Diet and diving behaviour of European Storm Petrels Hydrobates pelagicus in the Mediterranean (ssp. melitensis).

Unlike Atlantic populations, which feed on krill, Mediterranean populations feed mainly on pelagic fish Gymnammodites cicerellus. European Storm Petrels in the Mediterranean exploit pelagic fish which are taken by diving. This contrasts with the Atlantic populations which feed mainly on krill. Mediterranean birds also feed on Opossum Shrimps Mysidacea during short foraging trips made at night just outside the colony. Differences in diet between long and short foraging trips may be because adults have to forage for both themselves and their chicks

Estudo das isotermas de dessorção de sementes de cornichão (Lotus corniculátus L.).

SIEPE

Avaliação da tolerância de acesso do gênero Paspalum ao sombreamento.

Editado por Ana Rita de Araújo Nogueira, Simone Cristina Meo Niciura

Driving calmodulin protein towards conformational shift by changing ionization states of select residues

Proteins are complex systems made up of many conformational sub-states which are mainly determined by the folded structure. External factors such as solvent type, temperature, pH and ionic strength play a very important role in the conformations sampled by proteins. Here we study the conformational multiplicity of calmodulin (CaM) which is a protein that plays an important role in calcium signaling pathways in the eukaryotic cells. CaM can bind to a variety of other proteins or small organic compounds, and mediates different physiological processes by activating various enzymes. Binding of calcium ions and proteins or small organic molecules to CaM induces large conformational changes that are distinct to each interacting partner. In particular, we discuss the effect of pH variation on the conformations of CaM. By using the pKa values of the charged residues as a basis to assign protonation states, the conformational changes induced in CaM by reducing the pH are studied by molecular dynamics simulations. Our current view suggests that at high pH, barrier crossing to the compact form is prevented by repulsive electrostatic interactions between the two lobes. At reduced pH, not only is barrier crossing facilitated by protonation of residues, but also conformations which are on average more compact are attained. The latter are in accordance with the fluorescence resonance energy transfer experiment results of other workers. The key events leading to the conformational change from the open to the compact conformation are (i) formation of a salt bridge between the N-lobe and the linker, stabilizing their relative motions, (ii) bending of the C-lobe towards the N-lobe, leading to a lowering of the interaction energy between the two-lobes, (iii) formation of a hydrophobic patch between the two lobes, further stabilizing the bent conformation by reducing the entropic cost of the compact form, (iv) sharing of a Ca+2 ion between the two lobes

Seasonality of soil water exchange in the soybean growing season in southern Brazil

The processes of water transfer in the soil-plant-atmosphere system are strongly affected by soil use and management. Differences in the dynamics of soil water transfer between no-tillage (NT) and conventional tillage (CT) practices during a soybean (Glycine max) growing season in southern Brazil were assessed in this study. All the water balance components were analyzed during the soybean growing season (2009/2010). Rainfall, runoff, soil water storage and hydro-physical soil properties were analyzed under two tillage systems. The land-atmosphere water vapor exchanges, obtained from eddy covariance stations, were analyzed with regard to the soybean agroecosystem. Characterizations of soil water storage were also formulated in the 2006/2007 and 2008/2009 soybean growing seasons under the NT system. During the periods without rain, the soil water content under NT was greater than under CT. The soil superficial layer, more porous under NT, contributed to less runoff during rainy events. Moreover, under NT conditions the water supply was always high, between 0.2 - 0.5 m. The total evapotranspiration in the soybean agroecosystem growing season was 410.8 mm

Systematics of proton emission

A very simple formula is presented that relates the logarithm of the half-life, corrected by the centrifugal barrier, with the Coulomb parameter in proton decay processes. The corresponding experimental data lie on two straight lines which appear as a result of a sudden change in the nuclear shape marking two regions of deformation independently of the angular momentum of the outgoing proton. This feature provides a powerful tool to assign experimentally quantum numbers in proton emitters.Comment: 4 pages, 3 figure

Produção de forragem de populações de azevém anual em diferentes ambientes do Rio Grande do Sul.

O azevém anual (Lolium multiflorum Lam.) é uma das forrageiras mais utilizadas no RS durante o período frio do ano, seja na sobressemeadura em campos naturais, ou na formação de pastagens cultivadas. Porém, existem poucas cultivares registradas no Brasil. Assim, o objetivo do trabalho foi avaliar, em diferentes ambientes, algumas populações de azevém anual, visando a seleção de genótipos que apresentem um elevado potencial produtivo e o futuro lançamento de cultivares. Foram avaliadas sete populações, sendo comparadas com uma população comercial e com o cultivar LE-284. O experimento foi implantado em cinco diferentes regiões fisiográficas do RS e as variáveis analisadas foram produção de MS Total e produção de MS de Folhas, sendo procedida uma análise estatística conjunta para locais. A análise estatística indicou como significativa a interação local x população tanto para MS Total quanto para MS Folhas. A produção de MS Total não diferiu muito entre as populações na maioria dos locais. Porém, em alguns deles, a população Vacaria e o cultivar LE-284 apresentaram-se com produções inferiores. Por outro lado, as populações Trovão e Sarandi foram as melhores em Augusto Pestana e Eldorado do Sul, respectivamente. Quanto a produção de MS Folhas, a população comercial Comum-RS figurou entre as menos produtivas em todos os locais, exceto em São Gabriel, em função da sua maior precocidade reprodutiva

Análise do Fluxo de Co2 sobre uma Cultura de Soja

Análise do fluxo de CO2 sobre uma cultura de soj