Ruthenium 4d-to-2p X-ray Emission Spectroscopy: A Simultaneous Probe of the Metal and the Bound Ligands

Ruthenium 4d-to-2p X-ray emission spectroscopy (XES) was systematically explored for a series of Ru$^{2+}$ and Ru$^{3+}$ species. Complementary density functional theory calculations were utilized to allow for a detailed assignment of the experimental spectra. The studied complexes have a range of different coordination spheres, which allows the influence of the ligand donor/acceptor properties on the spectra to be assessed. Similarly, the contributions of the site symmetry and the oxidation state of the metal were analyzed. Because the 4d-to-2p emission lines are dipole-allowed, the spectral features are intense. Furthermore, in contrast with K- or L-edge X-ray absorption of 4d transition metals, which probe the unoccupied levels, the observed 4p-to-2p XES arises from electrons in filled-ligand- and filled-metal-based orbitals, thus providing simultaneous access to the ligand and metal contributions to bonding. As such, 4d-to-2p XES should be a promising tool for the study of a wide range of 4d transition-metal compounds

Ajuste do método de Priestley-Taylor às condições climáticas locais Adjustment of the Priestley-Taylor method to local climatic conditions

A sustentabilidade da agricultura irrigada depende primariamente do manejo eficiente da irrigação, de modo a aumentar a produtividade primária de uma cultura em determinada localidade. A eficiência no uso de água pode ser melhorada pelo próprio esquema de irrigação adotado, sendo essencialmente governado pelas condições climáticas. O planejamento da irrigação e a tomada de decisão são funções do conhecimento da demanda evaporativa da atmosfera, sendo expressa pela demanda potencial (ETo). Em geral, quase todos os métodos de estimativa de ETo reportados na literatura referem-se a valores diários, incluindo-se nessa situação as perdas noturnas de evaporação, as quais serão expressivas apenas em alguns dias após a chuva ou irrigação. Desenvolveu-se, no presente estudo, método corrigido para estimar ETo, baseado no balanço de energia local, a partir de dados meteorológicos monitorados em postos de observação de superfície durante o período de luz. Para validação do método de Priestley-Taylor ajustado às condições locais, foram utilizados dados observados em estação meteorológica automática instalada em Piracicaba - SP, bem como medidas lisimétricas coletadas na Fazenda Areião da área experimental da ESALQ/USP. Estudos de regressão revelaram que o método proposto apresentou excelentes resultados quando comparado com o método de Penman-Monteith e com medidas realizadas em lisímetros de pesagem com célula de carga, dados os elevados valores de coeficiente de determinação obtidos, podendo ser recomendado, portanto, em estudos de avaliação de consumo de água das culturas em diversas localidades.<br>The sustainability of irrigated agriculture depends primarily on the efficient management of irrigation in order to increase the crop primary productivity in a given site. The efficiency in water use can be enhanced by the irrigation schedule adopted, being mainly governed by the climatic conditions. The irrigation planning and the decision making is a function of the knowledge of atmospheric demand, which might be expressed by the reference evapotranspiration (ETo). In general, almost all the ETo estimation methods reported by the literature refers to daily values, including in such situation the night evaporation losses, which must be taken into account only during some days after rain or irrigation. In the current study a corrected method for estimating ETo, based on the local energy balance, was proposed from meteorological data monitored in an automated weather station throughout light periods. To validate the current methodology a set of climatic data observed in Piracicaba, SP, Brazil, as well as lysimetric measurements collected at the "Areião" Agricultural Experiment Station of the University of São Paulo - ESALQ/USP - were used for such a purpose. Regression analyses have revealed that the proposed method showed excellent results when compared with Penman-Monteith method and also with measurements made by weighting lysimeters, given the high coefficient of determination values obtained, being able to be recommended, however, in studies for assessment of crop water use at several sites

Crystal Structure of the human TIP41 Orthologue, TIPRL, reveals a novel fold and a binding site for the PP2AC C-TERMINUS

