Effects of normal and perturbed social play on the duration and amplitude of different types of infant smiles.

Different types of smiling varying in amplitude of lip corner retraction were investigated during 2 mother-infant games--peekaboo and tickle--at 6 and 12 months and during normally occurring and perturbed games. Using Facial Action Coding System (FACS), infant smiles were coded as simple (lip corner retraction only), Duchenne (simple plus cheek raising), play (simple plus jaw drop), and duplay (Duchenne plus jaw drop). In addition, again using FACS, the amplitude of lip corner retraction was coded on a 5-point scale. Rather than a single smile expression that differs only in amplitude, the authors found a complex family of different smile expressions differing in their duration and amplitude as a function of game, setup versus climax of the game, and perturbation. Both type of smiling and amplitude of smiling appear to be controlled independently by the infant in relation to the context. These findings reveal systematic and context-specific nuances in infant smiles in the 2nd half of the first year. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A randomized controlled trial of a coping group intervention for adults with HIV who are AIDS bereaved: Longitudinal effects on grief.

The authors sought to study the longitudinal effects of a cognitive-behavioral group intervention for coping with AIDS bereavement among a diverse sample of adults who were HIV positive. Participants (N = 267) were randomly assigned to receive the 12-week intervention or individual therapy upon request. Measures were administered at baseline, postintervention, and 4-, 8-, and 12-month follow-ups. Longitudinal data were analyzed with linear mixed models to examine change in grief by condition across the study period and the effect of the intervention on grief through its interaction with psychiatric distress. The authors used the Grief Reaction Index to assess grief and the Symptom Checklist-90-Revised to assess global psychiatric distress. Participants in both conditions reported decreases in grief severity. However, among those with higher levels of psychiatric distress, participants in the group intervention had significantly lower grief severity scores compared with participants in the individual therapy condition. The long-term effectiveness of this AIDS-bereavement intervention for psychiatrically distressed people with HIV/AIDS supports the need for tailored interventions among those at risk for complicated grief responses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influences of sexual sensation seeking, alcohol consumption, and sexual arousal on women's behavioral intentions related to having unprotected sex.

This experimental study examined effects of alcohol consumption and sexual sensation seeking on unprotected sex intentions, taking into account sexual arousal, indirectly discouraging sex, and condom insistence. Women (N = 173; mean age = 25.02) were randomly assigned to a control, placebo, low-dose beverage (target blood alcohol level = .04), or high- dose beverage (target blood alcohol level = .08) condition. Participants projected themselves into a hypothetical sexual interaction with a man in which no condom was available. Structural equation modeling demonstrated that both sexual sensation seeking and alcohol dose directly increased sexual arousal early in the interaction, but later sexual arousal indirectly increased unprotected sex intentions by decreasing endorsement of indirect discouragement and, in turn, condom insistence. These findings help to clarify the role of alcohol consumption and sensation seeking in women's sexual decision making and point to the importance of examining it as a multistage process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Efficacy of the Satz-Mogel short form WAIS—R for tumor patients with lateralized lesions.

The ability of the P. Satz and S. Mogel (1962) short form Wechsler Adult Intelligence Scale—Revised (WAIS—R) to provide equivalent information about IQ scores and age-corrected scale scores was examined as a function of side of lesion for 34 left hemisphere damaged (LHD) and 29 right hemisphere damaged (RHD) patients having primary brain tumors. Correlations between the 2 forms were significant for all WAIS—R scores with the exception of the Object Assembly subtest for RHD patients. The short form significantly overestimated Verbal IQ, Performance IQ, Full Scale IQ, Similarities, and Picture Arrangement subtest scores. It significantly underestimated Object Assembly subtest scores. A marked percentage of patients showed 1 or more category changes for most WAIS—R scores and 2 or more category changes for some of these scores. The distribution of discrepancies between scores and the number of category changes did not differ significantly for LHD and RHD patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Liquefaction and Undrained Response Evaluation of Sands from Drained Formulation

A general approach has been established to assess the undrained stress-strain curve and effective stress path under monotonic loading from drained triaxial tests. An appropriate formulation of a drained and drained rebounded (i.e., overconsolidated) triaxial test response is developed that, in turn, allows the assessment of developing liquefaction and the undrained behavior of saturated sands. The formulation presented is based upon reported experimental drained test results that were obtained from different investigators using different testing techniques. This formulation is a function of the confining pressure and basic properties of the sand, such as relative density, uniformity coefficient, and particle shape (roundness), which can be obtained from visual inspection. The approach is verified by comparing predicted and reported (observed) undrained behavior. The developed formulas allow one to predict the potential of sand to liquefy, the type of liquefaction, the peak and residual strength values, as well as the whole undrained stress-strain curve and effective stress path. The simplicity of this approach makes it an attractive general method to characterize the undrained behavior of sands in a preliminary analysis with no need to run sophisticated experimental tests.     

Seismic Soil-Pile-Structure Interaction Experiments and Analyses

A dynamic beam on a nonlinear Winkler foundation (or “dynamic p-y”) analysis method for analyzing seismic soil-pile-structure interaction was evaluated against the results of a series of dynamic centrifuge model tests. The centrifuge tests included two different single-pile-supported structures subjected to nine different earthquake events with peak accelerations ranging from 0.02 to 0.7g. The soil profile consisted of soft clay overlying dense sand. Site response and dynamic p-y analyses are described. Input parameters were selected based on existing engineering practices. Reasonably good agreement was obtained between calculated and recorded responses for both structural models in all earthquake events. Sensitivity of the results to dynamic p-y model parameters and site response calculations are evaluated. These results provide experimental support for the use of dynamic p-y analysis methods in seismic soil-pile-structure interaction problems.     

Detecting and Measuring Fine Roots in Minirhizotron Images Using Matched Filtering and Local Entropy Thresholding

An approach to automate the extraction and measurement of roots in minirhizotron images is presented. Two-dimensional matched filtering is followed by local entropy thresholding to produce binarized images from which roots are detected. After applying a root classifier to discriminate fine roots from unwanted background objects, a root labeling method is implemented to identify each root in the image. Once a root is detected, its length and diameter are measured using Dijkstra’s algorithm for obtaining the central curve and the Kimura–Kikuchi–Yamasaki method for measuring the length of the digitized path. Experimental results from a collection of peach (Prunus persica) root images demonstrate the effectiveness of the approach.     

能攀爬火山的空间机器人

一个由NASA喷气推进实验室的Issa A.D.Nesnas领导的工程师团队,还包括加州理工学院的Joel Burdick教授和他的学生,设计和测试了一个能在陡峭斜坡和岩石表面进行导航的轻型探路者机器人原型.这个两轮圆柱形的机器人被命名为Axel,是Axel探路者系统中的一员.该系列是用来探测行星表面的.