Characterizing neutral modes of fractional states in the second Landau level.

Fractionally charged quasiparticles, which obey non-abelian statistics, were predicted to exist in the ν=8/3, ν=5/2, and ν=7/3 fractional quantum Hall states (in the second Landau level). Here we present measurements of charge and neutral modes in these states. For both ν=7/3 and ν=8/3 states, we found a quasiparticle charge e=1/3 and an upstream neutral mode only in ν=8/3-excluding the possibility of non-abelian Read-Rezayi states and supporting Laughlin-like states. The absence of an upstream neutral mode in the ν=7/3 state also proves that edge reconstruction was not present in the ν=7/3 state, suggesting its absence also in ν=5/2 state, and thus may provide further support for the non-abelian anti-pfaffian nature of the ν=5/2 state.

Accumulation of metals in Elodea canadensis and Elodea nuttallii: implications for plant-macroinvertebrate interactions.

Elodea nuttallii and Elodea canadensis are considered good candidates for metal studies. Metal pollution can disturb the interactions between trophic levels. Our goals were 1) to analyse the metal content in plants, sediment and water from three polluted sites, and 2) to analyse the impact of metal contamination on plant consumption by macroinvertebrates. The concentrations of Cd, Cr, Cu, Mn, Ni, Pb, Zn and Fe and S were measured in water, sediment and in the two Elodea species during two years. Our results showed that metal accumulation varied according to site, metal and season. The ability to uptake metal was similar in E. canadensis and in E. nuttallii. No significant seasonal metal accumulation was established for plants or sediment. Metal accumulation in Elodea species in polluted sites had no impact on their palatability. The plant palatability depends on the season and varies according to the part of the plant. In autumn, apex was less consumed than defoliated and foliated stems.

Light flowers from coherent vertical-cavity surface-emitting laser arrays.

Emission of symmetric flower-shaped light patterns from coherently locked hexagonal vertical-cavity semiconductor laser arrays is reported. The flower patterns preserve their shape while propagating in free space. The emission of these unique light distributions is explained as being due to the combined effects of thermal lensing and the loss patterns employed for array definition. A theoretical model for strongly coupled arrays matches the results.

Beneficial effect of risperidone on sleep disturbance and psychosis following traumatic brain injury.

Severe disturbances of sleep architecture and circadian rhythms are common in traumatic brain injured patients; however, complete absence of the rapid eye movement sleep stage is very rare. We describe a brain injured patient with cognitive disturbances who developed severe alterations of sleep architecture, accompanied by paranoid and jealousy delusions. Following several trials with conventional antipsychotics his psychotic state stabilized but he continued to complain of insomnia and daytime fatigue. When treated with risperidone 2 mg/day, both his sleep and the delusional thoughts improved markedly and his daytime alertness increased. Severe deterioration of his support system brought about discontinuation of treatment with re-emergence of all symptoms.

Self-concept, marital vulnerability and brain damage.

The present study investigated the influence of a man's brain injury on both his and his wife's self-concept and perception of marital vulnerability. Thirty-six couples in which the husbands had brain damage and twenty-nine couples without disability filled out the Tennessee Self-concept Scale [1], and the Marital Vulnerability Scale [2]. Marital vulnerability of husbands with brain damage was found not to differ from that of the husbands in the control group. However, the marital vulnerability of the wives of the former husbands was lower than that of the other wives. Both men with brain damage and their wives exhibited a decrease in self-esteem and an increase in conflict and pathology. Brain damage appears to affect both the extent and direction of the relations between aspects of the self-concept and marital vulnerability differentially for husbands with brain damage and their wives. Practical and theoretical implications of the negative impact of brain damage upon the person with the damage, upon his wife, and upon their marital relationship are discussed.

Patient-controlled analgesia using a miniature electrochemically driven infusion pump.

We describe a miniature electrochemically driven, wrist-worn infusion pump. Generation of gas by an electrolytic reaction compresses a reservoir containing medication and provides a predictable and controllable infusion rate. The pump was used for patient-controlled analgesia (PCA) in women who required analgesia after Caesarean section. It was accepted readily and was convenient for both patients and nursing staff. This portable system, using a novel motive force, has advantages of convenience over larger systems and has sophisticated features not present in existing small systems. It has potential as a routine PCA device and it may have uses in other situations requiring convenient infusion or intermittent injection in an ambulatory setting.

Differential effect of right and left hemispheric lesions on two memory tasks: free recall and frequency judgement.

We investigated the relationship between lateralized cerebral damage and two memory tasks; free recall and frequency judgement. Free recall is considered to be processed effortfully while frequency judgement is considered to be processed automatically (Hasher and Zacks). Nine right brain-damaged patients (RBD), nine left brain-damaged patients (LBD) and nine control subjects participated in this study. It was hypothesized that RBD would show an advantage over LBD on the free-recall task, whereas LBD would show an advantage over RBD on the frequency-judgement task. In accordance with our hypothesis, free-recall was more impaired in LBD than in RBD. In the frequency-judgement task, an effect of laterality of lesion was found in high (4-6) and low (0-1) frequencies, but not in the medium (2-3) frequencies. The anticipated LBD advantage was shown in judgement of the high frequencies, but unexpectedly RBD performed better than LBD in low frequencies. The results are discussed in terms of the relationship between effortful and automatic memory processes and cerebral lateralization.

Why do they fall? Monitoring risk factors in nursing homes.

