The analysis of incomplete data using stochastic covariates

In the development of many diseases there are often associated random variables which continuously reflect the progress of a subject towards the final expression of the disease (failure). At any given time these processes, which we call stochastic covariates, may provide information about the current hazard and the remaining time to failure. Likewise, in situations when the specific times of key prior events are not known, such as the time of onset of an occult tumour or the time of infection with HIV-1, it may be possible to identify a stochastic covariate which reveals, indirectly, when the event of interest occurred. The analysis of carcinogenicity trials which involve occult tumours is usually based on the time of death or sacrifice and an indicator of tumour presence for each animal in the experiment. However, the size of an occult tumour observed at the endpoint represents data concerning tumour development which may convey additional information concerning both the tumour incidence rate and the rate of death to which tumour-bearing animals are subject. We develop a stochastic model for tumour growth and suggest different ways in which the effect of this growth on the hazard of failure might be modelled. Using a combined model for tumour growth and additive competing risks of death, we show that if this tumour size information is used, assumptions concerning tumour lethality, the context of observation or multiple sacrifice times are no longer necessary in order to estimate the tumour incidence rate. Parametric estimation based on the method of maximum likelihood is outlined and is applied to simulated data from the combined model. The results of this limited study confirm that use of the stochastic covariate tumour size results in more precise estimation of the incidence rate for occult tumours.     

The Prevention of Social Aggression Among Girls

This study represents the first systematic attempt to examine a theory‐based program designed to reduce girls' social aggression and increase positive leadership among peers. Fifth‐grade girls from six public schools were randomly assigned within classrooms to the social aggression prevention program (SAPP) and the comparison reading clubs. A school‐based small group program, the SAPP was demonstrated to have a positive impact for all students in the domain of social problem solving. For students with high baseline social problems, teachers reported positive changes in SAPP participants' prosocial behavior. In addition, the content of the program was critical: reading club participants improved their reading achievement at greater rates than SAPP participants. Targeting female students in a program focused on resolving social conflicts from multiple perspectives may be an important addition to broader, multilevel initiatives to prevent aggression and promote leadership in schools.     

Training with o (observing) and T (treatment) teams in live supervision: reflections in the looking glass*

Working with a treatment and observing team at the same time, behind the oneway mirror, offers a variety of ways to: (a) generate multiple realities; (b) work with two different models of family therapy simultaneously; and (c) provide feedback on the teams' own roles, rules and group process. The process that 6 trainees and two supervisors used with T and O teams to examine their own coevolution as a therapeutic system using the Milan model of family therapy and Ericksonian hypnotherapy is described. The article concludes with a discussion of the advantages and pitfalls of this type of dual supervision.     

Health education evaluation and beliefs and practices in rural Tamil Nadu

This paper reports the findings of 2 studies in North Arcot District of Tamil Nadu, one of which was an evaluation of health education programs. A wide range of information is made available on the local Tamil names for allopathic diseases, their etiology, beliefs related to preventive and curative practices, significance and medical consequences of recourse to doctors and practitioners of indigenous systems of medicine. The attitude survey covers a variety of topics about which not much is known -- immunization, sanitation, environment, antenatal care and allopathic medicine. The data suggest that allopathic treatment is preferred for most diseases, although traditional or spiritual methods continue to be used for certain diseases, many of which are believed to be the cause of infant and child mortality.     

Phonological Specificity in 12‐ and 17‐Month‐Old French‐Speaking Infants

The literature reports some contradictory results on the degree of phonological specificity of infants’ early lexical representations in the Romance language, French, and Germanic languages. It is not clear whether these discrepancies are because of differences in method, in language characteristics, or in participants’ age. In this study, we examined whether 12‐ and 17‐month‐old French‐speaking infants are able to distinguish well‐pronounced from mispronounced words (one or two features of their initial consonant). To this end, 46 infants participated in a preferential looking experiment in which they were presented with pairs of pictures together with a spoken word well pronounced or mispronounced. The results show that both 12‐ and 17‐month‐old infants look longer at the pictures corresponding to well‐pronounced words than to mispronounced words, but show no difference between the two mispronunciation types. These results suggest that, as early as 12 months, French‐speaking infants, like those exposed to Germanic languages, already possess detailed phonological representations of familiar words.     

Viewing the child as a participant within context

This paper explores tensions between the social nature of learning and the current emphasis upon individual support. The paper contrasts the focus upon context in discussions with parents and practitioners, with the focus upon the individual within formal and informal written documents. The analysis is partly situated within the first author’s experiences as a parent researcher, drawing additionally upon ethnographic research carried out with families involved in early intervention, including an evaluation of over 150 pages of documentation provided by a parent. It identifies the need for assessment and evaluation to focus upon and record the broad range of context that influences learning.     

Woman and Desire Why Women May Not Want to Want

Questioning why it is that female genitalia and desire are viewed in psychoanalytic theory as hidden, inaccessible, and lacking, the author examines 1) female genital representation, 2) girls' erotically desirous relationships to their mothers, and 3) the nature of women's experience in sexuality. The author proposes that the marker “absent” regarding female genitalia and desire may be a particular female form or protection against “castration” of sexual desire; males inflate whereas females may deflate their genital representation and desire. The author suggests that the female body lends itself-and, abetted by culture and psychoanalytic theory, is unconsciously used by females—to a specific form or protection of female desire.     

Methods to assess measurement error in questionnaires of sedentary behavior

Sedentary behavior has already been associated with mortality, cardiovascular disease, and cancer. Questionnaires are an affordable tool for measuring sedentary behavior in large epidemiological studies. Here, we introduce and evaluate two statistical methods for quantifying measurement error in questionnaires. Accurate estimates are needed for assessing questionnaire quality. The two methods would be applied to validation studies that measure a sedentary behavior by both questionnaire and accelerometer on multiple days. The first method fits a reduced model by assuming the accelerometer is without error, while the second method fits a more complete model that allows both measures to have error. Because accelerometers tend to be highly accurate, we show that ignoring the accelerometer's measurement error, can result in more accurate estimates of measurement error in some scenarios. In this article, we derive asymptotic approximations for the mean-squared error of the estimated parameters from both methods, evaluate their dependence on study design and behavior characteristics, and offer an R package so investigators can make an informed choice between the two methods. We demonstrate the difference between the two methods in a recent validation study comparing previous day recalls to an accelerometer-based ActivPal.     

Staying safe while consuming alcohol: a qualitative study of the protective strategies and informational needs of college freshmen

OBJECTIVE: In this qualitative study, the authors examined how students attempt to minimize harm to themselves and others when drinking. PARTICIPANTS: The authors recruited freshmen at a large, mid-Atlantic US public university during the fall semester of 2005 to participate in 8 focus groups. METHODS: The moderator's guide was developed through an iterative process that included input from experts and pilot testing. The researchers audiotaped focus group conversations, transcribed them, and subjected them to an interrater reliability check. Analysis was based on the framework of Information-Motivation-Behavioral Skills Model and a phenomenological approach. RESULTS: College students have a repertoire of coping strategies they use in an attempt to safeguard themselves and their friends from harm when drinking. Strategies encompass planning a safe context for drinking, using safety measures to minimize harm when drinking, and taking care of someone who has consumed too much alcohol. CONCLUSIONS: A harm-reduction focus that acknowledges and builds on existing protective strategies may be a promising avenue for alcohol interventions.