Neighborhood risk factors for low birthweight in Baltimore: a multilevel analysis

OBJECTIVES

Past research on low birthweight has focused on individual-level risk factors. We sought to assess the contribution of macrolevel social factors by using census tract-level data on social stratification, community empowerment, and environmental stressors.

METHODS

Census tract-level information on social risk was linked to birth certificate records from Baltimore, Md, for the period 1985 through 1989. Individual level factors included maternal education, maternal age, medical assistance health insurance (Medicaid), and trimester of prenatal care initiation. Methods of multilevel modeling using two-stage regression analyses were employed.

RESULTS

Macrolevel factors had both direct associations and interactions with low birthweight. All individual risk factors showed interaction with macrolevel variables; that is, individual-level risk factors for low birthweight behaved differently depending upon the characteristics of the neighborhood of residence. For example, women living in high-risk neighborhoods benefited less from prenatal care than did women living in lower-risk neighborhoods.

CONCLUSIONS

Multilevel modeling is an important tool that allows simultaneous study of macro- and individual-level risk factors. Multilevel analyses should play a larger role in the formulation of public health policies.

Prostatic-specific antigen: an immunohistologic marker for prostatic neoplasms

Antiserum to a human prostate-specific antigen was raised in a rabbit and utilized by immunoperoxidase staining to evaluate its potential value as a diagnostic histologic marker for tumors of prostatic origin. All primary and metastatic prostatic malignancies reacted positively, whereas nonprostatic neoplasms did not stain with this procedure. This is the first immunohistochemical marker for prostate gland epithelium which does not represent prostatic acid phosphatase.

Socioeconomic and food-related physical characteristics of the neighbourhood environment are associated with body mass index

OBJECTIVE

To determine whether socioeconomic and food-related physical characteristics of the neighbourhood are associated with body mass index (BMI; kg/m(2)) independently of individual-level sociodemographic and behavioural characteristics.

DESIGN AND METHODS

Observational study using (1) individual-level data previously gathered in five cross-sectional surveys conducted by the Stanford Heart Disease Prevention Program between 1979 and 1990 and (2) neighbourhood-level data from (a) the census to describe socioeconomic characteristics and (b) data obtained from government and commercial sources to describe exposure to different types of retail food stores as measured by store proximity, and count of stores per square mile. Data were analysed using multilevel modelling procedures. The setting was 82 neighbourhoods in agricultural regions of California.

PARTICIPANTS

7595 adults, aged 25-74 years.

RESULTS

After adjusting for age, gender, ethnicity, individual-level socioeconomic status, smoking, physical activity and nutrition knowledge, it was found that (1) adults who lived in low socioeconomic neighbourhoods had a higher mean BMI than adults who lived in high socioeconomic neighbourhoods; (2) higher neighbourhood density of small grocery stores was associated with higher BMI among women; and (3) closer proximity to chain supermarkets was associated with higher BMI among women.

CONCLUSION

Living in low socioeconomic neighbourhoods, and in environments where healthy food is not readily available, is found to be associated with increased obesity risk. Unlike other studies which examined populations in other parts of the US, a positive association between living close to supermarkets and reduced obesity risk was not found in this study. A better understanding of the mechanisms by which neighbourhood physical characteristics influence obesity risk is needed.

Prostate antigen: a new potential marker for prostatic cancer

A prostate-specific antigen, distinct from acid phosphatase, was identified by immunologic procedures in prostate tissues (normal, benign hypertrophic, and cancerous) and seminal plasma, as well as in sera of patients with prostatic cancer and of nude mice bearing human prostatic tumor. This antigen was shown by immunoperoxidase staining to be confined to epithelial cells comprising the prostatic ductal elements. Prostate antigen was purified from prostatic tissue and seminal plasma, and it was shown to have a molecular weight of 33,000-34,000 with no subunit component. The isoelectric point of purified antigen was around 6.9, though several unpurified isomers with different isoelectric points also were observed. Serum-borne prostate antigen showed a molecular weight of 90,000-100,000 but it exhibited a molecular weight of 36,000 in the presence of sodium dodecyl sulfate. A sandwich-type, peroxidase-linked immunosorbent assay capable of detecting 0.1 ng of the antigen per milliliter of blood was developed. With this technique, serum level of the antigen was found to increase in patients with prostatic cancer as compared with normal males. The prostate-specific antigen can be a useful marker for detection of prostatic cancer.

