Cytometry inference through adaptive atomic deconvolution

In this paper, we consider a statistical estimation problem known as atomic deconvolution. Introduced in reliability, this model has a direct application when considering biological data produced by flow cytometers. From a statistical point of view, we aim at inferring the percentage of cells expressing the selected molecule and the probability distribution function associated with its fluorescence emission. We propose here an adaptive estimation procedure based on a previous deconvolution procedure introduced by Es, Gugushvili, and Spreij [(2008), ‘Deconvolution for an atomic distribution’, Electronic Journal of Statistics, 2, 265–297] and Gugushvili, Es, and Spreij [(2011), ‘Deconvolution for an atomic distribution: rates of convergence’, Journal of Nonparametric Statistics, 23, 1003–1029]. For both estimating the mixing parameter and the mixing density automatically, we use the Lepskii method based on the optimal choice of a bandwidth using a bias-variance decomposition. We then derive some convergence rates that are shown to be minimax optimal (up to some log terms) in Sobolev classes. Finally, we apply our algorithm on the simulated and real biological data.     

The effects of direct experience on consumer product evaluation

The effects of different sales strategies on consumer product evaluation were investigated. It was expected that direct product experience could decrease economic product valuation. Experiments 1 and 2 studied the effects of product trials and money-back guarantees on consumer willingness to pay (WTP). It appeared that WTP was significantly lower after a product trial than with a money-back guarantee or normal sale. In Experiment 3 a structural equation model showed that product trials had a positive effect on attitude toward the product. Also, a negative effect on WTP was found when the effect was measured directly, but a positive effect when the effect was measured indirectly (through attitude).     

Work-related factors contributing to chronic disability in low back pain

Low back pain is a costly and incapacitating musculoskeletal disorder. Prospective studies documenting the capacity of work-related factors to predict chronicity are few in number, the methodology used is very diversified, and the results obtained diverge. The aim of the present study is to investigate the capacity of work-related objective (non-psychosocial) and psychosocial factors to predict chronic disability related to low back pain. A longitudinal prospective study with two measurement times was carried out. The sample (N = 258) consisted of workers with subacute low back pain who were on sick leave and receiving compensation from the CSST (Quebec Workers' Compensation Board). Of all the work-related variables measured, perceived stress and fears and beliefs about work were associated with return to work status at the six-month follow-up. The results obtained show the importance of considering fears and beliefs about work when identifying people in the subacute phase of low back pain who are at risk of developing chronic disability.     

Intergenerational reliance on social assistance: Evidence from Canada

This paper provides the first analysis of the intergenerational transmission of participation in a Canadian social assistance program. Two sources of intergenerational transmission are taken into account: one that is due to a possible causal link between parents' and children's participation, and one that is due to a correlation between individual and environment specific characteristics across generations. The basic data come from the Québec government's administrative records and cover 17,203 young people who were 18 years old in 1990 and whose parents were recipients of social assistance during at least one month between 1979 and 1990. The results reveal that, on average, a one-percentage unit increase in parental participation during the youth's pre-adult years (age 7–17) raises the youth's participation rate by 0.29 percentage unit during early adulthood (age 18–21). This impact is stronger during the early stages of childhood (age 7–9) and during late adolescence (age 16–17).     

Migration as a source of growth: The perspective of a developing country

This paper analyses the dynamics of migratory flows and growth in a developing economy. We show that when workers freely choose their location, some natives can rationally decide to return to their home country after they have accumulated a certain amount of knowledge abroad, while some prefer to stay permanently in the same economy (either at home or abroad). We point out that worker mobility can have an expansionary effect on the developing economy. Moreover, we show that in the long-run, as the sending economy develops, fewer natives are likely to emigrate and more migrants are likely to return. Received: 7 December 2000/Accepted: 25 April 2001     

Negotiating Informed Consent with Children in School‐Based Research: A Critical Review

The methods literature on research with children recognises the challenges of negotiating informed consent with this group. Special ‘child‐friendly’ techniques are advocated to overcome these challenges. We argue that, upon closer inspection, research with children foregrounds more fundamental problems with informed consent that are not easily resolved. Drawing from three ethical texts commonly consulted in our own research fields, we highlight problems of information, understanding, authority, capacity and voluntarity. We conclude that informed consent is more problematic than is generally admitted, and that researchers would benefit from more openly acknowledging its limitations.     

To Sample or Not to Sample? An Analysis of the Need for Salmonella Sampling of Smaller Poultry Processors

Within the European Union (EU), microbiological criteria (MC) sampling for Salmonella in poultry was introduced in 2005. In particular, processors had to meet a target of fewer than seven positive samples out of 50. However, processors producing small amounts of poultry meat did not have to sample if national authorities determined this was an acceptable risk. The U.K. Food Standards Agency (FSA) thus has a sampling regime based on throughput that allows smaller processors not to sample. In 2011, the limit of 7/50 was reduced to 5/50. Given the current uncertainty regarding U.K. trade relations with the EU, the U.K. FSA decided to conduct a new risk assessment of the risks of Salmonella produced by smaller processors, to determine whether sampling was now necessary. Current evidence suggests that an MC sampling regime in smaller slaughterhouses is not warranted from a national public health perspective. Because of the insensitivities of the MC sampling scheme, the introduction of MC sampling into smaller slaughterhouses would only be necessary if the suspected carcass prevalence was 15% or more. While our analysis is prone to uncertainty, we estimated that the carcass prevalence in smaller processors is below this. Thus, we recommended that the current sampling framework, allowing smaller processors not to sample, was still applicable.     

Validation of a French Canadian version of the Organizational Policies and Practices (OPP) questionnaire

Organizational factors are potentially powerful in accounting for work-related chronic disability following a musculoskeletal disorder. This study documents the psychometric qualities of the French Canadian version of the Organizational Policies and Practices questionnaire (OPP) [1] on a population of nurses (N=124). By excluding the two items composing the ergonomic practices factor, a factorial structure identical to that obtained by the OPP's authors is obtained for the disability management policies and practices factor, the people-oriented culture factor and the safety climate factor. The internal consistency coefficients (Cronbach's alpha) are satisfactory while the coefficients intraclass are less than those obtained by the authors in the test-retest. However, the test-retest interval is greater in this study. Consistent relationships are observed between the dimensions of the OPP and three job-related psychosocial indicators: perceived stress, social support and satisfaction. This suggests a good construct validity for the OPP. Although additional validation efforts are recommended, all of the results obtained support the validity and reliability of the French Canadian version of the OPP. This version can be used to examine the importance of organizational aspects in studies on the prevention of chronic disability.     

Efficacy of a group intervention for adult women survivors of sexual abuse

This study evaluates the effects of a group intervention for women sexually abused in childhood or adulthood. The sample consisted of 41 women involved in a group intervention based on a feminist approach offered by help centers for sexual assault victims in Quebec and 11 women in a wait-list comparison group. Results reveal that the group intervention reduced psychological distress and consequences associated with sexual abuse and that gains were maintained at three-month follow- up. Analyses of potential factors related to differential gains indicated that abuse-related variables and concurrent individual interventions were not linked to outcomes. Exploratory analyses suggested that women experiencing severe physical partner violence showed greater gains with respect to self-blame/stigmatization, sexual anxiety, and anxiety related to assertiveness.     

Mental budgeting and the management of household finance

Mental budgeting and financial management were investigated in a large sample of the Dutch population. Mental budgeting was quite common, and was explained from general education, having saving goals, financial knowledge, time orientation, and financial situation. Also, mental budgeting, in addition to effects of financial situation, time orientation and financial knowledge, was positively associated with having an overview of expenses and current accounts, and household financial management.