Nano Risk Analysis: Advancing the Science for Nanomaterials Risk Management

Scientists, activists, industry, and governments have raised concerns about health and environmental risks of nanoscale materials. The Society for Risk Analysis convened experts in September 2008 in Washington, DC to deliberate on issues relating to the unique attributes of nanoscale materials that raise novel concerns about health risks. This article reports on the overall themes and findings of the workshop, uncovering the underlying issues for each of these topics that become recurring themes. The attributes of nanoscale particles and other nanomaterials that present novel issues for risk analysis are evaluated in a risk analysis framework, identifying challenges and opportunities for risk analysts and others seeking to assess and manage the risks from emerging nanoscale materials and nanotechnologies. Workshop deliberations and recommendations for advancing the risk analysis and management of nanotechnologies are presented.     

Secondary agency conflicts: A synthesis and proposed measurement model

Secondary agency conflicts typically arise when ownership and control are combined in the hands of dominant shareholders who could then seek to misappropriate returns at the expense of minority shareholders. This type of agency conflict has attracted attention from researchers for the past nearly three decades. However, efforts at measuring secondary agency conflicts have been fragmented and scattered. The absence of a coherent and valid approach to assess the scope and intensity of secondary agency conflicts has impeded progress in both empirical and conceptual development of the topic area. Based on a review of the extant body of literature, this paper develops a composite Shareholder Inequity index that measures the potential for secondary agency conflicts employing three different governance dimensions that are grounded in the agency literature: blockholder power, differential control, and the absence of board neutrality. The index is tested and validated empirically using a sample of 748 publicly listed U.S. firms. The resulting Shareholder Inequity index demonstrates high levels of validity and reliability. Future corporate governance studies can utilize this validated measure to investigate potential secondary agency conflicts more consistently and rigorously in order to strengthen organizational theory development and research.     

Inventory placement problems in dynamic supply chains

Summary  In this paper a basic model for analyzing the inventory placement problem in a supply chain is developed. The problem will be studied for a capacitated, multi-stage supply chain facing a continuous, stochastic demand for a single period for a single product — a specialty item with a very short selling season. The objective is to maximize the probability of achieving a set profit level. We prove that finding an optimal stock investment at the stages entails solving a mixed binary integer linear program. We characterize properties of the stock investment, examine two interesting cases where the stock investments have a simple structure, and develop a branch and bound approach for solving the more general case.

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Zusammenfassung  In diesem Beitrag wird ein Grundmodell entwickelt, um das Problem der Lagerplatzierung in einer Lieferkette analysieren zu k?nnen. Das Problem wird für eine kapazitierte mehrstufige Lieferkette untersucht, wobei unterstellt wird, dass es um die Nachfrage nach einem einzigen Produkt für eine einzige Periode (einen Sonderartikel mit sehr kurzer Verkaufszeit) geht und diese Nachfrage stetig und stochastisch ist. Unter diesen Bedingungen soll die Wahrscheinlichkeit maximiert werden, ein vorgegebenes Gewinnniveau zu erreichen. Die Suche nach der optimalen Vorratsinvestition auf den Stufen der Lieferkette führt zur Formulierung eines gemischten ganzzahligen linearen Programmierungsproblems mit Bin?rvariablen. Die Eigenschaften der Bevorratungsinvestition werden charakterisiert, zwei interessante F?lle mit einer einfachen Struktur der Bevorratungsinvestition untersucht und ein Branch-and-Bound-Ansatz zur L?sung eines allgemeineren Problemfalls entwickelt.

