Comportamento de chamamento de Thyrinteina arnobia (Stoll) (Lepidoptera: Geometridae) em Psidium guajava, Eucalyptus grandis e em dieta artificial

Este estudo teve como objetivos determinar e comparar o efeito de três dietas: Psidium guajava, Eucalyptus grandis e dieta artificial no comportamento de chamamento e no padrão temporal do comportamento de chamamento de fêmeas virgens de Thyrinteina arnobia (Stoll). Foram analisados os parâmetros: tempo médio para o início do chamamento, número médio de chamamento, tempo médio de cada chamamento e tempo médio total de chamamento. Os bioensaios relacionados ao comportamento de chamamento de fêmeas virgens foram realizados durante seis escotofases consecutivas e as observações tomadas a cada 5 min., a 22 ± 1ºC, 70 ± 5% de UR e 10h de escotofase. As fêmeas, independente da dieta analisada, apresentaram duas posições diferentes de chamamento. A maioria das fêmeas virgens iniciou o chamamento na 1ª hora da 1ª escotofase. O padrão de chamamento da fêmea individualizada foi característico de um padrão contínuo. O tipo de dieta oferecida na fase larval influenciou o início do comportamento de chamamento (pré-chamamento) e o tempo médio total de chamamento. O tipo de dieta também alterou a coloração da glândula de feromônio.

Sites of Defoliation by Atta sexdens rubropilosa (Hymenoptera, Formicidae) in Artificial Plants

This study aimed to achieve a better understanding about the foraging behavior of leaf-cutter ant (Atta sexdens rubropilosa Forel) workers with respect to defoliation sites in plants. To accomplish that, artificial plants 70 cm in height were prepared and divided into four levels (heights), having natural plant leaves attached to them. Evaluations during the bioassays included the number of leaves dropped by the ants, as well as the percentage of plant mass removed. In all replicates, it became evident that the most exploited plant site is the apical region, which significantly differed from other plant levels.

Matemal separation affects cocaine-induced locomotion and response to novelty in adolescent, but not in adult rats

Maternal separation is known to exert long-term effects on both behavior and the neuroendocrine system. We investigated cocaine-induced locomotor activation as well as the locomotor and corticosterone response to forced novelty in maternally separated adolescent and adult rats. Maternal separation consisted of separating litters from their darns daily during 5 h from postnatal days 2 to 6. Control animals were subjected only to regular cage changes. Cocaine- (10 mg/kg, i.p.) and novelty-induced locomotion were recorded in an activity cage. After the animals were tested for behavioral response to novelty, trunk blood samples were collected and plasma corticosterone levels were determined by radioimmunoassay. Adolescent rats exposed to maternal separation exhibited an increased locomotor response to novelty and cocaine; corticosterone levels were lower in these adolescent animals, after exposure to the novel environment. These effects of materrial separation were not observed in rats that were tested as adults. Thus the maternal separation protocol produced enduring but transient changes in the behavioral response to cocaine and in the stress response to novelty. (C) 2004 Elsevier B.V. All rights reserved.

Repeated predictable or unpredictable stress: effects on cocaine-induced locomotion and cyclic AMP-dependent protein kinase activity

Stressful experiences appear to have a strong influence on susceptibility to drug taking behavior. Cross-sensitization between stress and drug-induced locomotor response has been found. Locomotor response to novelty or cocaine (10 mg/kg, i.p.), cyclic AMP-dependent protein kinase (PKA) activity in the nucleus accumbens and basal corticosterone levels were evaluated in male adult rats exposed to acute and chronic predictable or unpredictable stress. Rats exposed to a 14-day predictable stress showed increased locomotor response to novelty and to cocaine, whereas rats exposed to chronic unpredictable stress demonstrated increased cyclic AMP-dependent PKA activity in the nucleus accumbens. Both predictable and unpredictable stress increased basal corticosterone plasma levels. These experiments demonstrated that stress-induced early cocaine sensitization depends on the stress regime and is apparently dissociated from stress-induced changes in cyclic AMP-dependent PKA activity and corticosterone levels. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Effectiveness of Photogem (R) activated by LED on the decontamination of artificial carious bovine dentin

