Taste-sickness associations in young rats over varying delays,stimulus, and test conditions

We showed, as had previous investigators, that young rats formed taste-sickness associations that were weaker than those of mature rats; associations were not formed over a delay greater than 45 min, and aversions did not survive a 60-min test session. The difficulty young rats had withholding consumption and their poor sensitivity to taste and sickness contributed to the weak aversions. Choice tests revealed aversions that had apparently extinguished during a no-choice test, and animals that were allowed to mature prior to the first test readily withheld consumption for 60 min. Furthermore, young rats formed an aversion over a delay of 2.5 h when the concentrations of saccharin and lithium chloride were increased. Aversions to the stronger saccharin did not extinguish over two one-bottle tests and were retained for 52 days.     

Children's understanding of their research rights before and after debriefing: informed assent, confidentiality, and stopping participation

This study explored children's understanding of their research rights in the context of an investigation of how children cope with peer provocation. Participants were 178 children (97 girls and 81 boys) who had finished the second, fourth, and sixth grades (average ages: 8, 10, and 12, respectively). After children agreed to take part in research on "how kids get along together," as well as after debriefing, their perceptions of free assent, their understanding of what they would be doing and why, their belief in voluntary participation and freedom to withdraw, and their comprehension of confidentiality were assessed. The vast majority of participants gave assent freely and reported no undue pressure from their families or the experimenters to participate. Older children knew before participating in the research what their participation would involve, comprehended confidentiality, and understood the study's purpose after their participation, but second graders were less likely to understand these issues than fourth and sixth graders were. Following debriefing, children's understanding of their research rights was largely unchanged; most children still had difficulty describing the research goals.     

Effect of Oestrogen on Altering the Serum and Urinary Levels of Calcium,Phosphate and Magnesium in Hysterectomised Women Compared to Natural Menopausal South Indian Women: A Case Control Study

Given the paucity of studies conducted to know the effect of suddenness and earlier onset of endocrinological changes associated with hysterectomy, on the serum and urinary levels of calcium, magnesium and phosphate the present study was conducted to compare the levels of calcium, magnesium and phosphate in serum and urine of hysterectomised and natural menopausal south Indian women. This is a cross-sectional observational study. The study included three groups of 30 healthy premenopausal, 30 early surgical menopausal and 30 natural post menopausal women. Women suffering from any endocrine disease were excluded. Analysis was performed in serum and urine sample. The levels of calcium, magnesium and phosphate in serum and calcium/creatinine, magnesium/creatinine and phosphate/creatinine ratio were estimated in urine by spectrophotometric method. Hysterectomised women (serum calcium: 8.7 ± 0.09 mg/dl; urine calcium/creatinine: 0.16 ± 0.02) have significantly low serum calcium (p < 0.001) and high urinary calcium/creatinine (p = 0.002) ratio and post menopausal women (serum magnesium: 2.1 ± 0.03; serum phosphate: 4.4 ± 0.16; urinary calcium/creatinine: 0.17 ± 0.02; urinary magnesium/creatinine: 0.09 ± 0.01) have significantly high serum magnesium (p = 0.016), serum phosphate (p = 0.043) and high urinary calcium/creatinine (p = 0.002), magnesium/creatinine ratio (p = 0.025) compared to healthy pre menopausal women. Post menopausal women (serum calcium: 9.1 ± 0.08) have significantly high serum calcium and phosphate compared to hysterectomised women (serum phosphate: 3.93 ± 0.11). Hysterectomised women have significantly low serum calcium, oestrogen and high urinary calcium/creatinine ratio compared to healthy premenopausal women and low serum calcium and low serum phosphate compared to natural postmenopausal women. Natural postmenopausal women had low serum oestrogen and high serum magnesium, serum phosphate, urinary calcium creatinine ratio and urinary magnesium creatinine ratio compared to healthy premenopausal women.     

