Gender differences in the age-changing relationship between instrumentality and family contact in emerging adulthood.

Data from the Children in the Community Transitions Study were used to examine gender differences in the impact of family contact on the development of finance and romance instrumentality from ages 17 to 27 years. Family contact decreased among both men and women across emerging adulthood, although it decreased more rapidly in men than in women. Both finance and romance instrumentality increased for men and women across emerging adulthood. The growth rate did not differ between men and women in either domain, although men tended to be characterized by higher levels of instrumentality than women. There were noteworthy gender differences in the impact of family contact on the development of instrumentality. At age 17, family contact was negatively associated with instrumentality for both men and women; at age 27, the impact of family contact on instrumentality was less negative for women and was positive for men. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A study of lifting tasks performed on laterally slanted ground surfaces

Lifting in most industrial environments is performed on a smooth, level ground surface. There are, however, many outdoor work environments (e.g. agriculture and construction) that require manual material handling activities on variable grade ground surfaces. Quantifying the biomechanical response while lifting under these conditions may provide insight into the aetiology of lifting-related injury. The aim of the current study was to quantify the effect of laterally slanted ground surfaces on the biomechanical response. Ten subjects performed both isometric weight-holding tasks and dynamic lifting exertions (both using a 40% of max load) while standing on a platform that was laterally tilted at 0, 10, 20 and 30 degrees from horizontal. As the subject performed the isometric exertions, the electromyographic (EMG) activity of trunk extensors and knee extensors were collected and during the dynamic lifting tasks the whole body kinematics were collected. The whole body kinematics data were used in a dynamic biomechanical model to calculate the time-dependent moment about L5/S1 and the time-dependent lateral forces acting on the body segments. The results of the isometric weight-holding task show a significant (p < 0.05) effect of slant angle on the normalized integrated EMG values in both the left (increase by 26%) and right (increase by 70%) trunk extensors, indicating a significant increase in the protective co-contraction response. The results of the dynamic lifting tasks revealed a consistent reduction in the peak dynamic L5/S1 moment (decreased by 9%) and an increase in the instability producing lateral forces (increased by 111%) with increasing slant angle. These results provide quantitative insight into the response of the human lifter under these adverse lifting conditions.     

Field study of pulsed air sparging for remediation of petroleum hydrocarbon contaminated soil and groundwater

Recent laboratory-scale studies strongly suggested an advantage to operating air-sparging systems in a pulsed mode; however, little definitive field data existed to support the laboratory-scale observations. This study aimed to evaluate the performance of a field-scale pulsed air-sparging system during a short-term pilot test and during long-term system operation. The air-sparging system consisted of 32 sparging points and had been previously operated in a continuous mode for two years before the field study was performed. The field study used instruments with continuous data logging capabilities to monitor the dynamic responses of groundwater and soil vapor parameters to air injection. The optimum pulsing frequency was based on the evidence that the hydrocarbon volatilization and oxygen dissolution rates dramatically dropped after the air-sparging system reached steady state. The short-term pilot test results indicated a substantial increase in hydrocarbon volatilization and biodegradation in pulsed operation. On the basis of the results of the pilottest, the air-sparging system was set to operate in a pulsed mode at an optimum pulsing frequency. Operation parameters were collected 2, 8, and 12 months after the start of the pulsed operation. The long-term monitoring results showed thatthe pulsed operation increased the average hydrocarbon removal rate (kg/day) by a factor of up to 3 as compared to the previous continuous operation. The pulsed air sparging has resulted in higher reduction rates of dissolved benzene, toluene, ethylbenzene, and xylenes (BTEX) than were observed during the continuous operation. Among BTEX, benzene's reduction rate was the highest during the pulsed air-sparging operation.     

Risky driving habits and motor vehicle driver injury

Risky driving is an important cause of motor vehicle injury, but there is a lack of good epidemiological data in this field, particularly data comparing risky driving in younger drivers to those of other age groups. We examined the relationship between risky driving habits, prior traffic convictions and motor vehicle injury using cross-sectional data amongst 21,893 individuals in New Zealand, including 8029 who were aged 16-24 years. Those who reported frequently racing a motor vehicle for excitement or driving at 20 km/h or more over the speed limit, and those who had received traffic convictions over the past 12 months, were between two and four times more likely to have been injured while driving over the same time period. Driving unlicensed was a risk factor for older but not younger drivers, and driving at 20 km/h or more above the speed limits was a stronger risk factor for younger (<25 years) than older drivers. These results confirm the need for interventions targeting risky driving and suggest that different strategies may be required for different high-risk groups.     

