Brood parasitism and the evolution of cooperative breeding in birds.

The global distribution of cooperatively breeding birds is highly uneven, with hotspots in Australasia and sub-Saharan Africa. The ecological drivers of this distribution remain enigmatic yet could yield insights into the evolution and persistence of cooperative breeding. We report that the global distributions of avian obligate brood parasites and cooperatively breeding passerines are tightly correlated and that the uneven phylogenetic distribution of cooperative breeding is associated with the uneven targeting of hosts by brood parasites. With a long-term field study, we show that brood parasites can acquire superior care for their young by targeting cooperative breeders. Conversely, host defenses against brood parasites are strengthened by helpers at the nest. Reciprocally selected interactions between brood parasites and cooperative breeders may therefore explain the close association between these two breeding systems.

Laparoscopic liver surgery: parenchymal transection using saline-enhanced electrosurgery.

Minimally invasive liver resection (MILR) has evolved considerably in the past decade. Safe hepatic parenchymal transection, has been one of the technical hurdles that has become evident during the growth of MILR. Advances in technology have now made safe liver transection a reality allowing resections of greater magnitude. In this review, the precoagulation approach is described in both methodology and technique. Using this method of liver transection, we have been able to perform MILR of all varieties and magnitudes, with favorable patient outcomes. A detailed description of one particular device will be highlighted to disseminate our experience and thus broaden the technical options for hepatobiliary surgeons wishing to offer their patients a minimally invasive therapy.

Predictors of sexual transmission risk behaviors among HIV-positive young men.

Reduction in the incidence of high-risk sexual behaviors among HIV-positive men is a priority. We examined the roles of proximal substance use and delinquency-related variables, and more distal demographic and psychosocial variables as predictors of serious high-risk sexual behaviors among 248 HIV-positive young males, aged 15-24 years. In a mediated latent variable model, demographics (ethnicity, sexual orientation and poverty) and background psychosocial factors (coping style, peer norms, emotional distress, self-esteem and social support) predicted recent problem behaviors (delinquency, common drug use and hard drug use), which in turn predicted recent high-risk sexual behaviors. Hard drug use and delinquency were found to predict sexual risk behaviors directly, as did lower self-esteem, white ethnicity and being gay/bisexual. Negative peer norms strongly influenced delinquency and substance use and positive coping predicted less delinquency. In turn, less positive coping and negative peer norms exerted indirect effects on sexual transmission risk behavior through delinquency and hard drug use. Results suggest targeting hard drug use, delinquency, maladaptive peer norms, dysfunctional styles of escaping stress and self-esteem in the design of intervention programs for HIV-positive individuals.

Predicting protected sexual behaviour using the Information-Motivation-Behaviour skills model among adolescent substance abusers in court-ordered treatment.

The Information-Motivation-Behavioural skills model (Fisher & Fisher, 1992) was used to predict condom use among adolescents residing in a court-ordered inpatient substance abuse treatment programme (N = 271; 181 male and 90 female, primarily of minority ethnicity). In a predictive structural equation model, demographic variables, HIV transmission knowledge, and motivational variables of pro-condom norms and attitudes, and perceived susceptibility predicted condom use skills and condom use self-efficacy. Along with the other variables in the model, condom skills and condom self-efficacy were hypothesized to predict condom use over a three-month period. It was found that condom skills were predicted by greater age, pro-condom attitudes and greater perceived susceptibility. Condom self-efficacy was predicted by gender, pro-condom norms and condom attitudes. Condom use was significantly predicted by pro-condom norms and stronger condom self-efficacy. Both condom skills and knowledge did not significantly predict condom use. Significant demographic predictors of condom use included greater age and gender. Results suggest that changing personal attitudes about condoms and reinforcing the power of pro-condom beliefs among significant others will encourage condom use among adolescents who are at high risk for HIV and other STDs.

Impact of parent death and an intervention on the adjustment of adolescents whose parents have HIV/AIDS.