The DT-Polynomial Approach to Discrete Time-Varying Network Flow Problems

This paper introduces a polynomial operator called the DT-polynomial as a novel approach to network flow problems. The class of networks dealt with is time-varying in the sense that the capacity, cost, and travel-time of each edge may vary in discrete time. The Dt-polynomial is a polynomial in two operators, D (delay) and T (time), which is used for describing the time-varying transmission characteristics. The paper starts with the mathematics involving the DT-polynomials. A new shortest arrival route algorithm is presented, and its computational complexity is found to be favorable in comparison with others such as Dijkstra's method and the potential method derived from Ford-Fulkerson's technique. Furthermore, a dynamic flow problem is formulated and analyzed in terms of DT-polynomials, and a latest-departure earliest-arrival schedule is given. Finally, a modified DT-polynomial is applied to digital filter networks.     

Psychosocial correlates of child abuse potential in multiply disadvantaged adolescent mothers

OBJECTIVE: This study had two aims: First to examine psychosocial correlates of child maltreatment risk, and second to assess the validity of the CAP Inventory (Milner, 1986) with multiply disadvantaged teenage mothers. METHOD: Participants were 75 adolescent mothers who were wards of the Illinois child protection system. Mothers (aged 14-18) and infants participated in home-based psychosocial assessment of personal and parenting functioning. Group comparisons examined differences for mothers with elevated versus normal versus invalid CAP scores due to faking good. RESULTS: Findings indicated that abuse risk groups differed on emotional distress, social support satisfaction, reading achievement, and years of education, but not on parenting beliefs or quality of child stimulation. Differences favored the normal over the elevated risk group in all significant comparisons, whereas mothers with elevated faking good differed from normals only in lower reading achievement. Multiple regression analysis highlighted emotional distress, support dissatisfaction, and low achievement as significant predictors of greater abuse risk. CONCLUSIONS: Despite sharing multiple disadvantages, adolescent wards are a heterogeneous group who show different levels of psychosocial functioning corresponding to levels of child maltreatment risk. The findings provide support for the concurrent validity and clinical applicability of the CAP Inventory with disadvantaged teenage mothers.     

A follow-up study of recent special education graduates of learning disabilities programs

This study investigated the postschool vocational and community adjustment of recent special education graduates from a southwestern metropolitan school district. Sixty-four students with learning disabilities (LD) who had attended self-contained classes at 12 high schools were randomly selected. A questionnaire, administered either via the telephone or in person, was the source of data. Thirty-eight of the LD sample were in competitive employment. In general, the LD students received very few community services. For the most part, they received no agency support after graduation. Most of the LD subjects lived with parents or other relatives and most had a driver's license and car. Implications for postsecondary services and future research are discussed.     

Effects of a prenatal care intervention on the self-concept and self-efficacy of adolescent mothers

The objective of this study was to examine changes in self-concept and self-efficacy during the childbearing year among adolescent mothers (defined as young mothers up to age 20) who were involved in a behavioral intervention. Subjects included a sample of 282 urban, pregnant adolescents (94% African American, 4% white, 2% other). The Tennessee Self-Concept Scale (TSCS) was used to measure self-concept. A scale to measure the self-efficacy of the adolescent mother during the childbearing year was developed and evaluated. Questionnaires were administered during intake for prenatal care and in the postpartum period. In the larger study, the intervention was a peer-centered, mastery modeling intervention designed to increase self-efficacy, improve self-concept, and improve long- and short-term perinatal outcomes. The results in this portion of the data showed that self-concept increased significantly for young women in the experimental group but did not change significantly for young women in the control group. Changes were noted in the TSCS for overall self-concept as well as for several subscores, including identity, self-satisfaction, behavior, the personal self, the family self, and the social self. However, differences between groups did not reach significance once age, parity, site, and time were accounted for, except on TSCS subscales of identity and personal self. Between intake for prenatal care and postpartum, self-efficacy changed significantly for both the experimental and the control groups. Both groups increased in self-efficacy for labor and delivery and decreased in self-efficacy for infant care. In this group of mostly African American teens, peer support and small group care demonstrated positive effects on self-concept. Professional and peer interactions were equally associated in intervention and nonintervention groups with regard to self-efficacy.