Morfologia da micrópila e da superfície dos ovócitos de piracanjuba, Brycon orbignyanus (Osteichthyes, Characidae), sob microscopia eletrônica de varredura

This paper studied the morphology of oocytes of Brycon orbignyanus, (Osteichthyes, Characidae), through observation in Scanning Electron Microscopy (SEM). Fragments of the ovaries from adult females were collected. During the reproductive period, a hormonal induction in females was carried out to collect the oocytes after extrusion. The samples were fixed and processed for observation in SEM. Results showed that the oocytes of B. orbignyanus had a follicular epithelium formed by a single layer of cells with compressed shape, covering the whole radiatta zone that showed a smooth and regular surface with innumerable pores. The micropyle had a funnel-shaped, containing several furrows. The oocyte surface around the micropyle presented pores closer of each other than the other surface areas of radiatta zone.

Efeito da salinidade e do esgoto orgânico sobre a comunidade zooplanctônica, com ênfase nos copépodes, do estuário do rio Itanhaém, Estado de São Paulo

The objective of this work is to analyze the effects of salinity and wastewater on the zooplankton community of the Itanhaém river estuary, São Paulo state. Samples of zooplankton as well as physical and chemical variables of water were collected in four sites, located between the coastal line and the superior part of the estuary, including a secondary channel where wastewater is thrown without previous treatment. The samples were collected in low and high tide in winter and summer. Results showed that the estuary presents a temporal and spatial variation of physical and chemical characteristics, especially salinity, in function of the tide and seasonal variation of rain. The high values of salinity occurred in winter and high tide. Zooplankton community was adapted to the dynamic of salinity, and marine and estuarine species occurred in the low part of the estuary in winter. Although the Itanhaém river estuary has the same temporal and spatial dynamic of other estuaries, the values of salinity are low when compared with others located in the southern coast of São Paulo. Consequently, mainly oligohaline and fresh water species constitute the zooplankton community. These characteristics are due to the great drainage area of the Itanhaém river basin. The waste water modified physical and chemical characteristics of water that now presents higher concentrations of nutrients, higher values of suspended matter and lower concentrations of oxygen. It was observed a positive relation between the density of nauplii of copepods and organic pollution in this estuary.

Características hematológicas, bioquímicas e biométricas de Piaractus mesopotamicus Holmberg, 1887 (Osteichthyes: Characidae) oriundos de cultivo intensivo

Hematological characteristics are important tools for diagnosis and prognostic features in fish population and they contribute to the comprehension of comparative physiology, phylogenetic relation, food habit and other ecological parameters. Red blood cell count (RBC), white blood cell count (WBC), thrombocytes counts, glucose, cortisol, hepatosomatic and splenosomatic relation were evaluated in Piaractus mesopotamicus. The values of hepatosomatic relation varied from 0.67% to 2.79% and splenosomatic relation from 0.011% to 0.108%. RBC 1.870 to 4.590 × 106/μL, hemoglobin concentration 5.7 to 12.1g/dL, haematocrit 24.0% to 40.0%, mean corpuscular volume 98.0 to 174.0 fL, mean corpuscular haemoglobin concentration 19.1 to 34.2g/dL, glucose 40.6 to 89.2mg/dL and cortisol 4.73 to 110.5ng/dL The number of total thrombocytes was 12,160.0 to 89,280.0/μL and WBC 2,019.0 to 47,473.0/μL. Differential count of leucocytes showed 54.1% limphocytes, 10.9% neutrophils, 10.3% monocytes, 9.9% PAS-positive granular leukocytes (PAS-GL), 6.7% eosinophils, 0.3% basophils and 7.8% immature leucocytes. Variation of these haematological characteristics in the same fish species was observed, being considered as the normal variation in the fish concerned. Hence it is incorrect to assume that biological characteristics in fishes are distributed normally.

