Risk, seasonality and the asymmetric behaviour of stock returns

For some time there has been a puzzle surrounding the seasonal behaviour of stock returns. This paper demonstrates that there is an asymmetric relationship between systematic risk and return across the different months of the year for both large and small firms. In the case of both large and small firms systematic risk appears to be priced in only two months of the year, January and April. During the other months no persistent relationship between systematic risk and return appears to exist. The paper also shows that when systematic risk is priced, the size of the systematic risk premium is higher for large firms than for small firms and varies significantly across the months of the year.

Perception of risk, feelings of vulnerability and effects on driving behaviour in women drivers across the lifespan.

Sustained driving in older age has implications for quality of life and mental health. Studies have shown that despite the recognised importance of driving in maintaining health and social engagement, many women give up driving prematurely or adopt self-imposed restrictive driving practices. Emotional responses to driving have been implicated in these decisions. This research examined the effect of risk perception and feelings of vulnerability on women’s driving behaviour across the lifespan. It also developed and tested a modified theory of planned behaviour intervention to positively affect driving habits. The first two studies (N=395) used quantitative analysis to model driving behaviours affected by risk perception and feelings of vulnerability, and established that feelings of vulnerability do indeed affect women’s driving behaviour, specifically resulting in increases in driving avoidance and the adoption of maladaptive driving styles. Further, that self-regulation, conceptualised as avoidance, is used by drivers across the lifespan. Qualitative analysis of focus group data (N=48) in the third study provided a deeper understanding of the variations in coping behaviours adopted by sub-groups of drivers and extended the definition of self-regulation to incorporate adaptive coping strategies. The next study (N=64) reported the construction and preliminary validation of the novel self-regulation index (SRI) to measure wider self-regulation behaviours using an objective measure of driving behaviour, a simulated driving task. The understanding gained from the formative research was used in the final study, an extended theory of planned behaviour intervention to promote wider self-regulation behaviour, measured using the previously validated self-regulation index. The intervention achieved moderate success with changes in affective attitude and normative beliefs as well as self-reported behaviour. The results offer promise for self-regulation, incorporating a spectrum of planning and coping behaviours, to be used as a mechanism to assist drivers in achieving their personal mobility goals whilst promoting safe driving.

Quantitative risk management aids refinery construction

Conventional project management techniques are not always sufficient to ensure that schedule, cost and quality goals are met on large-scale construction projects. These jobs require complex planning, designing and implementation processes. The main reasons for a project's nonachievement in India's hydrocarbon processing industry are changes in scope and design, altered government policies and regulations, unforeseen inflation, under and/or improper estimation. Projects that are exposed to such an uncertain environment can be effectively managed by applying risk management throughout the project life cycle.

Risk-based model aids selection of pipeline inspection, maintenance strategies

The existing method of pipeline monitoring, which requires an entire pipeline to be inspected periodically, wastes time and is expensive. A risk-based model that reduces the amount of time spent on inspection has been developed. This model not only reduces the cost of maintaining petroleum pipelines, but also suggests an efficient design and operation philosophy, construction method and logical insurance plans.The risk-based model uses analytic hierarchy process, a multiple attribute decision-making technique, to identify factors that influence failure on specific segments and analyze their effects by determining the probabilities of risk factors. The severity of failure is determined through consequence analysis, which establishes the effect of a failure in terms of cost caused by each risk factor and determines the cumulative effect of failure through probability analysis.

Diving Behaviour of Red-Eared Sliders (Trachemys Scripta Elegans) Under the Risk of Predation

Predation risk influences a variety of behavioral decisions of many organisms and results in animals having to trade-offs safety with other behaviors. The effects of predation, however, have been largely ignored in the study of vertebrates that forage underwater (divers). I tested the predictions of an on optimal diving model that incorporates the risk of predation, using red eared slider turtles (Trachemys scripta elegans). Specifically, I tested the hypothesis that divers will increase their surface time when instantaneous risk decreases with time at the surface. By using a model aerial predator and exposing turtles to both risk and no risk treatments, I tested how turtles perceive risk at the surface and whether they increase or decrease their surface time depending on how they assess risk. The model's predictions for situations in which risk at the surface is decreasing with time spent there-likely to be the case for aerial predation-were supported by the results. I found that surface time and time spent submerged per dive were significantly greater when turtles were at risk and that turtles also spent more time resting at the bottom when exposed to this treatment. Interestingly, turtles under risk engaged in vigilance behaviors while on the bottom just prior to surfacing. This behavior could have implications for model predictions and future experiments are needed to test whether subsurface vigilance may alter diving decisions made under risk.

