Ecological distribution of the shrimp Pleoticus muelleri (Bate, 1888) (Decapoda : Penaeoidea) in southeastern Brazil

The abundance and ecological distribution of the shrimp Pleoticus muelleri as a function of certain environmental factors were investigated from January 1998 through December 1999 in the region of Ubatuba, São Paulo, Brazil. The collections were made monthly in the bays of Ubatumirim (UBM), Ubatuba (UBA) and Mar Virado (MV). Each bay was divided into six sampling transects, four transects parallel to the shoreline and two near the rocky shores on the opposite side. We employed a commercial shrimp boat equipped with two double-rig nets. A total of 6252 shrimp were collected, including 3321 from MV, 1467 from UBM, and 1464 from UBA. Most of the shrimp were caught in the deeper, higher-salinity areas. The high abundance of P. muelleri observed in the southern part of the region studied was related to a sediments with a higher percentage of silt and clay. The numbers of P. muelleri were positively correlated with periods of cooler temperatures. Thus, temperature and the type of sediment were determinant factors in the distribution of P. muelleri in this region.

LONGITUDINAL DISTRIBUTION OF MACROALGAE IN 2 TROPICAL LOTIC ECOSYSTEMS FROM SOUTHEASTERN BRAZIL

Macroalgal species richness and diversity were analysed along a longitudinal profile in small and large scales during Spring, Fall and Winter, respectively in a small stream and a mid size river in the northwest region of São Paulo State, southeastern Brazil (20 degrees 23'-20 degrees 49'S, 49 degrees 26'-51 degrees 19'W). Longitudinal variation in species richness and diversity in small scale was strongly associated with incident light. Microhabitat distribution (from data taken by quadrat technique) revealed no significant correlations. Principal coordinates analysis (PCO) indicated no consistent groupings among sampling sites in distinct seasons (Spring, Fall and Winter). Longitudinal analysis in large scale revealed different patterns in the two seasons sampled (Spring and Winter), whereas species diversity presented a consistent tl end: high upstream, low in mid reaches and higher downstream. It was associated with type of substratum in Spring, rocky substrata presenting the highest values for species richness and diversity. Weak correlations were observed in Winter. Microhabitat distribution showed significant correlations between species abundance and the following variables: positive for rocky substrata and current velocity and negative for sandyclayish substratum and macrophyte-dominated substratum. PCO delineated only one consistent grouping formed by the two headwater sites. Small scale macroalgal distribution corroborated the longitudinal pattern predicted by the River Continuum Concept, whereas the large scale approach showed a distribution more associated with substratum type than to light availability. These results showed an opposite trend in relation to the expected distributional pattern. Longitudinal distribution in macroalgal community structure has yet to be better documented, particularly for tropical streams and no generalization is possible at this stage.

Distribution of Cr, Ni, Cu, Cd and Pb in different molecular size of humic fractions extracted from water and sediment samples collected at Anhumas reservoir - Araraquara/SP

In this work was studied the distribution of Cr, Ni, Cu, Cd and Pb in humic fractions with different molecular size. The HS were extracted from waters (AHS), surface sediments (HESS), interface water sediment (HSIS) and bottom sediment (HSBS) collected in the Anhumas surface water collection reservoir, located in the district of Araraquara - São Paulo State Brazil. The humic substances were extracted by procedures recommended by International Humic Substances Society (IHSS). After purification by dialysis, the humic substances were fractionated using a multistage tangential flow ultrafiltration system. The fractionation patterns of HS characterized a mass distribution relatively uniform among the fractions with different molecular sizes, with larger values in the fractions F-2 (20.8%) and F-4 (23.8%), Except for the ions Pb(II) and Cu(II), which presented relatively higher concentrations in the fractions F-2 and F-4, respectively. In general, chromium, nickel, cadmium and lead have similar distributions in the five fractions with larger and medium molecular sizes (F-1 to F-5). With relation to the mass distributions in the different humic substances fractions extracted from sediment samples collected at three depth, they presented 42-48% of HS in the fractions with larger molecular sizes (F-1 and F-2), 29-31% in the middle fractions (F-3 and F-4) and 13-20% in the fractions with smaller molecular sizes (F-5 and F-6). In general, the metallic ions presented distributions similar among the respective fractions F-1 to F-6, Exceptions for Pb(II) and M(II) in surface sediment with concentrations relatively smaller in the fractions F-2 and F-4, respectively,

DISTRIBUTION OF DIFFERENT FIBER TYPES OF M-EXTENSOR CARPI RADIALIS LONGUS OF THE RAT

As revealed by the NADH-diaphorase and myosine ATPase, the M. extensor carpi radialis longus of the rat possesses at least 3 main kinds of fibres, with different distribution on the superficial and deep portions of the muscle. The superficial portion revealed that 67.68 % are FG (fast-twitch-glycolytic) fibres, 14.72 % are FOG (fast-twitch-oxidative) fibres and 17.60 % are SO (slow-twitch-glycolytic) fibres. Already the deep portion revealed that 71.29 % are SO (slow-twitch-glycolytic) fibres, 17.46 % are FOG (fast-twitch-oxidative-glycolytic) fibres and 11.25 % are FG (fast-twitch-glycolytic) fibres. The miosine ATPase reaction was used to demonstrate contracting characteristics. These findings suggest that the movements of fast contraction of the M. extensor carpi radialis longus are predominant.

