Genetic-based interactions among tree neighbors: identification of the most influential neighbors, and estimation of correlations among direct and indirect genetic effects for leaf disease and growth in Eucalyptus globulus.

An individual's genes may influence the phenotype of neighboring conspecifics. Such indirect genetic effects (IGEs) are important as they can affect the apparent total heritable variance in a population, and thus the response to selection. We studied these effects in a large, pedigreed population of Eucalyptus globulus using variance component analyses of Mycosphearella leaf disease, diameter growth at age 2 years, and post-infection diameter growth at ages 4 and 8 years. In a novel approach, we initially modeled IGEs using a factor analytic (FA) structure to identify the most influential neighbor positions, with the FA loadings being position-specific regressions on the IGEs. This involved sequentially comparing FA models for the variance-covariance matrices of the direct and indirect effects of each neighbor. We then modeled IGEs as a distance-based, combined effect of the most influential neighbors. This often increased the magnitude and significance of indirect genetic variance estimates relative to using all neighbors. The extension of a univariate IGEs model to bivariate analyses also provided insights into the genetic architecture of this population, revealing that: (1) IGEs arising from increased probability of neighbor infection were not associated with reduced growth of neighbors, despite adverse fitness effects being evident at the direct genetic level; and (2) the strong, genetic-based competitive interactions for growth, established early in stand development, were highly positively correlated over time. Our results highlight the complexities of genetic-based interactions at the multi-trait level due to (co)variances associated with IGEs, and the marked discrepancy occurring between direct and total heritable variances.

The effects of age and environment on the expression of inbreeding depression in Eucalyptus globulus.

Inbreeding adversely affects fitness traits in many plant and animal species, and the magnitude, stability and genetic basis of inbreeding depression (ID) will have short- and long-term evolutionary consequences. The effects of four degrees of inbreeding (selfing, f=50%; full- and half-sib matings, f=25 and 12.5%; and unrelated outcrosses, f=0%) on survival and growth of an island population of Eucalyptus globulus were studied at two sites for over 14 years. For selfs, ID in survival increased over time, reaching a maximum of 49% by age 14 years. However, their inbreeding depression for stem diameter remained relatively stable with age, and ranged from 28 to 36% across years and sites. ID for survival was markedly greater on the more productive site, possibly due to greater and earlier onset of inter-tree competition, but was similar on both sites for the diameter of survivors. The deleterious trait response to increasing inbreeding coefficients was linear for survival and diameter. Non-significant quadratic effects suggested that epistasis did not contribute considerably to the observed ID at the population level. Among- and within-family coefficients of variation for diameter increased with inbreeding degree, and the variance among the outcrossed families was significant only on the more productive site. The performance of self-families for diameter was highly stable between sites. This suggests that, for species with mixed mating systems, environmentally stable inbreeding effects in open-pollinated progenies may tend to mask the additive genotype-by-environment interaction for fitness traits and the adaptive response to the environment.

An international study of psychological problems in primary care. Preliminary report from the World Health Organization Collaborative Project on 'Psychological Problems in General Health Care'.

This article describes a large longitudinal multicenter collaborative study that investigated the form, frequency, course, and outcome of psychological problems that were seen in primary health care settings in 15 different sites around the world. The research employed a two-stage sampling design in which the 12-item General Health Questionnaire was administered to 26,422 persons aged 18 to 65 years who were consulting health care services. Of these persons, 5604 were selected for detailed examinations using standardized instruments and were followed up at 3 months and 1 year to provide information on course and outcome. All assessment instruments have been translated into 13 different languages. The project has produced a database that allows for the exploration of the nature of psychological disorders experienced by patients in general medical care and their association with physical illness, illness behavior, and disability over time.

Sleep and health: research and clinical perspectives.

