Sao Paulo State University

About: Sao Paulo State University is a education organization based out in São Paulo, Brazil. It is known for research contribution in the topics: Population & Context (language use). The organization has 55715 authors who have published 100436 publications receiving 1375332 citations.

Insertion Sequence IS26 Reorganizes Plasmids in Clinically Isolated Multidrug-Resistant Bacteria by Replicative Transposition

Abstract: Carbapenemase-producing Enterobacteriaceae (CPE), which are resistant to most or all known antibiotics, constitute a global threat to public health. Transposable elements are often associated with antibiotic resistance determinants, suggesting a role in the emergence of resistance. One insertion sequence, IS 26 , is frequently associated with resistance determinants, but its role remains unclear. We have analyzed the genomic contexts of 70 IS 2 6 copies in several clinical and surveillance CPE isolates from the National Institutes of Health Clinical Center. We used target site duplications and their patterns as guides and found that a large fraction of plasmid reorganizations result from IS 26 replicative transpositions, including replicon fusions, DNA inversions, and deletions. Replicative transposition could also be inferred for transposon Tn 4401 , which harbors the carbapenemase bla KPC gene. Thus, replicative transposition is important in the ongoing reorganization of plasmids carrying multidrug-resistant determinants, an observation that carries substantial clinical and epidemiological implications for understanding how such extreme drug resistance phenotypes evolve. IMPORTANCE Although IS 26 is frequently reported to reside in resistance plasmids of clinical isolates, the characteristic hallmark of transposition, target site duplication (TSD), is generally not observed, raising questions about the mode of transposition for IS 26 . The previous observation of cointegrate formation during transposition implies that IS 26 transposes via a replicative mechanism. The other possible outcome of replicative transposition is DNA inversion or deletion, when transposition occurs intramolecularly, and this would also generate a specific TSD pattern that might also serve as supporting evidence for the transposition mechanism. The numerous examples we present here demonstrate that replicative transposition, used by many mobile elements (including IS 26 and Tn 4401 ), is prevalent in the plasmids of clinical isolates and results in significant plasmid reorganization. This study also provides a method to trace the evolution of resistance plasmids based on TSD patterns.

HTRIdb: an open-access database for experimentally verified human transcriptional regulation interactions

Abstract: The modeling of interactions among transcription factors (TFs) and their respective target genes (TGs) into transcriptional regulatory networks is important for the complete understanding of regulation of biological processes. In the case of experimentally verified human TF-TG interactions, there is no database at present that explicitly provides such information even though many databases containing human TF-TG interaction data have been available. In an effort to provide researchers with a repository of experimentally verified human TF-TG interactions from which such interactions can be directly extracted, we present here the Human Transcriptional Regulation Interactions database (HTRIdb). The HTRIdb is an open-access database that can be searched via a user-friendly web interface and the retrieved TF-TG interactions data and the associated protein-protein interactions can be downloaded or interactively visualized as a network through the web version of the popular Cytoscape visualization tool, the Cytoscape Web. Moreover, users can improve the database quality by uploading their own interactions and indicating inconsistencies in the data. So far, HTRIdb has been populated with 284 TFs that regulate 18302 genes, totaling 51871 TF-TG interactions. HTRIdb is freely available at http://www.lbbc.ibb.unesp.br/htri. HTRIdb is a powerful user-friendly tool from which human experimentally validated TF-TG interactions can be easily extracted and used to construct transcriptional regulation interaction networks enabling researchers to decipher the regulation of biological processes.

An Efficient Codification to Solve Distribution Network Reconfiguration for Loss Reduction Problem

Abstract: Evolutionary algorithms have been used to try to solve distribution network reconfiguration for loss reduction problem with a certain degree of success. But some problems, specially related to a codification that is able to represent and work with a complex multiconstraint and combinatorial problem such as this one, have prevented the use of the full potential of these algorithms to find quality solutions for large systems with minor computational effort. This paper proposes a solution to this problem, with a new codification and using an efficient way for implementing the operator of recombination to guaranty, at all times, the production of new radial topologies. The algorithm is presented and tested in a real distribution system, showing excellent results and computational efficiency.

Plant height and hydraulic vulnerability to drought and cold

Abstract: Understanding how plants survive drought and cold is increasingly important as plants worldwide experience dieback with drought in moist places and grow taller with warming in cold ones. Crucial in plant climate adaptation are the diameters of water-transporting conduits. Sampling 537 species across climate zones dominated by angiosperms, we find that plant size is unambiguously the main driver of conduit diameter variation. And because taller plants have wider conduits, and wider conduits within species are more vulnerable to conduction-blocking embolisms, taller conspecifics should be more vulnerable than shorter ones, a prediction we confirm with a plantation experiment. As a result, maximum plant size should be short under drought and cold, which cause embolism, or increase if these pressures relax. That conduit diameter and embolism vulnerability are inseparably related to plant size helps explain why factors that interact with conduit diameter, such as drought or warming, are altering plant heights worldwide.

beta-Glucans in promoting health: prevention against mutation and cancer.

Abstract: The polysaccharides beta-glucans occur as a principal component of the cellular walls. Some microorganisms, such as yeast and mushrooms, and also cereals such as oats and barley, are of economic interest because they contain large amounts of beta-glucans. These substances stimulate the immune system, modulating humoral and cellular immunity, and thereby have beneficial effect in fighting infections (bacterial, viral, fungal and parasitic). beta-Glucans also exhibit hypocholesterolemic and anticoagulant properties. Recently, they have been demonstrated to be anti-cytotoxic, antimutagenic and anti-tumorogenic, making them promising candidate as pharmacological promoters of health.