The impact of parental death and the efficacy of a coping-skills intervention were examined on the adjustment of 211 adolescent children of parents with HIV/AIDS (PWH) over a 2-year period. During the follow-up period, 35% of the PWH died. Using longitudinal structural equation model, controlling for prior measures of adjustment at baseline, the authors found that children of deceased PWH reported significantly more emotional distress and problem behaviors 2 years later. Youth randomized with their parent to a coping-skills intervention reported significantly fewer problem behaviors and sexual partners 2 years later. Also, adolescents were better-adjusted 2 years later when their parents had reported less emotional distress and less severe physical health symptoms at baseline. Female adolescents reported more emotional distress at baseline and at 2 years than males; male adolescents reported more problem behaviors at baseline than the females.

Gender differences in the prediction of problem alcohol use in adulthood: exploring the influence of family factors and childhood maltreatment.

OBJECTIVE: The purpose of this study was to contrast men and women in prospective relationships among family-oriented and alcohol-related variables obtained during adolescence, childhood physical, emotional and sexual abuse collected retrospectively, and later adult problem alcohol use. METHOD: In structural equation models, early family processes (support/bonding, parent drug-use problems, parental divorce and childhood maltreatment) and prior alcohol use simultaneously predicted adult problem alcohol use at two later time points in a longitudinal community sample of 426 (305 female) adults. RESULTS: Significant relationships were found among family processes, childhood maltreatment, and problem alcohol use within time and longitudinally for both men and women. Greater family support/bonding during adolescence predicted less problem alcohol use in adulthood. Men and women who experienced sexual abuse as a child reported more problem alcohol use in adulthood. Problem alcohol use was stable across time. Men reported more problem alcohol use in adolescence and adulthood, and women reported more early sexual abuse. These results contradict those that find no significant relationships between childhood abuse and subsequent alcohol-related problems. Parental drug use problems during the participant's adolescence did not directly predict problem alcohol use in adulthood. The relationship was more indirect in that parental drug use was associated with family-related concomitants that in turn were significant predictors of more problem alcohol use in adulthood. CONCLUSIONS: The strong stability for problem alcohol use across the three time periods is a signal that alcohol use in adolescence should not be ignored; furthermore, family dynamics need attention in addressing problem alcohol use.

Conceptualizing the multidimensional nature of self-efficacy: assessment of situational context and level of behavioral challenge to maintain safer sex. National Institute of Mental Health Multisite HIV Prevention Trial Group.

A. Bandura (1991) argued that self-efficacy measurement should be specific both to the situation in which the behavior occurs and level of challenge in that situation. Measures consistent with the 2 dimensions were developed with graded challenge levels and differing gender-appropriate situations. Participants were 1,496 controls in the National Institute of Mental Health Multisite HIV Prevention Trial recruited from STD clinics and health service centers (925 women and 571 men). The authors tested 4 separate-sex confirmatory factor analysis models as follows: (a) Condom negotiation efficacy as a unitary construct across situations and gradation of difficulty; (b) situation as preeminent, which transfers across skills whatever the gradation of difficulty; (c) skill as predominant, irrespective of situation; and (d) a multidimensional design that simultaneously accounts for both situation and graded difficulty. Consistent with Bandura's theory, the multidimensional model provided the best fit for both samples.

Targeted mailed materials and the Medicare beneficiary: increasing mammogram screening among the elderly.

OBJECTIVES: Older women have the highest breast cancer rates but are underscreened relative to their risk. Racial/ethnic minority women especially have low screening rates, often because of financial constraints. In response, Medicare introduced subsidized biennial mammogram benefits in 1991. This study examined the effect on mammography rates of an intervention that informed women about the Medicare benefit. METHODS: A list frame method of subject selection was used to select random samples of eligible women from the Health Care Financing Administration's master beneficiary file. Women were interviewed by telephone in 1991 (N = 917) before the targeted mailing and in 1993 (N = 922). One control and 2 treatment communities participated. RESULTS: Mammogram use increased significantly among minorities in the treatment groups. Among minorities who received the intervention, Black women were twice as likely (odds ratio = 1.97) and Hispanic women were more than twice as likely (odds ratio = 2.33) to undergo screening relative to their untreated cohorts. CONCLUSIONS: A targeted low-cost mailed intervention can help increase screening rates among elderly minority women. The Health Care Financing Administration should promote its benefits aggressively if it expects to reach its target--elderly beneficiaries.

