A longitudinal study of noncustodial parents: Parents without children.

Reports the results of a 3-wave longitudinal study of a sizable, regionally representative sample of both noncustodial and custodial parents interviewed initially before their divorce was final. A model was tested that predicted the noncustodial parent's postdivorce contact with the child and the payment of child support from a series of factors related to a social exchange orientation. This orientation highlights the noncustodial parent's implicit calculation of the rewards vs the costs of continuing involvement and support of the child. It was found that noninvolvement was, in general, well-predicted, both cross-sectionally and longitudinally, by the model. The most powerful factor in the model was the noncustodial parent's perception that he or she had some control over the child's upbringing. Among fully employed noncustodial parents who reported high perceived control, there was an excellent record of involvement and child support payment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance of a high concentration Er/sup 3+/-doped alumino silicate fiber amplifier

We report the gain, noise figure, output saturation power, and conversion efficiency of a highly concentrated Er/sup 3+/-doped alumino silicate fiber amplifier. We obtain a gain per unit length of 1.0 dB/cm, which corresponds to the highest gain per unit length obtained in an Er/sup 3+/-doped fiber amplifier. The pump power threshold ranges from 2 to 5 mW, depending on the fiber length.     

Asymptotics of Largest Components in Combinatorial Structures

Given integers m and n, we study the probability that structures of size n have all components of size at most m. The results are given in term of a generalized Dickman function of n/m.     

LONG TERM STORAGE STABILITY OF MIDDLE DISTILLATE FUELS FROM A CHEMICAL MECHANISTIC POINT OF VIEW. PART 2.

The objective of this review is to (i) articulate the current level of understanding of the types of “reactive molecules” intimately involved in the long term oxidative storage instability of middle distillates, (11) review the types of chemical reaction mechanisms most likely involved in the “oxidative phase” of insoluble formation, (iii) review the postulated chemical mechanisms of stabilizer (additive) operation, and (iv) discuss future research areas that must be explored if a greater understanding and control of middle distillate instability is to be realized.     

When is less treatment better? The role of social anxiety in matching methadone patients to psychosocial treatments.

In response to a need to match drug users to the most appropriate and cost-effective level of care, it was hypothesized that socially anxious methadone-maintained patients would attain greater benefit from coping skills training provided in the context of a low-intensity enhanced standard methadone maintenance intervention (E-STD) than in the context of a high-intensity, socially demanding day treatment program (DTP). Social anxiety was assessed in 307 methadone-maintained patients using the Social Anxiety and Distress Scale prior to randomization to either E-STD or DTP. The hypothesis was supported: Socially anxious patients were drug free longer during treatment, were more likely to be abstinent at treatment completion, and had greater reductions in HIV risk behaviors if assigned to the lower intensity intervention, which was provided at ? the cost of the DTP. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selectors Make Set-Based Analysis Too Hard

A set-based program analysis establishes constraints between sets of abstract values for all expressions in a program. Solving the system of constraints produces a conservative approximation to the program's runtime flow of values. Some practical set-based analyses use explicit selectors to extract the relevant values from an approximation set. For example, if the analysis needs to determine the possible return values of a procedure, it uses the appropriate selector to extract the relevant component from the abstract representation of the procedure. In this paper, we show that this selector-based approach complicates the constraint solving phase of the analysis too much and thus fails to scale up to realistic programming languages. We demonstrate this claim with a full-fledged value flow analysis for case-lambda, a multi-branched version of lambda. We show how both the theoretical underpinnings and the practical implementation become too complex. In response, we present a variant of set-based closure analysis that computes equivalent results in a much more efficient manner.     

Poststress effects of danger and safety signals on gastric ulceration in rats.