Coordinated, network-based research as a strategic component of science in Brazil

Scientific research plays a fundamental role in the health and development of any society, since all technological advances depend ultimately on scientific discovery and the generation of wealth is intricately dependent on technological advance. Due to their importance, science and technology generally occupy important places in the hierarchical structure of developed societies, and they receive considerable public and private investment. Publicly funded science is almost entirely devoted to discovery, and it is administered and structured in a very similar way throughout the world. Particularly in the biological sciences, this structure, which is very much centered on the individual scientist and his own hypothesis-based investigations, may not be the best suited for either discovery in the context of complex biological systems, or for the efficient advancement of fundamental knowledge into practical utility. The adoption of other organizational paradigms, which permit a more coordinated and interactive research structure, may provide important opportunities to accelerate the scientific process and further enhance its relevance and contribution to society. The key alternative is a structure that incorporates larger organizational units to tackle larger and more complex problems. One example of such a unit is the research network. Brazil has utilized such networks to great effect in genome sequencing projects, demonstrating their relevance to the Brazilian research community and opening the possibility of their wider utility in the future.

Reproductive modes in frogs and their unexpected diversity in the Atlantic forest of Brazil

Amphibians, and especially the anurans (frogs and toads), exhibit a greater diversity of reproductive modes than other tetrapod vertebrates. Twenty-nine reproductive modes have been recognized for the anurans; we propose 10 more, elevating by more than 34% the number of reproductive modes known for anurans worldwide. These newly recognized reproductive modes for the frogs elevate by almost 48% the number of anuran reproductive modes known for the Neotropics. The highly complex topography of the Atlantic forest, breaking up the biome into many small microhabitats, and the high humidity, which reduces desiccation risks, have enabled the evolution of reproductive specializations such as eggs or tadpoles that develop out of water. Nearly 90% of the Atlantic forest has been cleared, and because several anurans are endemic to this region or have specialized reproductive modes dependent on the forest, this partly explains the generalized population declines and large numbers of species that have disappeared in the last few decades. © 2005 American Institute of Biological Sciences.

Avaliação ultraestrutural do colágeno do ligamento colateral medial associado ao ligamento oblíquo da articulaç ão do cotovelo de cão SRD após ensaio de tração

Ultrastructural evaluation of the collagen of the mongrel dog medial collateral ligament associated to the oblique ligament after strain. The present work aimed to observe the disposition of the collagen fibres of the medial collateral ligament of the elbow joint of the dog, when associated to the oblique ligament. Thus, 18 articulations were used, divided in three groups. A group had the medial collateral ligament collected and not stretched, other group had the collateral medial ligament stretched separately and the other group had both ligaments (medial collateral and oblique) stretched associately. The medial collateral ligament examined by scanning electron microscopy presented a wavy and reticular pattern of the collagen fibres when not submitted to strain, which was not totally destroyed when it was associated to the oblique ligament. When stretched separately, the medial collateral ligament after strain totally loses the reticular pattern, demonstrating the waste of the fibres to resist to the tension.

Morphology of oesophagus and crop of the partrigde Rhynchotus rufescens (Tiramidae)

Twenty adult partridges Rhynchotus rufescens were used to study the morphology of oesophagus and crop. Materials to the morphologic study were collected and lengths of the oesophagus and of the crop were measured. For histological study, fragments of the oesophagus and of the crop were stained routinely with Masson's trichrome stain. Total oesophagus was larger in females. In the entrance of the thorax, its ventral wall is enlarged broadly, forming the crop, which is larger in males. Oesophagus mucosa is constituted by stratified squamous epithelium, with mucous glands and lymphatic tissues. There are three layers of smooth muscle, involved in serosa. The histological structure of the crop is similar to the oesophagus. The mucous glands are reduced in size and the lymphatic tissues are dispersed in the connective tissue. There is a thin stratum of smooth muscle and other two wider layers of longitudinal and circular musculature.

Central nifedipine-induced alterations in salivary flow and compounds: Role of nitric oxide

The aim of this study was to examine the role of nifedipine and Nitric Oxide (NO) on salivary flow and compounds (salivary amylase, saliva total proteins, saliva calcium, sodium and potassium). Male Holtzman rats weighting 200-250 g were anesthetized with zoletil 50 mg kg -1 (tiletamine chloridrate 125.0 mg and zolazepan chloridrate 125.0 mg) into quadriceps muscle and stainless steel cannulas were implanted into their lateral ventricle of the brain (LV). Animals in divided group were injected with nifedipine (50 μg μL -1) alone and in combination with 7-nitroindazol (7-NIT) (40 μg μL -1), neuronal NO Sinthase Inhibitor (nNOSI) and Sodium Nitroprussate (SNP) (30 μg μL -1) NO donor agent. As a secretory stimuli, pilocarpine dissolved in isotonic was administered intraperitoneally (ip) at a dosage of 10 mg kg -1 body weight. Saliva was collected for 7 min with four cotton balls weighing approximately 20 mg each, two of which were placed on either side of the oral cavity, with the other two placed under the tongue. Nifedipine treatment induced a reduction in saliva secretion rate and concentration of amylase, total protein and calcium without changes in sodium and potassium concentration in comparison with controls. Co-treatment of animals with nifedipine and SNP retained flow rate and concentration of amylase, total protein and calcium in normal levels. Co-treatment of animals with nifedipine and 7-NIT potentiated the effect of nifedipine on the reduction of saliva secretion and concentrations of amylase, total protein and calcium. Nifedipine (dihydroperidine) calcium-channel blocker widely in use is associated with salivary dysfunction acting in the central nervous system structures. NO might be the mechanism for protective effect against the nifedipine-induce salivary dysfunction, acting in the CNS. © 2006 Asian Network for Scientific Information.

