The intergenerational cycle of teenage motherhood: An ecological approach.

Objective: Daughters of teenage mothers have increased risk for teenage childbearing, perpetuating intergenerational cycles. Using Ecological Systems Theory, this study prospectively examined risk factors for teenage childbearing among a national sample of adolescent girls. Design: Data came from the National Longitudinal Survey of Youth 1997. Participants (N = 1,430) were recruited in early adolescence and interviewed yearly for 6 years. Survival analysis was used to examine the rate of childbirth across the teenage years by maternal age at first birth. Hierarchical Cox regression was used to identify multivariate predictors of teenage childbearing and to test whether risk factors differed between daughters of teenage versus older mothers. Primary Outcome Measure: Age at first childbirth was based on cumulative information collected at yearly interviews. Results: Daughters of teenage mothers were 66% more likely to become teenage mothers, after accounting for other risks. Individual (school performance), family (maternal education, marital status, number of children), peer (dating history), and environmental (race, enrichment) factors predicted teenage childbearing. Risks unique to daughters of teenage mothers were deviant peer norms, low parental monitoring, Hispanic race, and poverty. Conclusion: Results support multidimensional approaches to pregnancy prevention, and targeted interventions addressing unique risk factors among daughters of teenage mothers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Socioeconomic position, health behaviors, and C-reactive protein: A moderated-mediation analysis.

Objective: We sought to understand the link between low socioeconomic position (SEP) and cardiovascular disease (CVD) by examining the association between SEP, health-related coping behaviors, and C-reactive protein (CRP), an inflammatory marker and independent risk factor for CVD, in a U.S. sample of adults. Design: We used a multiple mediation model to evaluate how these behaviors work in concert to influence CRP levels and whether these relationships were moderated by gender and race/ethnicity. Main outcome measures: CRP levels were divided into two categories: elevated CRP (3.1–10.0 mg/L) and normal CRP (≤3.0 mg/L). Results: Both poverty and low educational attainment were associated with elevated CRP, and these associations were primarily explained through higher levels of smoking and lower levels of exercise. In the education model, poor diet also emerged as a significant mediator. These behaviors accounted for 87.9% of the total effect of education on CRP and 55.8% the total effect of poverty on CRP. We also found significant moderation of these mediated effects by gender and race/ethnicity. Conclusion: These findings demonstrate the influence of socioeconomically patterned environmental constraints on individual-level health behaviors. Specifically, reducing socioeconomic inequalities may have positive effects on CVD disparities through reducing cigarette smoking and increasing vigorous exercise. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Epiphyseal distraction for bony bridges: a biomechanical and morphologic study

AT(D)PMg induces dissociation of the alpha 3 beta 3 complex of F1-ATPase from a thermophilic Bacillus strain. PS3, into the alpha 1 beta 1 heterodimers [(1991) Biochim. Biophys. Acta 1056, 279-284] but the location of the AT(D)PMg binding site responsible is not known. From the analysis of AT(D)PMg binding properties of the isolated mutant beta subunit, beta(Y341C), and the stability of the alpha 3 beta(Y341C)3 complex in the presence of AT(D)PMg, we conclude that binding of AT(D)PMg to the Tyr-341 site of the beta subunit(s) in the alpha 3 beta 3 complex triggers the dissociation of the alpha 3 beta 3 complex into the alpha 1 beta 1 heterodimers.     

Comparison of two standard methods for determination of free fatty acids content in oils extracted from oilseeds and vegetable oils

Two standard titrimetric procedures for determination of free fatty acids in vegetable oils and in oils extracted from oilseeds were examined using rapeseed oil, illipe nuts and fat, and groundnuts and groundnut oil as test materials. Both procedures involve dissolution of the fat in an organic solvent and titration with standard alkali solution using phenolphthalein as indicator. Results obtained using each of the two methods agree closely in most cases and certainly for commercial contractual purposes the two methods are interchangeable. Suggestions are made for modification of these methods particularly in regard to solvents and allowed variation in analysis results.     