The role of time and risk preferences in adherence to physician advice on health behaviour change

Acknowledgements The Interdisciplinary Chronic Disease Collaboration (ICDC) is funded through the Alberta Heritage Foundation for Medical Research (AHFMR) Inter-disciplinary Team Grants Program. AHFMR is now Alberta Innovates – Health Solutions (AI-HS). The funding agreement ensured the authors’ independence in designing the study, interpreting the data, writing, and publishing the report. The Chief Scientist Office of the Scottish Government Health and Social Care Directorates funds HERU. The views expressed in this paper are those of the authors only and not those of the funding bodies.

Travellers’ intention to purchase travel online: integrating trust and risk to the theory of planned behaviour

This study aims to determine which factors influence travellers’ intentions to purchase travel online by proposing and empirically testing a new model grounded on the theory of planned behaviour. In order to validate the model, a web-based questionnaire was applied and a total of 1732 valid responses were obtained. The findings show that attitudes, perceived risk, and perceived behavioural control have significant effects on intentions to purchase travel online. However, contrary to what was expected, neither trust nor the influence of others seems to directly affect intentions to purchase travel online. Finally, the paper discusses the findings with the implicationsfor theory and practice and makes several suggestions for future research.

Travellers’ intention to purchase travel online: integrating trust and risk to the theory of planned behaviour

This study aims to determine which factors influence travellers’ intentions to purchase travel online by proposing and empirically testing a new model grounded on the theory of planned behaviour. In order to validate the model, a web-based questionnaire was applied and a total of 1732 valid responses were obtained. The findings show that attitudes, perceived risk, and perceived behavioural control have significant effects on intentions to purchase travel online. However, contrary to what was expected, neither trust nor the influence of others seems to directly affect intentions to purchase travel online. Finally, the paper discusses the findings with the implications for theory and practice and makes several suggestions for future research.

Risco relativo para Aids de homens homo/bissexuais em relação aos heterossexuais

OBJETIVO: Analisar o risco relativo para Aids na população de homens que fazem sexo com homens em relação à população heterossexual masculina. MÉTODOS: Foram utilizadas estimativas sobre a proporção de homens que fazem sexo com homens no Brasil e dados de Aids do Sistema Nacionald e Agravos de Notificação. Foram calculadas estimativas para o risco relativo (RR) para Aids desta população em relação à população heterossexual masculina do Brasil; cidade e estado de São Paulo; e cidade e estado do Rio de Janeiro, para o período de 1996 a 2003. As trajetórias do RR neste período também foram analisadas. RESULTADOS: As estimativas do RR declinaram, mostrando tendência de estabilização: de 34,3 para 19,3 no País como um todo e entre 32,1 e 6,3 nos locais analisados. Para o País em 2003, o RR dos bissexuais masculinos em relação à população heterossexual masculina era 16. O RR para homossexuais exclusivos teve trajetória decrescente em todos os locais analisados, mas não para os bissexuais. CONCLUSÕES: O risco relativo para homens que fazem sexo com homens foi mais elevado em relação aos heterossexuais, em todos os locais. Esse resultado indica alta e persistente vulnerabilidade dessa população.