A pilot study identified 40 falls involving 29 patients from incident reports in a nursing home. About one fourth of the fallers fell more than once and accounted for about one fourth of the falls. The majority of research studies on falls were conducted in hospital settings on a one-time basis. Studies are needed in nursing homes to monitor risk factors on a continuous basis to design remedial nursing interventions. Age, male gender, mental impairment, and short stay were risk factors identified in this study. The association of dementia with falls is especially significant because of the increasing numbers of dementia patients in nursing homes. This pinpoints the need for special surveillance of these patients.

Critical thinking and nursing education.

This study evaluated the impact of nursing education on students' critical thinking abilities, as measured by the Watson-Glaser Critical Thinking Appraisal (WG). In addition, the WG and the NLN Pre-Admission Test were related to GPA and NCLEX. A sample of 108 AS and BS students at the University of Hawaii School of Nursing were tested at entry and exit. AS and BS students showed comparable improvement in critical thinking ability. NCLEX was best predicted by the GPA, which in turn summed up effects of WG and NLN. The results confirm the efficacy of nursing education in improving critical thinking skills and suggest that the GPA is more important than the WG in predicting the NCLEX. The latter effect was more prominent in the BS group. Further investigation of the role of critical thinking in nursing and academic performance is suggested.

Genetic polymorphisms among Ethiopian Jews in Israel.

A random sample of 111 Ethiopian Jews were studied for 24 polymorphic genetic markers in the blood. The results show the occurrence in high frequencies of many African genes in this population.

Children's perception of death in humans and animals as a function of age, anxiety and cognitive ability.

This study investigated the impact of age, cognitive level and anxiety level on children's conception of death in humans and animals. Children from three age groups (6-7; 8-9; 10-11) were divided into high and low anxiety levels and high and low cognitive abilities. Then, the children were administered two questionnaires on human and animal death. The findings show that there was a main effect of age, anxiety and cognition on the conception of both animal and human death. Human death scores were higher than animal death scores. The interactions indicate that anxiety has a stronger impact on cognitively high subjects than on cognitively low subjects and that cognition affects the animal death concept more than the human death concept.

Some common characteristics of latency-age suicidal children: a tentative model based on case study analyses.

Eleven latency-age (6 1/2 to 12 1/2) boys and girls who attempted or threatened suicide were investigated by means of the following information: intensive interviews, therapeutic meetings, direct observation in school, meetings with teachers, and survey of school records. The families of the children were also interviewed. In spite of the many differences between the children's personalities and backgrounds, some common dynamic features seemed to emerge: (a) There was a suicidal parent in the family, in most cases the mother; (b) Most of the families of these children were engaged in a major crisis, not necessarily centered around the suicidal child; (c) The children experienced demands by the parents to assume responsibilities which the children perceived as being beyond their capability; (d) There was a lack of satisfying relationships with adults; (e) Most children perceived death in a paradoxical way, believing that death was a need satisfying state yet fearing death; (f) The children showed strong positive strivings to say alive and were able to experience joy and happiness in spite of feelings of desperation and depression. A model based on the above multifaceted forces is presented. These forces consist of attractiveness of life, repulsiveness of life, attractiveness of death, and repulsiveness of death. Some of diagnostic and predictive uses of this model are elaborated.

Rat liver glycogen metabolism in the perinatal period.

The correlation between blood glucose levels, the concentration of glycogen, the activities of glycogen synthase and phosphorylase and their respective kinases and phosphatases was examined in liver of rat fetuses between day 18 of gestation and one day after birth. Between day 18 and 21 there is a rapid increase in the concentration of glycogen and in the activity of synthase a and a much slower increase in the activity of phosphorylase a. The activity of the respective kinases increased rapidly during this period and reached maximum on day 21. The activity of synthase phosphatase and phosphorylase phosphatase increased after day 18, to reach a maximum on day 19 and 20, respectively, but decreased again towards day 21. The possibility that the changes in glycogen concentration and enzyme activities were related to an effect of glucose or AMP on the respective phosphatases was considered. It was found that the Km of phosphorylase phosphatase for glucose in the prenatal period was 5--7 mM, as in the adult. Since the level of blood glucose during this period was constant (2.8 mM), an effect of glucose on phosphatase activity seems unlikely. AMP concentration increased between day 18 and 21 from 6--15 nmol/g. In view of the low level of phosphorylase a activity during this period, the increase in AMP concentration is not considered to be important in the regulation of glycogen breakdown at this time. Immediately after birth blood glucose levels dropped to 5 mg/dl. This was accompanied by a rapid decrease in glycogen concentration and in the activity of glycogen synthase and a rise in phosphorylase activity. Blood glucose levels returned to the initial level within 1 h after birth, whereas the changes in glycogen concentration and enzyme activities continued for at least 3 h after birth. On day 22 all parameters examined had reached the level found in adult rat liver. It is suggested that the rapid changes observed immediately after birth are due to an effect of gypoglycemia mediated by hormones and cannot be ascribed to direct effects of metabolites on the enzyme systems involved.

REM need in adolescents as indicated by resistance to REM deprivation.

The hypothesis that adolescents have an exceptionally strong need for REM sleep was tested by measuring their resistance to REM deprivation. Ten adolescents (aged 16 to 17 yr.) were compared with 12 young adults (aged 25 to 27 yr.) in a standard REM deprivation procedure. The adolescents had to be awakened significantly more times than the young adults; this is consistent with the hypothesis that adolescents have a greater need for REM sleep.