13C-N.M.R. STUDIES OF A FLASH PYROLYSIS TAR AND A SUPERCRITICAL GAS EXTRACT USING MODERN PULSE SEQUENCES

The oil and the asphaltene obtained from a flash pyrolysis tar of an Australian sub-bituminous coal and the oil and asphaltene from a supercritical gas extract of an Australian bituminous coal were studied by ¹³;c-n.m.r. apectroscopy using modern pulse sequences which distinguish between primary (CH₃), secondary (CH₂), tertiary )CH( and quaternary (C) carbons. The oil from the flash pyrolysis tar was further separated into three fractions by elution chromatography and these were also studied. All the samples studied contained considerable amounts of long unsubstituted aliphatic chains. In the flash pyrolysis tar, a sizeable proportion of the long chains had a CH = CH₂ end group pertaining to both 1-alkenea and those chains attached to aromatic rings (w-aryl-1-alkenes), but this was much less in the supercritical gas extract. From the quaternary and tertiary carbon subspectra, it appears that the division of the aromatic carbon signal at 129-130 ppm between aromatic CH and C carbons is not valid for polar fractions of coal liquids. Though these pulse sequences are very useful for obtaining information on well resolved signals, broad featureless signals often found in coal liquids pose considerable problems.     

Glomerular epithelial protein 1 and podocalyxin-like protein 1 in inflammatory glomerular disease (crescentic nephritis) in rabbit and man

The podocyte is the cell responsible in large part for maintaining the glomerular filtration barrier. Glomerular epithelial protein 1 (GLEPP1) is a novel receptor-like transmembrane protein tyrosine phosphatase present on the apical surface of podocyte foot processes. Podocalyxin-like protein 1 (PCLP1) is a transmembrane sialoglycoprotein which is also present on the foot process apical surface as well as on the surface of endothelial cells. GLEPP1 and PCLP1 are thought to play a role in regulating the structure and function of podocyte foot processes. Glomerular injury affecting the podocyte is likely to be reflected by changes in these proteins. GLEPP1 distribution in human renal biopsy with inflammatory glomerular disease and crescent formation was examined by immunocytochemistry. A model of inflammatory glomerular injury induced by guinea pig anti-rabbit basement membrane (anti-GBM) antibody was used to examine the distribution and amount of GLEPP1 and PCLP1 mRNA and protein. A biopsy study was done to determine whether the extent of GLEPP1 depletion from glomeruli at early time points (Day 7) would predict the severity of crescent formation at Day 30. Glomeruli from human renal biopsies with crescentic nephritis showed focal to diffuse disappearance of GLEPP1 protein. No GLEPP1 was present within the cellular crescent. By Day 4 of the rabbit anti-GBM model, before cellular crescents had formed, GLEPP1 protein was reduced from 127 +/- 28 X 10(7) to 30 +/- 5 X 10(7) molecules per glomerulus (p < 0.001), and GLEPP1 mRNA was reduced by 62% (p < 0.05). In contrast, at this time there was no significant reduction of PCLP1 protein from the normal number of 309 X 10(9) molecules per glomerulus and the PCLP1 mRNA level had not decreased. At Day 4, podocyte foot processes were effaced and proteinuria was present. Glomerular culture supernatants from Day 4 rabbits caused a reduction in GLEPP1 but not PCLP1 protein expression by cultured normal glomeruli, showing that a soluble factor was produced at Day 4 which reduced the number of GLEPP1 molecules in glomeruli. There was no detectable proteolysis of GLEPP1 or PCLP1 in glomeruli and no increase in GLEPP1 or PCLP1 excretion in urine. Therefore, the reduction in glomerular GLEPP1 was associated with reduced synthetic capacity. The proportion of glomeruli with reduced GLEPP1 at Day 7 of the model was significantly associated with the percent of glomeruli which had formed crescents at Day 30 (r = 0.86, p < 0.0001). GLEPP1 appears to be a sensitive indicator of glomerular injury during inflammation in man and in the rabbit model. A reduction in amount of GLEPP1 is associated with worse outcome for the glomerulus.     

Variations of nitrogen with silicon content of electrical steels

The nitrogen content of commercial heats of electrical steels has been observed to increase with decreasing silicon content prior to teeming despite a constant nitrogen content prior to addition of alloying silicon to molten steel. This behavior can be qualitatively described by a nitrogen transfer model which predicts: the rate of absorption of nitrogen by the metal is greater at lower silicon contents; a final nitrogen level increasing with decreasing silicon; the thermodynamic activity of nitrogen is approximately constant regardless of silicon content at teem time; the nitrogen level increases with longer holding times; and ladle practice will affect nitrogen levels.