Áreas de vulnerabilidade para co-infecção HIV-aids/TB em Ribeirão Preto, SP

OBJETIVO: Identificar áreas de vulnerabilidade para os casos novos de co-infecção HIV/tuberculose (TB). MÉTODOS: Estudo descritivo ecológico realizado por meio do georreferenciamento dos casos novos de HIV/TB notificados em Ribeirão Preto, SP, em 2006. Os dados foram obtidos do sistema de informação estadual paulista de notificação de TB. Os casos novos de co-infecção HIV/TB foram analisados conforme características sociodemográficas e clínicas e, posteriormente, georreferenciados na base cartográfica do município segundo endereço residencial. Os setores do município foram categorizados em três níveis socioeconômicos: inferior, intermediário e superior, com base na análise de componentes principais das variáveis do censo demográfico de 2000 (renda, instrução e percentagem de domicílios com cinco ou mais moradores). Foi calculada a incidência da co-infecção HIV/TB para cada nível socioeconômico. RESULTADOS: A co-infecção HIV/TB acometeu mais adultos do sexo masculino em idade economicamente ativa e a forma pulmonar da TB foi a mais comum. A distribuição espacial mostrou que as incidências nas áreas com níveis socioeconômicos intermediários e inferiores (8,3 e 11,5 casos por 100 mil habitantes, respectivamente) foram superiores àquela (4,8 casos por 100 mil habitantes) de nível socioeconômico superior. CONCLUSÕES: A taxa de incidência de co-infecção HIV/TB analisada por níveis socioeconômicos mostrou padraÞo espacial de distribuiçaÞo não homogêneo e apresentou valores mais altos em áreas de maior vulnerabilidade social. O estudo diagnosticou aìreas geograìficas prioritaìrias para o controle da co-infecção e a tecnologia do sistema de informação geográfica pode ser empregada no planejamento das ações em saúde pelos gestores municipais.

HLA-G 14-bp Insertion/Deletion Polymorphism Is a Risk Factor for HTLV-1 Infection

About 95% of HTLV-1 infected patients remain asymptomatic throughout life, and the risk factors associated with the development of related diseases, such as HAM/TSP and ATL, are not fully understood. The human leukocyte antigen-G molecule (HLA-G), a nonclassical HLA class I molecule encoded by MHC, is expressed in several pathological conditions, including viral infection, and is related to immunosuppressive effects that allow the virus-infected cells to escape the antiviral defense of the host. The 14-bp insertion/deletion polymorphism of exon 8 HLA-G gene influences the stability of the transcripts and could be related to HTLV-1-infected cell protection and to the increase of proviral load. The present study analyzed by conventional PCR the 14-bp insertion/deletion polymorphism of exon 8 HLA-G gene in 150 unrelated healthy subjects, 82 HTLV-1 infected patients with symptoms (33 ATL and 49 HAM), and 56 asymptomatic HTLV-1 infected patients (HAC). In addition, the proviral load was determined by quantitative real-time PCR in all infected groups and correlated with 14-bp insertion/deletion genotypes. The heterozygote genotype frequencies were significantly higher in HAM, in the symptomatic group, and in infected patients compared to control (p < 0.05). The proviral load was higher in the symptomatic group than the HAC group (p < 0.0005). The comparison of proviral load and genotypes showed that -14-bp/-14-bp genotype had a higher proviral load than +14-bp/-14-bp and +14-bp/+14-bp genotypes. Although HLA-G 14-bp polymorphism does not appear to be associated

Elevated Risk for HIV-1 Infection in Adolescents and Young Adults in Sao Paulo, Brazil

Background. Recent studies have sought to describe HIV infection and transmission characteristics around the world. Identification of early HIV-1 infection is essential to proper surveillance and description of regional transmission trends. In this study we compare people recently infected (RI) with HIV-1, as defined by Serologic Testing Algorithm for Recent HIV Seroconversion (STARHS), to those with chronic infection. Methodology/Principal Findings. Subjects were identified from 2002-2004 at four testing sites in Sao Paulo. Of 485 HIV-1-positive subjects, 57 (12%) were defined as RI. Of the participants, 165 (34.0%) were aware of their serostatus at the time of HIV-1 testing. This proportion was statistically larger (p<0.001) among the individuals without recent infection (n = 158, 95.8%) compared to 7 individuals (4.2%) with recently acquired HIV-1 infection. In the univariate analysis, RI was more frequent in,25 and >59 years-old age strata (p < 0.001). The majority of study participants were male (78.4%), 25 to 45 years-old (65.8%), white (63.2%), single (61.7%), with family income of four or more times the minimum wage (41.0%), but with an equally distributed educational level. Of those individuals infected with HIV-1, the predominant route of infection was sexual contact (89.4%), with both hetero (47.5%) and homosexual (34.5%) exposure. Regarding sexual activity in these individuals, 43.9% reported possible HIV-1 exposure through a seropositive partner, and 49.4% reported multiple partners, with 47% having 2 to 10 partners and 37.4% 11 or more; 53.4% of infected individuals reported condom use sometimes; 34.2% reported non-injecting, recreational drug use and 23.6% were reactive for syphilis by VDRL. Subjects younger than 25 years of age were most vulnerable according to the multivariate analysis. Conclusions/Significance. In this study, we evaluated RI individuals and discovered that HIV-1 has been spreading among younger individuals in Sao Paulo and preventive approaches should, therefore, target this age stratum.

