Mechanism of charge transport in castor oil-based polyurethane/carbon black composite (PU/CB)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Evidence that the Ceratobasidium-like white-thread blight and black rot fungal pathogens from persimmon and tea crops in the Brazilian Atlantic Forest agroecosystem are two distinct phylospecies

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

Black bean (Phaseolus vulgaris L.) as a protective agent against DNA damage in mice

This study was designed to evaluate the toxicogenetic or protective effect of cooked and dehydrated black beans (Phaseolus vulgaris L.) in bone marrow and peripheral blood cells of exposed mice. The frequency of micronuclei detected using the bone marrow erythrocyte micronucleus test and level of DNA lesions detected by the comet assay were chosen as end-points reflecting mutagenic and genotoxic damage, respectively. Initially, Swiss male mice were fed with a 20% black bean diet in order to detect mutagenic and genotoxic activity. However, no increase in the frequency of bone marrow micronucleated polychromatic erythrocytes (MN PCEs) or DNA lesion in leukocytes was observed. In contrast, received diets containing 1, 10 or 20% of black beans, a clear, but not dose-dependent reduction in the frequency of MN PCEs were observed in animals simultaneously treated with cyclophosphamide, an indirect acting mutagen. Similar results were observed in leukocytes by the comet assay. Commercial anthocyanin was also tested in an attempt to identify the bean components responsible for this protective effect. However, instead of being protective, the flavonoid, at the highest dose administered (50 mg/kg bw), induced primary DNA lesion, as detected by the comet assay. These data indicate the importance of food components in preventing genetic damage induced by chemical mutagens, and also reinforce the role of toxicogenetic techniques in protecting human health. (C) 2003 Elsevier Ltd. All rights reserved.

Necrotic skin lesion in a dog attributed to Loxosceles (brown spider) bite: a case report

Envenomations caused by Loxosceles (brown spider) have been reported throughout the world. Clinical signs associated to bites of these spiders involve dermonecrotic lesions and intense local inflammatory response, besides systemic manifestations such as intravascular hemolysis, thrombocytopenia, disseminated intravascular coagulation and acute renal failure. The present study aimed to report and to describe dermonecrotic lesions probably caused by a Loxosceles envenomation in a four year-old poodle female dog, treated at the Dermatology Service of the Veterinary Hospital of the Veterinary Medicine and Animal Husbandry School, São Paulo State University, Botucatu, Brazil. Initially, the animal presented two skin lesions with blackish aspect that evolved into ulcerative crusts. The owner reported the presence of a brown spider near the place where the animal spent most of the time. Histological examination of lesions revealed necrosis of the epidermis extending to adnexa and panniculi, which is compatible with Loxosceles bite reaction. The animal was treated with systemic antibiotic and local curatives. Lesions healed by second intention in two months.

Immunohistochemical and morphological features of a small bowel leiomyoma in a black crested macaque (Macaca nigra)

Background: Spontaneous gastrointestinal neoplasms in non-human primates are commonly seen in aged individuals. Due to genetic similarities between human and non-human primates, scientists have shown increasing interest in terms of comparative oncology studies.Case presentation: The present study is related to a case of an intestinal leiomyoma in a black crested macaque (Macaca nigra), kept on captivity by Mateca a Zoo, Pereira City, Colombia. The animal had abdominal distension, anorexia, vomiting, diarrhea and behavioral changes. Clinical examination showed an increased volume in the upper right abdominal quadrant caused by a neoplastic mass. The patient died during the surgical procedure. Necropsy revealed several small nodules in the peritoneum with adhesion to different portions of the small and large intestines, liver, stomach and diaphragm. Tissue samples were collected, routinely processed and stained by H&E. Microscopic examination revealed a mesenchymal tumor limited to tunica muscularis, resembling normal smooth muscle cells. Neoplastic cells were positive for alpha-smooth muscle actin and vimentin, and negative for cytokeratin AE1/AE3 by immunohistochemistry. Those morphological and immunohistochemical findings allowed to diagnose the intestinal leiomyoma referred above.Conclusion: Neoplastic diseases in primates have multifaceted causes. Their manifestations are understudied, leading to a greater difficulty in detection and measurement of the real impact provides by this disease.

