Controlling the uncontrolled: Are there incidental experimenter effects on physiologic responding?

The degree to which experimenters shape participant behavior has long been of interest in experimental social science research. Here, we extend this question to the domain of peripheral psychophysiology, where experimenters often have direct, physical contact with participants, yet researchers do not consistently test for their influence. We describe analytic tools for examining experimenter effects in peripheral physiology. Using these tools, we investigate nine data sets totaling 1,341 participants and 160 experimenters across different roles (e.g., lead research assistants, evaluators, confederates) to demonstrate how researchers can test for experimenter effects in participant autonomic nervous system activity during baseline recordings and reactivity to study tasks. Our results showed (a) little to no significant variance in participants' physiological reactivity due to their experimenters, and (b) little to no evidence that three characteristics of experimenters that are well known to shape interpersonal interactions-status (using five studies with 682 total participants), gender (using two studies with 359 total participants), and race (in two studies with 554 total participants)-influenced participants' physiology. We highlight several reasons that experimenter effects in physiological data are still cause for concern, including the fact that experimenters in these studies were already restricted on a number of characteristics (e.g., age, education). We present recommendations for examining and reducing experimenter effects in physiological data and discuss implications for replication

Rapid screening of environmental chemicals for estrogen receptor binding capacity.

Over the last few years, an increased awareness of endocrine disrupting chemicals (EDCs) and their potential to affect wildlife and humans has produced a demand for practical screening methods to identify endocrine activity in a wide range of environmental and industrial chemicals. While it is clear that in vivo methods will be required to identify adverse effects produced by these chemicals, in vitro assays can define particular mechanisms of action and have the potential to be employed as rapid and low-cost screens for use in large scale EDC screening programs. Traditional estrogen receptor (ER) binding assays are useful for characterizing a chemical's potential to be an estrogen-acting EDC, but they involve displacement of a radioactive ligand from crude receptor preparations at low temperatures. The usefulness of these assays for realistically determining the ER binding interactions of weakly estrogenic environmental and industrial compounds that have low aqueous solubility is unclear. In this report, we present a novel fluorescence polarization (FP) method that measures the capacity of a competitor chemical to displace a high affinity fluorescent ligand from purified, recombinant human ER-[alpha] at room temperature. The ER-[alpha] binding interactions generated for 15 natural and synthetic compounds were found to be similar to those determined with traditional receptor binding assays. We also discuss the potential to employ this FP technology to binding studies involving ER-ss and other receptors. Thus, the assay introduced in this study is a nonradioactive receptor binding method that shows promise as a high throughput screening method for large-scale testing of environmental and industrial chemicals for ER binding interactions

Carotid Intima-Media Thickness Progression in HIV-Infected Adults Occurs Preferentially at the Carotid Bifurcation and Is Predicted by Inflammation.

BackgroundShear stress gradients and inflammation have been causally associated with atherosclerosis development in carotid bifurcation regions. The mechanism underlying higher levels of carotid intima-media thickness observed among HIV-infected individuals remains unknown.Methods and resultsWe measured carotid intima-media thickness progression and development of plaque in the common carotid, bifurcation region, and internal carotid artery in 300 HIV-infected persons and 47 controls. The median duration of follow-up was 2.4 years. When all segments were included, the rate of intima-media thickness progression was greater in HIV-infected subjects compared with controls after adjustment for traditional risk factors (0.055 vs. 0.024 mm/year, P=0.016). Rate of progression was also greater in the bifurcation region (0.067 vs. 0.025 mm/year, P=0.042) whereas differences were smaller in the common and internal regions. HIV-infected individuals had a greater incidence of plaque compared with controls in the internal (23% vs. 6.4%, P=0.0037) and bifurcation regions (34% vs. 17%, P=0.014). Among HIV-infected individuals, the rate of progression in the bifurcation region was more rapid compared with the common carotid, internal, or mean intima-media thickness; in contrast, progression rates among controls were similar at all sites. Baseline hsCRP was elevated in HIV-infected persons and was a predictor of progression in the bifurcation region.ConclusionsAtherosclerosis progresses preferentially in the carotid bifurcation region in HIV-infected individuals. hsCRP, a marker of inflammation, is elevated in HIV and is associated with progression in the bifurcation region. These data are consistent with a model in which the interplay between hemodynamic shear stresses and HIV-associated inflammation contribute to accelerated atherosclerosis. (J Am Heart Assoc. 2012;1:jah3-e000422 doi: 10.1161/JAHA.111.000422.)Clinical trial registrationURL: http://clinicaltrials.gov. Unique identifier: NCT01519141

