Screening for childhood adversity: the what and when of identifying individuals at risk for lifespan health disparities.

Existing research on childhood adversity and health risk across the lifespan lacks specificity regarding which types of exposures to assess and when. The purpose of this study was to contribute to an empirically-supported framework to guide practitioners interested in identifying youth who may be at greatest risk for a lifelong trajectory of health disparities. We also sought to identify the point in childhood at which screening for adversity exposure would capture the largest group of at risk individuals for triage to prevention and intervention services. Participants (n = 4036) collected as part of the Midlife in the United States study reported their medical status and history including physical (cardiovascular disease, hypertension, obesity, diabetes, cancer) and mental health (depression, substance use problems, sleep problems). Participants indicated whether they were exposed to 7 adversities at any point in childhood and their age of exposure to 19 additional lifetime adversities before the age of 18. Parent drug abuse, dropping out or failing out of school, being fired from a job, and sexual assault during childhood exhibited the largest effect sizes on health in adulthood, which were comparable to the effects of childhood maltreatment. Childhood adversity screening in early adolescence may identify the largest proportion of youth at risk for negative health trajectories. The results of this descriptive analysis provide an empirical framework to guide screening for childhood adversity in pediatric populations. We discuss the implications of these observations in the context of prevention science and practice

Stability of diurnal cortisol measures across days, weeks, and years across middle childhood and early adolescence: Exploring the role of age, pubertal development, and sex.

Effective regulation of the hypothalamic-pituitary-adrenal axis (HPA-axis) has been linked to numerous health outcomes. Within-person variation in diurnal measures of HPA-axis regulation assessed over days, months, and years can range between 50-73% of total variation. In this study of 59 youth (ages 8-13), we quantified the stability of the cortisol awakening response (CAR), the diurnal slope, and tonic cortisol concentrations at waking and bedtime across 8 days (2 sets of 4 consecutive days separated by 3 weeks), 3 weeks, and 3 years. We then compared the stability of these indices across three key developmental factors: age, pubertal status, and sex. Youth provided 4 saliva samples per day (waking, 30 min post-waking, before dinner, and before bedtime) for 4 consecutive days during the 3rd week of an ongoing 8-week daily diary study. Youth repeated this same sampling procedure 3 weeks and 3 years later. Using multi-level modeling, we computed the amount of variance in diurnal HPA-axis regulation that was accounted for by nesting an individual's diurnal cortisol indices within days, weeks, or years. Across days, diurnal slope was the most stable index, whereas waking cortisol and CAR were the least stable. All indices except bedtime cortisol were similarly stable when measured across weeks, and all indices were uniformly stable when measured across 3 years. Boys, younger participants, and youth earlier in their pubertal development at study enrollment exhibited greater HPA-axis stability overall compared with females and older, more physically mature participants. We conclude that important within- and between-subjects questions can be answered about health and human development by studying HPA-axis regulation, and selection of the index of interest should be determined in part by its psychometric characteristics. To this end, we propose a decision tree to guide study design for research in pediatric samples by longitudinal timeframe and sample characteristics

A Test of the Particle Paradigm in N-Body Simulations

We present results of tests of the evolution of small ``fluid elements'' in cosmological N--body simulations, to examine the validity of their treatment as particles. We find that even very small elements typically collapse along one axis while expanding along another, often to twice or more their initial comoving diameter. This represents a possible problem for high--resolution uses of such simulations.Comment: Uses aasms4.sty; accepted for publication in ApJ Letters. Files available also at ftp://kusmos.phsx.ukans.edu/preprints/ates

Highly conserved type 1 pili promote enterotoxigenic E. coli pathogen-host interactions

Enterotoxigenic Escherichia coli (ETEC), defined by their elaboration of heat-labile (LT) and/or heat-stable (ST) enterotoxins, are a common cause of diarrheal illness in developing countries. Efficient delivery of these toxins requires ETEC to engage target host enterocytes. This engagement is accomplished using a variety of pathovar-specific and conserved E. coli adhesin molecules as well as plasmid encoded colonization factors. Some of these adhesins undergo significant transcriptional modulation as ETEC encounter intestinal epithelia, perhaps suggesting that they cooperatively facilitate interaction with the host. Among genes significantly upregulated on cell contact are those encoding type 1 pili. We therefore investigated the role played by these pili in facilitating ETEC adhesion, and toxin delivery to model intestinal epithelia. We demonstrate that type 1 pili, encoded in the E. coli core genome, play an essential role in ETEC virulence, acting in concert with plasmid-encoded pathovar specific colonization factor (CF) fimbriae to promote optimal bacterial adhesion to cultured intestinal epithelium (CIE) and to epithelial monolayers differentiated from human small intestinal stem cells. Type 1 pili are tipped with the FimH adhesin which recognizes mannose with stereochemical specificity. Thus, enhanced production of highly mannosylated proteins on intestinal epithelia promoted FimH-mediated ETEC adhesion, while conversely, interruption of FimH lectin-epithelial interactions with soluble mannose, anti-FimH antibodies or mutagenesis of fimH effectively blocked ETEC adhesion. Moreover, fimH mutants were significantly impaired in delivery of both heat-stable and heat-labile toxins to the target epithelial cells in vitro, and these mutants were substantially less virulent in rabbit ileal loop assays, a classical model of ETEC pathogenesis. Collectively, our data suggest that these highly conserved pili play an essential role in virulence of these diverse pathogens

Hydrodynamics at RHIC -- how well does it work, where and how does it break down?

