ESTRATÉGIA REPRODUTIVA E ALGUNS ASPECTOS DEMOGRÁFICOS DO CAMARÃO Palaemonetes carteri GORDON, 1935 NA AMAZONIA CENTRAL, RIO NEGRO

A ecologia do camarão Palaemonetes carteri Gordon, 1935 (Decapoda: Palaemonidae) foi estudada através de coletas mensais, realizadas de janeiro 1989 até maio 1990, na região de Manaus. P. carteri vive na liteira submersa dos igarapés de terra firme em áreas baixas inundadas periodicamente pelas enchentes dos rios. A estratégia de reprodução e a dinâmica da razão sexual foram estudados na base dos 4,441 indivíduos coletados. P. carteri mostrou um dimorfismo sexual do comprimento, as fêmeas sendo maiores que os machos. O período de reprodução foi restrito a enchente e a cheia das águas. O número de ovos por fêmea variou entre 5 e 39, sem nenhuma correlação com o tamanho das fêmeas. A razão sexual mostrou uma predominância de fêmeas sem nenhuma variação sazonal significativa.

Radial frequency stimuli and sine-wave gratings seem to be processed by distinct contrast brain mechanisms

An assumption commonly made in the study of visual perception is that the lower the contrast threshold for a given stimulus, the more sensitive and selective will be the mechanism that processes it. On the basis of this consideration, we investigated contrast thresholds for two classes of stimuli: sine-wave gratings and radial frequency stimuli (i.e., j0 targets or stimuli modulated by spherical Bessel functions). Employing a suprathreshold summation method, we measured the selectivity of spatial and radial frequency filters using either sine-wave gratings or j0 target contrast profiles at either 1 or 4 cycles per degree of visual angle (cpd), as the test frequencies. Thus, in a forced-choice trial, observers chose between a background spatial (or radial) frequency alone and the given background stimulus plus the test frequency (1 or 4 cpd sine-wave grating or radial frequency). Contrary to our expectations, the results showed elevated thresholds (i.e., inhibition) for sine-wave gratings and decreased thresholds (i.e., summation) for radial frequencies when background and test frequencies were identical. This was true for both 1- and 4-cpd test frequencies. This finding suggests that sine-wave gratings and radial frequency stimuli are processed by different quasi-linear systems, one working at low luminance and contrast level (sine-wave gratings) and the other at high luminance and contrast levels (radial frequency stimuli). We think that this interpretation is consistent with distinct foveal only and foveal-parafoveal mechanisms involving striate and/or other higher visual areas (i.e., V2 and V4).

Differential effects of aging on spatial contrast sensitivity to linear and polar sine-wave gratings

Changes in visual function beyond high-contrast acuity are known to take place during normal aging. We determined whether sensitivity to linear sine-wave gratings and to an elementary stimulus preferentially processed in extrastriate areas could be distinctively affected by aging. We measured spatial contrast sensitivity twice for concentric polar (Bessel) and vertical linear gratings of 0.6, 2.5, 5, and 20 cycles per degree (cpd) in two age groups (20-30 and 60-70 years). All participants were free of identifiable ocular disease and had normal or corrected-to-normal visual acuity. Participants were more sensitive to Cartesian than to polar gratings in all frequencies tested, and the younger adult group was more sensitive to all stimuli tested. Significant differences between sensitivities of the two groups were found for linear (only 20 cpd; P<0.01) and polar gratings (all frequencies tested; P<0.01). The young adult group was significantly more sensitive to linear than to circular gratings in the 20 cpd frequency. The older adult group was significantly more sensitive to linear than to circular gratings in all spatial frequencies, except in the 20 cpd frequency. The results suggest that sensitivity to the two kinds of stimuli is affected differently by aging. We suggest that neural changes in the aging brain are important determinants of this difference and discuss the results according to current models of human aging.

