Alimentation des ovins des marches de vente de betail dans la ville d’Abidjan, Côte d’Ivoire

Une étude a été menée pour déterminer l'alimentation, les lieux et contraintes d'approvisionnement des aliments des ovins présents sur les marchés à bétail dans la ville d'Abidjan. Elle a été réalisée à partir d'enquêtes et d'inventaires floristiques effectués sur les marchés à bétail. Il ressort de cette étude que les fourrages constitués, par ordre d'importance, des espèces telles que : Panicum maximum Jacq. (Poaceae), Chloris pilosa Schumach. (Poaceae), Brachiaria lata (Schumach.) Hub (Poaceae) ; Mariscus cylindristachyus Steud. (Cyperaceae), Cyperus longibracteatus (Cherm.) Kuk (Cyperaceae) sont les plus consommées par les animaux. Les lieux de collecte de ces fourrages sont les jachères, les abords de routes et les bas fonds de la ville. Certaines contraintes telles que : (i) manque de liquidité financière, (ii) retard dans les livraisons des fourrages, (iii) absence de structures adaptées à cette activité, (iiii) manque de moyens adéquats pour le prélèvement des fourrages rendent difficile le bon déroulement de l'approvisionnement de ces fourrages. Enfin le développement urbain, commande que l'on mette en place des structures spécialisées dans l'alimentation des ovins et identifie des lieux appropriés à l'approvisionnement en ces fourrages.Mots clés : Marché, ovins, fourrages, Côte d'Ivoire

THREE-DIMENSIONAL FINGERPRINT SPECTROSCOPY STUDY ON THE BIOPOLYMER SYSTEM OF POLYPHENOL OXIDASE BINDING WITH CUMALIC ACID

The protection of Cumalic acid (CA), antioxidant, in the biochemical process in nature has aroused great interest. Polyphenol oxidase (PPO), an enzyme, plays a vital function in aging and browning of plants, such as vegetables, fruits, and mushrooms. The interaction of CA and PPO reveals the important information in metabolism and aging. Thus, the molecular mechanism of CA binding with polyphenol oxidase (PPO) was explored by combining spectroscopic methods with molecular modeling. A three-dimensional fingerprint of the CA-PPO complex was built for the first time to characterize the biopolymer interaction between CA and PPO. Application of the spectroscopic methods indicated that CA effectively quenched the intrinsic fluorescence of PPO. The enthalpy change (ΔH°) and entropy change (ΔS°) suggested that the CA-PPO complex was predominantly stabilized by hydrophobic interactions CA and PPO. Building the λ-UV-F fingerprint of CA-PPO made it possible to demonstrate the three-dimensional interactions between CA and PPO. Subsequently, molecular modeling demonstrated that CA was primarily bound to PPO by hydrophobic interactions and hydrogen bonds located at amino acid residues Ala202, His38, His54, and Ser206. The computational simulations were consistent with the spectral experiments demonstrating confidence in the three-dimensional model determined of the CA-PPO interaction

Identification of essential histidine residues in a recombinant alpha-amylase of thermophilic and alkaliphilic Bacillus sp strain TS-23

To understand the structure-function relationships of a truncated Bacillus sp. strain TS-23 alpha-amylase, each of His-137, His-191, His-239, His-269, His-305, His-323, His-361, His-436, and His-475 was replaced with leucine. The molecular masses of the purified wild-type and mutant enzymes were approximately 54 kDa. The specific activity of His323Leu and His436Leu was decreased by more than 52%, while His239Leu, His305Leu, and His475Leu showed activity similar to that of the wild-type enzyme. As compared with the wild-type enzyme, His323Leu and His436Leu exhibited a 62% decrease in the value of k(cat)/K-m. Alterations in His-191, His-239, His-305, and His-475 did not cause a significant change in the K-m or k(cat) values. At 70degreesC, a decreased half-life was observed in His436Leu. These results indicate that His-137, His-269, and His-361 of Bacillus sp. strain TS-23 alpha-amylase are important for proper catalytic activity and that His-436 may contribute to the thermostability of the enzyme

Rock Compaction Fault Displacement Evidence from Analysis of Sub-Parallel Subsurface Strata

Sedimentary units often show compaction variation across fault blocks resulting from jarring vertical shortening; a common occurrence in growth fault system innate to the Niger Delta. Rock displacement traceable on slip surface with varied dip was mapped on 3D seismic data. Interpretation done on available well logs reveal existing zones of sand formation that fairly correlates with compaction patterns seen on seismic lines across fault blocks with reference to vertical deviations in horizons across fault planes. These anomalies were stochastically analyzed for its topology effects using Density logs from the field in an attempt to ascertain the influence of rock strata on fault displacement and how this translates to compaction patterns. It was discovered that the effect of differential compaction propelled by wobbly underlying rocks primarily drives the local complexities imaged on the seismic data as varied turgid deformation zones also prolific from computed seismic attributes