The aim of this study was the evaluation of the effectiveness of photodynamic therapy on the decontamination of artificially induced carious bovine dentin, using Photoge(R) as the photosensitizer agent and an LED device as a light source. Dentin samples obtained from bovine incisors were immersed in sterile broth supplemented by Lactobacillus acidophillus 10(8) colony formation units (CFU) and Streptococcus mutans 10 8 CFU. Different concentrations of photosensitizer, PA = 1 mg/ml, PB = 2 mg/ml, and PC = 3 mg/ml, and two fluences, D = 24 J/cm(2) and D = 48 J/cm(2), were investigated. After CFU counting per milligram of carious dentin and statistical analysis, we observed that the photodynamic therapy (PDT) parameters used were effective for bacterial reduction in the in vitro model under study. The best result was achieved with the application of Photoge(R) at 2 mg/ml and photoactivated under 24 J/cm(2) showing a survival factor of 0.14. At higher photosensitizer concentrations, a higher dark toxicity was observed. We propose a simple mathematical expression for the determination of PDT parameters of photosensitizer concentration and light fluence for different survival factor values. Since LED devices are simpler and cheaper compared to laser systems, it would be interesting to verify their efficacy as a light source in photodynamic therapy for the decontamination of carious dentin.

Susceptibilidade de Rhodnius neglectus, Rhodnius robustus e Triatoma infestans (Hemiptera, Reduviidae, Triatominae) à infecção por duas cepas de Trypanosoma cruzi (Kinetoplastidae, Trypanosomatidae) utilizando xenodiagnóstico artificial

A susceptibilidade de ninfas de 3º estádio de Rhodnius neglectus, R. robustus e Triatoma infestans às cepas Y e AMJM de Trypanosoma cruzi foi verificada utilizando xenodiagnóstico artificial. Para a leitura do xenodiagnóstico, as fezes dos triatomíneos foram examinadas a cada dois dias, a partir do 5º até o 31º dia pós infecção, pela técnica de compressão abdominal. Os resultados mostraram diferenças na susceptibilidade dos triatomíneos para as duas cepas estudadas e o período ótimo de leitura variou do 11º ao 19º dias para a cepa Y e do 11º ao 15º dias para a cepa AMJM. Também, pôde-se concluir que para a cepa Y, as três espécies de triatomíneos demonstraram boa susceptibilidade, enquanto para a cepa AMJM, a melhor susceptibilidade foi observada com R. neglectus, seguida pelo T. infestans e R. robustus.

Modeling and analysis of artificial neural networks applied in operations research

Artificial neural networks are dynamic systems consisting of highly interconnected and parallel nonlinear processing elements. Systems based on artificial neural networks have high computational rates due to the use of a massive number of these computational elements. Neural networks with feedback connections provide a computing model capable of solving a rich class of optimization problems. In this paper, a modified Hopfield network is developed for solving problems related to operations research. The internal parameters of the network are obtained using the valid-subspace technique. Simulated examples are presented as an illustration of the proposed approach. Copyright (C) 2000 IFAC.

Artificial neural networks applied in study of atmospheric parameters to high voltage substations concerning lightning

This gaper demonstrates that artificial neural networks can be used effectively for estimation of parameters related to study of atmospheric conditions to high voltage substations design. Specifically, the neural networks are used to compute the variation of electrical field intensity and critical disruptive voltage in substations taking into account several atmospheric factors, such as pressure, temperature, humidity, so on. Examples of simulation of tests are presented to validate the proposed approach. The results that were obtained by experimental evidences and numerical simulations allowed the verification of the influence of the atmospheric conditions on design of substations concerning lightning.

Nitrogen content identification in crop plants using spectral reflectance and artificial neural networks

The accurate identification of the nitrogen content in crop plants is extremely important since it involves economic aspects and environmental impacts. Several experimental tests have been carried out to obtain characteristics and parameters associated with the health of plants and its growing. The nitrogen content identification involves a lot of nonlinear parametes and complexes mathematical models. This paper describes a novel approach for identification of nitrogen content thought spectral reflectance of plant leaves using artificial neural networks. The network acts as identifier of relationships among pH of soil, fertilizer treatment, spectral reflectance and nitrogen content in the plants. So, nitrogen content can be estimated and generalized from an input parameter set. This approach can be form the basis for development of an accurate real time nitrogen applicator.