The relative contributions of lean tissue mass and fat mass to bone density in young women

Although obesity is associated with increased risk of many chronic diseases including cardiovascular disease, diabetes, hypertension, and cancer, there is little evidence to suggest that obesity increases risk of osteoporosis. In fact, both weight and body mass index (BMI) are positive predictors of bone mass in adults, suggesting that those who are overweight or obese may be at lower risk of osteoporosis. However, recent evidence suggests that in children and adolescents, obesity may be associated with lower rather than higher bone mass. To understand the relation of fat mass to bone mass, we examined data gathered from an ethnically diverse group of 921 young women, aged 20-25 years (317 African Americans, 154 Asians, 322 Caucasians, and 128 Latinas) to determine how fat mass (FM) as well as lean tissue mass (LTM) is associated with bone mass. Bone mass, FM, and LTM were measured using dual energy X-ray absorptiometry (GE Lunar Corp, Madison, WI). Bone mass was expressed as bone mineral density (BMD; g/cm2) and bone mineral apparent density (BMAD; g/cm3) for the spine and femoral neck, and as BMD and bone mineral content (BMC; g) for the whole body. Regression techniques were used to examine the following: (1) in separate equations, the associations of LTM and FM with each bone mass parameter; and (2) in the same equation, the independent contributions of LTM and FM to bone mass. LTM and FM were positively correlated with BMD at all skeletal sites. When the contributions of FM and LTM were examined simultaneously, both FM and LTM continued to be positively associated with bone mass parameters but the effect of FM was noted to be smaller than that of LTM. We conclude that in young women, LTM has a greater effect than fat mass on bone density per kg of tissue mass.

Violence by male partners against women during the childbearing year: a contextual analysis

OBJECTIVES

Many contextual analyses that bridge the micro-level-macro-level gap in identifying risk factors for adverse outcomes have not used methods appropriate for multilevel data. The purpose of this paper is to illustrate the application of appropriate multi-level analytic methods and discuss their implications for public health.

METHODS

A previously published individual-level model of physical violence perpetrated by male partners during the childbearing year was reanalyzed to include variables describing the neighborhoods where the women resided. Logistic regression with estimation methods of the generalized estimating equation was used for the contextual analysis. To assess the advantages of the generalized estimating equation over conventional logistic regression, both were used for the two-level model.

RESULTS

The regression coefficients from the contextual model differed from the betas obtained in the individual-level model. Not only were neighborhood-level variables related to the risk of partner-perpetrated violence, but the presence of these macro-level variables in the models modified the relationships of the individual-level variables to the risk of violence.

CONCLUSIONS

Two-level models that include individual- and community-level factors may be beneficial for purposes of explanation in public health research.

Low prevalence of neurological and neuropsychological abnormalities in otherwise healthy HIV-1-infected individuals: results from the multicenter AIDS Cohort Study