Rock Compaction Fault Displacement Evidence from Analysis of Sub-Parallel Subsurface Strata

Sedimentary units often show compaction variation across fault blocks resulting from jarring vertical shortening; a common occurrence in growth fault system innate to the Niger Delta. Rock displacement traceable on slip surface with varied dip was mapped on 3D seismic data. Interpretation done on available well logs reveal existing zones of sand formation that fairly correlates with compaction patterns seen on seismic lines across fault blocks with reference to vertical deviations in horizons across fault planes. These anomalies were stochastically analyzed for its topology effects using Density logs from the field in an attempt to ascertain the influence of rock strata on fault displacement and how this translates to compaction patterns. It was discovered that the effect of differential compaction propelled by wobbly underlying rocks primarily drives the local complexities imaged on the seismic data as varied turgid deformation zones also prolific from computed seismic attributes

Neutrino mean free paths in spin-polarized neutron Fermi liquids

Neutrino mean free paths in magnetized neutron matter are calculated using the Hartree-Fock approximation with effective Skyrme and Gogny forces in the framework of the Landau Fermi Liquid Theory. It is shown that describing nuclear interaction with Skyrme forces and for magnetic field strengths $log_{10} B(G) \gtrsim 17$, the neutrino mean free paths stay almost unchanged at intermediate densities but they largely increase at high densities when they are compared to the field-free case results. However the description with Gogny forces differs from the previous and mean free paths stay almonst unchanged or decrease at densities $[1-2]\rho_0$. This different behaviour can be explained due to the combination of common mild variation of the Landau parameters with both types of forces and the values of the nucleon effective mass and induced magnetization of matter under presence of a strong magnetic field as described with the two parametrizations of the nuclear interaction.Comment: 9 pages, 3 figure

Electromagnetic Probes

A review is presented of dilepton and real photon measurements in relativistic heavy ion collisions over a very broad energy range from the low energies of the BEVALAC up to the highest energies available at RHIC. The dileptons cover the invariant mass range \mll = 0 - 2.5 GeV/c$^2$, i.e. the continuum at low and intermediate masses and the light vector mesons, $\rho, \omega, \phi$. The review includes also measurements of the light vector mesons in elementary reactions.Comment: To be published in Landolt-Boernstein Volume 1-23A; 40 pages, 24 figures. Final version updated with small changes to the text, updated references and updated figure

Au+Au Reactions at the AGS: Experiments E866 and E917

Particle production and correlation functions from Au+Au reactions have been measured as a function of both beam energy (2-10.7AGeV) and impact parameter. These results are used to probe the dynamics of heavy-ion reactions, confront hadronic models over a wide range of conditions and to search for the onset of new phenomena.Comment: 12 pages, 14 figures, Talk presented at Quark Matter '9

The ARGO-YBJ Experiment Progresses and Future Extension

Gamma ray source detection above 30TeV is an encouraging approach for finding galactic cosmic ray origins. All sky survey for gamma ray sources using wide field of view detector is essential for population accumulation for various types of sources above 100GeV. To target the goals, the ARGO-YBJ experiment has been established. Significant progresses have been made in the experiment. A large air shower detector array in an area of 1km2 is proposed to boost the sensitivity. Hybrid detection with multi-techniques will allow a good discrimination between different types of primary particles, including photons and protons, thus enable an energy spectrum measurement for individual specie. Fluorescence light detector array will extend the spectrum measurement above 100PeV where the second knee is located. An energy scale determined by balloon experiments at 10TeV will be propagated to ultra high energy cosmic ray experiments

Lorentz breaking Effective Field Theory and observational tests

Analogue models of gravity have provided an experimentally realizable test field for our ideas on quantum field theory in curved spacetimes but they have also inspired the investigation of possible departures from exact Lorentz invariance at microscopic scales. In this role they have joined, and sometime anticipated, several quantum gravity models characterized by Lorentz breaking phenomenology. A crucial difference between these speculations and other ones associated to quantum gravity scenarios, is the possibility to carry out observational and experimental tests which have nowadays led to a broad range of constraints on departures from Lorentz invariance. We shall review here the effective field theory approach to Lorentz breaking in the matter sector, present the constraints provided by the available observations and finally discuss the implications of the persisting uncertainty on the composition of the ultra high energy cosmic rays for the constraints on the higher order, analogue gravity inspired, Lorentz violations.Comment: 47 pages, 4 figures. Lecture Notes for the IX SIGRAV School on "Analogue Gravity", Como (Italy), May 2011. V.3. Typo corrected, references adde