A Probabilistic Approach for Deriving Acceptable Human Intake Limits and Human Health Risks from Toxicological Studies: General Framework

The use of uncertainty factors in the standard method for deriving acceptable intake or exposure limits for humans, such as the Reference Dose (RfD), may be viewed as a conservative method of taking various uncertainties into account. As an obvious alternative, the use of uncertainty distributions instead of uncertainty factors is gaining attention. This paper presents a comprehensive discussion of a general framework that quantifies both the uncertainties in the no-adverse-effect level in the animal (using a benchmark-like approach) and the uncertainties in the various extrapolation steps involved (using uncertainty distributions). This approach results in an uncertainty distribution for the no-adverse-effect level in the sensitive human subpopulation, reflecting the overall scientific uncertainty associated with that level. A lower percentile of this distribution may be regarded as an acceptable exposure limit (e.g., RfD) that takes account of the various uncertainties in a nonconservative fashion. The same methodology may also be used as a tool to derive a distribution for possible human health effects at a given exposure level. We argue that in a probabilistic approach the uncertainty in the estimated no-adverse-effect-level in the animal should be explicitly taken into account. Not only is this source of uncertainty too large to be ignored, it also has repercussions for the quantification of the other uncertainty distributions.     

Parental unemployment and child health in China

This paper studies the causal effect of maternal and paternal unemployment on child health in China, analyzing panel data for the period 1997–2004, when the country underwent economic reforms leading to massive layoffs. Using a FE-IV strategy, we find that paternal unemployment reduces child health, while maternal unemployment has beneficial child health impacts. Analysis of channels shows that paternal and maternal unemployment have different effects on income, time use, and children’s diets. Though many estimates are imprecise, a key finding is that paternal unemployment significantly reduces children’s fat intake and dietary diversity. To the best of our knowledge, this is the first evidence on the causal effect of parental unemployment on the nutrient intake of children aged 0–17. In all, our estimates are consistent with the notion that traditional gender roles can explain why mothers’ and fathers’ unemployment affect child health differently.

     

An Adversarial Risk Analysis Framework for Cybersecurity

Risk analysis is an essential methodology for cybersecurity as it allows organizations to deal with cyber threats potentially affecting them, prioritize the defense of their assets, and decide what security controls should be implemented. Many risk analysis methods are present in cybersecurity models, compliance frameworks, and international standards. However, most of them employ risk matrices, which suffer shortcomings that may lead to suboptimal resource allocations. We propose a comprehensive framework for cybersecurity risk analysis, covering the presence of both intentional and nonintentional threats and the use of insurance as part of the security portfolio. A simplified case study illustrates the proposed framework, serving as template for more complex problems.     

Statistics in the High School Curriculum

Recent work, spearheaded by Charles Dunnett (1980a), leads to the conclusion that the Tukey-Kramer (TK) method (popularly known as “Kramer's Method”) is the recommended multiple comparisons procedure for the simultaneous estimation of all pairwise differences of means in an imbalanced one-way ANOVA design with homogeneous variances. Nine other multiple comparisons methods are compared to each other and to the TK method using the criteria of conservativeness, narrowness of confidence intervals, robustness, and ease of use. The degree of superiority of the TK method over these methods, especially over the popular Bonferroni method, is sufficient to warrant recommending its use. Because of the lack of robustness of the TK method in heterogeneous variance cases, other methods are recommended.     

Attitude theory and behavioral costs

The Fishbein and Ajzen reasoned action model is briefly introduced and some theoretical aspects of the model arc discussed. Based on a critical analysis of the act and behavioral category concepts in their model an alternative concept, ‘behavioral field’, is introduced. A behavioral field is defined as: ‘the total of acts that are perceived by the acting individual as leading to a common goal or valued state’. Then a distinction is made between goal acts and instrumental acts, Goal acts lead to goal attainment. Instrumental acts will bring the individual into the direction of his goal. It is argued that for acts that are predominantly instrumental other substitutable acts are available. The choice between suhstitutable instrumental acts is governed by both expected outcomes and the behavioral costs attached to the acts. Behavioral costs are defined as the behavioral price relative to the behavioral budget. The behavioral price is determined by tile time, psychic and physical task demand. The behavioral budget is a function of the goal importance of the behavioral field. Some further aspects of behavioral costs are then discussed. Several arguments to treat costs and outcomes separately in the explanation of behavior, are elaborated. Then some implications from the behavioral cost concept are drawn for attitude theory. Finally the entangling of costs and value is briefly discussed.