Variations in agronomic and grain quality traits of rice grown under irrigated lowland conditions in West Africa

Rice breeding in West Africa has been largely skewed toward yield enhancement and stress tolerance. This has led to the variable grain quality of locally produced rice in the region. This study sought to assess variations in the agronomic and grain quality traits of some rice varieties grown in this region, with a view to identifying sources of high grain yield and quality that could serve as potential donors in their breeding programs. Forty‐five varieties were grown under irrigated conditions in Benin and Senegal with two trials in each country. There were wide variations in agronomic and grain quality traits among the varieties across the trials. Cluster analysis using paddy yield, head rice yield, and chalkiness revealed that 68% of the total variation could be explained by five varietal groupings. One group comprising seven varieties (Afrihikari, BG90‐2, IR64, Sahel 108, WAT311‐WAS‐B‐B‐23‐7‐1, WAT339‐TGR‐5‐2, and WITA 10) had high head rice yield and low chalkiness. Of the varieties in this group, Sahel 108 had the highest paddy yield in three of the four trials. IR64 and Afrihikari had intermediate and low amylose content, respectively, with the rest being high‐amylose varieties. Another group of varieties consisting of B6144F‐MR‐6‐0‐0, C74, IR31851‐96‐2‐3‐2‐1, ITA222, Jaya, Sahel 305, WITA 1, and WITA 2 had high paddy yield but poor head rice yield and chalkiness. The use of materials from these two groups of varieties could accelerate breeding for high yielding rice varieties with better grain quality for local production in West Africa

The gravity duals of SO/USp superconformal quivers

We study the gravity duals of SO/USp superconformal quiver gauge theories realized by M5-branes wrapping on a Riemann surface ("G-curve") together with a Z_2-quotient. When the G-curve has no punctures, the gravity solutions are classified by the genus g of the G-curve and the torsion part of the four-form flux G_4. We also find that there is an interesting relation between anomaly contributions from two mysterious theories: T_{SO(2N)} theory with SO(2N)^3 flavor symmetry and \tilde{T}_{SO(2N)} theory with SO(2N) x USp(2N-2)^2 flavor symmetry. The dual gravity solutions for various SO/USp-type tails are also studied.Comment: 27 pages, 13 figures; v2 minor corrections, typos corrected, Figure 13 replaced, references adde

DIFFICULTÉS DE LA PARTICIPATION EN RECHERCHE- ACTION : retour d'expériences de modélisation d'accompagnement en appui à l'aménagement du territoire au Sénégal et à la Réunion

International audienceComment aider les institutions et acteurs locaux à investir davantage les processus d'affectation des terres pour aménager leur territoire ? La décentralisation de l'aménagement du territoire engagée à la Réunion et au Sénégal est inachevée. Malgré l'arsenal législatif, les populations locales semblent peu impliquées dans les décisions les concernant en raison notamment de la difficulté à appréhender la complexité des systèmes d'interactions entre dynamiques sociales et environnementales. Le projet Domino vise à accompagner les processus de décision en proposant aux acteurs de construire et d'explorer des scenarii prospectifs d'affectation des terres. Cette expérience de modélisation participative repose sur une dynamique partenariale complexe sur chaque terrain, source de difficultés. Conscients des dérives potentielles, nous discutons la nécessité de construire une démarche qualité de notre recherche-action. Mots clés : montage de partenariat, démarche qualité, modèle, changement social, ComMod, interdisciplinarité, décentralisation, foncier, Sénégal, Réunio

Holographic Entanglement Entropy at Finite Temperature

Using a holographic proposal for the entanglement entropy we study its behavior in various supergravity backgrounds. We are particularly interested in the possibility of using the entanglement entropy as way to detect transitions induced by the presence horizons. We consider several geometries with horizons: the black hole in $AdS_3$, nonextremal Dp-branes, dyonic black holes asymptotically to $AdS_4$ and also Schwarzschild black holes in global $AdS_p$ coordinates. Generically, we find that the entanglement entropy does not exhibit a transition, that is, one of the two possible configurations always dominates.Comment: v3: 31 pp, ten figures, modified to match version accepted by IJMP

