Semiparametric Additive Accelerated Life Models

In this paper we investigate the asymptotic properties of estimators obtained for the semiparametric additive accelerated life model proposed by Bagdonavicius & Nikulin (1995). This model generalizes the well known additive hazards model of survival analysis and is close to the general transformation model (see Dabrowska & Doksum, 1988). Asymptotic properties of the estimator of the regression parameter and the estimator of the reliability function are given in the case of right censoring for discretized data and a numerical example illustrates these results.     

Structural instability and alternative development scenarios

Many past societies grew and flourished for several generations, and some for many centuries, prior to experiencing calamities that lowered wealth and/or productivity below some “critical levels.” In some cases, a collapse occurred; in others, the population reductions caused by emigration, plague, or warfare not only extended societies’ survival but induced a growth resurgence. These varied historical development scenarios are captured using a comparative dynamic analysis of structurally unstable variations of the Solow–Swan growth model. These results would seem to be relevant for understanding possibilities in the contemporary world.     

A generalization of Turnbull’s estimator for nonparametric estimation of the conditional survival function with interval-censored data

Simple nonparametric estimates of the conditional distribution of a response variable given a covariate are often useful for data exploration purposes or to help with the specification or validation of a parametric or semi-parametric regression model. In this paper we propose such an estimator in the case where the response variable is interval-censored and the covariate is continuous. Our approach consists in adding weights that depend on the covariate value in the self-consistency equation proposed by Turnbull (J R Stat Soc Ser B 38:290–295, 1976), which results in an estimator that is no more difficult to implement than Turnbull’s estimator itself. We show the convergence of our algorithm and that our estimator reduces to the generalized Kaplan–Meier estimator (Beran, Nonparametric regression with randomly censored survival data, 1981) when the data are either complete or right-censored. We demonstrate by simulation that the estimator, bootstrap variance estimation and bandwidth selection (by rule of thumb or cross-validation) all perform well in finite samples. We illustrate the method by applying it to a dataset from a study on the incidence of HIV in a group of female sex workers from Kinshasa.     

Non‐parametric Estimation of Extreme Risk Measures from Conditional Heavy‐tailed Distributions

In this paper, we introduce a new risk measure, the so‐called conditional tail moment. It is defined as the moment of order a ≥ 0 of the loss distribution above the upper α‐quantile where α ∈ (0,1). Estimating the conditional tail moment permits us to estimate all risk measures based on conditional moments such as conditional tail expectation, conditional value at risk or conditional tail variance. Here, we focus on the estimation of these risk measures in case of extreme losses (where α ↓0 is no longer fixed). It is moreover assumed that the loss distribution is heavy tailed and depends on a covariate. The estimation method thus combines non‐parametric kernel methods with extreme‐value statistics. The asymptotic distribution of the estimators is established, and their finite‐sample behaviour is illustrated both on simulated data and on a real data set of daily rainfalls.     

Random effects models for operational patient pathways

Patient flow modeling is a growing field of interest in health services research. Several techniques have been applied to model movement of patients within and between health-care facilities. However, individual patient experience during the delivery of care has always been overlooked. In this work, a random effects model is introduced to patient flow modeling and applied to a London Hospital Neonatal unit data. In particular, a random effects multinomial logit model is used to capture individual patient trajectories in the process of care with patient frailties modeled as random effects. Intuitively, both operational and clinical patient flow are modeled, the former being physical and the latter latent. Two variants of the model are proposed, one based on mere patient pathways and the other based on patient characteristics. Our technique could identify interesting pathways such as those that result in high probability of death (survival), pathways incurring the least (highest) cost of care or pathways with the least (highest) length of stay. Patient-specific discharge probabilities from the health care system could also be predicted. These are of interest to health-care managers in planning the scarce resources needed to run health-care institutions.     

Prevalence of Sexual Abuse in Childhood: Some Critical Methodological Reflections

This article attempts to analyze the prevalence rates of sexual abuse in childhood reported in comparative empirical studies, giving an overview of a selection of representative studies reporting high rates of abuse and comparing it to an overview of studies reporting lower rates. Extremely discrepant rates of childhood sexual abuse are reported in a number of empirical studies conducted in this field over the past 26 years, particularly those looking beyond prevalence to study the links between this type of trauma and future motherhood. To shed light on the disparities in the reported prevalence rates, the article reviews the principal methodological biases that have contaminated the findings. The authors then offer several suggestions for improvement that might be implemented in future studies.     

Parental Divorce and Romantic Attachment in Young Adulthood: Important Role of Problematic Beliefs

In the current study 45 university students with either divorced or continuously married parents were surveyed about their romantic attachment, positive emotionality, depressive symptomology, self-esteem, and, when applicable, their retrospective beliefs about their parents’ marital dissolution. Findings revealed that parental divorce did not predict attachment insecurity, depression, or low self-esteem. In fact, adult children of divorced parents (ACDP) reported increased compassion, awe, enthusiasm, and perspective taking. Among ACDP, a composite factor representing increased fear of abandonment, peer rejection, and maternal blame was positively associated with adult attachment anxiety, even while controlling for parental conflict and divorce-related socioenvironmental disruption. Results are discussed in terms of their support of a complex understanding of the long-term effects of parental divorce, and in their inconsistency with a purely pathogenic model of parental divorce.     

Nested patterns in urban butterfly species assemblages: respective roles of plot management,park layout and landscape features

Increasing numbers of cities are currently developing sustainable policies aimed at promoting urban biodiversity and ecological dynamics through the planning of green networks and the implementation of more sustainable management practices. These human activities can strongly influence environmental factors on which the organization of ecological communities at different scales depends. Thus, it is of fundamental importance to understand the relative impact of local management, green space design and landscape features on the distribution and the abundance of species in urban areas. On the basis of 2 years of butterfly surveys in urban public parks within an extensive Mediterranean metropolitan area, Marseille (South-East France), the aim of this paper is to provide a better understanding of the effect of these three environmental scales (plot, park, landscape) on the composition and organization of species assemblages. Using variation partitioning and nestedness analysis on ecological data aggregated at plot-level and park-level respectively, we demonstrate the preponderant effect of landscape scale features on urban butterfly assemblages. Our results also highlight an important co-variation of plot management, park layout and urban landscape features, in their interaction with the community structure of urban butterflies. Although there is no significant species-area relationship, significantly nested patterns arise in species composition. Selective colonization appears as a driving force constraining the constitution of species assemblages within the city. However, a prospective study on adjacent more natural areas suggests that biotic limitations, interspecific competition and habitat filtering may play an important role if a larger portion of the urbanization gradient is explored, which remains to be investigated.     

Les sentinelles bancaires de l'antiblanchiment. Acteurs privés et policing économique

Private actors in finance, especially in the banking industry, play a leading role in the campaign, institutionalized during the 1990s, against money-laundering. Assigned the duty of detecting dubious transactions in their establishments, they are supposed to inform Tracfin, a finance intelligence unit located in the French Ministry of Finance, of their suspicions. The latter decides whether to alert judicial authorities. A set of interviews conducted with the ‘compliance officers’ in banks who supervise the implementation of regulations against money-laundering are analyzed in order to understand how persons whose normal duties are oriented toward commercial activities based on a high regard for privacy are being led to assume police duties and how they are performing in this new role.