Reproductive biology and seasonal distribution of Mustelus schmitti (Elasmobranchii : Triakidae) in the Rio de la Plata oceanic front, south-western Atlantic

The population structure and reproductive biology of Mustelus schmitti was analysed during autumn (1994, 1995) and spring (1994) in the Rio dc la Plata occanic front. The samples consisted mainly of a adult males and immature females, indicating that nursery areas are Situated elsewhere. In autumn, the highest female densities occurred between 36 degrees S and 35 degrees S, with densities decreasing further south, and high male densities occurred over all latitudes of the study area. In Spring, both Sexes occurred north of latitude 36 degrees 30 degrees S. Males attained Maturity at. 59 cm total length (TL), and females at 72 cmTL Litter size varied From one to ten in spring and two to nine in autumn, With embryos ranging from 9 to 26 cm and 7 to 26 cm TL respcctivcly the mean TL of embryos was significantly higher in spring (22 cm), suggesting that parturition Occurs ill late spring and summer. Litter size was found to Increase with female TL..

Geographical distribution of vampire bat-related cattle rabies in Brazil

Seventy-seven rabies virus (RV) isolates originating from Brazilian cattle were genetically characterized. Partial nucleoprotein gene sequences of these isolates were phylogenetically and geographically analyzed. Cattle isolates, which clustered with the vampire bat-related RV group, were further subdivided into nine genetic subgroups. These subgroups were distributed widely in lowland regions, with some subgroups separated from each other by mountain ranges. In addition, separation of the groups in mountainous regions was correlated with altitude. These results indicate that cattle rabies is derived from several regionally-defined variants, which suggests that its geographical distribution is related to that of the vampire bat population.

Localization and irregular distribution of Na,K-ATPase in myelin sheath from rat sciatic nerve

Sodium, potassium adenosine triphosphatase (Na,K-ATPase) is a membrane-bound enzyme that maintains the Na+ and K+ gradients used in the nervous system for generation and transmission of bioelectricity. Recently, its activity has also been demonstrated during nerve regeneration. The present study was undertaken to investigate the ultrastructural localization and distribution of Na,K-ATPase in peripheral nerve fibers. Small blocks of the sciatic nerves of male Wistar rats weighing 250-300g were excised, divided into two groups, and incubated with and without substrate, the para-nitrophenyl phosphate (pNPP). The material was processed for transmission electron microscopy, and the ultra-thin sections were examined in a Philips CNI 100 (TM) electron microscope. The deposits of reaction product were localized mainly on the axolemma, on axoplasmic profiles, and irregularly dispersed on the myelin sheath, but not in the unmyelinated axons. In the axonal membrane, the precipitates were regularly distributed on the cytoplasmic side. These results together with published data warrant further studies for the diagnosis and treatment of neuropathies with compromised Na,K-ATPase activity. (c) 2007 Elsevier Ltd. All rights reserved.

DISTRIBUTION OF THE NUMBER OF EURYTREMA SP EGGS PER GRAM OF FECES IN NATURALLY INFECTED CATTLE

Eurytrema sp. egg counts (epg) in the feces of naturally infected cattle were performed and the technique employed showed 94.2% probability of detecting positive cases of the infection with a single examination independently of the host parasite burden. It was also demonstrated that the epg of Eurytrema sp. follows a negative binomial distribution model and is characterized by its small magnitude.

Univariate and bivariate distribution of growth traits in beef buffaloes from Brazil

The aim of this study was to analyze the weight at birth (BW) and adjusted at 205 (W205), 365 (W365) and 550 (W55O) days in beef buffaloes from Brazil, using two approaches: parametric, by normal distribution, and non-parametric, by kernel function, and thus estimating the genetic, environmental and phenotypic correlation among traits. Information of 5,169 animals at birth (BW), 3,792 at 205 days (W205), 3.883 at 365 days (W365) and 1,524 at 550 days of age (W550) were used. The birth weight distribution presented an evident discrepancy in relation to the normal distribution. However, W205, W365 and W550 presented normal distributions. The birth weight presented weak genetic, environmental, and phenotypic associations with the other weight measurements. on the other hand, the weight traits at 205, 365, 550 days of age showed a high genetic correlation.

