Estimating Mixing Densities in Exponential Family Models for Discrete Variables

This paper is concerned with estimating a mixing density g using a random sample from the mixture distribution f(x)=∫f x | θ)g(θ)dθ where f(· | θ) is a known discrete exponen tial family of density functions. Recently two techniques for estimating g have been proposed. The first uses Fourier analysis and the method of kernels and the second uses orthogonal polynomials. It is known that the first technique is capable of yielding estimators that achieve (or almost achieve) the minimax convergence rate. We show that this is true for the technique based on orthogonal polynomials as well. The practical implementation of these estimators is also addressed. Computer experiments indicate that the kernel estimators give somewhat disappoint ing finite sample results. However, the orthogonal polynomial estimators appear to do much better. To improve on the finite sample performance of the orthogonal polynomial estimators, a way of estimating the optimal truncation parameter is proposed. The resultant estimators retain the convergence rates of the previous estimators and a Monte Carlo finite sample study reveals that they perform well relative to the ones based on the optimal truncation parameter.     

“Let’s talk about the real issue”: Localized perceptions of environment and implications for ecosocial work practice

ABSTRACT

This interpretive study investigated how residents from socioeconomically challenged communities in North St. Louis understand and make meaning of environmental change and its impact on their well-being. Based on these localized data, we argue that racial minorities facing socioeconomic challenges may experience some environmental issues as less of an immediate concern than violence and racism. However, race and racism shape both the realities of environmental threats as well as residents’ perceptions about environmental injustice in their communities. This study informs ecosocial work practices such as educating communities on local environmental issues and mobilizing community members toward environmental decision-making.     

The Missing Baby Bust: The Consequences of the COVID-19 Pandemic for Contraceptive Use,Pregnancy, and Childbirth Among Low-Income Women

Population Research and Policy Review - Multiple episodes in US history demonstrate that birth rates fall in response to recessions. However, the 2020 COVID-19 recession differed from earlier...     

Black Jacobins in Contemporary France: On Identities on Politics,Decolonial Critique,and the Other Blackness

Formerly, issues of race were written out of the public landscape of the French Republic. Now the “black condition” is openly debated. This shift is informed by self-identified black movements and their responses to French Republican avoidance of thematizing racialized social inequalities. It is simultaneously contested by groups that experience anti-black racism as it reduces their alternate use of race and ethnicity. Does blackness lead to the homogenization of black experiences or can it initiate solidarity? This article examines current debates on blackness in Paris by drawing upon ethnographic activist research with a black activist group. I analyze how the group maneuvers through a supposedly race-blind discourse, in which the act of identifying race risks being disqualified as communitarian. I argue that a conception of blackness is introduced that provides the potential to recognize the pluralities of blackness, re-shaping notions of blackness, and the abstract Republican model itself.     

Reliability and Validity of the European Portuguese Version of the Social Touch Questionnaire

Social touch is essential for physical and emotional well-being. However, different meanings can be attributed to physical contact during social interactions and may generate bonding or avoidant behaviors. This personal and unique experience is not usually taken into account in health and social care services. The aim of this study is to produce a valid and reliable European Portuguese version of the Social Touch Questionnaire (STQ, Wilhelm et al. in Biol Psychol 58:181–202, 2001. doi: 10.1016/S0301-0511(01)00113-2). The STQ is a self-report questionnaire for adolescents and adults measuring behaviors and attitudes towards social touch. The original version was translated into European Portuguese using a forward-back translation process and its feasibility was examined. To evaluate the psychometric properties, a total of 242 Portuguese university students participated in the study (21.3 ± 3.8 years). The STQ was considered feasible, showed adequate internal consistency (Cronbach’s α = .734), and the test–retest correlation with the STQ items demonstrated a high concordance between the tests over a two-week interval (ICC = .990; n = 50). Validity tests were performed, comparing the total score of the STQ with that of the anxiety and avoidance subscales of the Social Interaction and Performance Anxiety and Avoidance Scale (SIPAAS). A very significant conceptual convergence was confirmed between the STQ and with the SIPAAS-Anxiety (r = .64; p < .0001) and with the SIPAAS-Avoidance (r = .59; p < .0001). The exploratory factor analysis, with Promax rotation, revealed 3 factors: dislike of physical touch, liking of familiar physical touch and liking of public physical touch (Cronbach’s alphas ranged from .68 to .75). Psychometric properties confirmed the adaptation of the STQ to the Portuguese culture. It is a reliable and valid self-report questionnaire and it appears to be a useful tool to assess behaviors and attitudes towards social touch.     

