Motion estimation for cardiac emission tomography by optical flow methods.

This paper describes a new method for estimating the 3D, non-rigid object motion in a time sequence of images. The method is a generalization of a standard optical flow algorithm that is incorporated into a successive quadratic approximation framework. The method was evaluated for gated cardiac emission tomography using images obtained from a mathematical, 4D phantom and a physical, dynamic phantom. The results showed that the proposed method offers improved motion estimation accuracy relative to the standard optical flow method. Convergence of the proposed algorithm was evidenced with a monotonically decreasing objective function value with iteration. Practical application of the motion estimation method in cardiac emission tomography includes quantitative myocardial motion estimation and 4D, motion-compensated image reconstruction.

Invasive pneumococcal infections in pediatric cardiac transplant patients.

BACKGROUND: Bacterial infections cause significant morbidity and mortality in cardiac transplant patients. Because Streptococcus pneumoniae is the most prominent bacterial pathogen of childhood, the objective of this study was to define the role of S. pneumoniae as a pathogen in the cardiac transplant population. METHODS: Medical records of cardiac transplant patients from March, 1990, through November, 2000, were reviewed to identify invasive pneumococcal infections after transplantation. Demographic, clinical and microbiologic data were reviewed. RESULTS: Nine (11%) of 80 patients had 12 episodes of pneumococcal bacteremia for an incidence rate of 39 cases/1,000 patient years. Patients who were African-American, transplanted before 2 years of age and transplanted because of idiopathic dilated cardiomyopathy were at increased risk of invasive pneumococcal disease (P < 0.05). Six patients were eligible for the 23-valent pneumococcal polysaccharide vaccine before their first invasive infection, but only 1 had received it at the recommended age. Most isolates (82%) were penicillin-susceptible, and no single serotype predominated. There were 2 deaths in the study group, but each was unrelated to infection. Three patients (33%) had recurrent invasive disease with a second serotype an average of 12 months after the first infection. CONCLUSIONS: The incidence of pneumococcal bacteremia in cardiac transplant patients is higher than in the general pediatric population. Risks for infection were being African-American, being younger than 2 years at the time of transplant and being transplanted because of idiopathic cardiomyopathy. It is plausible that pneumococcal vaccine would decrease this risk.

Affective and behavioral responses to friends who neglect their friends for dating partners: influences of gender, jealousy and perspective.

Adolescents in the ninth grade (n=75) responded to a hypothetical situation involving an individual who neglects their friend as a result of their transition to steady dating. Results indicated that 53 per cent of girls and 32 per cent of boys reported past personal exclusion by their best friend who they perceived to be preoccupied by a romantic partner. Only 21 per cent of girls and 19 per cent of boys reported that they had ignored their best friend in the past while being preoccupied by a romantic partner. There were significant differences in emotional reactions of individuals depending on their gender, level of characteristic jealousy, and the perspective taken in the jealousy triangle. Analyses of suggested behavioral responses revealed a significant difference in verbosity depending on emotional reactions, gender, and level of characteristic jealousy. In general, the strategies adolescents' recommended for handling this situation were constructive, active responses that convey a continuing commitment to the relationship.

Children's interactions in triads: behavioral profiles and effects of gender and patterns of friendships among members.

In all, 56 triads of same-sex 3rd-, 4th-, and 5th-grade children were observed during an intimate discussion, a cooperative puzzle task, a competitive game, and free play. Observers coded triadic interaction using a Q sort and individual process ratings. Of particular interest was how gender and the pattern of friendship ties among group members related to children's behavior. Triads of girls were more intimate, exchanged more information, and were less aggressive than were triads of boys. Analyses of within-gender variability revealed 2 prototypical types of triads among boys but only 1 among girls. Girls and boys expressed similar attitudes toward triadic interaction in postsession interviews. However, girls', but not boys', attitudes were closely linked to the quality of interactions during the session. For both sexes, interaction was not strongly influenced by the initial configuration of friendship ties among triad members.

Social problem-solving skills of children with traumatic brain injury.

Studies of specific social skill deficits in adults with traumatic brain injury (TBI) have begun to appear [1,2], but there are few empirical studies of children with TBI. This study examined social problem-solving skills in boys and girls with TBI and a matched group of non-injured peers, ages 7-13. The TBI group generated fewer total solutions on a social problem-solving measure, largely reflecting situation-specific differences in generated solutions. The TBI group also generated fewer positive assertive, and more indirect responses to peer group entry situations than the comparison group. Implications are discussed for a model of social information processing in paediatric brain injury.

Behavioral, affective, and social correlates of involvement in cross-sex friendship in elementary school.

The purpose of this study was to compare children with and without cross-sex friends on measures of social and cognitive competence, endorsement of sex-role stereotypes, and family composition. Subjects were 723 third and fourth graders (377 girls, 346 boys) from diverse socioeconomic backgrounds; 35% were African American. Measures included sociometric assessments of peer acceptance, friendship, and behavioral reputation, as well as self-reports of perceived self-competence and endorsement of sex-role stereotypes. In addition, teachers completed ratings of children's social and cognitive competence. In all, 92 children, about 14% of the sample, had one or more reciprocal opposite-sex friends; for 21 of these children, their cross-sex friendships were their primary or only friendships. African American children were more likely than European American children to have opposite-sex friends. Involvement in cross-sex friendships was unrelated to the gender make-up of the classroom but was related to family structure. Comparisons of the children who had primarily or only cross-sex friends to matched groups of children who had only same-sex friends and to children who had cross-sex friends secondarily to same-sex ones revealed a number of differences between the groups in social competence and relationships with peers. Overall, children with primarily opposite-sex friends had poorer social skills than other children with friends, although they were less stereotyped about sex roles than other children, and were better adjusted than children with no friends on most measures. In contrast, children involved in opposite-sex friendship secondarily to same-sex friendship were as well adjusted socially as children with only same-sex friendships. These results suggest that children with cross-sex friends differ among themselves, depending on the primacy of the cross-sex relationship.

