The Algebra of Non-Local Charges in Non-Linear Sigma Models

We obtain the exact Dirac algebra obeyed by the conserved non-local charges in bosonic non-linear sigma models. Part of the computation is specialized for a symmetry group $O(N)$. As it turns out the algebra corresponds to a cubic deformation of the Kac-Moody algebra. The non-linear terms are computed in closed form. In each Dirac bracket we only find highest order terms (as explained in the paper), defining a saturated algebra. We generalize the results for the presence of a Wess-Zumino term. The algebra is very similar to the previous one, containing now a calculable correction of order one unit lower.Comment: 27 pages + figures available via ftp, Plain TeX, IFUSP/P-106

The Supereigenvalue Model in the Double-Scaling Limit

The double-scaling limit of the supereigenvalue model is performed in the moment description. This description proves extremely useful for the identification of the multi-critical points in the space of bosonic and fermionic coupling constants. An iterative procedure for the calculation of higher-genus contributions to the free energy and to the multi-loop correlators in the double-scaling limit is developed. We present the general structure of these quantities at genus g and give explicit results up to and including genus two.Comment: 19 pages, LaTe

Iterative Solution of the Supereigenvalue Model

An integral form of the discrete superloop equations for the supereigenvalue model of Alvarez-Gaume, Itoyama, Manes and Zadra is given. By a change of variables from coupling constants to moments we find a compact form of the planar solution for general potentials. In this framework an iterative scheme for the calculation of higher genera contributions to the free energy and the multi-loop correlators is developed. We present explicit results for genus one.Comment: 21 pages, LaTeX, no figure

Transferability Intercomparison: An Opportunity for New Insight on the Global Water Cycle and Energy Budget

A new approach, called transferability intercomparisons, is described for advancing both understanding and modeling of the global water cycle and energy budget. Under this approach, individual regional climate models perform simulations with all modeling parameters and parameterizations held constant over a specific period on several prescribed domains representing different climatic regions. The transferability framework goes beyond previous regional climate model intercomparisons to provide a global method for testing and improving model parameterizations by constraining the simulations within analyzed boundaries for several domains. Transferability intercomparisons expose the limits of our current regional modeling capacity by examining model accuracy on a wide range of climate conditions and realizations. Intercomparison of these individual model experiments provides a means for evaluating strengths and weaknesses of models outside their “home domains” (domain of development and testing). Reference sites that are conducting coordinated measurements under the continental-scale experiments under the Global Energy and Water Cycle Experiment (GEWEX) Hydrometeorology Panel provide data for evaluation of model abilities to simulate specific features of the water and energy cycles. A systematic intercomparison across models and domains more clearly exposes collective biases in the modeling process. By isolating particular regions and processes, regional model transferability intercomparisons can more effectively explore the spatial and temporal heterogeneity of predictability. A general improvement of model ability to simulate diverse climates will provide more confidence that models used for future climate scenarios might be able to simulate conditions on a particular domain that are beyond the range of previously observed climates

Análise faunística de cochonilhas (hemiptera: sternorrhyncha) na cultura da videira no município de Pinto Bandeira, Rio Grande do Sul, Brasil.

O Rio Grande do Sul é o principal estado produtor de uvas e vinhos do país, com destaque para a região da Serra Gaúcha. Um dos principais problemas enfrentados pelos viticultores é a presença de cochonilhas que ocorrem na parte aérea da cultura e que, dependendo da severidade dos danos causam a morte da planta. Nesse trabalho foi realizada uma análise faunística das cochonilhas presentes na parte aérea de videiras, no município de Pinto Bandeira, RS. As amostragens foram realizadas quinzenalmente em vinhedo comercial de 1 ha de Vitis vinifera L. cultivar Merlot. Foram coletadas amostras de cochonilhas presentes no ritidoma e brotações, de janeiro de 2011 a janeiro de 2013. A triagem e identificação dos espécimes foram realizadas em laboratório com o auxílio de microscópio óptico e bibliografia especializada. Os dados obtidos foram analisados a partir da determinação da frequência, constância e dominância. Foram identificadas duas espécies de cochonilhas incluídas em Diaspididae - Hemiberlesia latanie e Pseudaonidia marquesi; e uma em Monophlebidae - Icerya schrottkyi. Hemiberlesia latanie foi a espécie que apresentou 89,72% de frequência, I. schrottkyi 7,13% e P. marquesi 3,14%. Hemiberlesia latanie foi a cochonilha dominante, mais frequente e constante no vinhedo

AKT1 and MYC induce distinctive metabolic fingerprints in human prostate cancer

Cancer cells may overcome growth factor dependence by deregulating oncogenic and/or tumor-suppressor pathways that affect their metabolism, or by activating metabolic pathways de novo with targeted mutations in critical metabolic enzymes. It is unknown whether human prostate tumors develop a similar metabolic response to different oncogenic drivers or a particular oncogenic event results in its own metabolic reprogramming. Akt and Myc are arguably the most prevalent driving oncogenes in prostate cancer. Mass spectrometry-based metabolite profiling was performed on immortalized human prostate epithelial cells transformed by AKT1 or MYC, transgenic mice driven by the same oncogenes under the control of a prostate-specific promoter, and human prostate specimens characterized for the expression and activation of these oncoproteins. Integrative analysis of these metabolomic datasets revealed that AKT1 activation was associated with accumulation of aerobic glycolysis metabolites, whereas MYC overexpression was associated with dysregulated lipid metabolism. Selected metabolites that differentially accumulated in the MYC-high versus AKT1-high tumors, or in normal versus tumor prostate tissue by untargeted metabolomics, were validated using absolute quantitation assays. Importantly, the AKT1/MYC status was independent of Gleason grade and pathologic staging. Our fi ndings show how prostate tumors undergo a metabolic reprogramming that refl ects their molecular phenotypes, with implications for the development of metabolic diagnostics and targeted therapeutics.Instituto de Investigaciones Bioquímicas de La PlataFacultad de Ciencias Médica

Evolutionary Relationships of Ljungan Virus Variants Circulating in Multi-Host Systems across Europe

The picornavirus named ‘Ljungan virus’ (LV, species Parechovirus B) has been detected in a dozen small mammal species from across Europe, but detailed information on its genetic diversity and host specificity is lacking. Here, we analyze the evolutionary relationships of LV variants circulating in free-living mammal populations by comparing the phylogenetics of the VP1 region (encoding the capsid protein and associated with LV serotype) and the 3Dpol region (encoding the RNA polymerase) from 24 LV RNA-positive animals and a fragment of the 5′ untranslated region (UTR) sequence (used for defining strains) in sympatric small mammals. We define three new VP1 genotypes: two in bank voles (Myodes glareolus) (genotype 8 from Finland, Sweden, France, and Italy, and genotype 9 from France and Italy) and one in field voles (Microtus arvalis) (genotype 7 from Finland). There are several other indications that LV variants are host-specific, at least in parts of their range. Our results suggest that LV evolution is rapid, ongoing and affected by genetic drift, purifying selection, spillover and host evolutionary history. Although recent studies suggest that LV does not have zoonotic potential, its widespread geographical and host distribution in natural populations of well-characterized small mammals could make it useful as a model for studying RNA virus evolution and transmission