Morphological aspects of spermatogenic cells at different stages of sexual maturation in black isogenic C57BL/6/Uni mice

In order to study the morphological changes that occur in cells of the testes of isogenic black mouse C57BL/6/Uni into three periods during spermatogenetic used 15 mice divided into 3 groups of 5 animals with 40,50 and 60 days of age. The mice were sacrificed and weighed. Testicles were weighed and measured, and histologically processed and stained with HE, PAS and Masson Massom-H and evaluated under light microscopy. It was observed that group I with 40 days of age in the seminifcrous tubules had a lumen with sparse small amount of interstitial tubular cells. In the seminiferous epithelium type A spermatogonia, intermediate and B were identified, which occupied the compartment adbasal and intermingled with these cells in spermatocytes I in Pachytene and leptotene was observed, whereas in the adluminal compartment Golgi phase spermatids we observed the presence of acrosomal granule. In group II, the cells of the seminiferous epithelium were developed and it was observed in round spermatids cephalic hood phase plus many elongated spermatids in acrosome phase and Sertoli cells. In Group III, 60 days old, it was found that seminiferous epithelium which was of the tubules had elongated spermatids in acrosome phase and maturation, with elongated nuclei and acrosomal system typical of spermiation in the presence of sperm and residual bodies near the tubular lumen. Therefore morphological evolution of germ cell testicular spermatids can be checked and recognized in its four phases: Golgi, cap, acrosome and maturation over the age of the animal.

The effect of hunger level on predation dynamics in the spider Nesticodes rufipes: a functional response study

It is well known that a predator has the potential to regulate a prey population only if the predator responds to increases in prey density and inflicts greater mortality rates. Predators may cause such density-dependent mortality depending on the nature of the functional and numerical responses. As spiders are usually faced with a shortage of prey, the killing behavior of the spider Nesticodes rufipes at varying densities of Musca domestica was examined here through laboratory functional response experiments where spiders were deprived of food for 5 (well-fed) or 20 days (hungry). An additional laboratory experiment was also carried out to assess handling time of spiders. The number of prey killed by spiders over 24- and 168-h periods of predator-prey interaction was recorded. Logistic regression analyses revealed the type II functional response for both well-fed and hungry spiders. We found that the lower predation of hungry spiders during the first hours of experimentation was offset later by an increase in predation ( explained by estimated handling times), resulting in similarity of functional response curves for well-fed and hungry spiders. It was also observed that the higher number of prey killed by well-fed spiders over a 24- h period of spider-prey interaction probably occurred due to their greater weights than hungry spiders. We concluded that hungry spiders may be more voracious than well-fed spiders only over longer time periods, since hungry spiders may spend more time handling their first prey items than well-fed spiders.

The role of habitat heterogeneity for the functional response of the spider Nesticodes rufipes (Araneae : Theridiidae) to houseflies

We investigated whether or not different degrees of refuge for prey influence the characteristic of functional response exhibited by the spider Nesticodes rufipes on Musca domestica, comparing the inherent ability of N. rufipes to kill individual houseflies in such environments at two distinct time intervals. To investigate these questions, two artificial habitats were elaborated in the laboratory. For 168 h of predator-prey interaction, logistic regression analyses revealed a type 11 functional response, and a significant decrease in prey capture in the highest prey density was observed when habitat complexity was increased. Data from habitat 1 (less complex) presented a greater coefficient of determination than those from habitat 2 (more complex), indicating a higher variation of predation of the latter. For a 24 h period of predator-prey interaction, spiders killed significantly fewer prey in habitat 2 than in habitat 1. Although prey capture did not enable data to fit properly in the random predator equation in this case, predation data from habitat 2 presented a higher variation than data from habitat 1, corroborating results from 168 h of interaction. The high variability observed on data from habitat 2 (more complex habitat) is an interesting result because it reinforces the importance of refuge in promoting spatial heterogeneity, which can affect the extent of predator-prey interactions.