Chemometric analysis of Hymenoptera toxins and defensins: A model for predicting the biological activity of novel peptides from venoms and hemolymph

When searching for prospective novel peptides, it is difficult to determine the biological activity of a peptide based only on its sequence. The trial and error approach is generally laborious, expensive and time consuming due to the large number of different experimental setups required to cover a reasonable number of biological assays. To simulate a virtual model for Hymenoptera insects, 166 peptides were selected from the venoms and hemolymphs of wasps, bees and ants and applied to a mathematical model of multivariate analysis, with nine different chemometric components: GRAVY, aliphaticity index, number of disulfide bonds, total residues, net charge, pI value, Boman index, percentage of alpha helix, and flexibility prediction. Principal component analysis (PCA) with non-linear iterative projections by alternating least-squares (NIPALS) algorithm was performed, without including any information about the biological activity of the peptides. This analysis permitted the grouping of peptides in a way that strongly correlated to the biological function of the peptides. Six different groupings were observed, which seemed to correspond to the following groups: chemotactic peptides, mastoparans, tachykinins, kinins, antibiotic peptides, and a group of long peptides with one or two disulfide bonds and with biological activities that are not yet clearly defined. The partial overlap between the mastoparans group and the chemotactic peptides, tachykinins, kinins and antibiotic peptides in the PCA score plot may be used to explain the frequent reports in the literature about the multifunctionality of some of these peptides. The mathematical model used in the present investigation can be used to predict the biological activities of novel peptides in this system, and it may also be easily applied to other biological systems. © 2011 Elsevier Inc.

Qualidade microbiológica da água e histopatologia de brânquias de peixes provenientes de pisciculturas do município de itapecuru-mirim, Estado do Maranhão

The present study evaluated the microbiological water quality and tissue lesions in gills from Nile tilapia (Oreochromis niloticus) and hybrid tambacu (Colossoma macropomum female x Piaractus mesopotamicus male). For this, water and gills were collected from fish farming at six locations in Itapecuru- Mirim County, Maranhão State. Microbiological water analyses revealed contamination by total coliforms, Escherichia coli and heterotrophic bacteria. In the gills, we observed a diversity of Gram-positive and Gramnegative bacteria. The tissue lesions were: lamellar fusion, interlamellar hyperplasia, sub-epithelial edema and telangiectasia. Inflammatory lesions were not observed. Significant statistical difference (p > 0.05) was not detected when comparing different gills lesions during rainy and dry season. The correlation between lesion and pond type was statistically different (p < 0.05) for lamellar fusion and interlamellar hyperplasia which occurred more frequently at ground ponds. Regarding the frequency of lesions in the different fish species, there was statistical difference (p < 0.05), and the tambacu was more sensitive to lamellar fusion while tilapia was more sensitive for the other lesions. In relation to the sampling stations, there was statistical difference for all the gill lesions. In conclusion, tissue lesions are nonspecific and function as a defense mechanism against polluted aquatic environments, without infectious character.

Biogeografia histórica do gênero Brachygastra Perty, 1833 (Hymenoptera: Vespidae: Polistinae: Epiponini)

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

A evolução biológica no ensino médio no Estado de São Paulo: competências curriculares, orientações didáticas e indicadores de aprendizagem

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O laboratório de anatomia sob a perspectiva da 'descrição densa': interfaces da cultura e o ensino de Ciências

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Concepções de médicos/as e enfermeiros/as sobre questões de gênero na saúde

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O saber ambiental na formação dos professores de biologia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)