Correction methods for ties in rank correlations

Equal values are common when rank methods are applied to rounded data or data consisting solely of small integers. A popular technique for resolving ties in rank correlation is the mid-rank method: the mean of the rankings remains unaltered, but the variance is reduced and modified according to the number and location of ties. Although other methods for breaking ties were proposed in the literature as early as 1939, no such procedure has gained such wide acceptance as mid-ranks. This research analyses various techniques for assigning ranks to tied values, with two objectives: (1) to enable the computation of rank correlation coefficients, such as those of Spearman, Kendall and Gini, by using the usual definition applied in the absence of ties, and (2) to determine whether it really makes a difference which of the various techniques is selected and, if so, which technique is most appropriate for a given application.     

A blocked Gibbs sampler for NGG-mixture models via a priori truncation

We define a new class of random probability measures, approximating the well-known normalized generalized gamma (NGG) process. Our new process is defined from the representation of NGG processes as discrete measures where the weights are obtained by normalization of the jumps of Poisson processes and the support consists of independent identically distributed location points, however considering only jumps larger than a threshold \(\varepsilon \). Therefore, the number of jumps of the new process, called \(\varepsilon \)-NGG process, is a.s. finite. A prior distribution for \(\varepsilon \) can be elicited. We assume such a process as the mixing measure in a mixture model for density and cluster estimation, and build an efficient Gibbs sampler scheme to simulate from the posterior. Finally, we discuss applications and performance of the model to two popular datasets, as well as comparison with competitor algorithms, the slice sampler and a posteriori truncation.     

Is corporate governance of private equity targets more effective for risk mitigation?

Journal of Management and Governance - Private equity is a source of finance and a governance device characterised by active monitoring through sponsors that intervene in targets’ corporate...     

Well-Being and Affective Commitment among Ambulance Volunteers: A Mediational Model of Job Burnout

ABSTRACT

Burnout represents a relevant risk for ambulance volunteers. According to the Job Demands-Resources model, role conflict and social support can be considered as antecedents of burnout which, in turn, may lower affective commitment. This study aims to investigate the relationship between social support, role conflict, and affective commitment, as mediated by job burnout. Survey data were collected from 352 Italian volunteers and analyzed using structural equation modeling methods. Social support was confirmed as a protective factor, and role conflict as an antecedent of burnout which, in turn, decreases affective commitment. The relationship between role conflict and affective commitment is mediated by burnout which, on the contrary, does not mediate the effect of social support on affective commitment. Social support may protect against burnout. Because of its positive effects on a personal and an organizational level, affective commitment may be increased raising levels of supervisor support and reshaping role expectations. It could be useful to carry out future longitudinal studies, in order to confirm the antecedents and effects of job burnout; furthermore, this research should be extended to other ambulance organizations, in order to generalize the results; finally, multi-group analyses would allow to bring out possible differences between paid-staff and volunteers.     

What does being an adult mean? Comparing young people’s and adults’ representations of adulthood

This article aims at exploring the representations young people and adults attribute to the concept of adulthood in order to analyse the effects these ideas have on their reciprocal perception and recognition. In so doing, it draws upon data collected through a grounded theory study, which has been conducted in Italy involving young people and adults in semi-structured qualitative interviews. Data show that an outdated traditional model is still used by both the samples to determine who is an adult and when the adult status is acquired without discussing its validity in front of a changed social scenario. An evaluative function is added to traditional transitional markers of adulthood, which are used by both young people and adults to accuse each other of being ‘not mature enough’. A discrepancy between the shared ideal representations of adulthood and the actual possibility the two generations have to meet those social expectations in their lives emerge. The implications of these results for youth transitions to adulthood are discussed in the light of the high level of intergenerational inequality characterising the Italian context.     

Citalopram-Associated Gambling: A Case Report

Pathological gambling behaviour is a side effect of dopaminergic drugs used in Parkinson’s disease, but has seldom been reported with selective serotonin reuptake inhibitors. A 58-years-old woman with somatisation disorder since the age of 20 and recent-onset major depression (at 54 years) received 40 mg/day intravenous citalopram, thereafter switching to the same dose of oral citalopram to treat her comorbid psychiatric disorders after showing poor response to paroxetine for one year. Her anxious and depressive symptoms were moderately reduced after 7 months of oral citalopram, but simultaneously, the patient admitted gambling. We gradually discontinued citalopram and introduced pregabalin and alprazolam; this was followed by a reduction of gambling compulsions, but the somatisation and depressive symptoms did not further improve. Pathological gambling may be mediated by an interplay of 5-HT_1A serotonergic and D₂ dopaminergic mechanisms. Citalopram affects both these mechanisms in areas that were shown to be involved in gambling behaviour, but while dopaminergic effects of citalopram appear to be consistent with the induction of gambling, its serotonergic mechanisms are rather inconsistent. In our patient, mood destabilisation induced by citalopram may have contributed to the first onset of pathological gambling.     

The contribution of emotion knowledge,language ability,and maternal emotion socialization style to explaining toddlers’ emotion regulation

In this study, we set out to advance understanding of the association between emotion knowledge (EK) and emotion regulation (ER) in toddlerhood, by innovatively examining a model that simultaneously takes into account both individual factors, such as age, gender, and language ability, and contextual factors, such as maternal emotion socialization styles (coaching vs. dismissing). Participants were 242 toddlers (141 girls; M_age = 28.79 months, SD = 3.48) and their mothers (M_age = 35.60 years; SD = 4.95). We evaluated children’s language ability and ER via parent‐report questionnaires, assessing their EK via a direct measure individually administered at the nursery. The mothers also completed a questionnaire on their own emotion socialization style. Children’s EK was positively correlated with their ER skills as reported by their parents. Structural equation modeling showed that emotion‐dismissing maternal behaviors were significantly negatively associated with toddlers’ emotional competencies whereas maternal emotion‐coaching styles were significantly positively associated with higher levels of these competences. Finally, language ability was positively associated with ER. We discuss the theoretical and educational implications of these outcomes, as well as potential new lines of inquiry.     

Sex-specific associations between sleep and mental health in university students: a large cross-sectional study

Abstract

Objective: To examine the associations between sleep problems and mental health dimensions in university students, and the effect of sex on these associations. Participants: Self-reported survey data from 3,483 students aged 18–30?years was drawn from a larger web-based study (i-Share) conducted in France in the years 2013–2017. Methods: We performed logistic regression analyses stratified by sex using insufficient sleep duration, poor sleep quality, difficulty initiating sleep and excessive daytime sleepiness, in relation with stress, self-esteem, depression and anxiety. Results: All sleep problems were strongly associated with all mental health dimensions, particularly anxiety, in female students. Sleep and mental health problems were also associated in male students, with the exception of low self-esteem, but odds ratios were lower than for female students. Conclusions: Present findings warrant attention to propose early interventions targeting sleep and mental health in the university setting taking sex into account.