An ultra-low-power programmable analog bionic ear processor

We report a programmable analog bionic ear (cochlear implant) processor in a 1.5-microm BiCMOS technology with a power consumption of 211 microW and 77-dB dynamic range of operation. The 9.58 mm x 9.23 mm processor chip runs on a 2.8 V supply and has a power consumption that is lower than state-of-the-art analog-to-digital (A/D)-then-DSP designs by a factor of 25. It is suitable for use in fully implanted cochlear-implant systems of the future which require decades of operation on a 100-mAh rechargeable battery with a finite number of charge-discharge cycles. It may also be used as an ultra-low-power spectrum-analysis front end in portable speech-recognition systems. The power consumption of the processor includes the 100 microW power consumption of a JFET-buffered electret microphone and an associated on-chip microphone front end. An automatic gain control circuit compresses the 77-dB input dynamic range into a narrower internal dynamic range (IDR) of 57 dB at which each of the 16 spectral channels of the processor operate. The output bits of the processor are scanned and reported off chip in a format suitable for continuous-interleaved-sampling stimulation of electrodes. Power-supply-immune biasing circuits ensure robust operation of the processor in the high-RF-noise environment typical of cochlear implant systems.     

Fixation disparity: binocular vergence accuracy for a visual display at different positions relative to the eyes

Some observers do not fixate accurately at the point of regard: Their vergence angle (between the visual axes of the two eyes) may correspond to points slightly nearer or farther away. This vergence error, or fixation disparity, was measured with nonius (vernier) lines at six positions of a visual display relative to the eyes. At viewing distances of 40, 60, and 100 cm, the display was located either at eye level or at a downward inclination of gaze direction of -25 degrees relative to horizontal. Viewing conditions resembled typical office work. Lowering the screen induced a near shift in mean vergence response of 0.6 min arc, irrespective of viewing distance; the closer the screen, the more distant was the vergence response relative to the target (by 2.5 min arc on average). The slope of this proximity-fixation-disparity curve is an individual parameter of the vergence system. Actual or potential applications of this research include recommendations for the comfortable viewing distance of visual displays.     

ADAPT: A Predictive Cognitive Model of User Visual Attention and Action Planning

We present a computational cognitive model of novice and expert aviation pilot action planning called ADAPT that models performance in a dynamically changing simulated flight environment. We perform rigorous tests of ADAPT's predictive validity by comparing the performance of individual human pilots to that of their respective models. Individual pilots were asked to execute a series of flight maneuvers using a flight simulator, and their eye fixations and control movements were recorded in a time-synched database. Computational models of each of the 25 individual pilots were constructed, and the individual models simulated execution of the same flight maneuvers performed by the human pilots. The time-synched eye fixations and control movements of individual pilots and their respective models were compared, and rigorous tests of ADAPT's predictive validity were performed. The model explains and predicts a significant portion of pilot visual attention and control movements during flight as a function of piloting expertise. Implications for adaptive training systems are discussed.     

Role of manual-guided training in the conduct and efficacy of interpersonal psychotherapy for depression.

This article reviews findings from manual-guided training programs in short-term interpersonal psychotherapy (IPT) for depression, an exploratory treatment that focuses on symptom reduction and improvement of social functioning. The literature revealed (a) that experienced, dynamically trained therapists were able to achieve a high level of competence in IPT after comparatively brief training and were able to maintain adherence to the manual over a lengthy study; (b) that general dimensions of the psychotherapy process, including therapist warmth and patient difficulty, were highly correlated with ratings of therapist competence in the performance of IPT; and (c) that therapists judged as performing IPT more competently tended to be more effective. Although definitive evidence on the effectiveness of manual-guided training is lacking, the use of manuals and systematic therapist training appear to be useful for the conduct of psychotherapy efficacy research. Findings showing that manual adherence is related to therapist efficacy suggest a role for these procedures in clinical training and competency determination. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social influences on children's problem solving.

Three studies examined the nature and limiting conditions of effects of peer interaction on children's problem solving. 150 children (4 to 11 years old) worked alone or with a same-age peer at a computer. Age, task complexity, and task familiarity were found to qualify effects of peer interaction on both motivation and learning. At all ages, except when the task was very complex or very familiar, working with a peer increased task engagement and positive affect. For younger preschool children, working with a peer had no effect on retention of simple or moderately complex tasks but had a negative effect on retention of more complex tasks. For older preschool children, peer interaction had a positive effect on retention of simple tasks, a neutral effect on retention of moderately complex tasks, and a negative effect on retention of more complex tasks. For elementary-school children, peer interaction had a positive effect on retention of even the most complex tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)