Using Bi-Weekly Surveys to Portray Adolescent Partnership Dynamics: Lessons From a Mobile Diary Study.

Partnership formation is an important developmental task for adolescents, but cross-sectional and periodic longitudinal studies have lacked the measurement precision to portray partnership stability and flux and to capture the range of adolescent partnership experiences. This article assesses the promises and challenges of using bi-weekly mobile diaries administered over the course of a year to study adolescent partnership dynamics. Descriptive findings illustrate the potential of bi-weekly diaries for both capturing the longitudinal complexity and fluidity of adolescent partnerships as well as for reducing retrospection biases. Results also underscore several challenges, including those posed by missing data, and highlight several strategies for maximizing participant engagement and reliably tracing adolescent partnerships

Polychromatic gap solitons and breathers in nonlinear waveguide arrays

We predict the spatial localization of multiple wavelength components in the form of stationary polychromatic gap solitons and dynamic multi-gap breathers, and observe experimentally tunable spatio-spectral trapping of supercontinuum radiation in nonlinear periodic photonic structures

Nonlinear spectral-spatial control and localization of supercontinuum radiation

We present the first observation of spatiospectral control and localization of supercontinuum light through the nonlinear interaction of spectral components in extended periodic structures. We use an array of optical waveguides in a LiNbO3 crystal and employ the interplay between diffraction and nonlinearity to dynamically control the output spectrum of the supercontinuum radiation. This effect presents an efficient scheme for optically tunable spectral filtering of supercontinua

Proximal oxidation as a director of self organisation

Self-organising templates used as etch masks and growth seeds enable efficient mass fabrication of nanoscale device layers. In this work we introduce a new way to direct self-organisation of nanoscale pore formation during anodisation of metal layers of direct relevance to nanofabrication process flows. We demonstrate and quantitatively characterise how proximal surface oxidation frustrates and redirects random pore ordering in the film. Our results show a strict correlation between pore formation and oxide thickness on the aluminium surface providing important information on pore nucleation and growth in substrate-supported thin films and confirming the predictions of several existing theoretical models on pore growth. We find a linear relation between applied voltage and intrinsic self-organising interpore distance for supported thin films (from 80 to 150 nm) over a wide potential window between 40 and 120 V, mirroring behavior of thicker unsupported foils but with a different coefficient of proportionality. Using this technique, we are able to produce arbitrary and highly regular patterns of pores while manipulating pore pitch up to 20% from the natural spacing. This work demonstrates for the first time how local oxidation can direct self-organisation

Mental Health of Parents and Life Satisfaction of Children: A Within-Family Analysis of Intergenerational Transmission of Well-Being

This paper addresses the extent to which there is an intergenerational transmission of mental health and subjective well-being within families. Specifically it asks whether parents’ own mental distress influences their child’s life satisfaction, and vice versa. Whilst the evidence on daily contagion of stress and strain between members of the same family is substantial, the evidence on the transmission between parental distress and children’s well-being over a longer period of time is sparse. We tested this idea by examining the within-family transmission of mental distress from parent to child’s life satisfaction, and vice versa, using rich longitudinal data on 1,175 British youths. Results show that parental distress at year t-1 is an important determinant of child’s life satisfaction in the current year. This is true for boys and girls, although boys do not appear to be affected by maternal distress levels. The results also indicated that the child’s own life satisfaction is related with their father’s distress levels in the following year, regardless of the gender of the child. Finally, we examined whether the underlying transmission correlation is due to shared social environment, empathic reactions, or transmission via parent-child interaction