Severity of homelessness and adverse birth outcomes.

Predictors and the prevalence of adverse birth outcomes among 237 homeless women interviewed at 78 shelters and meal programs in Los Angeles in 1997 were assessed. It was hypothesized that they would report worse outcomes than national norms, that African Americans would report the worst outcomes because of their greater risk in the general population, and that homelessness severity would independently predict poorer outcomes beyond its association with other adverse conditions. Other predictors included reproductive history, behavioral and health-related variables, psychological trauma and distress, ethnicity, and income. African Americans and Hispanics reported worse outcomes than are found nationally, and African Americans reported the worst outcomes. In a predictive structural equation model, severity of homelessness significantly predicted low birth weight and preterm births beyond its relationship with prenatal care and other risk factors.

Correlates of HIV risk-taking behaviors among African-American college students: the effect of HIV knowledge, motivation, and behavioral skills.

This study identifies theoretically based predictors of condom use in a sample of 253 sexually active African-American college students recruited from two historically African-American colleges. The Information-Motivation-Behavioral (IMB) skills model of AIDS-preventive behavior was employed to delineate the roles of HIV/AIDS knowledge, experiences with and attitudes toward condom use, peer influences, perceived vulnerability, monogamy, and behavioral skills. A predictive structural equation model revealed significant predictors of more condom use including: male gender, more sexual HIV knowledge, positive experiences and attitudes about condom use, nonmonogamy, and greater behavioral skills. Results imply that attention to behavioral skills for negotiating safer sex and training in the proper use of condoms are key elements in reducing high risk behaviors. Increasing the specific knowledge level of college students regarding the subtleties of sexual transmission of HIV is important and should be addressed. Heightening students' awareness of the limited protection of serial monogamy, and the need to address gender-specific training regarding required behavior change to reduce transmission of HIV should be an additional goal of college health professionals.

Burnout in substance abuse counselors. Impact of environment, attitudes, and clients with HIV.

Due to associations between acquired immunodeficiency sydnrome (AIDS) and substance abuse, many substance abuse treatment counselors have clients with human immunodeficiency virus (HIV)/AIDS. We assess the contribution of various hypothesized predictors of burnout among 134 substance abuse counselors working with clients with HIV/AIDS. Counselors reported practice-related variables, including support from coworkers and supervisors, caseload, percentage of HIV-positive clients, and whether they worked at a methadone clinic, and personal characteristics of job efficacy and education. The three burnout dimensions were emotional exhaustion, depersonalization, and personal accomplishment. Emotional exhaustion was significantly predicted by less support, less efficacy, and working in a methadone clinic. Depersonalization was predicted by less efficacy, less support, and working in a methadone clinic. Personal accomplishment was predicted by having a lower percentage of clients with HIV/AIDS, and more efficacy, support, and education. We present empirically based suggestions for interventions that can prevent or limit burnout.

Gender differences in behavioural and psychosocial predictors of HIV testing and return for test results in a high-risk population.

We assessed gender differences in psychosocial and behavioural predictors of HIV testing and returning for results in a high-risk sample of 1,049 predominately minority, impoverished, homeless and/or drug-abusing women (n = 621) and men (n = 428). Predictors included latent variables representing injection drug use, self-esteem, social support, AIDS knowledge, poor access to health services, perceived risk for AIDS, sexual risk behaviour and the mediators of positive and negative coping styles. Significant predictors of test and return for women included injection drug use, greater social support, more AIDS knowledge, a higher perceived risk for AIDS and a positive coping style. Significant predictors for the men included injection drug use, greater AIDS knowledge, a higher perceived risk for AIDS and a positive coping style. Although greater social support was not significant for the men, the significant predictors of HIV testing and return were generally similar for the men and women. However, the men evaluated their risk of AIDS significantly lower than the women, although they reported more sexual risk behaviours and equally risky injection drug use behaviours. Results suggest that interventions designed to increase AIDS knowledge, to raise the perception of risk and to promote a positive coping style would be effective in encouraging more HIV testing for both men and women, but raising perceptions of what constitutes personal risk behaviours may need special emphasis when delivering prevention programmes to men.

