Method for Efficiency and Time Response Measurement on Diverse Target Ion Sources with Stable Alkali

International audienceDevelopments of new setups for radioactive ion beam production by the isotope-separator-on-line (ISOL) method are underway at GANIL in the frame of the SPIRAL (Système de Production d'Ions Radioactifs Accélérés en Ligne) and SPIRAL-II projects. The measurement of total efficiency and time behaviour of these new target/ion-source systems (TISSs) is a crucial step for these devices which aims to produce short-lived isotopes with high intensity. The overall atom-to-ion transformation efficiency depends on several processes: diffusion of the atoms out of the production target, effusion towards the ion source and ionization. The efficiency can be extracted using the ratio between the emerging yield and implanted flux in the TISS. Several methods have already been developed to achieve these measurements: the use of stable or radioactive beams, gas injection, or the introduction of solid material into the TISS. This paper focuses primarily on a method that uses stable alkali. A pulsed/CW alkali ion gun has been built and will be used to optimise diverse TISSs

The role of C-terminal amidation in the membrane interactions of the anionic antimicrobial peptide, maximin H5

Maximin H5 is an anionic antimicrobial peptide from amphibians, which carries a C-terminal amide moiety, and was found to be moderately haemolytic (20%). The α-helicity of the peptide was 42% in the presence of lipid mimics of erythrocyte membranes and was found able to penetrate (10.8mNm(-1)) and lyse these model membranes (64 %). In contrast, the deaminated peptide exhibited lower levels of haemolysis (12%) and α-helicity (16%) along with a reduced ability to penetrate (7.8mNm(-1)) and lyse (55%) lipid mimics of erythrocyte membranes. Taken with molecular dynamic simulations and theoretical analysis, these data suggest that native maximin H5 primarily exerts its haemolytic action via the formation of an oblique orientated α-helical structure and tilted membrane insertion. However, the C-terminal deamination of maximin H5 induces a loss of tilted α-helical structure, which abolishes the ability of the peptide's N-terminal and C-terminal regions to H-bond and leads to a loss in haemolytic ability. Taken in combination, these observations strongly suggest that the C-terminal amide moiety carried by maximin H5 is required to stabilise the adoption of membrane interactive tilted structure by the peptide. Consistent with previous reports, these data show that the efficacy of interaction and specificity of maximin H5 for membranes can be attenuated by sequence modification and may assist in the development of variants of the peptide with the potential to serve as anti-infective

Avaliação para tolerância à deficiência de fósforo no solo em seleção recorrente de arroz de terras altas.

O objetivo deste estudo foi avaliar progênies da população CNA9|3|1 de arroz de terras altas da Embrapa, em melhoramento por meio de SR, quanto à eficiência no uso do P no solo através do caráter produção de grãos (PG, em kg ha-1)

Arachnida at "Reserva Ducke", Central Amazonia/Brazil

The class Arachnida contains 11 recent orders: Acari, Amblypygi, Araneae, Opiliones, Palpigradi, Pseudoscorpiones, Ricinulei, Schizomida, Scorpiones, Solifugae and Uropygi (Thelyphonida). In total, >570 families, >9165 genera and >93455 species are known world-wide. More than 136 families, >482 genera and >1547 described species occur in Amazonia. Data show, that almost one-fourth of the families presently known in the Arachnida and about 2% of the worlds described species are represented in Amazonia. In the forest reserve 'Reserva Ducke' near Manaus, the Acari-Oribatida represent 45 families, 72 genera and 35 described species, the Aranea 30 families, 143 genera and 295 described species, the Opiliones 5 families, 7 genera and 8 decribed species, the Scorpiones 2 families, 4 genera and 5 described species, the Pseudoscorpiones 6 families, 11 genera, and 15 described species, the Schizomida, 1 family, 2 genera and 2 described species, and the Amblypygi, Palpigradi, Solifugae and Uropygi (Thelyphonida) one species each. Most names are liste

Eficiência da utilização de potássio, cálcio e magnésio em 16 híbridos de sorgo.

O presente trabalho foi conduzido em casa de vegetação do Departamento de Fototecnia, da Universidade Federal de Viçosa, entre os meses de maio a setembro de 1977, para avaliar a eficiência de utilização de potássio, cálcio e magnésio, em dezesseis híbridos de sorgo (Sorghum bico/ar (L.) Moench) e teve a finalidade de se verificar a aplicabilidade do conceito de "eficiência nutricional"

BRSMG Alterosa: cultivar de arroz para plantio em várzeas mineiras.

O processo de indicação de cultivares de arroz para plantios comerciais é contínuo e dinâmico, periodicamente recomendam-se novas cultivares em substituição àquelas menos produtivas e/ou com menor aceitação comercial. É dentro desta linha de ação que a EPAMIG e a Embrapa Arroz e Feijão, por meio do Programa de Melhoramento Genético de Arroz Irrigado, testa a cada ano diversas linhagens e cultivares, em diferentes locais de Minas Gerais, visando oferecer as melhores opções aos orizicultores, no que tange à escolha de cultivares apropriadas às suas lavouras cultivadas em várzeas

Determination of the Gamow-Teller Quenching Factor from Charge Exchange Reactions on 90Zr

Double differential cross sections between 0-12 degrees were measured for the 90Zr(n,p) reaction at 293 MeV over a wide excitation energy range of 0-70 MeV. A multipole decomposition technique was applied to the present data as well as the previously obtained 90Zr(p,n) data to extract the Gamow-Teller (GT) component from the continuum. The GT quenching factor Q was derived by using the obtained total GT strengths. The result is Q=0.88+/-0.06 not including an overall normalization uncertainty in the GT unit cross section of 16%.Comment: 11 papes, 4 figures, submitted to Physics Letters B (accepted), gzipped tar file, changed content