Proposal for the Establishment of a Cooperative Programme for Field Bean Research in Latin America and the Caribbean Zone

Document prepared by Luis Marcano for the TAC mission to review research needs for protein production in tropical America, detailing the justification, objectives, programs, activities, and budget of the proposed PROFRIJOL cooperative program for bean research in Latin America and the Caribbean. Agenda item presented at TAC Seventh Meeting, February 1974. Also discussed at CGIAR ICW July August 1974

Performance of HPGe Detectors in High Magnetic Fields

A new generation of high-resolution hypernuclear gamma$-spectroscopy experiments with high-purity germanium detectors (HPGe) are presently designed at the FINUDA spectrometer at DAPhiNE, the Frascati phi-factory, and at PANDA, the antiproton proton hadron spectrometer at the future FAIR facility. Both, the FINUDA and PANDA spectrometers are built around the target region covering a large solid angle. To maximise the detection efficiency the HPGe detectors have to be located near the target, and therefore they have to be operated in strong magnetic fields B ~ 1 T. The performance of HPGe detectors in such an environment has not been well investigated so far. In the present work VEGA and EUROBALL Cluster HPGe detectors were tested in the field provided by the ALADiN magnet at GSI. No significant degradation of the energy resolution was found, and a change in the rise time distribution of the pulses from preamplifiers was observed. A correlation between rise time and pulse height was observed and is used to correct the measured energy, recovering the energy resolution almost completely. Moreover, no problems in the electronics due to the magnetic field were observed.Comment: submitted to Nucl. Instrum. Meth. Phys. Res. A, LaTeX, 19 pages, 9 figure

Hyperons in a relativistic mean-field approach to asymmetric nuclear matter

Relativistic mean-field theory with $\delta$ meson, nonlinear isoscalar self-interactions and isoscalar-isovector cross interaction terms with parametrizations obtained to reproduce Dirac-Brueckner-Hartree-Fock calculations for nuclear matter is used to study asymmetric nuclear matter properties in $\beta$-equilibrium, including hyperon degrees of freedom and (hidden) strange mesons. Influence of cross interaction on composition of hyperon matter and electron chemical potential is examined. Softening of nuclear equation of state by the cross interactions results in lowering of hyperonization, although simultaneously enhancing a hyperon-induced decrease of the electron chemical potential, thus indicating further shift of a kaon condensate occurence to higher densities.Comment: 11 pages, 7 figures, 3 tables, published in Phys. Rev.

Digestão de óleo lubrificante encapsulado em forno de microondas com radiação focalizada por adição de amostra ao reagente pré-aquecido.

FOCUSED-MICROWAVE-ASSISTED DIGESTION OF ENCAPSULATED LUBRICATING OILS: GRADUAL SAMPLEADDITION TO PRE-HEATED ACID. The applicability of the recently proposed procedure based on gradual sample addition tomicrowave-assisted pre-heated concentrated acid is limited by the sample viscosity. In this work, lubricating oil samples with high viscositywere encapsulated and manually added to the microwave-assisted pre-heated concentrated digestion mixture. The procedure was appliedfor determination of Al, Ca, Cr, Cu, Fe, Mg, Ni, P, Pb, Si, Sn, Sr, V, W, and Zn in lubricating oil by inductively coupled plasma opticalemission spectrometry (ICP OES). Determined and certified values for Ca, Mg, P, and Zn in lubricating oil were in agreement at a 95% confidence level

Prospecção de SNPs no gene TNFa e sua possível associação à verminose gastrintestinal em caprinos.

O objetivo desse estudo foi investigar a associação entre marcadores moleculares do tipo SNP (Polimorfismo de base única) prospectados no gene TNFa (fator de necrose tumoral alfa) e resistência à verminose gastrintestinal em caprinos. Para isso, foram produzidos 229 caprinos a partir de animais das raças Saanen, raça considerada susceptível a endoparasitas gastrintestinais e Anglo-nubiana, raça considerada resistente. Para a prospecção de SNPs, foram sequenciados 44 animais extremos para OPG (contagem de ovos por grama de fezes) escolhidos a partir dos resíduos obtidos através do modelo estatístico usado para corrigir os dados fenotípicos para as variações ambientais. O sequenciamento inclui quatro regiões do gene TNFa. Nestas regiões, foram encontrados dez SNPs: dois estão localizados na região promotora do gene, dois no intron 2 e seis no exon 4. Através da aplicação do teste de Fisher foi encontrada uma associação de cinco dos SNPs prospectados ( P ≤ 0,05), o que indica que esses SNPs são potenciais marcadores moleculares para resistência à verminose gastrintestinal

Comparação de diferentes protocolos para visualização de DNA separado por eletroforese em gel de agarose utilizando-se os corantes fluorescentes brometo de etídeo e GelRedr.

O brometo de etídio é um corante fluorescente mutagênico utilizado para a visualização de ácidos nucléicos separados pela técnica analítica de eletroforese em gel. Há um corante alternativo, apresentado comercialmente como GelRedR (Biotium), que tem se destacado por não ter ação mutagênica. Sua estrutura ainda não é de conhecimento público por estar sob processo de patente, porém sabe-se que sua massa molar é pelo menos 3 vezes maior do que a do primeiro. Comumente, o brometo de etídeo, e mais recentemente o GelRed são utilizados segundo diferentes protocolos, utilizados no gel de agarose antes da polimerização do mesmo, em banho, após a eletroforese ou diretamente na amostra

New detectors for the kaon and hypernuclear experiments with KaoS at MAMI and with PANDA at GSI

The KaoS spectrometer at the Mainz Microtron MAMI, Germany, is perceived as the ideal candidate for a dedicated spectrometer in kaon and hypernuclei electroproduction. KaoS will be equipped with new read-out electronics, a completely new focal plane detector package consisting of scintillating fibres, and a new trigger system. First prototypes of the fibre detectors and the associated new front-end electronics are shown in this contribution. The Mainz hypernuclei research program will complement the hypernuclear experiments at the planned FAIR facility at GSI, Germany. At the proposed antiproton storage ring the spectroscopy of double Lambda hypernuclei is one of the four main topics which will be addressed by the PANDA Collaboration. The experiments require the operation of high purity germanium (HPGe) detectors in high magnetic fields (B= 1T) in the presence of a large hadronic background. The performance of high resolution Ge detectors in such an environment has been investigated.Comment: Presentation at International Symposium on the Development of Detectors for Particle, Astroparticle and Synchrotron Radiation Experiments, Stanford, Ca (SNIC06), 6 pages, LaTeX, 11 eps figure

Σ−p\Sigma^- p emission rates in K−K^- absorptions at rest on 6^6Li, 7^7Li, 9^{9}Be, 13^{13}C and 16^{16}O

An experimental study of the $K^-_{stop}A\rightarrow \Sigma^- p A'$ reaction on $A=^6$Li, $^7$Li, $^9$Be, $^{13}$C and $^{16}$O $p$-shell nuclei is presented. The data were collected by the FINUDA spectrometer operating at the DA$\Phi$NE $\phi$-factory (LNF-INFN, Italy). Emission rates for the reaction in the mentioned nuclei are measured and compared with the few existing data. The spectra of several observables are discussed; indications of Quasi-Free absorptions by a $(np)$ pair embedded in the $A$ nucleus can be obtained from the study of the missing mass distributions.Comment: Version accepted by PR