     

Toward Disaster‐Resilient Cities: Characterizing Resilience of Infrastructure Systems with Expert Judgments

Resilient infrastructure systems are essential for cities to withstand and rapidly recover from natural and human‐induced disasters, yet electric power, transportation, and other infrastructures are highly vulnerable and interdependent. New approaches for characterizing the resilience of sets of infrastructure systems are urgently needed, at community and regional scales. This article develops a practical approach for analysts to characterize a community's infrastructure vulnerability and resilience in disasters. It addresses key challenges of incomplete incentives, partial information, and few opportunities for learning. The approach is demonstrated for Metro Vancouver, Canada, in the context of earthquake and flood risk. The methodological approach is practical and focuses on potential disruptions to infrastructure services. In spirit, it resembles probability elicitation with multiple experts; however, it elicits disruption and recovery over time, rather than uncertainties regarding system function at a given point in time. It develops information on regional infrastructure risk and engages infrastructure organizations in the process. Information sharing, iteration, and learning among the participants provide the basis for more informed estimates of infrastructure system robustness and recovery that incorporate the potential for interdependent failures after an extreme event. Results demonstrate the vital importance of cross‐sectoral communication to develop shared understanding of regional infrastructure disruption in disasters. For Vancouver, specific results indicate that in a hypothetical M7.3 earthquake, virtually all infrastructures would suffer severe disruption of service in the immediate aftermath, with many experiencing moderate disruption two weeks afterward. Electric power, land transportation, and telecommunications are identified as core infrastructure sectors.     

"Fundamental causes" of social inequalities in mortality: a test of the theory

Medicine and epidemiology currently dominate the study of the strong association between socioeconomic status and mortality. Socioeconomic status typically is viewed as a causally irrelevant "confounding variable" or as a less critical variable marking only the beginning of a causal chain in which intervening risk factors are given prominence. Yet the association between socioeconomic status and mortality has persisted despite radical changes in the diseases and risk factors that are presumed to explain it. This suggests that the effect of socioeconomic status on mortality essentially cannot be understood by reductive explanations that focus on current mechanisms. Accordingly, Link and Phelan (1995) proposed that socioeconomic status is a "fundamental cause" of mortality disparities-that socioeconomic disparities endure despite changing mechanisms because socioeconomic status embodies an array of resources, such as money, knowledge, prestige, power, and beneficial social connections, that protect health no matter what mechanisms are relevant at any given time. We identified a situation in which resources should be less helpful in prolonging life, and derived the following prediction from the theory: For less preventable causes of death (for which we know little about prevention or treatment), socioeconomic status will be less strongly associated with mortality than for more preventable causes. We tested this hypothesis with the National Longitudinal Mortality Study, which followed Current Population Survey respondents (N = 370,930) for mortality for nine years. Our hypothesis was supported, lending support to the theory of fundamental causes and more generally to the importance of a sociological approach to the study of socioeconomic disparities in mortality.     

AIDS, Sexuality and African American Adolescent Females

Many African American adolescent females do not have sufficient information to break the cycle of unintended pregnancy and sexually transmitted diseases, in a society where we are bombarded from dusk to dawn with sexually explicit images. Knowledge alone does not change behavior, but it does provide the basis for decisions that promote sexual health. Adolescents are too often driven by curiosity and pressure to perform sexually. The ability to make the right decisions about sex is a skill that develops slowly throughout life. However, teens are impulsive and possess an attitude of invincibility. Youth cannot rely on the community to educate them about the dangers of unprotected sex. The African American community has never welcomed the topic of sexuality into our homes. Presently, the age old tradition of telling youth what they should and should not do without giving them the specific information about sex or sexual behavior continues. Prevention must be strongly emphasized. Schools must play role in the war against irresponsible sexual behavior and AIDS. This paper will describe an innovative group project designed to educate African American female teens about sexuality in an urban school setting. The topic of sex generated confusing and powerful feelings that were expressed in the group. Group members learned how to protect themselves, nurture themselves and value themselves. The goal of the group was to impart knowledge, change risky behaviors, validate their existence and listen to their stories.     

Population Growth and the Local Provision of Services: The Role of Primary Schools in Portugal

Population Research and Policy Review - The shrinking population in many European regions has led to a debate on the relation between the local provision of services of general interest and the...