An item response tree model with not-all-distinct end nodes for non-response modelling

The non-response model in Knott et al. (1991, Statistician, 40, 217) can be represented as a tree model with one branch for response/non-response and another branch for correct/incorrect response, and each branch probability is characterized by an item response theory model. In the model, it is assumed that there is only one source of non-responses. However, in questionnaires or educational tests, non-responses might come from different sources, such as test speededness, inability to answer, lack of motivation, and sensitive questions. To better accommodate such more realistic underlying mechanisms, we propose a a tree model with four end nodes, not all distinct, for non-response modelling. The Laplace-approximated maximum likelihood estimation for the proposed model is suggested. The validation of the proposed estimation procedure and the advantage of the proposed model over traditional methods are demonstrated in simulations. For illustration, the methodologies are applied to data from the 2012 Programme for International Student Assessment (PISA). The analysis shows that the proposed tree model has a better fit to PISA data than other existing models, providing a useful tool to distinguish the sources of non-responses.     

Static balance in children with developmental coordination disorder

The purpose of this study was to compare the postural sway profiles of 9/10-year-old children with developmental coordination disorder and balance problems (DCD-BP, n=64) with those of non-DCD children (n=71). We measured center of pressure excursions in conditions with and without vision for 30s while standing still on the dominant leg, the non-dominant leg, or both legs. Sway area, total path length, and Romberg's quotient were analyzed. Most measures differed significantly between groups, except sway area when the children stood with vision on either the dominant leg or both legs. When standing on the dominant leg or both legs, DCD-BP children demonstrated greater total path length in all conditions and a greater sway area in without-vision conditions. DCD-BP children showed more difficulty standing on the non-dominant leg with eyes both open and closed. While boys showed results similar to the total group, the girls with DCD-BP only exhibited significant differences in three conditions with eyes closed, but not with eyes open. Analysis of Romberg's coefficient also indicated that children with DCD-BP did not over-rely on visual information.     

Effects of amount of information on judgment accuracy and confidence

When a person evaluates his or her confidence in a judgment, what is the effect of receiving more judgment-relevant information? We report three studies that show when judges receive more information, their confidence increases more than their accuracy, producing substantial confidence–accuracy discrepancies. Our results suggest that judges do not adjust for the cognitive limitations that reduce their ability to use additional information effectively. We place these findings in a more general framework of understanding the cues to confidence that judges use and how those cues relate to accuracy and calibration.     

A multichannel PC tachistoscope with high resolution and fast display change capability

The number of channels that PC tachistoscopes can have has increased recently (Bokhorst, 1995; Myors, 1998); however, neither the quality of display nor speed of image switching has been improved. This article shows the capability of VESA’s VBE 3.0 standard (1998) for increasing the number of channels of high-quality images. And the refresh rate can be set to the fastest cathode ray tube (CRT) scanning rate the monitor can tolerate in order to reduce the timing delay of changing display. A PCTSCOPE library was written in C to provide these capabilities, which is compatible with conventional DOS real mode. The PC tachistoscope can have numbers of channels with various resolutions and colors and different refresh rates. For example, 25 images with the resolution of 640 × 480 pixels and 256 colors can be loaded to video memory, and vertical refresh rate can be set to 180 Hz. It takes less than 6 msec to change the display among 25 channels in synchronizing with the start of the video scanning frame. In this library, the number of channels, the resolution of the images, and the speed of changing display all are improved. The multichannel PC tachistoscope with this technique is especially suitable for research requiring high-quality images and rapid successive presentation of stimuli.     

Effect of external motion on correspondence between infant actigraphy and maternal diary

Correspondence between infant actigraphy and mother-recorded diary differed significantly when receiver–operator function area under the curve, correlation, and logistic regression was calculated with and without excluding periods of external motion. External motion occurred in 40% of recording time and significantly changed activity count per epoch.     

