Annual, seasonal and spatial variation of abundance of the shrimp Artemesia longinaris (Decapoda : Penaeoidea) in south-eastern Brazil

The influence of several environmental factors oil the abundance and spatial-temporal distribution of the shrimp Artemesia longinaris were investigated from January 1998 to December 1999 in the Ubatuba region of São Paulo State, Brazil. Collections were performed monthly in the bays of Ubatumirim (UBM), Ubatuba (UBA) and Mar Virado (MV). Six sampling transects were estabilshed in each bay, four were parallel to the shore line, and two were next to the rocky shores. A commercial shrimp fishing boat equipped with two 'double-rig' nets was used. A total of 11,503 individuals was collected, including 1633 from UBM, 6344 from UBA and 3526 from MV the majority of the captured specimens came from the deeper areas (15 to 20 m) with high salinity (34 to 36 ppt). The highest abundance of A. longinaris in Ubatuba bay was recorded in areas where fine and very fine sand comprised more than 70% of the sediment. Moreover, the abundance of A. longinaris followed a seasonal trend, being higher during the summer, when intrusions of cold South Atlantic Coastal Waters (SACW) are frequent. Thus, type of sediment, temperature and salinity are determinant factors in the distribution of A. longinaris in the studied region.

Temporal variation in the abundance of two species of thrushes in relation to fruiting phenology in the Atlantic rainforest

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

Factors regulating diversity and abundance of fish communities in Pantanal lagoons, Brazil

The factors effecting fish species richness, evenness and relative abundance in 19 floodplain lagoons in the Pantanal (Brazil) were examined. Richness and evenness were strongly correlated with the lagoon's: (i) isolation time from the main river; (ii) depth; and (iii) distance from the main river. Abundance of the five dominant fish species was correlated mainly with: (a) macrophyte cover; (b) the distance from the main river; and (c) piscivore abundance. These results suggest that the species select lagoons to avoid or minimize their confinement in inappropriate floodplain habitats. A combination of strategies, together with variations in the lagoon's connection period, determines the diversity and abundance of the fish species in the Nhecolandia Pantanal.

Activity pattern of Cuniculus paca (Rodentia: Cuniculidae) in relation to lunar illumination and other abiotic variables in the southern Brazilian Amazon

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

EMG amplitude and frequency parameters of muscular activity: Effect of resistance training based on electromyographic fatigue threshold

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Screening of bacterial strains for pectinolytic activity: characterization of the polygalacturonase produced by Bacillus sp

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

Relic abundance of mass-varying cold dark matter particles

In models of coupled dark energy and dark matter the mass of the dark matter particle depends on the cosmological evolution of the dark energy field. In this Letter we exemplify in a simple model the effects of this mass variation on the relic abundance of cold dark matter. (c) 2005 Elsevier B.V. All rights reserved.

Powder X-ray characterization of lithium thiazoildine-4-carboxylate

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

Mutagenic activity removal of selected disperse dye by photoeletrocatalytic treatment

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

Abundance of MyoD and myostatin transcripts in chicken embryos submitted to distinct incubation temperatures and timing exposures

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

Study of Ti-modified columbite route and the effect of lithium doping in 0.9PMN-0.1PT ceramics

The influence of lithium on the structural characteristics of PMN-PT ceramic was studied. The synthesis of PMN-PT powders using this precursor leads to the formation of high amount of perovskite phase. The insertion of Li(+) ions in B-site affects the microstructure because the rise in mass transport changes the mechanical characteristics of sintered ceramic. Higher values of K(m) and T(m) were gotten when lithium is inserted into perovskite phase. Secondary phase was found when lithium content increase beyond 1 mol%, besides the occurrence of transgranular fractures in sintered ceramic. Also, the additive acts increasing the relaxor behavior.

