Salivary cortisol as a predictor of socioemotional adjustment during kindergarten: a prospective study.

This study, based on a sample of 172 children, examined the relation between average afternoon salivary cortisol levels measured at home at age 4.5 years and socioemotional adjustment a year and a half later, as reported by mothers, fathers, and teachers. Cortisol levels were hypothesized to be positively associated with withdrawal-type behaviors (e.g., internalizing, social wariness) and inversely related to approach-type behaviors, both negative and positive (e.g., externalizing, school engagement). Higher cortisol levels at age 4.5 predicted more internalizing behavior and social wariness as reported by teachers and mothers, although child gender moderated the relation between cortisol and mother report measures. An inverse relation was found between boys' cortisol levels and father report of externalizing behavior. A marginal inverse relation was found between child cortisol levels and teacher report of school engagement. Behavior assessed concurrently with cortisol collection did not account for the prospective relations observed,suggesting that cortisol adds uniquely to an understanding of behavioral development.

Urkinase: structure of acetate kinase, a member of the ASKHA superfamily of phosphotransferases.

Acetate kinase, an enzyme widely distributed in the Bacteria and Archaea domains, catalyzes the phosphorylation of acetate. We have determined the three-dimensional structure of Methanosarcina thermophila acetate kinase bound to ADP through crystallography. As we previously predicted, acetate kinase contains a core fold that is topologically identical to that of the ADP-binding domains of glycerol kinase, hexokinase, the 70-kDa heat shock cognate (Hsc70), and actin. Numerous charged active-site residues are conserved within acetate kinases, but few are conserved within the phosphotransferase superfamily. The identity of the points of insertion of polypeptide segments into the core fold of the superfamily members indicates that the insertions existed in the common ancestor of the phosphotransferases. Another remarkable shared feature is the unusual, epsilon conformation of the residue that directly precedes a conserved glycine residue (Gly-331 in acetate kinase) that binds the alpha-phosphate of ADP. Structural, biochemical, and geochemical considerations indicate that an acetate kinase may be the ancestral enzyme of the ASKHA (acetate and sugar kinases/Hsc70/actin) superfamily of phosphotransferases.

Genetic analyses of focal aspects of infant temperament.

The authors explored the genetic and environmental underpinnings of individual differences in temperament with a sample of 604 3- to 16-month-old infant twins and their parents. Mothers completed Rothbart's Infant Behavior Questionnaire (IBQ), and a subsample of 140 9-month-old twins participated in behavioral assessment of temperament in the laboratory as well. For IBQ Smiling and Laughter and Duration of Orienting, both additive genetic and shared environmental effects were needed to best represent the data. Shared environmental effects fully accounted for cotwin similarity for IBQ Soothability, and conversely, additive genetic effects fully accounted for cotwin similarity for the IBQ Distress to Limitations, Distress to Novelty, and Activity Level scales. With the subsample, the authors fit a multivariate model to mother report, father report, and lab measures of stranger distress and found that genetic influences were most important for the covariation among these measures.

Fear and anger regulation in infancy: effects on the temporal dynamics of affective expression.

Emotion regulation has been conceptualized as the extrinsic and intrinsic processes responsible for monitoring, facilitating, and inhibiting heightened levels of positive and negative affect. Regulation of distress is related to the use of certain behavioral strategies. Our study examined whether putative regulatory behaviors widely assumed to be conceptually associated with these strategies are actually empirically associated with the changes in fearful and angry distress in 6-, 12-, and 18-month-old infants. Our key finding was that the use of some putative regulatory behaviors (e.g., distraction and approach) reduced the observable intensity of anger but were less effective in reducing the intensity of fear. The results suggest (1) caution in assuming that postulated regulatory behaviors actually have general distress-reducing effects and (2) the likelihood that "distress" is too global a construct for research on emotion regulation.

Toddler and childhood temperament: expanded content, stronger genetic evidence, new evidence for the importance of environment.

