Non-Supersymmetric Attractor Flow in Symmetric Spaces

We derive extremal black hole solutions for a variety of four dimensional models which, after Kaluza-Klein reduction, admit a description in terms of 3D gravity coupled to a sigma model with symmetric target space. The solutions are in correspondence with certain nilpotent generators of the isometry group. In particular, we provide the exact solution for a non-BPS black hole with generic charges and asymptotic moduli in N=2 supergravity coupled to one vector multiplet. Multi-centered solutions can also be generated with this technique. It is shown that the non-supersymmetric solutions lack the intricate moduli space of bound configurations that are typical of the supersymmetric case.Comment: 50 pages, 4 figures; v2: Reference added. To appear in JHE

Assessing the effectiveness of a local agricultural research committee in diffusing sustainable cocoa production practices: the case of capsid control in Ghana

The conventional method of `delivering¿ technologies recommended by researchers to farmers through extension has proved ineffective, resulting in a persistent low (3.5% over ten years) adoption of research-based cocoa technologies. The present study was conducted in the Eastern Region of Ghana and assessed the impact of the Local Agricultural Research Committee (LARC) approach on the diffusion of capsid management knowledge and practices, developed with the LARC, to others in the community. Capsids (Sahlbergella singularis and Distantiella theobroma) were diagnosed as the most serious production constraint. LARC members engaged in intensive interactive learning and experimentation to control them. The interactive approach developed by the International Centre for Tropical Agriculture was used to link the LARC with community farmers, a majority of whom aspired to produce organic cocoa for a premium. The LARC acquired vital agro-ecological knowledge on capsid management, including skills in scouting for capsids to determine their temporal distribution and systematic experimentation with control methods, before presenting its results to the community. This article reports on a survey comparing three categories of farmers: LARC members, exposed and non-exposed community farmers, so as to assess the diffusion and impact of LARC knowledge co-production. The results show that the LARC approach significantly influenced acquisition and diffusion of knowledge and practices

Applying SNP marker technology in the cacao breeding programme in Ghana

In this investigation 45 parental cacao plants and five progeny derived from the parental stock studied were genotyped using six SNP markers to determine off-types or mislabeled clones and to authenticate crosses made in the Cocoa Research Institute of Ghana (CRIG) breeding programme. Investigation was based on the 5\u2019 nuclease SNPassay using Illustra Hot Start mix Ready-To-Go PCR strips and BioTek FLx800TBP Fluorescence Microplate Reader. In a group of six cacao plants labeled as PA150 clones and another five labeled as Pound7, one clone in each group was unambiguously determined as off-type or mislabeled. Similarly, in a cohort of 23 PA7 "clones", four genotypes were differentiated. Cross-checking the fidelity of five progeny from the parental stock under study, it was established that no errors were made in the crossing. The most significant outcome of this study, however, was that out of the four categories of 23 PA7 candidate parental trees only one category can be comparable to the reference clone in the International Cacao Germplasm collection, Trinidad (ICG,T); thus informing the need for further work to find the correct clone among these for the breeding programme. It was thus concluded that thissimple yet cutting-edge genotyping procedure can be used in applied cocoa breeding programmes in a cocoa producing country. This work represents a first step in the genotypic characterisation of the CRIG germplasm collection and Seed Gardens.Au cours de cette recherche, 45 plants de cacao parentaux et 5 descendants d\ue9rivant du stock parental ont \ue9t\ue9 g\ue9notyp\ue9 en utilisant 6 marqueurs SNP, afin de d\ue9terminer les clones mal \ue9tiquet\ue9s et d\u2019authentifier les croisements effectu\ue9s dans le programme d\u2019am\ue9lioration de l\u2019Institut de Recherche sur le Cacao au Ghana (CRIG). Cette \ue9tude a \ue9t\ue9 bas\ue9e sur les 5' nucl\ue9ases SNP en utilisant des bandes PCR "Hot Start mix Ready-To-Go PCR strips" et un Lecteur Microplat \ue0 Fluorescence "BioTek FLx800TBP". Au sein d\u2019un groupe de six plants de cacao \ue9tiquet\ue9 PA150 et d\u2019un autre groupe de cinq \ue9tiquet\ue9 Pound 7, il a \ue9t\ue9 d\ue9termin\ue9 sans ambigu\ueft\ue9 qu\u2019un clone par groupe \ue9tait mal \ue9tiquet\ue9. De fa\ue7on similaire, quatre g\ue9notypes diff\ue9rents ont \ue9t\ue9 identifi\ue9s dans une m\ueame cohorte de clones 23PA7. En v\ue9rifiant la fid\ue9lit\ue9 de cinq descendants issus du stock parental \ue9tudi\ue9, il a \ue9t\ue9 \ue9tabli qu\u2019aucune erreur n\u2019avait \ue9t\ue9 faite lors du croisement. Le r\ue9sultat le plus significatif de cette \ue9tude a \ue9t\ue9 que, sur quatre cat\ue9gories de 23 candidats PA7 de souches parentales, une seule pouvait \ueatre comparable au clone de r\ue9f\ue9rence dans la collection Internationale du Germoplasme de Cacao, Trinidad (ICG,T), d\ue9montrant ainsi la n\ue9cessit\ue9 de travaux suppl\ue9mentaires pour d\ue9terminer le clone exact parmi ceux \ue9voqu\ue9s pr\ue9c\ue9demment. Il a ainsi \ue9t\ue9 conclu que cette m\ue9thode avant-gardiste de g\ue9notypage, pourtantsimple, peut \ueatre utilis\ue9e dans les programmes appliqu\ue9s d\u2019am\ue9lioration du cacao dans un pays producteur. Ce travail repr\ue9sente une premi\ue8re \ue9tape dans la caract\ue9risation g\ue9n\ue9tique de la collection du germoplasme CRIG et jardins semenciers