Dipole Coupling Effect of Holographic Fermion in the Background of Charged Gauss-Bonnet AdS Black Hole

We investigate the holographic fermions in the charged Gauss-Bonnet $AdS_{d}$ black hole background with the dipole coupling between fermion and gauge field in the bulk. We show that in addition to the strength of the dipole coupling, the spacetime dimension and the higher curvature correction in the gravity background also influence the onset of the Fermi gap and the gap distance. We find that the higher curvature effect modifies the fermion spectral density and influences the value of the Fermi momentum for the appearance of the Fermi surface. There are richer physics in the boundary fermion system due to the modification in the bulk gravity.Comment: 16 pages, accepted for publication in JHE

Beyond LLM in M-theory

The Lin, Lunin, Maldacena (LLM) ansatz in D = 11 supports two independent Killing directions when a general Killing spinor ansatz is considered. Here we show that these directions always commute, identify when the Killing spinors are charged, and show that both their inner product and resulting geometry are governed by two fundamental constants. In particular, setting one constant to zero leads to AdS7 x S4, setting the other to zero gives AdS4 x S7, while flat spacetime is recovered when both these constants are zero. Furthermore, when the constants are equal, the spacetime is either LLM, or it corresponds to the Kowalski-Glikman solution where the constants are simply the mass parameter.Comment: 1+30 pages, footnote adde

On N = 2 Truncations of IIB on T^{1,1}

We study the N=4 gauged supergravity theory which arises from the consistent truncation of IIB supergravity on the coset T^{1,1}. We analyze three N=2 subsectors and in particular we clarify the relationship between true superpotentials for gauged supergravity and certain fake superpotentials which have been widely used in the literature. We derive a superpotential for the general reduction of type I supergravity on T^{1,1} and this together with a certain solution generating symmetry is tantamount to a superpotential for the baryonic branch of the Klebanov-Strassler solution.Comment: 32 pages, v2:references adde

Fermions and Type IIB Supergravity On Squashed Sasaki-Einstein Manifolds

We discuss the dimensional reduction of fermionic modes in a recently found class of consistent truncations of type IIB supergravity compactified on squashed five-dimensional Sasaki-Einstein manifolds. We derive the lower dimensional equations of motion and effective action, and comment on the supersymmetry of the resulting theory, which is consistent with N=4 gauged supergravity in $d=5$, coupled to two vector multiplets. We compute fermion masses by linearizing around two $AdS_{5}$ vacua of the theory: one that breaks N=4 down to N=2 spontaneously, and a second one which preserves no supersymmetries. The truncations under consideration are noteworthy in that they retain massive modes which are charged under a U(1) subgroup of the $R$-symmetry, a feature that makes them interesting for applications to condensed matter phenomena via gauge/gravity duality. In this light, as an application of our general results we exhibit the coupling of the fermions to the type IIB holographic superconductor, and find a consistent further truncation of the fermion sector that retains a single spin-1/2 mode.Comment: 43 pages, 2 figures, PDFLaTeX; v2: added references, typos corrected, minor change

Disordered Systems and the Replica Method in AdS/CFT

We formulate a holographic description of effects of disorder in conformal field theories based on the replica method and the AdS/CFT correspondence. Starting with $n$ copies of conformal field theories, randomness with a gaussian distribution is described by a deformation of double trace operators. After computing physical quantities, we take the $n \to 0$ limit at the final step. We compute correlation functions in the disordered systems by using the holographic replica method as well as the formulation in the conformal field theory. We find examples where disorder changes drastically the scaling of two point functions. The renormalization group flow of the effective central charge in our disordered systems is also discussed.Comment: 26 pages, references added, published versio