Pressure Sensing Based on Nonconventional Air-Guiding Transmission Windows in Hollow-Core Photonic Crystal Fibers

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Non-conventional core-guided transmission windows within the visible spectral range are identified in commercial hollow-core photonic crystal fibers designed to operate at 1550 nm. These windows are likely to be related to higher-order cladding photonic bandgaps and are found to be highly dependent on the cladding microstructure, thus being affected by pressure-induced stress/deformation. 20-cm-long fiber samples are then used to demonstrate simple and temperature-independent hydrostatic pressure sensing with two different setups. While in the first setup pressure is externally applied to the fiber and results in operation in the hundreds of kgf/cm(2) (or tens of MPa) range, the second setup applies pressure directly to fiber internal microstructure and is sensitive to pressures down to a fraction of kgf/cm(2) (hundredths of MPa). The fact that pressure is directly transduced into transmitted power greatly simplifies the required sensor interrogation setup.271116051609Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CAPES [0156/05-1

The Lsm1-7/Pat1 complex binds to stress-activated mRNAs and modulates the response to hyperosmotic shock

RNA-binding proteins (RBPs) establish the cellular fate of a transcript, but an understanding of these processes has been limited by a lack of identified specific interactions between RNA and protein molecules. Using MS2 RNA tagging, we have purified proteins associated with individual mRNA species induced by osmotic stress, STL1 and GPD1. We found members of the Lsm1-7/Pat1 RBP complex to preferentially bind these mRNAs, relative to the non-stress induced mRNAs, HYP2 and ASH1. To assess the functional importance, we mutated components of the Lsm1-7/Pat1 RBP complex and analyzed the impact on expression of osmostress gene products. We observed a defect in global translation inhibition under osmotic stress in pat1 and lsm1 mutants, which correlated with an abnormally high association of both non-stress and stress-induced mRNAs to translationally active polysomes. Additionally, for stress-induced proteins normally triggered only by moderate or high osmostress, in the mutants the protein levels rose high already at weak hyperosmosis. Analysis of ribosome passage on mRNAs through co-translational decay from the 5' end (5P-Seq) showed increased ribosome accumulation in lsm1 and pat1 mutants upstream of the start codon. This effect was particularly strong for mRNAs induced under osmostress. Thus, our results indicate that, in addition to its role in degradation, the Lsm1-7/Pat1 complex acts as a selective translational repressor, having stronger effect over the translation initiation of heavily expressed mRNAs. Binding of the Lsm1-7/Pat1p complex to osmostress-induced mRNAs mitigates their translation, suppressing it in conditions of weak or no stress, and avoiding a hyperresponse when triggered

Regulation of proteinaceous effector expression in phytopathogenic fungi

Effectors are molecules used by microbial pathogens to facilitate infection via effector-triggered susceptibility or tissue necrosis in their host. Much research has been focussed on the identification and elucidating the function of fungal effectors during plant pathogenesis. By comparison, knowledge of how phytopathogenic fungi regulate the expression of effector genes has been lagging. Several recent studies have illustrated the role of various transcription factors, chromosome-based control, effector epistasis, and mobilisation of endosomes within the fungal hyphae in regulating effector expression and virulence on the host plant. Improved knowledge of effector regulation is likely to assist in improving novel crop protection strategies

Desatando a trama das redes assistenciais sobre drogas: uma revisão narrativa da literatura

Acalorados debates sobre determinados modelos de tratamento para usuários de drogas ocorrem no âmbito da academia, das políticas públicas, além da mídia. A rede assistencial sobre drogas é apresentada neste contexto como um importante mecanismo, mas sua construção torna-se um desafio. Assim, realizou-se uma análise crítica da literatura acadêmica acerca das redes assistenciais sobre drogas, na forma de uma revisão narrativa, visando levantar seus desafios e possibilidades de consolidação. Os resultados encontrados foram: a) uma escassez de estudos específicos sobre a rede assistencial sobre drogas; b) cobertura insuficiente e desintegrada frente à demanda de tratamento; c) necessidade de se repensar o papel dos Centros de Atenção Psicossocial para Álcool e outras Drogas, visando seu fortalecimento, expansão, melhoria estrutural e readequação de práticas; d) ausência de análises críticas sobre o processo de construção dos modelos assistenciais sobre drogas nos serviços públicos; e, e) responsabilidade do Estado em fornecer melhores alternativas ao panorama encontrado, avançando no fortalecimento das ações intersetoriais, articulação do cuidado e no aprimoramento das condições de trabalho

Characterization of the nonlinear susceptibility of monolayer MoS2 using second- and third-harmonic generation microscopy

Second- and third-harmonic generation microscopy of monolayer MoS2 is reported for imaging and characterization of the materials nonlinearity. A telecommunication wavelength pump is used, revealing the materials promise for use in nonlinear optical devices

Integrative analysis of osmoregulation in yeast Saccharomyces cerevisiae

Similar to other unicellular organisms, yeasts frequently encounter environmental stress such as heat shock, osmotic stress, and nutrition limitations, which challenge their growth potential. To survive, all living cells must be able to adapt to changes in their surrounding environment. A set of adaptive responses is triggered that leads to repair of cellular damage in order to overcome these stress conditions. The aim of this thesis is to determine how yeast cells respond to changes in osmolarity and water activity. Upon hyperosmotic shock, water flows out of the cell, resulting in cell shrinkage, and consequently an increase in the concentrations of all substances present in the cytoplasm. Cells adapt their internal osmolarity by gaining an appropriate cell volume as well as an internal water concentration that is optimal for biochemical processes to recover turgor pressure. Osmoregulation is an active process which is mainly regulated by the High Osmolarity Glycerol (HOG) pathway and controls the cellular water balance. The HOG pathway is one of the four yeast MAP kinase pathways. It conveys the hyper osmolarity stress stimulus into the cell machinery and instigates appropriate responses, including global readjustment of gene expression, changes in translational capacity, transient cell cycle arrest, and accumulation of the compatible solute glycerol. Together, these processes result in osmoadaptation. In this thesis I investigated the quantitative characteristics of osmoregulation in the yeast Saccharomyces cerevisiae. I applied a combination of traditional molecular approaches and frontline technologies for comprehensive and quantitative measurements, such as high throughput experiments, synthetic biology, single cell analysis and mathematical modeling to understand the interdependence and timeline of different osmoadaptation process