Depression and maltreatment as predictors of social competence and social problem-solving skills in school-age children.

Childhood depression and child maltreatment have been shown to be important predictors of childhood adjustment problems, including difficulties in the spheres of home, school, and peer relationships. In this study, depression and maltreatment were used to predict social competence and social problem-solving skills, as rated by self, parent, and teacher. The total sample contained 68 children (35 girls, 33 boys), most of whom were at high-risk either due to poverty, physical abuse and neglect (as determined by substantiated Protective Services reports), or exposure to negative life events. Hierarchical multivariate regression analyses were used to identify the contribution of depression and maltreatment to social competence and social problem-solving skills. Depression predicted parents' and teachers' ratings of social competence and parents' ratings of peer rejection. Additionally, depression predicted children's ratings of social competence and both measures of social problem-solving skills. Maltreatment predicted parents' and teachers' ratings of social competence. Gender predicted teachers' ratings of peer rejection and social competence. An additive effect of depression and maltreatment was found such that children who are depressed and maltreated have the lowest social competence as rated by parents and teachers. These children are, therefore, doubly at risk for problems in future relationships.

Chemical restraints and children: autonomy or veracity?

TOPIC: The ethical issues involved in chemical control of children with attention deficit disorder (ADD). PURPOSE: To assist nurses giving chemical injections to children to make ethically based decisions. SOURCE: Application of ethical principles in a specific clinical situation. CONCLUSIONS: The author concludes that institutionalized children deserve competent nurses who are able to make ethical or moral decisions concerning these young patients' care.

The lived experience of Native Americans with diabetes within a transcultural nursing perspective.

The purpose of this study was to advance transcultural nursing knowledge based on the lived experiences of Native Americans with non-insulin dependent diabetes mellitus (NIDDM). The phenomenological qualitative research method was used to discover Native Americans lived experiences. Data was gathered in rural Oklahoma through non-structured interviews and clinical observations of Native Americans with NIDDM. The interviews were transcribed and analyzed for themes and patterns of similar statements among informants. Six major thematic categories were identified: reactions to NIDDM, responses to loss of health, identification with others, fear associated with the disease process, peace related to the diagnosis of NIDDM, and grieving associated with the diagnosis of NIDDM. The informants' experiences were reconstructed into transformed meanings that characterized the lifeworld of Native Americans with NIDDM.

On the inactivation of bacteria by singlet oxygen--another view.

Midden and Dahl, in a recent paper, have presented important data on the inactivation of bacteria by singlet oxygen. In analyzing the data, use was made of a theory published earlier by the present author. The purpose of this paper is to point out that theory and experiment can be brought into better agreement by assuming that the interaction of singlet oxygen with the bacteria takes place in an essentially lipid environment rather than aqueous.

Thoracic trauma. Nursing assessment and management.

The importance of the respiratory system to total body functioning cannot be overemphasized. It is imperative that the nurse realize that the first priority in trauma care is to maintain and support the respiratory system. The nurse must be able to rapidly and effectively perform a primary survey, recognize the clinical manifestations of life-threatening thoracic injuries, and intervene in the care of the patient to help stabilize and maintain the patient's respiratory function. The nurse must not only be able to asses, but must also be able to technically intervene rapidly and effectively. Other potential life-threatening injuries must remain uppermost in the nurse's mind. Continual, ongoing monitoring of the patient's status must be an integral part of the nurse's actions. If these activities are judiciously employed, perhaps the mortality rate will decrease and the thoracic trauma victim will survive, capable of leading a full and productive life in our society. This is quality patient care.

Ciliated Protozoa in marine pollution studies. A conspectus.

The ecological role of the marine ciliates is discussed with reference to the interaction of this group with contaminants. While the ciliates may be of some value in routine screening of potential toxins, simple laboratory bioassays are unlikely to be of predictive value in assessing threats to the marine environment. There is some evidence that ciliates may take part in the transfer and transformation of potential pollutants. Further field and laboratory studies are required in order to identify and quantify the role of ciliates in these processes.

Optical absorption in glass: investigation using an acoustic technique.

Experimental studies have indicated that chopped light entering a high pressure gas cell may produce sound in the gas even though the gas is not ir absorbing. Investigation into the source of this sound showed it to be due to interaction of the incident light with the cell window. The dependence of the sound pressure amplitude on cell pressure p0 indicates a p0(1/2) dependence, implying that the responsible mechanism is a diffusion process. Application of theory is successful in explaining both the quantitative and qualitative aspects of the data if the existence of an optically absorbing surface layer is assumed. The results obtained here are in general consistent with data obtained from studies of laser damage in glasses at high intensities.