Quantum coherence of discrete kink solitons in ion traps.

We propose to realize quantized discrete kinks with cold trapped ions. We show that long-lived solitonlike configurations are manifested as deformations of the zigzag structure in the linear Paul trap, and are topologically protected in a circular trap with an odd number of ions. We study the quantum-mechanical time evolution of a high-frequency, gap separated internal mode of a static kink and find long coherence times when the system is cooled to the Doppler limit. The spectral properties of the internal modes make them ideally suited for manipulation using current technology. This suggests that ion traps can be used to test quantum-mechanical effects with solitons and explore ideas for the utilization of the solitonic internal modes as carriers of quantum information.

Long-term neurological sequelae of hemolytic-uremic syndrome: a preliminary report.

Seven patients with hemolytic-uremic syndrome who had major neurological symptoms during the acute illness were neurologically and cognitively evaluated prospectively several years after recovery from the illness. Four patients showed evidence of subtle neurological sequelae, including posturing, clumsiness, poor fine-motor coordination, hyperactivity, and distractibility. Psychoeducational evaluation of all seven subjects revealed mean scores within the average range in cognitive abilities, academic achievement, single word receptive vocabulary, visual/motor planning, overall adaptive functioning, and hyperactivity. The lapse of time (minimum of 7 years) between the acute illness and the psychometric evaluation could have been responsible for our normal results.

Quality of toddler-mother attachment in children with Down syndrome: limits to interpretation of strange situation behavior.

Researchers studying social-emotional development have argued that primary attachment relationships, established by the end of the first year of life, are important organizing factors that influence the trajectory of development throughout childhood. Central to this argument is a dimension of "attachment security," along which attachments differ. For normally developing infants and toddlers, attachment security is assessed using the Ainsworth Strange Situation. However, it is not clear that this procedure is appropriate for evaluating attachment security in atypical populations. In this report, 3 samples of children with Down Syndrome (total N = 138) were assessed using the Strange Situation. The procedures were scored according to traditional protocols. Although the 3 samples differed with respect to chronological and developmental age, they showed basic similarity with respect to attachment variables. However, developmentally younger children were more difficult to classify using the standard scoring rules. Scores and classifications for the sample were compared to scores from a sample of normally developing children tested at about 12 months of age. Significant differences with respect to the distributions of cases to classification categories and with respect to the interactive scale scores suggest that the Strange Situation may be measuring different aspects of behavior for children with Down Syndrome, even when they are tested at similar developmental age levels.

Patterns of temperament variation in three groups of developmentally delayed preschool children: mother and father ratings.

Patterns of temperament variation in the developmentally delayed preschool population have not been adequately studied. The present paper reports temperament data for children 2 to 4 1/2 years old: 32 with Down's syndrome, 29 with neurological problems, and 35 with delays of unknown etiologies, as reported by their mothers and fathers. Results indicate that children in the total delayed sample are more approaching, less intense, less persistent, and have higher thresholds for stimulation than those in the normative sample. There were differences among the three groups in activity level, approach/withdrawal, and distractibility. Furthermore, on these three dimensions, mothers scored their children as more difficult than did fathers. These data highlight the need for adequate norms for subgroups of delayed children, and suggest that inclusion of temperament assessment can be a useful part of the clinical care of delayed children and their parents.

Family responses to developmentally delayed preschoolers: etiology and the father's role.

Parents of 59 developmentally delayed preschoolers (18 with Down syndrome, 19 with neurological problems, and with 22 unknown etiologies) responded to questionnaires and structured interviews to assess parental stress and support, locus of control, and self-esteem. There were group differences in maternal reports of positive experience with the child, self-esteem, reported support, and relations with grandparents. With the exception of self-esteem, all comparisons favored the Down syndrome group. Fathers reported fewer distress symptoms, higher self-esteem, more internal locus of control, and less support than did mothers. These findings indicate a need to understand individual differences among families of delayed children and illustrate that the effects of a child's handicap on fathers differ from those upon mothers.

The synergistic tumoricidal activity of anticancer drugs and oxidative burst-triggered macrophages.

The anticancer drugs adriamycin (ADR) and actinomycin D (AMD) were tested for their effect on the oxidative burst (OB) of mouse peritoneal macrophages (MPM) and on the killing of tumor cells by OB-stimulated MPM. The oxidative burst of MPM determined by hydrogen peroxide (H2O2) production was severely impaired by ADR (10 micrograms/ml) and AMD (40 micrograms/ml) after a 1 h treatment and by lower concentrations of the drugs following a 24 h treatment. The toxicity of the drugs against MPM was comparable to their effect on EL4 cells. Pretreatment of EL4 and TLX-9 tumor cells with sublethal amounts of ADR for 4 h rendered the cells sensitive to the cytotoxic effect of OB-stimulated MPM which were otherwise unable to kill these cells. It seems that anticancer drugs and OB-stimulated macrophages can cooperate in the destruction of tumor cells in vitro.