Overall, the Workshop covered most of the principal areas which will be the focus of the Worldwide Project on Sleep and Health. Presentations ranged from the basic science of melatonin receptors to the epidemiology of untreated insomnia, and finally, to the education of primary care physicians. It was emphasized that there is a need for more data, and new experimental paradigms are necessary for successful public health initiatives dealing with sleep disorders.

Randomized, double-blind comparison of venlafaxine and fluoxetine in outpatients with major depression.

BACKGROUND: This was an 8-week, multicenter, randomized, double-blind, parallel-group study of the efficacy and tolerability of venlafaxine and fluoxetine. METHOD: Outpatients with DSM-III-R major depression, a minimum score of 20 on the 21-item Hamilton Rating Scale for Depression (HAM-D), and depressive symptoms for at least 1 month were eligible. Patients were randomly assigned to treatment with venlafaxine, 37.5 mg twice daily, or fluoxetine, 20 mg once daily. The dose could be increased to venlafaxine, 75 mg twice daily, or fluoxetine, 20 mg twice daily, after 3 weeks for a poor response. The primary efficacy variables were the final on-therapy scores on the HAM-D, Montgomery-Asberg Depression Rating Scale (MADRS), and Clinical Global Impressions Severity of Illness (CGI-S) and Improvement (CGI-I) scales. RESULTS: Three hundred eighty-two patients were randomly assigned to therapy and included in the intent-to-treat analysis. Both venlafaxine and fluoxetine produced significant reductions from baseline to day 56 in mean HAM-D, MADRS, and CGI-S scores, but no significant differences were noted between groups. Among patients who increased their dose at 3 weeks, significantly (p < .05) more patients taking venlafaxine than taking fluoxetine had a CGI-I score of 1 (very much improved) at the final evaluation. The most frequent adverse events were nausea, headache, and dizziness with venlafaxine and nausea, headache, and insomnia with fluoxetine. CONCLUSION: These results support the efficacy and tolerability of venlafaxine in comparison with fluoxetine for treating outpatients with major depression.

Sleep and cognitive (memory) function: research and clinical perspectives.

The field of memory and sleep is controversial and extremely interesting, and the relationships between thought processes, i.e. cognition and sleep, have recently been examined in a variety of clinical and basic research settings, as well as being the object of intense interest by the general public. For example, there are data which demonstrate that insomnia, as well as specific sleep disorders, can have a negative impact on sleep cognition as well as affect daytime patterns of cognitive functioning. Thus, sleep, disturbed sleep and the lack of sleep appear to affect cognitive and memory functions. An International Workshop dealing with Sleep and Cognitive Function: Research and Clinical Perspectives was convened in Cancún, Mexico, 1-4 March 1999 under the auspices of the World Health Organization Worldwide Project on Sleep and Health and the World Federation of Sleep Research Societies. A great number of areas of intersection between sleep and cognitive function were examined during the course of the Workshop, such as aging, cognition and sleep and the dream process and sleep. The results of these discussions are included in a WHO publication (WHO Doc.: MSD/MBD/00.8). In the present report we concentrate on presenting a summary of a coherent set of data which examine memory consolidation during sleep and the impact of insomnia on cognitive functions. Based upon these data, a review of memory and drug effects that are sleep-related, and an examination of the relationship between hypnotics and cognitive function are included. Finally, a summary of recommendations of the Workshop participants is presented.

The World Health Organization's global initiative on neurology and public health.

In 1993, the World Health Organization launched a global initiative aimed at increasing public and professional awareness of the public health aspects of neurological disorders. The initial phase of this project has been carried out through the organization of a series of symposia on prevalence, severity and costs of neurological disorders including dementia, stroke, epilepsy and headache. The main objective of the next phase of the project is to develop an international educational programme on neurology and public health and to establish a network of training centres in different regions of the world.

Amineptine (Survector 100) in the treatment of depression in Brazil.