Effects of lithium and myoinositol on the rat bisected vas deferens

1. The effects of lithium (Li+) on the concentration-response curves (CRC) to norepinephrine (NE) and acetylcholine (Ach) on the bisected rat vas deferens (RVD) were investigated, as well as its action on the neuronal uptake of [H-3] NE.2. Li+ did not affect the 50% effective concentration (EC(50)) of NE and Ach in the epididymal (EP) portion of the RVD.3. Li+ caused a significant increase of the EC(50) to NE and Ach in the prostatic (PP) portion of the RVD. This shift to the right of the CRC to NE was prevented by the presence of myoinositol.4. Incubation of the PP of the RVD with Li+, increased the neuronal uptake of NE. The simultaneous incubation with myoinositol prevented this increase.5. After the pre-treatment of the rats with 6-hydroxydopamine (6-OHDA), or in the presence of cocaine, Li+ failed to desensitize the PP of the RVD to NE.6. These results suggest that the effect of Li+ on the PP of the RVD occurs mainly at the pre-synaptic level and may be related to the increase of neuronal uptake and to the interference of Li+ on phosphatidylinositol hydrolysis.

Composition and abundance of marine shrimps (Crustacea, Decapoda, Penaeidea) in Ubatuba bay, Ubatuba (SP), Brazil

This work aims to analyse the composition, abundance and distribution of the Penaeidea species which occur in the Ubatuba Bay (23 degrees 26'S and 45 degrees 02'W). The samples were monthly collected from October/1992 to September/1993. Each collect was composed of two parallel radials: the first (radial ''A'') was carried out in the mid region of the bay and the second one (radial ''B'') in the bay mouth. The trawls took one hour in a boat equipped with one otter-trawl (10 mm of mesh). The registered environmental factors were depth, bottom water temperature, granulometric composition and organic content of the sediment. After the trawls, the shrimp were separated from other marine organisms and counted. Eight species of shrimp were obtained: Xiphopenaeus kroyeri; Artemesia longinaris; Penaeus (L.) schmitti; P. (F.) brasiliensis; Trachypenaeus; constrictus; Sicyonia typica; S. dorsalis and Pleoticus muelleri. The most abundant species were X. kroyeri, A. longinaris, P. muelleri and T. constrictus. It was verified a very strong seasonality among the species. The X. kroyeri species occurred in both radials along the months but its abundance decreased from a November to March. Such fact is attributed to the temperature which reached a minimum value of 20 degrees C during this period. The species A. longinaris and P. muelleri were more frequent in the radial B which was caracterized by 14 +/- 1.3 m of depth, low organic content in the sediment (2.97%) and granulometric composition of medium sand. The distribution and abundance of these shrimps in the bay, beyond the hydrological features can be related to biotic factors as food availability, migration, inter and intra specific relations (competition, predation, etc.).

Red and blue emissions of europium doped gadolinium silicate from porous silica matrix and hydroxide carbonate with spherical shaped particles

In this work, Eu(III) and Eu(II) doped gadolinium silicates has been obtained as compact tubes starting from spherical gadolinium hydroxide carbonate using the pores of silica matrix as support and its surface as reagent. Eu(III) doped gadolinium silicate with hexagonal phase shows an interesting visible shifted charge transfer band when compared to disilicate with orthorhombic phase that was also obtained. Eu(II) gadolinium silicate has been prepared using CO atmosphere presenting an intense blue emission. The divalent europium system shows a potential application as an UV-blue converter. The samples were characterized by scanning electron microscopy (SEM), X-ray powder diffractometry (XRD) and photoluminescence spectroscopy. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Electrical percolation during gelation of lithium doped siloxane-poly(oxyethylene) hybrids

Gelation mechanisms of lithium-doped Siloxane-Poly(oxyethylene) (PEO) hybrids containing polymer of two different molecular weight (500 and 1900 g/mol) were investigated through the evolution of the electrical properties during the solgel transition. The results of electrical measurements, performed by in-situ complex impedance spectroscopy, were correlated with the coordination and the dynamical properties of the lithium ions during the process as shown by Li-7 NMR measurements. For both hybrids sols, a decrease of the conductivity is observed at the initial gelation stage, due to the existence of an inverted percolation process consisting of the progressive separation of solvent molecules containing conducting species in isolated islands during the solid network formation. An increase of conductivity occurs at more advanced stages of gelation and aging, attributed to the increasing connectivity between PEO chains promoted by the formation of crosslinks of siloxane particles at their extremities, favoring hopping motions of lithium ions along the chains.