Second T = 3/2 state in 9^9B and the isobaric multiplet mass equation

Recent high-precision mass measurements and shell model calculations~[Phys. Rev. Lett. {\bf 108}, 212501 (2012)] have challenged a longstanding explanation for the requirement of a cubic isobaric multiplet mass equation for the lowest $A = 9$ isospin quartet. The conclusions relied upon the choice of the excitation energy for the second $T = 3/2$ state in $^9$B, which had two conflicting measurements prior to this work. We remeasured the energy of the state using the $^9{\rm Be}(^3{\rm He},t)$ reaction and significantly disagree with the most recent measurement. Our result supports the contention that continuum coupling in the most proton-rich member of the quartet is not the predominant reason for the large cubic term required for $A = 9$ nuclei

Recherche par une technique d'hémagglutination passive des traces sérologiques des principaux virus respiratoires des bovins et de Chlamydia psittaci dans un échantillon de la population des bovidés du Togo

D'après les résultats obtenus par la technique d'hémagglutination passive, le principal virus respiratoire des bovins du Togo est celui de la rhinotrachéite infectieuse bovine. Les autres virus et Chlamydia psittaci semblent avoir moins d'importanc

Modern African nuclear detector laboratory: Development of state-of-the-art in-house detector facility at the University of the Western Cape

The upcoming detector facility aims at developing new state-of-the-art particle detectors as well as providing hands-on training to postgraduate students using both analog and digital signal processing from nuclear radiation detectors. The project is two-fold and aims at developing: 1) ancillary detectors to be coupled with the new GAMKA array at iThemba LABS. Of particular interest to our group is the determination of nuclear shapes, which depend on the hyperfine splitting of magnetic substates; 2) PET scanners for cancer imaging using a cheaper technology. Performance of NaI(Tl) inorganic scintillator detectors has been evaluated using PIXIE-16 modules from XIA digital electronics. Gamma-ray energy spectra were acquired from 60Co and 137Cs radioactive sources to calculate the detector resolution as well as to optimize the digital parameters. The present study focuses on improving and optimizing the slow and fast filter parameters for NaI(Tl) detectors which can eventually be used in the list mode of data aquisition

Farmers' perceptions on mechanical weeders for rice production in sub-Saharan Africa

Competition from weeds is one of the major biophysical constraints to rice (Oryza spp.) production in sub-Saharan Africa. Smallholder rice farmers require efficient, affordable and labour-saving weed management technologies. Mechanical weeders have shown to fit this profile. Several mechanical weeder types exist but little is known about locally specific differences in performance and farmer preference between these types. Three to six different weeder types were evaluated at 10 different sites across seven countries – i.e., Benin, Burkina Faso, Côte d'Ivoire, Ghana, Nigeria, Rwanda and Togo. A total of 310 farmers (173 male, 137 female) tested the weeders, scored them for their preference, and compared them with their own weed management practices. In a follow-up study, 186 farmers from Benin and Nigeria received the ring hoe, which was the most preferred in these two countries, to use it during the entire crop growing season. Farmers were surveyed on their experiences. The probability of the ring hoe having the highest score among the tested weeders was 71%. The probability of farmers’ preference of the ring hoe over their usual practices – i.e., herbicide, traditional hoe and hand weeding – was 52, 95 and 91%, respectively. The preference of this weeder was not related to gender, years of experience with rice cultivation, rice field size, weed infestation level, water status or soil texture. In the follow-up study, 80% of farmers who used the ring hoe indicated that weeding time was reduced by at least 31%. Of the farmers testing the ring hoe in the follow-up study, 35% used it also for other crops such as vegetables, maize, sorghum, cassava and millet. These results suggest that the ring hoe offers a gender-neutral solution for reducing labour for weeding in rice as well as other crops and that it is compatible with a wide range of environments. The implications of our findings and challenges for out-scaling of mechanical weeders are discussed

Reorientation-effect measurement of the first 2+ state in 12C : Confirmation of oblate deformation

A Coulomb-excitation reorientation-effect measurement using the TIGRESS γ−ray spectrometer at the TRIUMF/ISAC II facility has permitted the determination of the 〈21 +‖E2ˆ‖21 +〉 diagonal matrix element in 12C from particle−γ coincidence data and state-of-the-art no-core shell model calculations of the nuclear polarizability. The nuclear polarizability for the ground and first-excited (21 +) states in 12C have been calculated using chiral NN N4LO500 and NN+3NF350 interactions, which show convergence and agreement with photo-absorption cross-section data. Predictions show a change in the nuclear polarizability with a substantial increase between the ground state and first excited 21 + state at 4.439 MeV. The polarizability of the 21 + state is introduced into the current and previous Coulomb-excitation reorientation-effect analyses of 12C. Spectroscopic quadrupole moments of QS(21 +)=+0.053(44) eb and QS(21 +)=+0.08(3) eb are determined, respectively, yielding a weighted average of QS(21 +)=+0.071(25) eb, in agreement with recent ab initio calculations. The present measurement confirms that the 21 + state of 12C is oblate and emphasizes the important role played by the nuclear polarizability in Coulomb-excitation studies of light nuclei