A latent variable analysis of coexisting emotional deficits in substance abusers: alexithymia, hostility, and PTSD.

The emotional disturbance of substance abusers is often described as an inability to identify and express feelings coupled with an excess vulnerability to experience negative affect. However, there is only limited empirical support for this perspective. To validate this description, we first defined components of alexithymia, hostility, and posttraumatic stress disorder (PTSD) derived from established measures of each by conducting confirmatory factor analyses based on a self-report data set from a clinical sample of 253 alcoholics and drug addicts. We then fashioned and tested overarching latent variables representing the three aspects of emotional dysfunction (i.e., alexithymia, hostility, and PTSD) and finally tested the correlations among these overarching variables. We found a strong association between a factor labeled Bottled-Up Emotions and another labeled Neurotic Hostility (r = .62) as well as an association between PTSD and Bottled-Up Emotions (r = .66). The structure, magnitude, and intercorrelation of the latent variables did not depend on the type of psychoactive substance abused. These results support the view that features of alexithymia and hostility coexist in substance abusers and that this joint deficit is part of a broad disturbance across multiple psychological domains including pathological response to traumatic stress.

Personal, cognitive, behavioral, and demographic predictors of HIV testing and STDs in homeless women.

Using a multiracial sample of 621 homeless women, we tested a latent variable causal model of personal, cognitive, behavioral, and demographic predictors of two coping mediators and the outcome variables of HIV testing and return for test results and a recent STD infection. HIV testing and return were predicted by more social support, greater AIDS knowledge, greater perceived risk for AIDS, and more problem-focused coping strategies. Recent STDs were predicted by more AIDS knowledge, emotion-focused coping strategies, and risky sexual behavior and one measured variable, crack cocaine use. Emotion-focused coping strategies were predicted by drug use, less self-esteem, more social support, and greater perceived risk for AIDS. Hispanics reported less emotion-focused coping strategies than African-Americans. Predictors of problem-focused coping strategies included less drug use, more self-esteem, more social support, more AIDS knowledge, and less risky sexual behavior. African-Americans reported less problem-focused coping strategies than Latinas. Indirect effects on the outcomes mediated through coping styles are also reported. Theoretical and practical implications of results for community outreach are discussed.

Predicting health services utilization among homeless adults: a prospective analysis.

This study expands on the Andersen-Newman health services utilization (HSU) model. In a community-based homeless sample (n = 363) baseline predisposing, enabling, and needs-based variables predicted hospitalization and ambulatory outpatient service utilization within 1 year after baseline. Standard predisposing and enabling variables were supplemented with latent constructs representing substance use, mental illness, poor housing status, social support, community support, and barriers to health care. Need is represented by baseline health status. Poor physical health, more barriers, drug use, African American ethnicity, less community support, and less education predicted hospitalization, the least desirable form of HSU. Poor health, female gender, a regular source of care, community support, drug use, and fewer alcohol problems predicted an office visit. Because outpatient visits for acute conditions provide an opportunity for generally neglected preventive services and health screenings, this study suggests convenient multiservice health-related programs for the homeless that include drug and alcohol treatment.

"Reactive filtration": use of functionalized porous polymer monoliths as scavengers in solution-phase synthesis.

[reaction: see text] Solid functionalized porous monolithic disks with reactive polymer chains grafted to their inner pore surface have been developed for scavenging excess reagents from reaction mixtures. A poly(chloromethylstyrene-co-divinylbenzene) monolith was cut into disks and activated by graft polymerizing 4-vinyl-2,2-dimethylazlactone to its pore surface. In contrast to the direct copolymerization of reactive monomers, grafting increases the accessibility of the reactive groups. Application of the reactive disks is demonstrated in the scavenging of excess amines from reaction mixtures in different solvents.