Acute effect of alcohol intake on sine-wave Cartesian and polar contrast sensitivity functions

The aim of this study was to assess contrast sensitivity for angular frequency stimuli as well as for sine-wave gratings in adults under the effect of acute ingestion of alcohol. We measured the contrast sensitivity function (CSF) for gratings of 0.25, 1.25, 2.5, 4, 10, and 20 cycles per degree of visual angle (cpd) as well as for angular frequency stimuli of 1, 2, 4, 24, 48, and 96 cycles/360°. Twenty adults free of ocular diseases, with normal or corrected-to-normal visual acuity, and no history of alcoholism were enrolled in two experimental groups: 1) no alcohol intake (control group) and 2) alcohol ingestion (experimental group). The average concentration of alcohol in the experimental group was set to about 0.08%. We used a paradigm involving a forced-choice method. Maximum sensitivity to contrast for sine-wave gratings in the two groups occurred at 4 cpd sine-wave gratings and at 24 and 48 cycles/360° for angular frequency stimuli. Significant changes in contrast sensitivity were observed after alcohol intake compared with the control condition at spatial frequency of 4 cpd and 1, 24, and 48 cycles/360° for angular frequency stimuli. Alcohol intake seems to affect the processing of sine-wave gratings at maximum sensitivity and at the low and high frequency ends for angular frequency stimuli, both under photopic luminance conditions.

Teoria da organizaçao e sociedades subdesenvolvidas

O texto aborda a questão da Teoria Organizacional como existente nos meados da década de 1960, enquanto expressão na racionalidade instrumental weberiana. Fazendo uso de um referencial teórico estruturalista, como o apresentado por Amitai Etzioni, procura dimensionar a lacuna entre as sociedades ocidentais e as não ocidentais. O centro do argumento é que as sociedades ocidentais, ao longo de seu processo formativo, acabaram por caracterizar-se como mais adequadas ao surgimento e funcionamento das organizações formais enquanto expressão da racionalidade instrumental. Exigências organizacionais formais seriam a subordinação do interesse individual ao geral, adesão a uma postura epistemológica pragmática, comportamento calcado em neutralidade emocional (Sine ira ac studio) e capacidade de objetivação sob a forma de ação organizada. As sociedades não ocidentais apresentariam, por sua própria formação e gênese, dificuldades maiores para abrigar e desenvolver organizações formais, caindo no círculo vicioso da baixa densidade organizacional.

Treatment of depression in older adults beyond fluoxetine

This review aimed to discuss the importance of the comprehensive treatment of depression among older adults in Brazil. The abuse of selective serotonin reuptake inhibitors, including fluoxetine hydrochloride, as antidepressants has been considered a serious public health problem, particularly among older adults. Despite the consensus on the need for a comprehensive treatment of depression in this population, Brazil is still unprepared. The interface between pharmacotherapy and psychotherapy is limited due to the lack of healthcare services, specialized professionals, and effective healthcare planning. Fluoxetine has been used among older adults as an all-purpose drug for the treatment of depressive disorders because of psychosocial adversities, lack of social support, and limited access to adequate healthcare services for the treatment of this disorder. Preparing health professionals is a sine qua non for the reversal of the age pyramid, but this is not happening yet.

Prodromal Questionnaire: translation, adaptation to Portuguese and preliminary results in ultra-high risk individuals and first episode psychosis

OBJECTIVE: The Prodromal Questionnaire (PQ) is a 92-item self-report screening tool for individuals at ultra-high risk (UHR) to develop psychosis. This study aims to present the translation to Portuguese and preliminary results in UHR and first episode (FE) psychosis in a Portuguese sample. METHODS: The PQ was translated from English to Portuguese by two bilingual researchers from the research program on early psychosis of the Instituto de Psiquiatria HCFMUSP, São Paulo, Brazil (ASAS - "Evaluation and Follow up of Adolescents and Young Adults in São Paulo") and back translated by two other researchers. The study participants (n = 11-) were evaluated through the Portuguese version of the Prodromal Questionnaire (PQ) and SIPS. RESULTS: The individuals at UHR (n = 7) presented a lower score than first episode patients (n = 4). The UHR mean scores and standard deviation on Portuguese version of the PQ were: 13.0 ± 10.0 points on positive symptoms subscale, and FE patients: 33.0 ± 10.0. CONCLUSION: The UHR and FE patients' of this study presented PQ scores similar to the ones found in the literature; what suggests that it is possible to use the PQ in Brazilian help-seeking individuals as a screening tool.