Portuguese adopted adolescents' perception of attachment relationships to parents

The establishment of emotional bonds is one of the most important tasks of the adoptive family. Most research about attachment in adoption focuses on young adopted children, as opposed to adoptees in other stages of development. The present study aims at assessing the adopted adolescents' self‐perception of attachment relationships with their adoptive parents, by pairing them with a group of institutionalized adolescents and another one of adolescents in the community. One hundred sixty‐five adolescents (55 adopted, 55 in residential care, and 55 living with their birth family), aged 12 to 19, participated in this study. Data were collected using the Inventory of Parent and Peer Attachment to assess attachment relationships with parents on three dimensions: trust, communication, and alienation. The results showed that adoptees perceived their relationship with their parents in a similar way to peers in the community and presented higher results when compared to institutionalized adolescents in trust and communication and lower scores in alienation. The results highlighted the relevance of family context experiences and suggested that adoption can offer the possibility of building a secure attachment relationship, which is not the case in the context of collective care, as happens within institutionalized care.     

Reciprocal relationships among alcohol use, risk perception, and sexual victimization: a prospective analysis

OBJECTIVE: The authors' purpose in this study was to assess longitudinally the relationships among alcohol use, risk perception, and sexual victimization. PARTICIPANTS: Three hundred and seventy-two women from 2 midsized universities made up the sample. METHODS: Participants filled out questionnaires regarding history of sexual victimization, alcohol use, and perceived personal risk for sexual assault in the following 2 months. The authors then reassessed participants at 2 follow-up periods. RESULTS: The pattern of results suggested that that the relationship between alcohol use and sexual victimization was complex and that alcohol use may moderate the relation between history of victimization and revictimization for women with sexual assault histories. In particular, results indicated an increase in risk for sexual revictimization with increases in alcohol use for women with a history of sexual victimization. The data did not, however, support a reciprocal relationship between sexual assault and drinking (eg, in that a sexual victimization during one time period did not predict drinking behaviors in subsequent time periods). CONCLUSIONS: These results underscore the importance of both alcohol and sexual assault programming on college campuses.     

Fuzzy System Dynamics Risk Analysis (FuSDRA) of Autonomous Underwater Vehicle Operations in the Antarctic

With the maturing of autonomous technology and better accessibility, there has been a growing interest in the use of autonomous underwater vehicles (AUVs). The deployment of AUVs for under-ice marine science research in the Antarctic is one such example. However, a higher risk of AUV loss is present during such endeavors due to the extreme operating environment. To control the risk of loss, existing risk analyses approaches tend to focus more on the AUV's technical aspects and neglect the role of soft factors, such as organizational and human influences. In addition, the dynamic and complex interrelationships of risk variables are also often overlooked due to uncertainties and challenges in quantification. To overcome these shortfalls, a hybrid fuzzy system dynamics risk analysis (FuSDRA) is proposed. In the FuSDRA framework, system dynamics models the interrelationships between risk variables from different dimensions and considers the time-dependent nature of risk while fuzzy logic accounts for uncertainties. To demonstrate its application, an example based on an actual Antarctic AUV program is presented. Focusing on funding and experience of the AUV team, simulation of the FuSDRA risk model shows a declining risk of loss from 0.293 in the early years of the Antarctic AUV program, reaching a minimum of 0.206 before increasing again in later years. Risk control policy recommendations were then derived from the analysis. The example demonstrated how FuSDRA can be applied to inform funding and risk management strategies, or broader application both within the AUV domain and on other complex technological systems.     

Are midwifery clients in Ontario making informed choices about prenatal screening?

BackgroundInformed choice is often lacking in women's decisions about prenatal screening.AimThe aim of this study is to evaluate how well midwives in Ontario, Canada are facilitating informed choice in this area.MethodsAn Internet-based survey was used to investigate 171 midwifery clients’ knowledge, attitude towards and experience of prenatal genetic screening tests, and to determine the proportion of study participants who made an informed choice about prenatal screening.FindingsAll participants demonstrated adequate knowledge of prenatal screening. The vast majority (93.0%) of participants made an informed choice. Participants who chose to screen had lower knowledge scores than those who opted out of screening. Client satisfaction rates in regard to care received in this area ranged from 97% to 100%.ConclusionsResults of this study suggest that Ontario midwives are effective in conveying information on prenatal genetic screening, contributing to high levels of client knowledge and satisfaction in comparison to similar studies in other jurisdictions.