Viral perturbations of host networks reflect disease etiology

Many human diseases, arising from mutations of disease susceptibility genes (genetic diseases), are also associated with viral infections (virally implicated diseases), either in a directly causal manner or by indirect associations. Here we examine whether viral perturbations of host interactome may underlie such virally implicated disease relationships. Using as models two different human viruses, Epstein-Barr virus (EBV) and human papillomavirus (HPV), we find that host targets of viral proteins reside in network proximity to products of disease susceptibility genes. Expression changes in virally implicated disease tissues and comorbidity patterns cluster significantly in the network vicinity of viral targets. The topological proximity found between cellular targets of viral proteins and disease genes was exploited to uncover a novel pathway linking HPV to Fanconi anemia

Angiotensin-(1–7) and the G Protein-Coupled Receptor Mas Are Key Players in Renal Inflammation

Angiotensin (Ang) II mediates pathophysiologial changes in the kidney. Ang-(1–7) by interacting with the G protein-coupled receptor Mas may also have important biological activities

Lectures on on Black Holes, Topological Strings and Quantum Attractors (2.0)

In these lecture notes, we review some recent developments on the relation between the macroscopic entropy of four-dimensional BPS black holes and the microscopic counting of states, beyond the thermodynamical, large charge limit. After a brief overview of charged black holes in supergravity and string theory, we give an extensive introduction to special and very special geometry, attractor flows and topological string theory, including holomorphic anomalies. We then expose the Ooguri-Strominger-Vafa (OSV) conjecture which relates microscopic degeneracies to the topological string amplitude, and review precision tests of this formula on ``small'' black holes. Finally, motivated by a holographic interpretation of the OSV conjecture, we give a systematic approach to the radial quantization of BPS black holes (i.e. quantum attractors). This suggests the existence of a one-parameter generalization of the topological string amplitude, and provides a general framework for constructing automorphic partition functions for black hole degeneracies in theories with sufficient degree of symmetry.Comment: 103 pages, 8 figures, 21 exercises, uses JHEP3.cls; v5: important upgrade, prepared for the proceedings of Frascati School on Attractor Mechanism; Sec 7 was largely rewritten to incorporate recent progress; more figures, more refs, and minor changes in abstract and introductio

Mirid feeding preference as influenced by light and temperature mediated changes in plant nutrient concentration in cocoa

Cocoa mirids are the most important insect pests of cocoa in West Africa. This study investigated the effect of environmental parameters that are modulated by overhead shade, i.e. light intensity and temperature, on nutrient and phenolic concentrations in cocoa and their subsequent effect on mirid feeding. Eight-month-old cocoa seedlings were maintained for 50 days in two growth chambers set to day temperatures of 25oC or 30oC. Each chamber had sections with different light intensities (541, 365 and 181 µmolm-2s-1 PAR). For the field studies at Akim-Tafo in Ghana, eight-month-old plants of three cocoa clones were subjected to shaded (PAR= 180 µmol m-² s-1, between 11:00 and 12:00) and unshaded (PAR= 1767 µmol m-² s-1 between 11:00 and 12:00) treatments for 50 days after which nutrient measurements and mirid choice tests were carried out. No significant effect of environment was observed on the phenolic concentration of stems under controlled environment chamber conditions. However, in the field, the phenolic concentration of stems was significantly greater for unshaded compared with shaded plants (P=0.04). Under controlled conditions, the leaf nitrogen concentration increased slightly with light intensity (P=0.003). The same trend was seen in stems but only at 30oC. In the field, the impact of overhead shade on nitrogen varied between cocoa clones. The concentration of carbohydrates in both leaves and stems in the field was higher under unshaded conditions. When subjected to feeding tests, stems from unshaded cocoa had significantly more mirid feeding lesions (P=0.003) after 24 hours exposure to mirids compared to shaded cocoa. Mirid feeding therefore appears not to be deterred by the higher phenolic levels but rather there was a preference for cocoa tissue grown under unshaded conditions. These findings highlight the need to consider the growing environment of cocoa clones when screening for varieties with resistance to mirids

Insect succession on three coffee types in Ghana

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