Instant of chair-rise lift-off can be predicted by foot-floor reaction forces

OBJECTIVE: To develop a predictive model of the lift-off event during chair rise in healthy subjects, using foot-floor reaction forces. BACKGROUND: An important event during chair rise is lift-off from the seat: the transition from the inherently stable three-point contact to the unstable two-point contact. There is no consistent or generally agreed upon method for estimating the time of lift-off when an instrumented seat is unavailable. METHODS: Twenty healthy volunteers were divided into a testing set and training set. Each subject performed repeated chair rise trials at different speeds. Seat-floor and foot-floor forces, recorded with two force platforms, were used to develop a model of the lift-off event. RESULTS: The magnitude of the vertical foot-floor reaction at lift-off (F0VF) was linearly related (R2 = 0.71, P < 0.001) to the peak vertical foot-floor reaction force (FMVF). A linear model was developed for the training group, which enabled prediction of lift-off time for the testing group with an absolute average error of 6 ms (about 1 data frame at 150 Hz). The linear model derived for the entire sample was: F0VF = 28.14 + FMVF * (0.6434). CONCLUSIONS: The lift-off event for healthy subjects performing chair rise can be accurately predicted from foot-floor reaction forces, without requiring an instrumented seat.     

Configuration-specific attentional modulation of flanker- -target lateral interactions

Elements of a contour are often easier to detect when they possess collinearity, with their local orientations matching the global orientation of the contour. We recently reported attentional modulation of such lateral interactions between a central near-threshold target Gabor patch and flanking high-contrast patches (Freeman et al, 2001 Nature Neuroscience 4 1032-1036). Here, we examined whether such attentional effects reflect specific modulation of mechanisms sensitive to collinear configurations, or instead more general modulation of sensitivity to either the global or local orientation-components of the stimulus. Thresholds for detecting a central Gabor target were measured, while observers also judged the Vernier alignment between one pair of flankers and ignored a second flanker pair (when present). Target contrast-thresholds were facilitated only when attending collinear flankers. There was no facilitation when attending flankers that shared only local orientation with the target, or flankers that fell on a global axis aligned with target orientation but having orthogonal local orientation. Ignored collinear flankers had no effect on target thresholds. These results demonstrate strong and specific attentional modulation of contour-integration mechanisms in early vision sensitive to collinear configurations.     

Dream content of schizophrenic, nonschizophrenic mentally ill, and community control adolescents

This study compared the manifest dream content of 20 schizophrenic adolescent inpatients whose medications were stable for at least four weeks, 21 adolescent inpatients with other mental disorders (nonschizophrenic group) matched for age and gender, and 31 matched community controls. All participants were administered the standardized Formal Dream Content Rating Scale (FDCRS), which evaluates dream-related anxiety, cognitive disturbance, implausibility, involvement, primitivity, and recall, as well as two additional scales measuring emotional expression and duration of dream report. The Positive and Negative Symptoms Scale (PANSS) was administered to the two inpatient groups. The community controls demonstrated more involvement and emotional expression than the schizophrenic patients; furthermore, they demonstrated more implausibility and had a greater duration of dream report compared with the nonschizophrenic group. In the schizophrenic patients only, elevated scores on the negative subscale of the PANSS were significantly correlated with lower scores on involvement, emotional expression, and dream recall. No relationship was found between the positive subscale of the PANSS and any of the FDCRS subscales. These results suggest that psychopathology per se, rather than the specific psychiatric disturbance, may be associated with impoverishment of dream content, and that negative, rather than positive, schizophrenic symptomatology may be influential in the dream content of schizophrenic youngsters.     

Jealousy and the meaning (or nonmeaning) of violence

Previous research has indicated that jealousy is one of the major triggers of domestic violence. Three studies here examined North Americans' ambivalent feelings about jealousy and jealousy-related aggression. In Study 1, it was shown that participants believed both that jealousy can be a sign of insecurity and a sign of love. In Study 2, it was shown that this equating of jealousy with love can lead to the tacit acceptance of jealousy-related violence. In Study 3, it was shown that a relative acceptance of jealousy-related aggression extends to cases of emotional and sexual abuse by husbands against their wives. In both Studies 2 and 3, men who hit or abused their wives over a jealousy-related matter were judged to romantically love their wives as much as those who did not engage in abuse. Violence in the context of a non-jealousy-related argument was seen quite negatively, but it lost a great deal of its negativity in the jealousy case.     

Male honor and female fidelity: implicit cultural scripts that perpetuate domestic violence

Two studies explored how domestic violence may be implicitly or explicitly sanctioned and reinforced in cultures where honor is a salient organizing theme. Three general predictions were supported: (a) female infidelity damages a man's reputation, particularly in honor cultures; (b) this reputation can be partially restored through the use of violence; and (c) women in honor cultures are expected to remain loyal in the face of jealousy-related violence. Study 1 involved participants from Brazil (an honor culture) and the United States responding to written vignettes involving infidelity and violence in response to infidelity. Study 2 involved southern Anglo, Latino, and northern Anglo participants witnessing a "live" incident of aggression against a woman (actually a confederate) and subsequently interacting with her.     

The equivocal meanings of time: Exploratory and structural analyses

This study addresses itself to the question of how people conceive of time. On the basis of philosophical, scientific, and cultural positions, we identified those beliefs which contribute to the basic meanings of time and generate the specific themes by which time is conceptualized. A questionnaire of beliefs about time was completed by 392 students. An exploratory factor analysis yielded seven factors, which qualified time as destructive, constructive, fluid, elusive, cyclical, eternal, and mysterious. The factor scales significantly related to gender, origin, faculty association, and death anxiety. A structural equation modeling approach was employed to test a model of second-order factors which presumably tapped evaluative aspects and perhaps thus related to the affective basis of the attitude toward time. The model assumed three general factors: Assuring Time, Disquieting Time, and Dynamic-Ambivalent Time. The results showed that the model provided an acceptable fit. Our results validate the time conception questionnaire developed in this study.     

Impact of Internal Auditing on Branch Bank Performance: A Field Experiment

We conducted an experiment to assess the contribution of internal auditing to organizational effectiveness. We randomly assigned 224 bank branches to experimental conditions (audited or not audited) and monitored their performance for a year. Performance significantly improved during the half year following the audit in the experimental branches, in contrast to a decline in the control branches due to poor general business conditions. The contribution of auditing to performance is discussed in terms of learning, motivation, deterrence, and process improvement.