Accurate description of the prevalence of neurological impairment in healthy individuals who are infected with human immunodeficiency virus type 1 (HIV-1) has relevance for public health policy, for employment issues, and for planning future health needs. Within the Multicenter AIDS Cohort Study, we determined the cross-sectional prevalence of neurological abnormalities in 270 HIV-1 seropositive homosexual and bisexual men in Centers for Disease Control Groups II and III, using a control group of 193 HIV-1 seronegative homosexual men. Utilizing a neurological and neuropsychological screening battery, we found no differences in the prevalence of neuropsychiatric symptoms or in neuropsychological performance. One hundred nineteen subjects with abnormalities on screening tests completed additional neuropsychological testing and had neurological examinations. The majority had normal results and the frequency of neurological abnormalities and impaired neuropsychological performance was not significantly increased among HIV-1 seropositive subjects. Most of the abnormalities could be attributed to causes other than HIV-1. One subject had mild HIV-1-related dementia, yielding a prevalence of 3.7:1,000 (95% confidence interval: 0.19-23.7:1,000). Magnetic resonance imaging demonstrated sulcal prominence and focal areas of high signal intensity in white matter in 63% of HIV-1 seropositive subjects and 48% of uninfected control subjects. Abnormalities in cerebrospinal fluid were noted in 23 (85%) of 27 HIV-1-infected individuals. Our studies indicate that the prevalence of dementia and other HIV-1-related neurological disorders is very low among healthy HIV-1 seropositive homosexual men. The confounding effects of factors such as substance abuse or preexisting medical conditions must be considered in the neurological evaluation of such patients.

Efficacy of relapse prevention: a meta-analytic review

Although relapse prevention (RP) has become a widely adopted cognitive-behavioral treatment intervention for alcohol, smoking, and other substance use, outcome studies have yielded an inconsistent picture of the efficacy of this approach or conditions for maximal effectiveness. A meta-analysis was performed to evaluate the overall effectiveness of RP and the extent to which certain variables may relate to treatment outcome. Twenty-six published and unpublished studies with 70 hypothesis tests representing a sample of 9,504 participants were included in the analysis. Results indicated that RP was generally effective, particularly for alcohol problems. Additionally, outcome was moderated by several variables. Specifically, RP was most effective when applied to alcohol or polysubstance use disorders, combined with the adjunctive use of medication, and when evaluated immediately following treatment using uncontrolled pre-post tests.

Intersection of Living in a Rural Versus Urban Area and Race/Ethnicity in Explaining Access to Health Care in the United States

OBJECTIVES

To examine whether living in a rural versus urban area differentially exposes populations to social conditions associated with disparities in access to health care.

METHODS

We linked Medical Expenditure Panel Survey (2005-2010) data to geographic data from the American Community Survey (2005-2009) and Area Health Resource File (2010). We categorized census tracts as rural and urban by using the Rural-Urban Commuting Area Codes. Respondent sample sizes ranged from 49 839 to 105 306. Outcomes were access to a usual source of health care, cholesterol screening, cervical screening, dental visit within recommended intervals, and health care needs met.

RESULTS

African Americans in rural areas had lower odds of cholesterol screening (odds ratio[OR] = 0.37; 95% confidence interval[CI] = 0.25, 0.57) and cervical screening (OR = 0.48; 95% CI = 0.29, 0.80) than African Americans in urban areas. Whites had fewer screenings and dental visits in rural versus urban areas. There were mixed results for which racial/ethnic group had better access.

CONCLUSIONS

Rural status confers additional disadvantage for most of the health care use measures, independently of poverty and health care supply.

Acquired immunodeficiency syndrome (AIDS)-free time after human immunodeficiency virus type 1 (HIV-1) seroconversion in homosexual men. Multicenter AIDS Cohort Study Group

To estimate the time interval between human immunodeficiency virus type 1 (HIV-1) seroconversion and acquired immunodeficiency syndrome (AIDS) diagnosis in homosexual men, prospective incident cohorts are difficult to obtain and, if assembled, provide few events owing to the long incubation time. Although seroprevalent cohorts are numerous in size and events, the information is limited due to the unknown times since seroconversion. To combine the information provided by 1,628 seroprevalent men (304 AIDS cases) and 233 seroconverters (12 AIDS cases) being followed in a multicenter study since 1984, the postseroconversion changes in hematologic variables occurring in the incident cohort were used to develop a model that allowed for the imputation of the unknown times since seroconversion for the seroprevalent cohort. Nonparametric life table methods incorporating truncation and censoring were applied for the estimation of the probability distribution of the AIDS-free time after seroconversion. The precision of the estimates was evaluated using bootstrap methods. The analysis suggested that AIDS is unlikely (less than 0.5%) in the first year; 78% of seropositive homosexual men remain AIDS-free 60 months after seroconversion; and the AIDS incidence increases for months 12-36 and levels off at 38 per 1,000 person-semesters for months 42-60. The nonparametric estimate of the incidence rate suggests a median AIDS-free time of 11 years, which is longer than previous estimates based on parametric models.

