New and Standard Physics contributions to anomalous Z and gamma self-couplings

We examine the Standard and the New Physics (NP) contributions to the ZZZ, ZZgamma and Zgammagamma neutral gauge couplings. At the one-loop level, if we assume that there is no CP violation contained in NP beyond the Standard Model one, we find that only CP conserving neutral gauge couplings are generated, either from the standard quarks and leptons, or from possible New Physics (NP) fermions. Bosonic one-loop diagrams never contribute to these couplings, while the aforementioned fermionic contributions satisfy hZ3=-fgamma5, hZ4=hgamma4=0. We also study examples of two-loop NP effects that could generate non vanishing h4 couplings. We compare quantitative estimates from SM, MSSM and some specific examples of NP contributions, and we discuss their observability at future colliders.Comment: 20 pages and 9 figures. e-mail: [email protected]

Search for Gamma-rays from Lightest Kaluza-Klein ParticleDark Matter with GLAST

The Gamma-Ray Large Area Space Telescope (GLAST), scheduled to be launched in 2007, is the next generation satellite for high-energy gamma-ray astronomy. The Large Area Telescope (LAT), GLAST main instrument, has a wide field of view (> 2 sr), a large effective area and a 20 MeV-300 GeV energy range. It provides excellent high-energy gamma-ray observations for Dark-Matter searches. Here we study the possibility to detect gamma-rays coming from Lightest Kaluza-Klein Particle (LKP) annihilations in the context of the minimal Universal Extra Dimensions (UED) models. We perform the analysis for different LKP masses and for a Galactic Center (GC) Navarro, Frenk and White (NFW) halo model modified by a boost factor parameter. Finally we give an estimate of the background to obtain the expected total gamma-ray flux and the corresponding expected GLAST sensitivity

Pollination and biological control research: are we neglecting two billion smallholders

Food insecurity is a major world problem, with ca. 870 million people in the world being chronically undernourished. Most of these people live in tropical, developing regions and rely on smallholder farming for food security. Solving the problem of food insecurity is thought to depend, in part, on managing ecosystem services, such as the pollination of crops and the biological control of crop pests, to enhance or maintain food production. Our knowledge regarding regulating ecosystem services in smallholder-farmed (or dualistic) landscapes is limited and whilst pollination has been the focus of considerable research, the provision of natural enemy services, important for every crop worldwide, has been relatively neglected. In order to assess whether ecosystem-service research adequately represents smallholder-farmed landscapes, whilst also considering climatic region and national economic status, we examined the constituent studies of recent quantitative reviews relevant to biological control and pollination. No regulating ecosystem service meta-analysis, to our knowledge, has focussed on smallholder agriculture despite its importance to billions of peoples’ local food security. We found that whilst smallholdings contributed 16% of global farmland area and 83% of the global agricultural population (estimated using FAO’s World Census of Agriculture 2000) only 22 of 190 studies (12%), overall, came from smallholder-farmed landscapes. These smallholder studies mostly concerned coffee production (16 studies). Individual reviews of biological control were significantly and strongly biased towards data from large-scale farming in temperate regions. In contrast pollination reviews included more smallholder studies and were more balanced for climate regions. The high diversity of smallholder-farmed landscapes implies that more research will be needed to understand them compared to large-scale landscapes but we found far more research from the latter. We highlight that these skews in research effort have implications for sustainable intensification and the food security of billions in the developing world. In particular we urge for balance in future ecosystem-services research and synthesis by greater consideration of a diverse range of smallholder-farmed landscapes in Africa and continental Asia

The CD81 Partner EWI-2wint Inhibits Hepatitis C Virus Entry

Two to three percent of the world's population is chronically infected with hepatitis C virus (HCV) and thus at risk of developing liver cancer. Although precise mechanisms regulating HCV entry into hepatic cells are still unknown, several cell surface proteins have been identified as entry factors for this virus. Among these molecules, the tetraspanin CD81 is essential for HCV entry. Here, we have identified a partner of CD81, EWI-2wint, which is expressed in several cell lines but not in hepatocytes. Ectopic expression of EWI-2wint in a hepatoma cell line susceptible to HCV infection blocked viral entry by inhibiting the interaction between the HCV envelope glycoproteins and CD81. This finding suggests that, in addition to the presence of specific entry factors in the hepatocytes, the lack of a specific inhibitor can contribute to the hepatotropism of HCV. This is the first example of a pathogen gaining entry into host cells that lack a specific inhibitory factor

Zebrafish screen identifies novel compound with selective toxicity against leukemia

To detect targeted antileukemia agents we have designed a novel, high-content in vivo screen using genetically engineered, T-cell reporting zebrafish. We exploited the developmental similarities between normal and malignant T lymphoblasts to screen a small molecule library for activity against immature T cells with a simple visual readout in zebrafish larvae. After screening 26 400 molecules, we identified Lenaldekar (LDK), a compound that eliminates immature T cells in developing zebrafish without affecting the cell cycle in other cell types. LDK is well tolerated in vertebrates and induces long-term remission in adult zebrafish with cMYC-induced T-cell acute lymphoblastic leukemia (T-ALL). LDK causes dephosphorylation of members of the PI3 kinase/AKT/mTOR pathway and delays sensitive cells in late mitosis. Among human cancers, LDK selectively affects survival of hematopoietic malignancy lines and primary leukemias, including therapy-refractory B-ALL and chronic myelogenous leukemia samples, and inhibits growth of human T-ALL xenografts. This work demonstrates the utility of our method using zebrafish for antineoplastic candidate drug identification and suggests a new approach for targeted leukemia therapy. Although our efforts focused on leukemia therapy, this screening approach has broad implications as it can be translated to other cancer types involving malignant degeneration of developmentally arrested cells

SUSY Les Houches Accord 2

The Supersymmetry Les Houches Accord (SLHA) provides a universal set of conventions for conveying spectral and decay information for supersymmetry analysis problems in high energy physics. Here, we propose extensions of the conventions of the first SLHA to include various generalizations: the minimal supersymmetric standard model with violation of CP, R-parity, and flavor, as well as the simplest next-to-minimal model