Using samples of twins and singletons totaling 715 individuals, the authors document heritable influences on various temperamental dimensions during the toddler and preschooler age ranges, which have been somewhat understudied relative to infants and older adolescents. In contrast to instruments on which prior literature is based, the Toddler Behavior Assessment Questionnaire and the Children's Behavior Questionnaire offer assessment of positive affectivity (separately from negative affectivity) and of emotional regulation. Positive affect reveals substantial shared environmental influence, and emotion regulation reveals additive genetic influence. Evidence for genetic variance in temperament is strengthened because intraclass correlations from many of these questionnaire scales show no evidence of "too-low" dizygotic correlations that imply contrast effects. Suggestive evidence is offered that psychometric characteristics of the questionnaires can affect biometric inferences.

Crystallization of acetate kinase from Methanosarcina thermophila and prediction of its fold.

The unique biochemical properties of acetate kinase present a classic conundrum in the study of the mechanism of enzyme-catalyzed phosphoryl transfer. Large, single crystals of acetate kinase from Methanosarcina thermophila were grown from a solution of ammonium sulfate in the presence of ATP. The crystals diffract to beyond 1.7 A resolution. Analysis of X-ray data from the crystals is consistent with a space group of C2 and unit cell dimensions a = 181 A, b = 67 A, c = 83 A, beta = 103 degrees. Diffraction data have been collected from the crystals at 110 and 277 K. Data collected at 277 K extend to lower resolution, but are more reproducible. The orientation of a noncrystallographic two-fold axis of symmetry has been determined. Based on an analysis of the predicted amino acid sequences of acetate kinase from several organisms, we hypothesize that acetate kinase is a member of the sugar kinase/actin/hsp70 structural family.

Ethnography, epidemiology and infertility in Egypt.

Infertility in the developing world has been relatively neglected as an international health problem and a topic of social scientific and epidemiological inquiry. In this study, we examine factors placing poor urban Egyptian men and women at risk of infertility, and we explore the sociocultural and political-economic contexts in which these health-demoting factors are perpetuated. Our approach to the problem of Egyptian infertility attempts an explicit merging of ethnographic and epidemiological research designs, methods of data collection and analysis, and interpretive insights to provide improved understanding of the factors underlying infertility in the urban Egyptian setting.

Infertility, infection, and iatrogenesis in Egypt: the anthropological epidemiology of blocked tubes.

In this article, we integrate medical anthropological and analytical epidemiological methods, forms of data analysis, and interpretive insights to examine the culture-specific behavioral factors that place poor, urban Egyptian women at risk of tubal-factor infertility (TFI). Such risk factors include biomedically and ethnomedically produced iatrogenesis, including the consequences of the practice of female circumcision, and male sexual behavior leading to sterilizing sexually transmitted diseases (STDs) in their female sexual partners. We examine the socio-cultural and political-economic context in which infertility-producing behavioral risk factors are maintained, and we explore the ways in which these risk factors are perceived by biomedically trained Egyptian gynecologists.

Infant resuscitation is associated with an increased risk of left-handedness.

The etiology of left lateral preference is not well understood, but some studies have suggested that it can be caused by complications at birth. The authors used data from the Child Health and Development Study, a large prospective study of pregnancy and child development conducted 1959-1966 in the San Francisco Bay Area of California, to examine the association between specific birth stressors and hand and foot preference. The study population consisted of 6,968 5-year-olds with no severe congenital abnormalities, and the authors controlled for potential demographic confounders and familial left-handedness. Infants who required resuscitation after delivery or who were twins or triplets were about twice as likely to demonstrate left hand preference at age 5 years (odds ratio (OR) = 1.8, 95% confidence interval (CI) 1.3-2.5, and OR = 2.2, 95% CI 1.2-4.0, respectively). Left-footedness was also significantly associated with the same stressors. No other individual stresses were significantly associated with left-lateral preference, and a composite measure indicated only a weak association. Although males, blacks, and those with left-handed siblings are more likely to show left lateral preference, these variables do not confound the association between birth stress and left lateral preference. These results indicate that specific types of birth stress are strongly associated with left hand and foot preference; however, much of the left laterality in non-clinical populations remains unexplained.