Husbandry, nutrition and productivity of goats and sheep in tropical Africa

Examines sheep and goat husbandry including breed types and ownership; nutrition and productivity. Tabulates their contribution to liveweight biomass, meat production, and registered slaughtering. Shows some measured production parameters for African goats and sheep in semi-arid areas. Looks at the potential for improved production

Evaluation of Shugor, Dubasi and Watish subtypes of Sudan Desert sheep at the El-Huda National Sheep Research Station, Gezira Province, Sudan

Presents results obtained from a trial conducted at El-Huda National Sheep Research Station, Sudan, Shugor, Dubasi and Watish subtypes of Sudan Desert sheep to compare productivity, reproductivity and animal performance, with particular reference to lambing, lambing intervals, body weight, growth rates and mortality rates, incl. recommendations for further investigations

Livestock production in central Mali: Long-term studies on cattle and small ruminants in the agropastoral system

Presents results of a 6 year study on the livestock production systems, management practices herd & flock demography in an agropastoral system in central Mali as well as reproductive performance growth rate, weights, mortality, offtake and productivity in terms of meat & milk yield of cattle & small ruminants; includes recommendations on means of improving the system and future research

Performances de reproduction du dromadaire. Base empirique

Cet article est une synthèse des données empiriques et des observations provenant la plupart d'études de terrain sur les performances de reproduction du dromadaire. Des références sont faites à de nombreux pays d'Afrique et d'Asie. L'âge élevé à la première parturition (60 mois), le long intervalle entre les mises bas (24 mois et plus) et la réforme relativement précoce des reproductrices (à partir de 10 ans) sont responsables du faible nombre de jeunes, en moyenne moins de 3, par carrière de reproductrice. Le dromadaire présente un cycle de reproduction fortement influencé par la saison dans la plupart des régions mais les raisons en sont encore mal connues. Les performances de reproduction peuvent être accrues en réduisant en même temps l'âge à la première parturition et l'intervalle de mise bas, et en augmentant la durée de reproduction de la femelle

Livestock production in central Mali

Summarizes a baseline study of the traditional livestock production system of central Mali, classifying production systems in the study in the study zone according to the degree of dependence on livestock products for gross revenue or food supply of the household or production unit, and according to types of agriculture associated w. livestock. Describes primary resources available for livestock production; livestock numbers & movement patterns; the agropastoral system; and the pastoral system associated w. rice cultivation in the Niger innundation zone

Characterisation of Kenana cattle at Um Banein, Sudan

Results of a study carried on the reproductive performance, herd management, weight & growth, milk production & mortality of Kenana cattle at Um Banein Livestock Research Station (Sudan)

1D vs. 2D shape selectivity in the crystallization-driven self-assembly of polylactide block copolymers

yes2D materials such as graphene, LAPONITE® clays or molybdenum disulfide nanosheets are of extremely high interest to the materials community as a result of their high surface area and controllable surface properties. While several methods to access 2D inorganic materials are known, the investigation of 2D organic nanomaterials is less well developed on account of the lack of ready synthetic accessibility. Crystallization-driven self-assembly (CDSA) has become a powerful method to access a wide range of complex but precisely-defined nanostructures. The preparation of 2D structures, however, particularly those aimed towards biomedical applications, is limited, with few offering biocompatible and biodegradable characteristics as well as control over self-assembly in two dimensions. Herein, in contrast to conventional self-assembly rules, we show that the solubility of polylactide (PLLA)-based amphiphiles in alcohols results in unprecedented shape selectivity based on unimer solubility. We use log Poct analysis to drive solvent selection for the formation of large uniform 2D diamond-shaped platelets, up to several microns in size, using long, soluble coronal blocks. By contrast, less soluble PLLA-containing block copolymers yield cylindrical micelles and mixed morphologies. The methods developed in this work provide a simple and consistently reproducible protocol for the preparation of well-defined 2D organic nanomaterials, whose size and morphology are expected to facilitate potential applications in drug delivery, tissue engineering and in nanocomposites.University of Warwick, Materials GRP, EPSRC, The Royal Society, ER

Crossover between ionic/covalent and pure ionic bonding in magnesium oxyde clusters

An empirical potential with fluctuating charges is proposed for modelling (MgO)_n clusters in both the molecular (small n) and bulk (n->infty) regimes. Vectorial polarization forces are explicitely taken into account in the self-consistent determination of the charges. Our model predicts cuboid cluster structures, in agreement with previous experimental and theoretical results. The effective charge transferred between magnesium and oxygen smoothly increases from 1 to 2, with an estimated crossover size above 300 MgO molecules

Critical temperature for the two-dimensional attractive Hubbard Model

The critical temperature for the attractive Hubbard model on a square lattice is determined from the analysis of two independent quantities, the helicity modulus, $\rho_s$, and the pairing correlation function, $P_s$. These quantities have been calculated through Quantum Monte Carlo simulations for lattices up to $18\times 18$, and for several densities, in the intermediate-coupling regime. Imposing the universal-jump condition for an accurately calculated $\rho_s$, together with thorough finite-size scaling analyses (in the spirit of the phenomenological renormalization group) of $P_s$, suggests that $T_c$ is considerably higher than hitherto assumed.Comment: 5 pages, 6 figures. Accepted for publication in Phys. Rev.