Ethnic issues in the epidemiology of childhood obesity

Childhood obesity may be seen as a marker for high-risk dietary and physical inactivity practices. Recent increases in the prevalence of overweight and obesity among American children are not limited to one age, gender, or ethnic group, which suggests that unique behaviors of the members of various racial or ethnic subgroups of the population are unlikely to be the major contributing factors. Rather, it seems that environmental changes promoting increased energy intake and decreased energy output are occurring and have widespread impact on children from various backgrounds. Although no ethnic group is immune from the current shift in energy balance, differential rates of overweight seem to exist among ethnic groups. National probability samples of African-American, Hispanic, and white children in the United States provide clear evidence that white children are at lower risk for childhood overweight than are African-American or Hispanic children. Of concern is the lack of national data on the prevalence of overweight and obesity for Native-American and Asian-American groups. Also of concern is the aggregation of racial and ethnic subgroups, which may render prevalence rates meaningless. This possibility is clearly true with some surveys of weight status that combine diverse populations, such as Asians and Pacific Islanders, into one group. The high rates of obesity in African-American, Hispanic, and Native-American children are of concern. Although parental SES is associated inversely with childhood obesity among whites, higher SES does not seem to protect African-American and Hispanic children against obesity. In these groups, childhood obesity does not seem to be associated significantly with parental income and education. Health consequences of childhood obesity include a higher prevalence of type 2 diabetes and an increased risk for adverse levels of lipids, lipoproteins, and blood pressure. The effects of recently reported unprecedented levels of childhood overweight on subsequent risk for obesity in middle age are not known until future longitudinal data can be collected. It seems likely, however, that future health consequences of current early and severe childhood obesity will be staggering. Funding for adult follow-up of longitudinal studies of high-risk African American, Hispanic, and Native-American children is needed urgently to provide information on the long-term effects of childhood obesity. Halting the obesity epidemic is a formidable task, but the success in recent decades of drastically reducing childhood undernutrition offers hope and should spur similar action and leadership efforts. Promotion of efforts to reduce excess caloric intake with efforts to increase energy expenditure should receive paramount attention in the design of health programs. Given the relatively few published obesity-prevention and treatment studies that are designed to address specific cultural issues, it is important to promote the development of culturally appropriate intervention strategies that are shown to be effective among youth of diverse backgrounds. Although the dietary and activity goals will be similar, parental, family, and community messages and techniques grounded in cultural traditions and norms will be different for each ethnic group. This approach is crucial in the United States, a country with an increasingly diverse population.

Removal of some metal ions by activated carbon prepared from Phaseolus aureus hulls

Removal of lead [Pb(II)], zinc [Zn(II)], copper [Cu(II)], and cadmium [Cd(II)] from aqueous solutions using activated carbon prepared from Phaseolus aureus hulls (ACPAH), an agricultural waste was studied. The influence of various parameters such as effect of pH, contact time, adsorbent dose, and initial concentration of metal ions on the removal was evaluated by batch method. The removal of metal ions by ACPAH was pH dependent and the optimum pH values were 7.0, 8.0, 7.0 and 6.0 for Cu(II), Cd(II), Zn(II), and Pb(II), respectively. The sorption isotherms were studied using Langmuir, Freundlich, Dubinin-Radushkevich (D-R), and Temkin isotherm models. The maximum adsorption capacity values of ACPAH for metal ions were 21.8 mg g(-1) for Pb(II), 21.2 mg g(-1) for Zn(II), 19.5 mg g(-1) for Cu(II), and 15.7 mg g(-1) for Cd(II). The experiments demonstrated that the removal of metal ions followed the pseudo-second-order kinetic model. Desorption experiments were carried out using HCl solution with a view to regenerate the spent adsorbent and to recover the adsorbed metal ions.