Feeding habits of the spider crab Libinia spinosa H. Milne Edwards, 1834 (Decapoda, Brachyura) in Ubatuba Bay, São Paulo, Brazil

The main goal of this study was the identification of the items of the diet of the L. spinosa, based on the stomach contents analysis. The crabs were obtained from Ubatuba region north-eastern shore of São Paulo State. In the laboratory, all the individuals were dissected, the stomach was retreated and fixed in 10% formaline. The alimentary items were identified under stereomicroscope and analysed by the method of Frequency of Occurrence. A total of 194 stomachs was analysed and nine alimentary items were obtained. Unindentified material was found in 98% of analysed stomach and poriferan were present in less then 1% of stomachs. These results pointed a diversified diet explored by this crab, as well as the employment of some different methods for food intake. This suggested that these crabs could occupy different position in the trophic chain.

Prior residence and body size influence interactions between black sea urchins

Body size and prior residence can modulate agonistic interaction in several animal species, but scientists know little about these relationships in echinoderms. In this study, we tested the effects of these traits on interactions in the black sea urchin (Echinometra lucunter). After a sea urchin was isolated for 24-h in a glass tank to establish prior residence, we introduced an intruder animal adjacent to the resident in the tank and observed interactions for 30 min. The intruder animal was larger, smaller, or size-matched to the resident. We found body size and prior residence concomitantly modulated interactions among black sea urchins, with prior residence as the major determinant. Black sea urchins mainly exhibited opponent inspection and fleeing responses during interaction to avoid fights, especially when a fight could be seriously disadvantageous (small intruder vs. large resident). (C) 2008 Elsevier B.V. All rights reserved.

Black sea urchins evaluate predation risk using chemical signals from a predator and injured con- and heterospecific prey

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Morphological investigations of the surface epithelium of ductuli efferentes of black isogenic mice (Mus musculus)

Morphological investigations of the epithelial cell types that line the ductuli efferentes (DE) of black isogenic mice confirm absorption of the luminal fluid phase by endocytosis as the main function of ductuli efferentes (DE) in this species. :Furthermore, all the histochemical and ultrastructural observations on the DE epithelial histoarchitecture indicate other cellular functions such as exocytosis and probably secretion: including an aprocrine secretory process.

Postlarval stages and growth patterns of the spider crab Pyromaia tuberculata (Brachyura, Majidae) from laboratory-reared material

The spider crab Pyromaia tuberculata was introduced into southeastern Brazil; ovigerous material was collected and reared in the laboratory. Morphologic changes and growth patterns of post-larval development are reported. Results show that within-stage size variation is lowest in mature stages, especially in the case of females in which there is an apparent size threshold for the last juvenile stages to undergo the puberty molt. A prepuberty molt taking place at the fourth crab stage is indicated by analyzing the allometric growth of the abdomen in females. In contrast, the same procedure using the allometric growth of chelae failed in detecting both the prepuberty and puberty molts in males. Conversely to females, which develop a complex brood chamber at the puberty molt, the enlargement of chelae was not consistent in all postpuberty males. The short instar sequence of this species, in no case exceeding nine stages, is marked by conspicuous morphologic alterations achieved at each molt. Almost all stages can be identified by examining diagnostic features of rostrum, abdomen, sternum, and pleopods.

Reproductive output of the spider crab Epialtus bituberculatus (H. Milne Edwards, 1834) (Crustacea, Decapoda, Brachyura) associated with beds of the alga Sargassum cymosum (C. Agardh, 1820) on the southeastern Brazilian coast

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of architectural angularity on refugia selection by the brown spider, Loxosceles gaucho

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)