Morphometric variability in populations of Palaemonetes spp. (Crustacea, Decapoda, Palaemonidae) from the Peruvian and Brazilian Amazon Basin

Morphometric variability among shrimp populations of the genus Palaemonetes Heller, 1869 from seven lakes (Huanayo and Urcococha, in Peru; Amanã, Mamirauá, Camaleão, Cristalino e Iruçanga, in Brasil) in the Amazon Basin, presumably belonging to Palaemonetes carteri Gordon, 1935 and Palaemonetes ivonicus Holthuis, 1950, were studied. The morphometric studies were carried out from the ratios obtained from the morphometric characters. Multivariated analysis (Principal Components Analysis-PCA, Discriminant Function Analysis and Cluster Analysis) were applied over the ratios. Intra- and interpopulation variations of the rostrum teeth, and the number of spines in the male appendix, were analyzed through descriptive statistics and bivariate analysis (Spearman Rank Correlation test). Results indicated a wide plasticity and overlapping in the studied ratios between populations. The Principal Components Analysis was not able to separate different populations, revealing a large intrapopulation plasticity and strong interpopulation similarity in the studied ratios. Although the Discriminant Functions Analysis was not able to fully discriminate populations, they could be allocated in three subgroups: 1) Cristalino and Iruçanga; 2) Huanayo, Urcococha and Camaleão and 3) Mamirauá and Amanã. The first two groups were morphometrically separated from each other, whereas the third one presented a strong overlap with the former two. The Cluster Analysis confirmed the first two subgroups separation, and indicated that the first and third groups were closely related. Rostrum teeth and number of spines in the appendix masculina showed a large intrapopulation variation and a strong overlapping among the studied populations, regardless of the species.

Contribuição para o conhecimento das doenças do grupo "Tifo Exantemático" do Brasil: (Tifo Exantemático Neotrópico)

O A. recapitula os dados já conhecidos sôbre a filtrabilidade de muitas Rickettsias e sôbre o que êle chama o ciclo evolutivo das mesmas, citando os trabalhos de S. B. Dulky e E. Gordon sôbre a Coxiella papilliae e a observação de A. Donatien e F. Lestoquard bem como os de P. Giraud. Refere-se à filtrabilidade do agente da febre "Q". Reporta-se depois aos trabalhos de Mme. Ruth Rein Gutfreund sôbre os achados de Rickettsia prowazedi em animais domésticos na Etiópia e a transmissão dos mesmos pelos carrapatos, dizendo que isto confirma suas próprias idéias, de há muito emitidas, de que não há no grupo tifo exantemático, de regra, especificidade estrita para os transmissores, não podendo êste carácter servir de base para classificações racionais. Descreve um caso clínico, mostrando a dificuldade de diagnóstico cofundido com a febre tifóide, mesmo com longa prática do exame na doença e que só a inoculação em animais sensíveis - aqui os cobaios - pode decidir a questão. Estuda depois dois surtos epidêmicos de tifo exantemático neotrópico - em 1950 em Carmópolis (Minas Gerais); outro em 1956, Mucuri (Bahia). Em ambos, a percentagem de mortes dos casos graves, não tratados, foi elevada e a terapêutica pelos antibióticos, principalmente a Cloromicetina e Terramicina foi brilhante. Nestes dois surtos epidêmicos com já se vira em 1941 (4 casos na mesma residência) e 1948 (6 casos na mesma moradia), apuraram-se 2 e 3 casos da doença na mesma casa. As reações de Fixação de Complemento (R.F.C.), Weil-Feliz (W.F.) e Widal - confirmam o diagnóstico de tifo exantemático neotrópico.

Blood parasites of some birds from São Paulo State, Brazil

A total of 3.449 birds, representing 195 species of 33 families from three areas in São Paulo State, Brazil, were examined for hematozoa during the period 1967-1972. Only 268 birds (7.8%) of 21 families harbored a blood parasite, which represented by species of Haemoproteus (3.5%), microfilaria (2.6%), Plasmodium (1.8%), Trypanosoma (0.8%) and Leucocytozoon (0.06%). The prevalence was similar in each of the six years of the study but a marked decrease in prevalence was noted in February and June of each year. The prevalence of parasitism was significantly different in each of the three areas sampled.