Accuracy of edge detection methods with local information in speckled imagery

We compare the accuracy of five approaches for contour detection in speckled imagery. Some of these methods take advantage of the statistical properties of speckled data, and all of them employ active contours using B-spline curves. Images obtained with coherent illumination are affected by a noise called speckle, which is inherent to the imaging process. These data have been statistically modeled by a multiplicative model using the G0 distribution, under which regions with different degrees of roughness can be characterized by the value of a parameter. We use this information to find boundaries between regions with different textures. We propose and compare five strategies for boundary detection: three based on the data (maximum discontinuity on raw data, fractal dimension and maximum likelihood) and two based on estimates of the roughness parameter (maximum discontinuity and anisotropic smoothed roughness estimates). In order to compare these strategies, a Monte Carlo experience was performed to assess the accuracy of fitting a curve to a region. The probability of finding the correct edge with less than a specified error is estimated and used to compare the techniques. The two best procedures are then compared in terms of their computational cost and, finally, we show that the maximum likelihood approach on the raw data using the G0 law is the best technique.     

Posttraumatic Stress and Mental Health Functioning of Sexually Abused Children

This study examined the relationship between levels of posttraumatic stress and overall mental health functioning of fifty-three sexually abused children. This study analyzes the relationships between the mental health functioning of sexual abuse victims and PTSD, using data collected from the Non-Offending Parents Project. Unlike numerous earlier studies, standardized instruments (the Child Assessment Schedule and the Child Posttraumatic Stress Reaction Index) were used for data collection. Data analysis supported the hypothesis that the posttraumatic stress level of children who have been sexually abused is associated with level of child mental health functioning. Nearly all the children in the study were experiencing a clinical level of posttraumatic stress, and were diagnosed as having PTSD. Child Assessment Schedule subscale areas which were related to posttraumatic stress level included worries, physical complaints, moods, school functioning, family, and fears.     

Hispanics in Higher Education and the Texas Top 10% Law

This paper examines the consequences of changes in Hispanic college enrollment after affirmative action was banned and replaced by an admission guarantee for students who graduate in the top 10% of their high school class. We use administrative data on applicants, admittees, and enrollees from the two most selective public institutions and Texas Education Agency data about high schools to evaluate whether and how application, admission, and enrollment rates changed under the three admission regimes. Despite popular claims that the top 10% law has restored diversity to Texas’s public flagships, our analyses that account for secular changes in the size of graduation cohorts show that Hispanics are more disadvantaged relative to whites under the top 10% admission regime at both University of Texas at Austin and Texas A&M University. Simulations of Hispanics’ gains and losses at each stage of the college pipeline reveal that affirmative action is the most efficient policy to diversify college campuses, even in highly segregated states like Texas.     

Complementarity and Leverage as Drivers of the Stock Market Reaction to Global Alliance Formation

Companies are increasingly using global alliances to accelerate their international expansion. This paper identifies the critical factors that influence how the stock market will react to news of this type of alliance. We argue that abnormal returns on such news depend on the degree to which partners fill gaps in their international networks. We also argue that these alliances should be designed to take advantage of these complementarities in a well-defined geographical area. An empirical analysis of the stock market reaction to 72 global alliances by listed Spanish companies confirmed the importance of complementarity and leverage in explaining abnormal returns, and the irrelevance of the region of origin of the partner.     

Measuring Regional Performance in the Italian NHS: Are Disparities Decreasing?

Social Indicators Research - Given the regional disparities that historically characterize the Italian context, in this paper we propose a framework to evaluate the regional health care...     

Multilevel Factors Influencing Maternal Stress During the First Three Years

This prospective study applies family stress theory to the influence of personal, child, and familial factors on a mother's parenting stress during the first 3 years of her infant's life. Participants included 134 mothers and their infants at ages 1, 6, 15, 24, and 36 months from one site of a multisite, longitudinal study. Mother's personality was most predictive of parenting stress cross‐sectionally and longitudinally. Intimacy with partner reduced parenting stress early in the infant's life and at 36 months, whereas general social support was more important in the second year. Child temperament was influential at 1 and 36 months. Counterintuitively, mothers who were more satisfied with work or school choices were more likely to be chronically stressed. Implications are discussed.     

Combined physical and psychosexual therapy for provoked vestibulodynia-an evaluation of a multidisciplinary treatment model

Our objective is to standardize and evaluate a combined physical and psychosexual therapy for women with provoked vestibulodynia. Twenty-four patients underwent the treatment program. Sessions with a psychosexual counselor included issues on sexual functioning, psychological adjustments, and stress elimination. Exercises for mucosal desensitization and reestablishment of pelvic floor function were supervised by a midwife. A questionnaire was used for evaluation at a minimum of 6 months after the treatment. The mean number of appointments to the counselor was 12 (4-24) and 15 (9-26) to the midwife during a mean period of 53 weeks (19-92). Nineteen women (79%) considered themselves to be cured or having greatly improved. Intercourse frequency was increased (p = 0.001) and coital pain was reduced (p = 0.02) after completing the treatment. Improvements in sexual functioning and coping strategies for psychological impairment and stress were reported. Women with provoked vestibulodynia benefit from a multidisciplinary treatment model including desensitization of the vestibular mucosa, rehabilitation of the pelvic floor, and psychosexual adjustments.     

The Impact of Democracy on Well-being

Can governance impact directly on well-being? In this paper we examine subjective well-being using data for a cross section of countries from the World Values data set. We find that regional democratic satisfaction impacts on both individual happiness and life satisfaction. However, the impact is less evident for women, rich people and for those in rich countries. The fact that the governance variable analysis is based on regional differences in democratic satisfaction reminds us that governance and indeed happiness often differs within countries as well as between them. The use of regional satisfaction in this manner helps overcome endogeneity problems which would be present if we were to use individual democratic satisfaction. Other significant determinants of happiness include settlement size, marital status, income, unemployment and being part of a linguistic minority/majority grouping.