Prenatal factors associated with breastfeeding duration: recommendations for prenatal interventions

This study of 198 urban breastfeeding women examined the psychosocial, demographic, and medical factors identified prenatally that may be associated with longer breastfeeding duration and may serve as suitable areas for prenatal breastfeeding promotion interventions. Of 11 psychosocial and demographic factors examined, 5 were important influences on breastfeeding duration: anticipated length of breastfeeding, normative beliefs, maternal confidence, social learning, and behavioral beliefs about breastfeeding. Methods of multivariate linear regression were used to identify prenatal factors that influenced anticipated length. Of the 10 factors entered into the regression model, parity, plans to return to work or school by six months postpartum, and maternal confidence were the most significant factors affecting anticipated length of breastfeeding. Our data suggest several factors amenable to intervention during the prenatal period that appear to influence breastfeeding duration. Prenatal promotion efforts could easily incorporate strategies that influence factors such as normative and behavioral beliefs and maternal confidence.

Bone acquisition and loss in children and adults with cystic fibrosis: a longitudinal study

OBJECTIVES

To determine patterns of bone mineral acquisition in children and young adults with cystic fibrosis (CF) and to identify clinical and laboratory correlates of change in bone mineral density (BMD).

STUDY DESIGN

Bone mineral and clinical status were assessed in 41 patients with CF (26 female, aged 9 to 50 years) at baseline and 1.5 years later. Bone mineral content of the lumber spine, femoral neck, and whole body was determined by dual-energy x-ray absorptiometry and expressed as BMD and bone mineral apparent density (BMAD). Changes in weight, height, pubertal status, glucocorticoid use, physical activity, disease severity, and biochemical markers of bone turnover were examined for associations with changes BMD and BMAD.

RESULTS

Mean BMD Z-scores (adjusted for age and sex) were reduced at the spine, hip, and whole body at baseline in both adults and youths, and decreased further at all sites among youths at follow-up (-0.4 at spine, p < 0.05; -0.3 at hip, p < 0.10; -0.5 for whole body, p < 0.0005). These data indicate failure to gain bone mineral at the expected rate. BMAD was also reduced at follow-up, suggesting that the observed osteopenia could not be explained by small bone size. Bone loss at multiple sites was observed in four youths and two adults. In general glucocorticoid use, change in body mass, physical activity, and disease severity were the most significant correlates for change in BMD and in BMD Z-score.

CONCLUSIONS

Osteopenia in CF generally reflects inadequate gains in bone mineral, although bone loss may occur, particularly in patients requiring glucoc therapy. Late gains in bone mineral may accompany weight gain and pubertal development, but the catch-up appears to be incomplete.

Preparation and use of fibrin glue in surgery

Fibrin glue (FG) is used to control bleeding, to adhere tissues together, and to seal tissue defects. FG is prepared from platelet-rich plasma or by mixing concentrated fibrinogen solutions with thrombin. Concentrated fibrinogen solutions are produced by cryoprecipitation or by chemical precipitation of plasma. The literature on FG preparation is reviewed in order to compare the advantages and disadvantages of the different products reported and to summarize the clinical applications. It is concluded that additional studies are needed to fully evaluate the advantages and disadvantages of fibrinogen concentrated using cryoprecipitation and chemical precipitation and that specific advantages exist for use of both pooled homologous and autologous blood.