Brucellosis in Sub-Saharan Africa:Current challenges for management, diagnosis and control

Brucellosis is a highly contagious zoonosis caused by bacteria of the genus Brucella and affecting domestic and wild mammals. In this paper, the bacteriological and serological evidence of brucellosis in Sub-Saharan Africa (SSA) and its epidemiological characteristics are discussed. The tools available for the diagnosis and treatment of human brucellosis and for the diagnosis and control of animal brucellosis and their applicability in the context of SSA are presented and gaps identified. These gaps concern mostly the need for simpler and more affordable antimicrobial treatments against human brucellosis, the development of a B. melitensis vaccine that could circumvent the drawbacks of the currently available Rev 1 vaccine, and the investigation of serological diagnostic tests for camel brucellosis and wildlife. Strategies for the implementation of animal vaccination are also discussed.Publishe

Avantages de la parité entre le FCFA et l'euro

The objective of this document is to highlight the possible advantages of the docking of the CFA franc to the euro. Indeed, the current orientation of socio-political and economic debates, and even of certain articles, is increasingly believing that the main problem of the Franc Zone countries intheir development process would be the linkage of the CFA franc to the euro. Thus, a total and radical separation would be necessary between France and the countries of the Franc Zone so that the latter could hope to reach rapid development; this implies that they should have their currency.It is clear from our study that the stowage of the CFA franc is indeed an advantage for the countries of the Franc Zone; it would be fair for the latter to know how to take advantage of it. Indeed, the evolution of indicators in these countries shows that the fixed parity since 1 January 1999 betweenthe euro and the two CFA Francs favors the monetary and financial stability of the countries of the Franc Zone. By way of illustration, inflation has historically been much better controlled in the countries of the franc zone than in the rest of sub-Saharan Africa. Second, by guaranteeing theconvertibility of CFA francs, the mechanism of the account of operations greatly contributes to strengthen the credibility of these currencies. In addition, by removing the currency risk within the zone and reducing it to external partners, the Franc Zone contributes to the integration of membercountries into international trade. Finally, by establishing a common set of rules, the Franc Zone plays a catalytic role of solidarity and regional integrationLe présent document a pour objectif de ressortir les éventuels avantages de l’arrimage du Franc CFA à l’euro. En effet, l’orientation que prennent aujourd’hui les débats sociopolitiques et économiques, et même certains articles de recherche, laissent de plus en plus croire que le principalproblème des pays de la Zone Franc dans leur processus de développement serait l’arrimage du Franc CFA à l’euro. Ainsi, il faudrait une séparation totale et radicale entre la France et les pays de la Zone Franc pour que ces derniers puissent espérer tendre rapidement vers le développement, cela implique qu’il faudrait également qu’ils aient leur monnaie.Il ressort de notre étude que l’arrimage du Franc CFA à l’euro a des avantages que les pays de la Zone Franc devraient mettre à profit dans l’orientation de leurs stratégies de politiques économiques. En effet, l’évolution d’indicateurs de ces pays montre d’une part que la fixité des parités de change depuis le 1er janvier 1999 entre l'euro et les deux Francs CFA d’une part et entre l’euro et le Franc comorien d’autre part favorise la stabilité monétaire et financière des pays de la Zone Franc. À titre d’illustration l’inflation est historiquement bien mieux maitrisée dans les paysde la Zone franc que dans le reste de l’Afrique subsaharienne. Ensuite, en garantissant la convertibilité des francs CFA et du Franc comorien, le mécanisme du compte d'opérations contribue largement à renforcer la crédibilité de ces monnaies. De plus, en supprimant le risque de change àl'intérieur de la zone et en le réduisant vis-à-vis des partenaires extérieurs, la Zone Franc contribue à l'insertion des pays membres dans les échanges internationaux. Enfin, avec l’instauration des critères de convergence multilatérale dans l’Union Monétaire Ouest Africaine (UMOA) et dans l’Union Monétaire d’Afrique Centrale, la Zone Franc joue un rôle catalyseur de la solidarité et de l’intégration régionale