Amineptine was studied in open, simple, and comparative trials in several Latin American countries, primarily in Brazil, Uruguay, and Chile. These countries developed studies with this antidepressant in an individualized way in different centers as well as multicenter studies under single coordination. The author analyzes the results of two of these studies. Generally, amineptine showed a positive result in depression in which the inhibition symptom is predominant. This drug also showed a good tolerance: it may be prescribed to elderly patients with depression and to people who suffer from diseases for which the classic antidepressants cannot be recommended. Many other studies on this drug were developed among the general practitioners in view of its rapid onset of action and also its easy clinical handling. Many people who suffer from depression are not treated by psychiatrists; it is very important that other specialists take notice of these effective and safe antidepressants. It is also very interesting to compare these studies to others that have already been developed in several other countries so that a better comprehension of the phenomenon of depression and its treatment can be reached.

Efficacy and safety of tianeptine in the treatment of depressive disorders in comparison with fluoxetine*

Depression is treated by a great variety of antidepressant treatments. SSRIs (such as fluoxetine) are well known: it is, however, sure that further progress is needed and the search for antidepressants with other mechanisms of action (such as tianeptine) or different efficacy is still of interest. A multinational study compared tianeptine with fluoxetine in 387 patients with Depressive Episode, or Recurrent Depressive Disorder, or Bipolar Affective Disorder (ICD-10), in a double-blind parallel group design. They were treated for six weeks. At inclusion, no significant difference between groups was shown. Final MADRS scores were 15.7 and 15.8 with tianeptine and fluoxetine, respectively (ITT population) (p = 0.944). MADRS responders were 58% and 56% with tianeptine and fluoxetine, respectively (p = 0.710). No statistical difference was observed for the other efficacy parameters. Thirty-six withdrawals occurred in each group, without any difference for the reasons of discontinuation. There was no major difference between groups for the other safety parameters. In this study, both tianeptine and fluoxetine exhibited a good efficacy and safety. Copyright 1999 Elsevier Science B. V. All rights reserved.

Experimental treatment with sodium stibogluconate of hamsters infected with Leishmania (Leishmania) chagasi and Leishmania (Leishmania) amazonensis.

The present paper reports the experimental treatment of hamsters infected with Leishmania chagasi and Leishmania amazonensis with sodium stibogluconate (20 mg/kg/day x 20 days). Only with L. chagasi did the treatment result in the complete elimination of parasites from the spleen. However, no parasitological cure was achieved in hamsters infected with L. amazonensis.

[Psychosocial aspects of dance and music of the Brazilian carnival]. / Aspects psycho-sociaux de la danse et de la musique du "carnaval" brésilien.

In this paper the author analyses the rites of Carnival, a sociocultural phenomenon that has aroused the interest of sociologists and anthropologists through out the world. He emphasizes the importance of Carnival as a psychic stabilizing mechanism, responsible for the reduction of psychiatric cases observed during this period. He studies the origins of Brazilian culture, the peculiarities the meeting of the African folklore and mysticism with the European folklore has created, and also the results of such interaction. In tracing the origins of Carnival rites, the author points out the significant role played by the dynamic and contagious rhythm of the music, that generates an unrestrained atmosphere in which enthusiastic singing and dancing act as elements of catharsis, liberation, compensation and social integration.

Electric and magnetic field effects on the excitonic properties of elliptic core-multishell quantum wires.

The effect of eccentricity distortions of core-multishell quantum wires on their electron, hole and exciton states is theoretically investigated. Within the effective mass approximation, the Schrödinger equation is numerically solved for electrons and holes in systems with single and double radial heterostructures, and the exciton binding energy is calculated by means of a variational approach. We show that the energy spectrum of a core-multishell heterostructure with eccentricity distortions, as well as its magnetic field dependence, are very sensitive to the direction of an externally applied electric field, an effect that can be used to identify the eccentricity of the system. For a double heterostructure, the eccentricities of the inner and outer shells play an important role on the excitonic binding energy, especially in the presence of external magnetic fields, and lead to drastic modifications in the oscillator strength.