Bone mineral acquisition in healthy Asian, Hispanic, black, and Caucasian youth: a longitudinal study

Ethnic and gender differences in bone mineral acquisition were examined in a longitudinal study of 423 healthy Asian, black, Hispanic, and white males and females (aged 9-25 yr). Bone mass of the spine, femoral neck, total hip, and whole body was measured annually for up to 4 yr by dual energy x-ray absorptiometry. Age-adjusted mean bone mineral curves for areal (BMD) and volumetric (BMAD) bone mineral density were compared for the 4 ethnic groups. Consistent differences in areal and volumetric bone density were observed only between black and nonblack subjects. Among females, blacks had greater mean levels of BMD and BMAD at all skeletal sites. Differences among Asians, Hispanics, and white females were significant for femoral neck BMD, whole body BMD, and whole body bone mineral content/height ratio, for which Asians had significantly lower values; femoral neck BMAD in Asian and white females was lower than that in Hispanics. Like the females, black males had consistently greater mean values than nonblacks for all BMD and BMAD measurements. A few differences were also observed among nonblack male subjects. Whites had greater mean total hip BMD, whole body BMD, and whole body bone mineral content/height ratio than Asian and Hispanic males; Hispanics had lower spine BMD than white and Asian males. The tempo of gains in BMD varied by gender and skeletal site. In females, total hip, spine, and whole body BMD reached a plateau at 14.1, 15.7, and 16.4 yr, respectively. For males, gains in BMD leveled off at 15.7 yr for total hip and at age 17.6 yr for spine and whole body. Black and Asian females and Asian males tended to reach a plateau in BMD earlier than the other ethnic groups. The use of gender- and ethnic-specific standards is recommended when interpreting pediatric bone densitometry data.

Differences in bone mineral in young Asian and Caucasian Americans may reflect differences in bone size

Bone mineral content (BMC) and areal bone mineral density (BMD) have been reported to be lower in Asian than in Caucasian adults. To determine if racial differences in bone mass are present in younger subjects and whether they reflect differences in estimated volumetric bone density or in bone size, we compared measurements of bone mineral in healthy young Asian- and Caucasian-American males and females. Bone mineral was measured at the lumbar spine (L2-L4), femoral neck (FN), and whole body (WB) by dual-energy X-ray absorptiometry (DXA) in 99 Asians (49 females, 50 males) and 103 Caucasians (54 females, 49 males) ages 9-26 years. Results were expressed as BMC, BMD, and apparent density (BMAD), an estimate of volumetric bone density that reduces the effect of bone size. Subjects were compared on the basis of chronological age as well as by Tanner stage to correct for potential differences in the timing of puberty. Habitual dietary intake and physical activity were also assessed and correlated with bone mineral. The Asian and Caucasian cohorts differed in body size, diet, and physical activity. Asian females were shorter than the Caucasian females at all stages of puberty and weighed less at pre-/early puberty (p < 0.05). Asian males were older than Caucasians at midpuberty (p < 0.01) and weighed less than the Caucasian males at pubertal maturity (p = 0.001). Asian youths also consumed less calcium and reported less weight-bearing activity. Racial differences were most apparent when comparing BMC data. Asian males had greater spine BMC at midpuberty and lower WB BMC at maturity (p < 0.05). Asian females had lower FN BMC through midpuberty and lower WB BMC in pre-/early puberty (p < 0.05). WB BMD and WB BMC/height values were significantly lower in mature Asian versus Caucasian males. No significant racial differences in BMAD were observed. Multivariate regression analysis indicated that the differences in BMD and BMAD between Asian and Caucasian subjects were largely attributable to differences in weight and pubertal stage, and, at the FN, in weight-bearing activity. Further, the explanatory variables were less strongly associated with BMAD than with BMD. In summary, no significant differences in BMD were found between Asian and Caucasian youths through midpuberty; however, WB BMD and WB BMC/height values were lower in Asian males at sexual maturity. We conclude that observed differences in bone mineral between Asians and Caucasians may be partially attributed to the smaller bone size of Asians.