Late Entry into HIV Care: Estimated Impact on AIDS Mortality Rates in Brazil, 2003-2006

Background: Worldwide, a high proportion of HIV-infected individuals enter into HIV care late. Here, our objective was to estimate the impact that late entry into HIV care has had on AIDS mortality rates in Brazil. Methodology/Principal Findings: We analyzed data from information systems regarding HIV-infected adults who sought treatment at public health care facilities in Brazil from 2003 to 2006. We initially estimated the prevalence of late entry into HIV care, as well as the probability of death in the first 12 months, the percentage of the risk of death attributable to late entry, and the number of avoidable deaths. We subsequently adjusted the annual AIDS mortality rate by excluding such deaths. Of the 115,369 patients evaluated, 50,358 (43.6%) had entered HIV care late, and 18,002 died in the first 12 months, representing a 16.5% probability of death in the first 12 months (95% CI: 16.3-16.7). By comparing patients who entered HIV care late with those who gained timely access, we found that the risk ratio for death was 49.5 (95% CI: 45.1-54.2). The percentage of the risk of death attributable to late entry was 95.5%, translating to 17,189 potentially avoidable deaths. Averting those deaths would have lowered the 2003-2006 AIDS mortality rate by 39.5%. Including asymptomatic patients with CD4(+) T cell counts >200 and <= 350 cells/mm(3) in the group who entered HIV care late increased this proportion by 1.8%. Conclusions/Significance: In Brazil, antiretroviral drugs reduced AIDS mortality by 43%. Timely entry would reduce that rate by a similar proportion, as well as resulting in a 45.2% increase in the effectiveness of the program for HIV care. The World Health Organization recommendation that asymptomatic patients with CD4(+) T cell counts <= 350 cells/mm(3) be treated would not have a significant impact on this scenario.

The prediction of disease risk in genomic medicine

In recent years, the phrase 'genomic medicine' has increasingly been used to describe a new development in medicine that holds great promise for human health. This new approach to health care uses the knowledge of an individual's genetic make-up to identify those that are at a higher risk of developing certain diseases and to intervene at an earlier stage to prevent these diseases. Identifying genes that are involved in disease aetiology will provide researchers with tools to develop better treatments and cures. A major role within this field is attributed to 'predictive genomic medicine', which proposes screening healthy individuals to identify those who carry alleles that increase their susceptibility to common diseases, such as cancers and heart disease. Physicians could then intervene even before the disease manifests and advise individuals with a higher genetic risk to change their behaviour - for instance, to exercise or to eat a healthier diet - or offer drugs or other medical treatment to reduce their chances of developing these diseases. These promises have fallen on fertile ground among politicians, health-care providers and the general public, particularly in light of the increasing costs of health care in developed societies. Various countries have established databases on the DNA and health information of whole populations as a first step towards genomic medicine. Biomedical research has also identified a large number of genes that could be used to predict someone's risk of developing a certain disorder. But it would be premature to assume that genomic medicine will soon become reality, as many problems remain to be solved. Our knowledge about most disease genes and their roles is far from sufficient to make reliable predictions about a patient’s risk of actually developing a disease. In addition, genomic medicine will create new political, social, ethical and economic challenges that will have to be addressed in the near future.