidelines.

Running in the Family – Paternalism and Familiness in the Development of Family Businesses

The study focuses on two features of family businesses (FBs), namely familiness and paternalism. These two concepts are inseparable in two ways: inseparable from family businesses and also from each other. Family businesses differ from one another in the degree of family involvement, leadership and management in the business. Paternalism as a leadership attitude is naturally present in FBs, especially in the founding stage of development. This feature provides the solid bases for establishing a strong and proud culture built around the personality and success of the founder. This characteristic however can become a major hindering factor upon succession. Through a review of the literature and the INSIST studies for Central Europe this study aims to identify the supportive and limiting factors of both phenomena and examine the case studies of the INSIST research project for signs of the existence of these supportive and limiting factors. It is found that the degree of familiness in these firms is a sliding scale and a lack of familiness is not a precursor for failure. Paternalism is found to be broken down into authoritarian, benevolent, moral and enlightened. After discovering studies claiming that paternalism is a stage in the process of leadership style changing from participative to autocratic (or vice versa) and that Central Europe and the current era of instability and uncertainty lead to employees preferring a more autocratic or paternalistic style, our findings suggest that there are more driving than restraining forces for family firms adopting a paternalistic style. Furthermore many cases appear to be on the path from an authoritative towards a more enlightened paternalistic leadership style either out of choice in the search to shake off the drawbacks of other types of paternalism or as part of a natural evolution of this particular leadership style within the context of this study.

Water Demand and Allocation in the Mara River Basin, Kenya/Tanzania in the Face of Land Use Dynamics and Climate Variability

The Mara River Basin (MRB) is endowed with pristine biodiversity, socio-cultural heritage and natural resources. The purpose of my study is to develop and apply an integrated water resource allocation framework for the MRB based on the hydrological processes, water demand and economic factors. The basin was partitioned into twelve sub-basins and the rainfall runoff processes was modeled using the Soil and Water Assessment Tool (SWAT) after satisfactory Nash-Sutcliff efficiency of 0.68 for calibration and 0.43 for validation at Mara Mines station. The impact and uncertainty of climate change on the hydrology of the MRB was assessed using SWAT and three scenarios of statistically downscaled outputs from twenty Global Circulation Models. Results predicted the wet season getting more wet and the dry season getting drier, with a general increasing trend of annual rainfall through 2050. Three blocks of water demand (environmental, normal and flood) were estimated from consumptive water use by human, wildlife, livestock, tourism, irrigation and industry. Water demand projections suggest human consumption is expected to surpass irrigation as the highest water demand sector by 2030. Monthly volume of water was estimated in three blocks of current minimum reliability, reserve (>95%), normal (80–95%) and flood (40%) for more than 5 months in a year. The assessment of water price and marginal productivity showed that current water use hardly responds to a change in price or productivity of water. Finally, a water allocation model was developed and applied to investigate the optimum monthly allocation among sectors and sub-basins by maximizing the use value and hydrological reliability of water. Model results demonstrated that the status on reserve and normal volumes can be improved to ‘low’ or ‘moderate’ by updating the existing reliability to meet prevailing demand. Flow volumes and rates for four scenarios of reliability were presented. Results showed that the water allocation framework can be used as comprehensive tool in the management of MRB, and possibly be extended similar watersheds.

The impact of culture and corporate governance in dividend policy: evidence from emerging and developed countries

The present research aims to analyse the impact of corporate governance and cultural dimensions in dividend policy. The corporate governance and dividend policy have a close relationship, in that both are evidenced in literature to mitigate agency problems. Cultural factors are also related to agency problems. The existence of agency problems and their solutions differs across countries and it is related to the implementation of the mechanisms of governance. So, cultural factors may have influence on corporate governance and dividend policy. Our sample consists in 1 232 companies belonging to the main indices of 38 countries classified as emerging or developed. To measure the quality of firm level corporate governance, we use the ASSET4 Corporate Governance Performance Index, developed by Thomson Reuters, and as proxy of culture we use three cultural dimensions developed by Geert Hofstede, namely uncertainty avoidance, masculinity and indulgence. We obtained significant empirical evidence that firms with high quality of corporate governance pay higher dividends. With regard to cultural factors, we confirm that in countries with high levels of masculinity and uncertainty avoidance, the dividend payout ratio is lower. On the other hand, countries with high level of indulgence have higher dividend payout ratio. However, we verify that the impact of cultural effects is minimized when the firms have a high quality level of corporate governance. Additionally, we found that the impact of corporate governance and cultural factors in dividend policy differs when dealing with emerging or developed countries.