Bone mass and hip axis length in healthy Asian, black, Hispanic, and white American youths

The primary objective of this study was to examine the associations of ethnicity, diet (calcium, protein, energy), and weight-bearing activity with dual-energy X-ray absorptiometry (DXA)-measured bone mass and hip axis length (HAL) in 423 Asians, blacks, Hispanics, and non-Hispanic Caucasians, aged 9-25 years. Bone mass was expressed as bone mineral content (BMC), bone mineral density (BMD), and bone mineral apparent density (BMAD). The data were analyzed using multiple linear regression, after stratifying for gender and pubertal stage and adjusting for height and weight. With few exceptions, Asians and Hispanics had comparable bone mass to whites at all pubertal stages. Greater femoral neck BMAD in black than white females was observed at all pubertal stages. Black males displayed greater BMD and BMAD than white males at all sites in early puberty and at the femoral neck in maturity. Calcium was positively and protein negatively related to BMAD at the femoral neck in early pubertal females. Among males, calcium was negatively associated with whole body BMC and BMD and spine BMD and BMAD in midpuberty. Weight-bearing activity was not associated with bone mass in females; in males, it was positively related only to femoral neck BMC in early puberty. There was an absence of evidence for ethnic differences in HAL among females. In males, we observed shorter HAL in mature Asians and blacks than whites. Neither diet nor activity was associated with HAL.

Collagen fibres with improved strength for the repair of soft tissue injuries

Our laboratory has developed a process for self-assembly of high strength collagen fibres in vitro which exhibit the characteristic D period. These fibres can be cross-linked by severe dehydration (dehydrothermal cross-linking) at elevated temperature and formulated into devices used to repair soft tissues. This study was conducted to evaluate the effects of dehydrothermal cross-linking time and temperature on the tensile mechanical properties of collagen fibres. The results discussed indicate that the tensile strength of reconstituted collagen fibres is optimized by cross-linking for 5 d at 110 degrees C. Tensile strength and modulus values of 91.8 and 896 MPa are reported for fibres cross-linked in this manner. High tensile strength and modulus values are especially important in developing biodegradable materials that promote healing of orthopaedic structures.

Efficacy of relapse prevention: a meta-analytic review

Although relapse prevention (RP) has become a widely adopted cognitive-behavioral treatment intervention for alcohol, smoking, and other substance use, outcome studies have yielded an inconsistent picture of the efficacy of this approach or conditions for maximal effectiveness. A meta-analysis was performed to evaluate the overall effectiveness of RP and the extent to which certain variables may relate to treatment outcome. Twenty-six published and unpublished studies with 70 hypothesis tests representing a sample of 9,504 participants were included in the analysis. Results indicated that RP was generally effective, particularly for alcohol problems. Additionally, outcome was moderated by several variables. Specifically, RP was most effective when applied to alcohol or polysubstance use disorders, combined with the adjunctive use of medication, and when evaluated immediately following treatment using uncontrolled pre-post tests.

Task analysis in curriculum design: a hierarchically sequenced introductory mathematics curriculum

A method of systematic task analysis is applied to the problem of designing a sequence of learning objectives that will provide an optimal match for the child's natural sequence of acquisition of mathematical skills and concepts. The authors begin by proposing an operational definition of the number concept in the form of a set of behaviors which, taken together, permit the inference that the child has an abstract concept of "number". These are the "objectives" of the curriculum. Each behavior in the defining set is then subjected to an analysis that identifies hypothesized components of skilled performance and prerequisites for learning these components. On the basis of these analyses, specific sequences of learning objectives are proposed. The proposed sequences are hypothesized to be those that will best facilitate learning, by maximizing transfer from earlier to later objectives. Relevant literature on early learning and cognitive development is considered in conjunction with the analyses and the resulting sequences. The paper concludes with a discussion of the ways in which the curriculum can be implemented and studied in schools. Examples of data on individual children are presented, and the use of such data for improving the curriculum itself, as well as for examining the effects of other treatment variables, is considered.