Automatic detection of thermal damage in grinding process by artificial neural network

Esse trabalho tem por objetivo o desenvolvimento de um sistema inteligente para detecção da queima no processo de retificação tangencial plana através da utilização de uma rede neural perceptron multi camadas, treinada para generalizar o processo e, conseqüentemente, obter o limiar de queima. em geral, a ocorrência da queima no processo de retificação pode ser detectada pelos parâmetros DPO e FKS. Porém esses parâmetros não são eficientes nas condições de usinagem usadas nesse trabalho. Os sinais de emissão acústica e potência elétrica do motor de acionamento do rebolo são variáveis de entrada e a variável de saída é a ocorrência da queima. No trabalho experimental, foram empregados um tipo de aço (ABNT 1045 temperado) e um tipo de rebolo denominado TARGA, modelo ART 3TG80.3 NVHB.

Analysis of forecasting capabilities of ground surfaces valuation using artificial neural networks

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo comportamental, hormonal e histopatológico de animais com perda de peso progressina (SEP) e da variável peso associada a uma nova classificação ontogenética em Callithrix jacchus

The use of non-human primates in scientific research has contributed significantly to the biomedical area and, in the case of Callithrix jacchus, has provided important evidence on physiological mechanisms that help explain its biology, making the species a valuable experimental model in different pathologies. However, raising non-human primates in captivity for long periods of time is accompanied by behavioral disorders and chronic diseases, as well as progressive weight loss in most of the animals. The Primatology Center of the Universidade Federal do Rio Grande do Norte (UFRN) has housed a colony of C. jacchus for nearly 30 years and during this period these animals have been weighed systematically to detect possible alterations in their clinical conditions. This procedure has generated a volume of data on the weight of animals at different age ranges. These data are of great importance in the study of this variable from different perspectives. Accordingly, this paper presents three studies using weight data collected over 15 years (1985-2000) as a way of verifying the health status and development of the animals. The first study produced the first article, which describes the histopathological findings of animals with probable diagnosis of permanent wasting marmoset syndrome (WMS). All the animals were carriers of trematode parasites (Platynosomum spp) and had obstruction in the hepatobiliary system; it is suggested that this agent is one of the etiological factors of the syndrome. In the second article, the analysis focused on comparing environmental profile and cortisol levels between the animals with normal weight curve evolution and those with WMS. We observed a marked decrease in locomotion, increased use of lower cage extracts and hypocortisolemia. The latter is likely associated to an adaptation of the mechanisms that make up the hypothalamus-hypophysis-adrenal axis, as observed in other mammals under conditions of chronic malnutrition. Finally, in the third study, the animals with weight alterations were excluded from the sample and, using computational tools (K-means and SOM) in a non-supervised way, we suggest found new ontogenetic development classes for C. jacchus. These were redimensioned from five to eight classes: infant I, infant II, infant III, juvenile I, juvenile II, sub-adult, young adult and elderly adult, in order to provide a more suitable classification for more detailed studies that require better control over the animal development

Distribuição diária do comportamento da mosca da fruta Anastrepha zenildae Zucchi, (Diptera: Tephritidae) em laboratório.

The knowledge of Anastrepha zenildae behavioral aspects combined with the biology of Tephritidae may contribute to monitoring and control programs of this fruit fly that is considered as economically important to the Rio Grande do Norte state. In order to characterize the daily activity profile of this species, we studied the behaviors of resting, locomotion, feeding, cleaning, courtship, copulation and oviposition of animals submitted to an artificial 12:12h light-dark cycle (750:1lux) with controlled temperature (26±2 °C). The observations were made with groups of 16 males and 16 females during 3 consecutive days each generation from parental to F5. Resting, locomotion, feeding and cleaning data were recorded as frequency and time of occurrence by scanning technique in 15 minutes windows per hour, with a record each minute. Courtship, copulation and oviposition were recorded as frequency, time of occurrence and duration by al occurrences technique. Resting was the most frequent behavior with males resting more than females. Locomotion was more evident in the first half of the ligh phase with higher values in females. Cleaning and feeding behaviors were more frequent in the second half of the light phase for both sexes with females eating more frequently than males. During the courtship, males were grouped in lek formations showing wings vibration and pheromone liberation. Courtship occurred more frequently 4 to 7 h after lights on (81,9%) with copulations being more frequent 6 h after lights on with a mean duration of 58,1±40,4 min. Copulation attempts were observed in males inside and outside the lek with aggressive behavior being observed only between males in the lek. Oviposition behavior was similar to that described for other species of the genus with a peak of this activity 2-3 h after the lights on, mean duration of 43, 7±34, 8 sec and 2 to 5 eggs by event. According to the results, sexual behavior of A. zenildae is temporally different of other sympatric species of the genus, being favorable to the reproductive isolation as well as the use of resources as oviposition substrate.