NUSAP Method for Evaluating the Data Quality in a Quantitative Microbial Risk Assessment Model for Salmonella in the Pork Production Chain

The numeral unit spread assessment pedigree (NUSAP) system was implemented to evaluate the quality of input parameters in a quantitative microbial risk assessment (QMRA) model for Salmonella spp. in minced pork meat. The input parameters were grouped according to four successive exposure pathways: (1) primary production (2) transport, holding, and slaughterhouse, (3) postprocessing, distribution, and storage, and (4) preparation and consumption. An inventory of 101 potential input parameters was used for building the QMRA model. The characteristics of each parameter were defined using a standardized procedure to assess (1) the source of information, (2) the sampling methodology and sample size, and (3) the distributional properties of the estimate. Each parameter was scored by a panel of experts using a pedigree matrix containing four criteria (proxy, empirical basis, method, and validation) to assess the quality, and this was graphically represented by means of kite diagrams. The parameters obtained significantly lower scores for the validation criterion as compared with the other criteria. Overall strengths of parameters related to the primary production module were significantly stronger compared to the other modules (the transport, holding, and slaughterhouse module, the processing, distribution, and storage module, and the preparation and consumption module). The pedigree assessment contributed to select 20 parameters, which were subsequently introduced in the QMRA model. The NUSAP methodology and kite diagrams are objective tools to discuss and visualize the quality of the parameters in a structured way. These two tools can be used in the selection procedure of input parameters for a QMRA, and can lead to a more transparent quality assurance in the QMRA.     

Measuring Inequity Aversion in a Heterogeneous Population Using Experimental Decisions and Subjective Probabilities

We combine choice data in the ultimatum game with the expectations of proposers elicited by subjective probability questions to estimate a structural model of decision making under uncertainty. The model, estimated using a large representative sample of subjects from the Dutch population, allows both nonlinear preferences for equity and expectations to vary across socioeconomic groups. Our results indicate that inequity aversion to one's own disadvantage is an increasing and concave function of the payoff difference. We also find considerable heterogeneity in the population. Young and highly educated subjects have lower aversion for inequity than other groups. Moreover, the model that uses subjective data on expectations generates much better in‐ and out‐of‐sample predictions than a model which assumes that players have rational expectations.     

What's in a name? Current effects of family politicization on legislative candidates’ career start in Belgium

In this article we measure the effect of inherited political capital in the form of family politicization on legislative candidates’ recruitment age and early careers. We differentiate the concept of family politicization between a narrow (i.e., party political) and a broad (i.e., non-party-political) interpretation. Results indicate that narrow family politicization is the only type that plays a role in speeding up political recruitment. However, only the route to candidacy is affected by family politicization, whereas for the route to power other factors absorb this effect, mainly the candidates’ pre-electoral party engagement. This implies that candidates from narrowly politicized families do not merely rely on inherited political capital to get elected, which rejects a popular opinion. On the other hand, the result that parental talking and brokerage professions speed up the candidates’ election, indicate that the home environment does not play a neutral role in the early career path either.     

The impact of foster children's behavioural problems on Flemish foster mothers' parenting behaviour

Foster children often have behavioural problems. Behavioural problems influence the level of parenting stress and can lead to a breakdown. In this study, parenting behaviour of foster mothers is mapped, and the influence of behavioural problems and parenting stress on the parenting behaviour 2 years later is examined. Data of behavioural problems, family stress and parenting were gathered from 49 foster mothers. Problem behaviour has a direct negative impact on parenting and leads to less support and more negative control. It also results in more parenting stress. Foster parents need to be trained aiming at preventing ineffective parenting. The well‐being of foster parents needs to be guarded. Higher levels of parenting stress lead to less effective parenting.     

Foster care placement breakdown in the Netherlands and Flanders: Prevalence,precursors, and associated factors

Family foster care is the option of choice for children in need of out‐of‐home care in Flanders and the Netherlands. Foster care is however a vulnerable intervention, and questions can be raised as to its efficacy. Although the literature on placement breakdown has made significant progress during the last years, empirical knowledge regarding breakdown in Flanders and the Netherlands remains scant. Consequently, this study aimed at investigating prevalence and precursors of breakdowns in long‐term foster care, the duration of placement before breakdown, and the association of child and placement characteristics with breakdown. Case files of 271 Dutch and 309 Flemish foster children were analysed with a coding scheme designed for this study. After 6 years, 398 placements had terminated: 169 placements broke down and 229 placements ended positively. Placements broke down mainly because of behavioural problems of the foster child, foster parents' parenting problems, and conflicts between birth and foster parents. Foster children with behavioural problems, older foster children, foster children denied treatment, and foster children in care because of sexual abuse were more at risk of breakdown. Assessing these factors is important when evaluating the appropriateness of a family foster care placement.     

An evaluation of the bootstrap for model validation in mixture models

Bootstrapping has been used as a diagnostic tool for validating model results for a wide array of statistical models. Here we evaluate the use of the non-parametric bootstrap for model validation in mixture models. We show that the bootstrap is problematic for validating the results of class enumeration and demonstrating the stability of parameter estimates in both finite mixture and regression mixture models. In only 44% of simulations did bootstrapping detect the correct number of classes in at least 90% of the bootstrap samples for a finite mixture model without any model violations. For regression mixture models and cases with violated model assumptions, the performance was even worse. Consequently, we cannot recommend the non-parametric bootstrap for validating mixture models.

The cause of the problem is that when resampling is used influential individual observations have a high likelihood of being sampled many times. The presence of multiple replications of even moderately extreme observations is shown to lead to additional latent classes being extracted. To verify that these replications cause the problems we show that leave-k-out cross-validation where sub-samples taken without replacement does not suffer from the same problem.     

The Boric Acid Powder Treatment of Vulvovaginal Candidiasis

Abstract

This double blind comparison of fourteen daily intravaginal gelatin capsules containing 600 mg of boric acid powder versus identical capsules containing 100,000 units of nystatin diluted to volume with cornstarch found vulvovaginal candidiasis albicans cure rates for boric acid to be 92% seven to ten days after treatment and 72% at thirty days, whereas the nystatin cure rates were 64% at seven to ten days and 53% at thirty days. Speed of alleviation of signs and sumptoms was similar with both drugs. There were no untoward side effects, and cervical cytology was not affected. In vitro studies found boric acid to be fungistatic and its effectiveness to be unrelated to pH. Blood boron analyses indicated little absorption from the vagina and a half life of less than 12 hours. A 30% follow-up of 2,030 nonstudy patients revealed wet mount and symptom cure rates of 93% within two weeks and 88% within four weeks. Patient acceptance was better than with “messy” vaginal creams, and self-made boric acid powder capsules are inexpensive, 31¢ for fourteen, compared with costly, commonly prescribed medication.     

Postdivorce Relationships in Families and Children's Psychosocial Adjustment

Divorced mothers and their school-aged children in 50 single-mother families and 37 stepfather families reported on mothers' ex-partner relationships, children's relationships with both parents, and children's well-being. A 2 (family structure) × 2 (gender) multivariate analysis of variance revealed a main effect of gender: Mothers with sons report higher levels of ex-partner relationship satisfaction. An interaction effect was also found: Boys in single-mother families report more acceptance and fewer conflicts than boys in stepfather families. Multiple regression analysis revealed that mother–ex-partner relationships are associated with children's problem behavior, whereas child–nonresidential father relationships are associated with positive aspects of children's well-being. The results indicate that family structure itself is not associated with child adjustment. What matters most is the quality of family relationships.