Biosorption of Pb2+ from aqueous solutions by Moringa oleifera bark: equilibrium and kinetic studies

Biosorption of Pb(2+) from aqueous solution by biomass prepared from Moringa oleifera bark (MOB), an agricultural solid waste has been studied. Parameters that influence the biosorption such as pH, biosorbent dose, contact time and concentration of metal ion were investigated. The experimental equilibrium adsorption data were tested by four widely used two-parameter equations, the Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Temkin isotherms. Results indicated that the data of Pb(2+) adsorption onto MOB were best fit by the Freundlich model. The adsorption capacity (Q(m)) calculated from the Langmuir isotherm was 34.6mgPb(2+)g(-1) at an initial pH of 5.0. Adsorption kinetics data were analyzed using the pseudo-first-, pseudo-second-order equations and intraparticle diffusion models. The results indicated that the adsorption kinetic data were best described by pseudo-second-order model. Infrared (IR) spectral analysis revealed that the lead ions were chelated to hydroxyl and/or carboxyl functional groups present on the surface of MOB. Biosorbent was effective in removing lead in the presence of common metal ions like Na(+), K(+), Ca(2+) and Mg(2+) present in water. Desorption studies were carried out with dilute hydrochloric acid for quantitative recovery of the metal ion as well as to regenerate the adsorbent. Based on the results obtained such as good uptake capacity, rapid kinetics, and its low cost, M. oleifera bark appears to be a promising biosorbent material for the removal of heavy metal ions from wastewater/effluents.

Randomized trial of enhanced anticipatory guidance for injury prevention

OBJECTIVE

To develop and evaluate an injury prevention anticipatory guidance training program for pediatric residents.

DESIGN

Thirty-one residents were randomly assigned to an intervention or control group. Both groups attended a 1-hour seminar about injury prevention and the American Academy of Pediatrics TIPP (The Injury Prevention Program) materials. The intervention group also received 5 hours of experiential instruction on injury prevention content and counseling skills (SAFE Counseling Framework). Families with infants from birth to age 6 months were enrolled in the study (N = 196); they were followed up until the child was aged 12 to 18 months. Data were collected by means of baseline and follow-up interviews, audiotapes of medical visits, parent exit surveys, and home observations.

SETTING

A hospital-based continuity clinic that serves families living in low-income, inner-city neighborhoods.

OUTCOMES

Physician counseling and parent satisfaction, knowledge, beliefs, and behaviors.

RESULTS

Parents seen by physicians in the intervention group received significantly more injury prevention counseling for 5 of the 6 safety practices, and they were significantly more satisfied with the help their physicians provided on safety topics. They were no less satisfied with their physicians' counseling on other anticipatory guidance topics. Parents' knowledge, beliefs, and home safety behaviors did not differ between the 2 groups.

CONCLUSIONS

The frequency and impact of pediatric counseling can be enhanced by experiential training that targets specific injury hazards. Because low-income families face many barriers to carrying out the recommended safety practices, supplemental strategies are needed to ensure safer homes.

The proteolytic activity of human prostate-specific antigen

Human prostate-specific antigen has been found to exhibit a mild activity of protease at neutral pH. This finding is based on two observations: a proteolytic activity was always associated with the antigen fractions during purification, and the proteolytic activity and the antigen were precipitated with specific antibody to the antigen. In comparison with physico-chemical and catalytic properties of known proteases, human prostate-specific antigen is a distinct neutral protease.

Complexation of arsenate with humic substance in water extract of compost

The interactions of environmental toxicants with organic substances affect the speciation and dynamics, and subsequent toxicity, mobility, and fate of toxicants in the environment. For the purpose of understanding the complexation of As(V) with humic substances, arsenate-containing solutions with As concentrations from 1 to 8 mgl(-1) were prepared to react with the water extract of compost (WEC). All the reaction systems including the control were incubated for 48 h at 25 degrees C. The complexation of As(V) with humic substance was examined by dialysis and ion exchange techniques. From 30% to 51% of added As(V) reacted with organic substance in WEC to form an As-metal-organic complex. This was verified as a hydrophobic organic fraction after separation of As-metal-organic complex fraction from the hydrophilic fraction by XAD-8 resin. The complex substance was also identified as a humic substance by the method of proton binding formation function determination. This suggests that cations, such as Ca and Mg, and especially Fe, Al, and Mn act in cation bridging in the complexation of As(V) with humic substance. The role of metals in the complexation of As(V) with humic substance in terrestrial and especially aquatic environments thus merits close attention.