I review the successes and limitations of the ideal fluid dynamic model in describing hadron emission spectra from Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC).Comment: 8 pages, 4 figures. Invited talk presented at Strange Quark Matter 2004 (Cape Town, Sep. 15-20, 2004). Proceedings to appear in Journal of Physics

Linking Models in Land Use Simulation: Application of the Land Use Scanner to Changes in Agricultural Area

When we model land use change, we utilize ¿ consciously or unconsciously ¿ other models as well. The variables we regard as exogenous are often generated endogenously by a different model. We are not always fully aware of the implications of this for our modelling exercises. The model which generated the demographic growth that we use in forecasting the need for residential space may have used assumptions that are at variance with ours. The model resulting in claims for agricultural land may have already taken competing claims into account ¿ whereas our land use model may simulate this competition all over again. The data used for different models may not be compatible. Conversely, our land use simulation exercises can also be used by others as input. A model for the agricultural sector, for instance, must consider the constraint of available land ¿ especially whether the land required is available in a particular area which is regarded as optimal for a particular production line. Land use models can provide that input. The Agricultural Economics Research Institute in The Hague, uses a number of models at various spatial levels ¿ from the individual farm to the global economy ¿ and for different purposes. Recently, the linkages between these models have received more attention, which also lays bare the compatibility problems between them. In order to examine both the possibilities and the problems inherent in these linkages, a research project on this `model train¿ has been undertaken. Based on two opposing scenarios prepared by the Dutch Central Planning Bureau, the study calculates the long-term consequences of these scenarios: beginning with a general equilibrium model at global level (GTAP) through a sectoral model at national and regional scale - the Dutch Regionalized Agricultural Model (DRAM) ¿ to a model assessing ecological effects in a local area (SOMMA). The Land Use Scanner, a land use information system and simulation model for the Netherlands, has been used to predict changes in the agricultural area for the regions used in DRAM. The land claims, which are an exogenous variable in the Land Use Scanner, were generated from projections of future population and GDP, on the basis of their historical correlation with land use. This project has led to interesting insights into the problems of linking models. It is hoped that these insights will help to improve the models we use ¿ including land use models. The paper highlights the importance of making modelling assumptions explicit, such that the outcome of one model can indeed be a useful input into another one. The integrated modelling approach yields more consistent projections of land use

Biological Rhythms Workshop I: Introduction to Chronobiology

In this chapter, we present a series of four articles derived from a Introductory Workshop on Biological Rhythms presented at the 72nd Annual Cold Spring Harbor Symposium on Quantitative Biology: Clocks and Rhythms. A diverse range of species, from cyanobacteria to humans, evolved endogenous biological clocks that allow for the anticipation of daily variations in light and temperature. The ability to anticipate environmental variation promotes optimal performance and survival. In the first article, Introduction to Chronobiology, we present a brief historical timeline of how circadian concepts and terminology have emerged since the early observation of daily leaf movement in plants made by an astronomer in the 1700s. Workshop Part IA provides an overview of the molecular basis for rhythms generation in several key model organisms, Workshop Part IB focuses on how biology built a brain clock capable of coordinating the daily timing of essential brain and physiological processes, and Workshop Part IC gives key insight into how researchers study sleep and rhythms in humans

Social Value Orientation, Expectations, and Cooperation in Social Dilemmas:A Meta-analysis

Interdependent situations are pervasive in human life. In these situations, it is essential to form expectations about the others’ behaviour to adapt one’s own behaviour to increase mutual outcomes and avoid exploitation. Social value orientation, which describes the dispositional weights individuals attach to their own and to another person’s outcome, predicts these expectations of cooperation in social dilemmas—an interdependent situation involving a conflict of interests. Yet, scientific evidence is inconclusive about the exact differences in expectations between prosocials, individualists, and competitors. The present meta-analytic results show that, relative to proselfs (individualists and competitors), prosocials expect more cooperation from others in social dilemmas, whereas individualists and competitors do not significantly differ in their expectations. The importance of these expectations in the decision process is further highlighted by the finding that they partially mediate the well-established relation between social value orientation and cooperative behaviour in social dilemmas. In fact, even proselfs are more likely to cooperate when they expect their partner to cooperate