Market Openness, Transition Economies and Subjective Wellbeing

This study attempts to examine the impact on subjective wellbeing (SWB) of economic openness as a social institution. The empirical testing of the liberal argument for the importance of market openness in human wellness is based on a cross-national design. Average scores of ‘feeling of happiness’ in 65 countries and ‘life satisfaction’ in 76 countries measured during the 1990s that are drawn from the World Database of Happiness overseen by Veenhoven (2006) are modeled as dependent variables. Regression analysis generates favorable results for the liberal argument in that length of being an open economy (versus closed economy) boosts the level of happiness, while transition to openness augments life satisfaction. Although the post communist countries registered less happiness in the early phase of transition towards the market economy, in general, our model specification indicates that an open market in itself was not responsible for this region’s unpleasant psychology.     

Rapid stimulatory effects of testosterone upon myotubule metabolism and sugar transport,as assessed by silicon microphysiometry

A considerable number of studies have revealed behavioral circumstances that give rise to small or transient differences in circulating testosterone concentrations; however, careful consideration of androgen physiology leads to the disquieting conclusion that these differences are often unlikely to have much physiologic or behavioral significance. In the present report, we observe that small transients of testosterone secretion could have very rapid anabolic effects on a cultured muscle-derived cell line. Specifically, we have examined the effects of testosterone on metabolism in cultured C2C12 myotubules, using a silicon microphysiometer. The instrument monitors cellular extrusion of protons and acidic metabolites, and such extrusion is directly linked to ATP hydrolysis, thus providing a real-time measure of cellular metabolism. Testosterone caused a small but significant increase in metabolism. The most striking feature of this effect was its rapidity, in that it occurred within 3 hr. This rapid enhancement of metabolism suggested that testosterone might be enhancing substrate uptake even more rapidly. Indeed, we found that testosterone increased 2-deoxyglucose uptake within 1 min. The rapidity of this effect seemed to preclude mediation by classical intracellular steroid receptors. In support of this, we were unable to detect specific intracellular binding of testosterone. These findings show that testosterone can exert rapid anabolic effects on substrate transport and metabolism in myotubules. Should this finding general to muscle in vivo, it suggests that relatively small individual differences in testosterone profiles, in response to various social interactions, may have very real consequence for subsequent muscle physiology. © 1996 Wiley-Liss, Inc.     

Why Is Cancer Genetic Counseling Underutilized by Women Identified as at Risk for Hereditary Breast Cancer? Patient Perceptions of Barriers Following a Referral Letter

Family history information comprises an important tool in identifying and referring patients at risk for hereditary breast and ovarian cancer (HBOC) to cancer genetic counseling. Despite recommendations and support provided by numerous professional organizations, cancer genetic counseling services are underutilized by atrisk patients. This study aimed to: (1) determine the rate of genetic counseling utilization following a referral letter, (2) characterize factors (barriers and supports) which influenced uptake of services, and (3) identify potential strategies for increasing utilization. This study evaluated the uptake of cancer genetic counseling among 603 screening mammography patients identified as having an increased risk for HBOC based on National Comprehensive Cancer Network (NCCN) guidelines. At risk individuals and their primary care providers were mailed a referral letter recommending genetic counseling. Three focus groups (N = 24) were conducted to identify responses to receiving a letter recommending genetic counseling, barriers to seeking genetic counseling, and facilitating factors to utilizing these services. Participant responses were qualitatively analyzed using thematic and cross case analysis. Within one year, 50/603 (8 %) of the identified at-risk women completed a genetic counseling appointment. Participant-perceived barriers which influenced their decision not to seek genetic counseling included lack of relevance and utility, limited knowledge about genetic counseling, concerns about the genetic counseling process, and concerns about cost and insurance coverage. Participant-perceived facilitating factors which would support a decision to seek genetic counseling included greater awareness and education about genetic counseling services when receiving a referral, and improved follow up and guidance from their provider. Findings from this study support the need for patient and primary care provider education, and improved provider-patient communication to increase uptake of genetic counseling services.