Differential distribution of functional alpha(1)-adrenergic receptor subtypes along the rat tail artery

The rat tail artery has been used for the study of vasoconstriction mediated by alpha(1A)-adrenoceptors (ARs). However, rings from proximal segments of the tail artery (within the initial 4 cm, PRTA) were at least 3- fold more sensitive to methoxamine and phenylephrine (n = 6 - 12; p < 0.05) than rings from distal parts (between the sixth and 10th cm, DRTA). Interestingly, the imidazolines N-[ 5-( 4,5- dihydro- 1H- imidazol-2-yl)-2-hydroxy-5,6,7,8- tetrahydronaphthalen- 1- yl] methanesulfonamide hydrobromide (A-61603) and oxymetazoline, which activate selectively alpha(1A)- ARs, were equipotent in PRTA and DRTA (n = 4 - 12), whereas buspirone, which activates selectively alpha(1D)-AR, was approximate to 70-fold more potent in PRTA than in DRTA (n = 8; p < 0.05). The selective alpha(1D)-AR antagonist 8-[2-[4-(methoxyphenyl)-1-piperazinyl] ethyl]-8-azaspiro[4.5] decane-7,9-dione dihydrochloride (BMY- 7378) was approximate to 70- fold more potent against the contractions induced by phenylephrine in PRTA (pK(B) of approximate to 8.45; n = 6) than in DRTA (pK B of approximate to 6.58; n = 6), although the antagonism was complex in PRTA. 5-Methylurapidil, a selective alpha(1A)-antagonist, was equipotent in PRTA and DRTA (pK(B) of approximate to 8.4), but the Schild slope in DRTA was 0.73 +/- 0.05 ( n = 5). The noncompetitive alpha(1B)-antagonist conotoxin rho-TIA reduced the maximal contraction induced by phenylephrine in DRTA, but not in PRTA. These results indicate a predominant role for alpha(1A)-ARs in the contractions of both PRTA and DRTA but with significant coparticipations of alpha(1D)-ARs in PRTA and alpha(1B)-ARs in DRTA. Semiquantitative reverse transcription-polymerase chain reaction revealed that mRNA encoding alpha(1A)- and alpha(1B)-ARs are similarly distributed in PRTA and DRTA, whereas mRNA for alpha(1D)-ARs is twice more abundant in PRTA. Therefore, alpha(1)-ARs subtypes are differentially distributed along the tail artery. It is important to consider the segment from which the tissue preparation is taken to avoid misinterpretations on receptor mechanisms and drug selectivities. antagonism was complex in PRTA. 5- Methylurapidil, a selective alpha(1A)-antagonist, was equipotent in PRTA and DRTA (pK(B) of approximate to 8.4), but the Schild slope in DRTA was 0.73 +/- 0.05 ( n = 5). The noncompetitive alpha(1B)-antagonist conotoxin rho-TIA reduced the maximal contraction induced by phenylephrine in DRTA, but not in PRTA. These results indicate a predominant role for alpha(1A)-ARs in the contractions of both PRTA and DRTA but with significant coparticipations of alpha(1D)-ARs in PRTA and alpha(1B)-ARs in DRTA. Semiquantitative reverse transcription-polymerase chain reaction revealed that mRNA encoding alpha(1A)- and alpha(1B)- ARs are similarly distributed in PRTA and DRTA, whereas mRNA for alpha(1D)-ARs is twice more abundant in PRTA. Therefore, alpha(1)-ARs subtypes are differentially distributed along the tail artery. It is important to consider the segment from which the tissue preparation is taken to avoid misinterpretations on receptor mechanisms and drug selectivities.

Identification, content, and distribution of type VI collagen in bovine tendons

Tendon composition changes according to differentiation, mechanical load, and aging. In this study, we attempted to identify, localize, and quantify type VI collagen in bovine tendons. Type VI collagen was identified by the electrophoretic behavior of the alpha chains and Western blotting, and by rotary shadowing. Type VI collagen was extracted from powdered tendon with three sequential 24-h extractions with 4 M guanidine-HCl. The amount of type VI collagen was determined by enzyme-linked immunosorbent assay for purely tensional areas and for the compressive fibrocartilage regions of the deep flexor tendon of the digits, for the corresponding fetal and calf tendons, and for the extensor digital tendon. The distal fibrocartilaginous region of the adult tendon was richer in type VI collagen than the tensional area, reaching as much as 3.3 mg/g (0.33%) of the wet weight. Calf tendons showed an accumulation of type VI at the fibrocartilage site. Immunocytochemistry demonstrated that type VI collagen was evenly distributed in the tensional areas of tendons but was highly concentrated around the fibrochondrocytes in the fibrocartilages. The results demonstrate that tendons are variable with regard to the presence and distribution of type VI collagen. The early accumulation of type VI collagen in the region of calf tendon that will become fibrocartilage in the adult suggests that it is a good marker of fibrocartilage differentiation. Furthermore, the distribution of type VI collagen in tendon fibrocartilage indicates that it organizes the pericellular environment and may represent a survival factor for these cells.

Species distribution of the Halophilous-psamophilous community along the coast of the Espirito-Santo state

The purpose of the present work was the study of the composition and distribution of the species in halophilous-psamophilous communities, utilizing the square method in 10 beaches of the Espirito Santo coast. The data of presence and cover of each species for the calculation of frequency and dominance, respectively, were obtained from twenty contiguous square of each of five 20 meters samplings, in a total of one hundred squares for each beach. Mariscus pedunculatus, Panicum racemosum, Ipomoea pes-caprae, I. littoralis and Blutaparon portulacoides were the most dominant species in the analyzed beaches.