Knowledge of and attitudes toward sexual and reproductive health among college students

Abstract Introduction: Knowledge provides the foundation for values, attitudes and behavior. Knowledge about sexual and reproductive health (SRH) and positive attitudes are essential for implementing protective behaviors. Objectives: The aim of this study was to evaluate SRH knowledge and attitudes in college students and their association with sexual and reproductive behaviors. Material and methods: A cross-sectional study was conducted in a sample of 1946 college students. The data were collected using a self-report questionnaire on the sociodemographics characteristics of the sample, an inventory on SRH knowledge and an attitude scale, and were analyzed with descriptive and inferential statistics (ANOVA and Pearson’s correlation). Results: The sample was 64% female and 36% male, with a mean age of 21 years. The majority were sexually active and used contraception. The SRH knowledge was moderate (22.27 ± 5.79; maximum score = 44), while the average SRH attitude score was more favorable (118.29 ± 13.92; maximum score = 140). Female and younger students studying life and health sciences had higher (P < .05) SRH knowledge and attitude scores. The consistent use of condom and health care surveillance were highly dependent on the students’ SRH knowledge and attitudes. Engagement in sexual risk behaviors was associated with lower scores for these variables. Conclusions: Strategies to increase SRH knowledge and attitudes are important tools for improving protective behaviors, especially with respect to contraception, health care surveillance and exposure to sexual risk. Older males studying topics other than life sciences should be a priority target for interventions due to their higher sexual risk

Tail conditional expectation for multivariate distributions : a game theory approach

This paper proposes using the Shapley values in allocating the total tail conditional expectation (TCE) to each business line (X j, j = 1, ... , n) when there are n correlated business lines. The joint distributions of X j and S (S = X1 + X2 + ⋯ + X n) are needed in the existing methods, but they are not required in the proposed method.

Evaluating the whole-life cost implication of revocability and disruption in office retrofit building projects

Retrofit buildings are becoming popular in the United Kingdom as well as many parts of the advanced economies. Existing whole-life costing models have however, not proven to be robust enough to deal with building retrofit scenarios. Recent research has made a case for the existence of revocability and disruption in building retrofit investments. This paper evaluates the whole-life cost implication of revocability and disruption in office retrofit building projects. The potential implication of revocability and disruption are evaluated based on probability and fuzzy logic principles respectively. Two case study projects are selected to appraise the economic potentials of revocability and disruption. It was found that the average cost of revocability relative to the initial capital cost can be up to 119% over a 60-year life. It was also found that the average cost of disruption relative to the initial capital cost can be up to 12%. Future studies will utilise sensitivity analysis in assessing the relative preference of building retrofit configurations in office building projects. The external validity of this work is moderate, as the intention is to establish analytical generalisation rather than statistical generalisation for office retrofit building projects.

Supervivencia y mortalidad por tipo de terapia de reemplazo renal, en pacientes con enfermedad renal crónica terminal, en una cohorte de pacientes asegurados en Colombia

En Colombia se ha podido establecer que la incidencia y mortalidad de la Enfermedad Renal Crónica Terminal continúan en aumento en los últimos 6 años a pesar de las estrategias de intervención para prevención y control de la enfermedad implementadas nivel nacional. Este trabajo busca establecer la línea de base para la población asegurada en Colombia, frente a la supervivencia de pacientes en terapia de remplazo renal (TRR).

Cardiorespiratory fitness and cardiometabolic risk factors in schoolchildren from Colombia: The FUPRECOL Study

The objectives of this study are to investigate the association between cardiorespiratory fitness and cardiovascular risk factors in schoolchildren and to evaluate the degree of association between overall and abdominal adiposity and cardiorespiratory fitness. A total of 1,875 children and adolescents attending public schools in Bogota, Colombia (56.2% girls; age range of 9–17.9 years). A cardiovascular risk score (Z-score) was calculated and participants were divided into tertiles according to low and high levels of overall (sum of the skinfold thicknesses) and abdominal adiposity. Schoolchildren with a high level of overall adiposity demonstrated significant differences in seven of the 10 variables analyzed (i.e. systolic and diastolic blood pressure, triglycerides, triglycerides/HDL-c ratio, total cholesterol, glucose and cardiovascular risk score). Schoolchildren with high levels of both overall and abdominal adiposity and low cardiorespiratory fitness had the least favorable cardiovascular risk factors score. These findings may be relevant to health promotion in Colombian youth.

Favourable areas for expansion and reintroduction of Iberian lynx accounting for distribution trends and genetic diversity of the European rabbit

Although on a local scale Iberian lynx distribution is determined by the availability of prey rabbits, recent modelling analyses have uncovered broad-scale disagreements between these two species’ distribution trends. These analyses showed also that the lynx had become restricted to only a fraction of the rabbit’s genetic diversity, and that this could be jeopardising its survival in the face of environmental hazards and uncertainty. In the present paper, a follow-up was carried out through the building of lynx and rabbit distribution models based on the most recent Spanish mammal atlas. Environmental favourability values for lynx and rabbit were positively correlated within the lynx’s current distribution area, but they were negatively correlated within the total Spanish area where lynx used to occur in the 1980’s. Environmental favourability for rabbits was significantly higher where lynx maintains reproductive populations than where it recently disappeared, indicating that rabbit favourability plays an important role and can be a good predictor of lynx persistence. The lynx and rabbit models were extrapolated to predict favourable areas for both species in Spain as well as in Portugal, on the original scale of the distribution data (10x10 km) and on a 100 times finer spatial resolution (1x1 km). The lynx and rabbit models were also combined through fuzzy logic to forecast the potential for lynx occurrence incorporating information on favourable areas for its main prey. Several areas are proposed as favourable for lynx expansion or re-introduction,

Confidence intervals for large non- centrality parameter

We use asymptotic linearity to derive confidence intervals for large noncentrality parameters. These results enable us to measure relevance of effects and interactions in multifactors models when we get highly statistically significant the values of F tests statistics. We show how to use our approach by considering two sets of data as application examples.