Gastric ulceration of rats stressed by restraint in 19°C water for 75 min was markedly increased by allowing a 75-min postrestraint room-temperature rest period during which the rat was exposed to cues that had previously been associated with the delivery of 80 5-s uncontrollable electric shocks distributed over four sessions. This effect obtained equally without regard to whether "danger cues" were punctate signals or constant contextual cues or whether contextual ones were interrupted by punctate safety signals. The experimental treatments used were unusual in that they equated the groups on their total conditioning history and thus allowed a more pure look at the poststress effect than heretofore. Other groups provided controls for prior shocks, rest, and their interaction as well as handling. Analyses of corticosterone after the stress or stress-rest cycle revealed only a general decline in corticosterone levels with rest undifferentiated across groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Are asthmatic children educationally handicapped?

Discusses the impact of asthma on children's educational experiences. Respiratory arrest or hypoxia may lead to neuropsychological changes in a few cases, and some medications may produce mild, temporary changes, affecting learning and classroom performance. For most asthmatic children, their illness does not result in permanent brain function changes that compromise their educational adaptation and performance. Increased school absence, stress of chronic illness, isolation from peers, diminished physical activities, reduced adult expectations and self esteem, and depression can compromise children's academic adaptation and progress. Co-occurrence of factors like severe illness, poverty, and family dysfunction may increase the risk for educational and psychosocial impairment. Systematic and comprehensive education of asthmatic patients, their parents, and school personnel is crucial to improving the control of asthma and activity level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Maximum Likelihood Stereo Algorithm

A stereo algorithm is presented that optimizes a maximum likelihood cost function. The maximum likelihood cost function assumes that corresponding features in the left and right images are normally distributed about a common true value and consists of a weighted squared error term if two features are matched or a (fixed) cost if a feature is determined to be occluded. The stereo algorithm finds the set of correspondences that maximize the cost function subject to ordering and uniqueness constraints. The stereo algorithm is independent of the matching primitives. However, for the experiments described in this paper, matching is performed on the $cf4$individual pixel intensities.$cf3$ Contrary to popular belief, the pixel-based stereo appears to be robust for a variety of images. It also has the advantages of (i) providing adensedisparity map, (ii) requiringnofeature extraction, and (iii)avoidingthe adaptive windowing problem of area-based correlation methods. Because feature extraction and windowing are unnecessary, a very fast implementation is possible. Experimental results reveal that good stereo correspondences can be found using only ordering and uniqueness constraints, i.e., withoutlocalsmoothness constraints. However, it is shown that the original maximum likelihood stereo algorithm exhibits multiple global minima. The dynamic programming algorithm is guaranteed to find one, but not necessarily the same one for each epipolar scanline, causing erroneous correspondences which are visible as small local differences between neighboring scanlines. Traditionally, regularization, which modifies the original cost function, has been applied to the problem of multiple global minima. We developed several variants of the algorithm that avoid classical regularization while imposing several global cohesiveness constraints. We believe this is a novel approach that has the advantage of guaranteeing that solutions minimize the original cost function and preserve discontinuities. The constraints are based on minimizing the total number of horizontal and/or vertical discontinuities along and/or between adjacent epipolar lines, and local smoothing is avoided. Experiments reveal that minimizing the sum of the horizontal and vertical discontinuities provides the most accurate results. A high percentage of correct matches and very little smearing of depth discontinuities are obtained. An alternative to imposing cohesiveness constraints to reduce the correspondence ambiguities is to use more than two cameras. We therefore extend the two camera maximum likelihood toNcameras. TheN-camera stereo algorithm determines the “best” set of correspondences between a given pair of cameras, referred to as the principal cameras. Knowledge of the relative positions of the cameras allows the 3D point hypothesized by an assumed correspondence of two features in the principal pair to be projected onto the image plane of the remainingN− 2 cameras. TheseN− 2 points are then used to verify proposed matches. Not only does the algorithm explicitly model occlusion between features of the principal pair, but the possibility of occlusions in theN− 2 additional views is also modeled. Previous work did not model this occlusion process, the benefits and importance of which are experimentally verified. Like other multiframe stereo algorithms, the computational and memory costs of this approach increase linearly with each additional view. Experimental results are shown for two outdoor scenes. It is clearly demonstrated that the number of correspondence errors is significantly reduced as the number of views/cameras is increased.