Submitted by Luciane Willcox ([email protected]) on 2017-04-11T19:37:48Z No. of bitstreams: 1 Crystal structure of the human Tip41 orthologue, TIPRL, reveals a novel fold and a binding site for the PP2Ac C-terminus.pdf: 2132858 bytes, checksum: f3c011ca732ddc9cb6872d8a9f79a48c (MD5)Approved for entry into archive by Manoel Barata ([email protected]) on 2017-07-26T14:29:12Z (GMT) No. of bitstreams: 1 Crystal structure of the human Tip41 orthologue, TIPRL, reveals a novel fold and a binding site for the PP2Ac C-terminus.pdf: 2132858 bytes, checksum: f3c011ca732ddc9cb6872d8a9f79a48c (MD5)Made available in DSpace on 2017-07-26T14:29:12Z (GMT). No. of bitstreams: 1 Crystal structure of the human Tip41 orthologue, TIPRL, reveals a novel fold and a binding site for the PP2Ac C-terminus.pdf: 2132858 bytes, checksum: f3c011ca732ddc9cb6872d8a9f79a48c (MD5) Previous issue date: 2016Institute of Chemistry, University of Campinas, Campinas, SP, Brazil. / Brazilian National Laboratory for Biosciences, Center for Research in Energy and Materials, Campinas, SP, Brazil. / Institute of Biology, University of Campinas, Campinas, SP, Brazil.Institute of Chemistry, University of Campinas, Campinas, SP, Brazil. / Brazilian National Laboratory for Biosciences, Center for Research in Energy and Materials, Campinas, SP, Brazil.Brazilian National Laboratory for Biosciences, Center for Research in Energy and Materials, Campinas, SP, Brazil.Fundação Oswaldo Cruz. Instituto Carlos Chagas. Curitiba, PR, Brasil.Diamond Light Source, Chilton, UK.Diamond Light Source, Chilton, UK.Physics Institute of São Carlos, University of São Paulo, São Carlos, SP, Brazil.Institute of Chemistry, University of Campinas, Campinas, SP, Brazil.Institute of Chemistry, University of Campinas, Campinas, SP, Brazil.Brazilian National Laboratory for Biosciences, Center for Research in Energy and Materials, Campinas, SP, Brazil.Institute of Chemistry, University of Campinas, Campinas, SP, Brazil.TOR signaling pathway regulator-like (TIPRL) is a regulatory protein which inhibits the catalytic subunits of Type 2A phosphatases. Several cellular contexts have been proposed for TIPRL, such as regulation of mTOR signaling, inhibition of apoptosis and biogenesis and recycling of PP2A, however, the underlying molecular mechanism is still poorly understood. We have solved the crystal structure of human TIPRL at 2.15Å resolution. The structure is a novel fold organized around a central core of antiparallel beta-sheet, showing an N-terminal α/β region at one of its surfaces and a conserved cleft at the opposite surface. Inside this cleft, we found a peptide derived from TEV-mediated cleavage of the affinity tag. We show by mutagenesis, pulldown and hydrogen/deuterium exchange mass spectrometry that this peptide is a mimic for the conserved C-terminal tail of PP2A, an important region of the phosphatase which regulates holoenzyme assembly, and TIPRL preferentially binds the unmodified version of the PP2A-tail mimetic peptide DYFL compared to its tyrosine-phosphorylated version. A docking model of the TIPRL-PP2Ac complex suggests that TIPRL blocks the phosphatase’s active site, providing a structural framework for the function of TIPRL in PP2A inhibition

Densitometria clínica: posições oficiais 2006 Clinical densitometry: official positions 2006

Descrevemos as posições oficiais da Sociedade Brasileira de Densitometria Clínica (SBDens) para a realização e o relato do exame de densitometria óssea. Essas posições foram obtidas por consenso em encontro realizado em São Paulo no ano de 2006. A SBDens contou com o apoio de várias sociedades científicas descritas no texto.<br>We describe the official positions of the Brazilian Society for Clinical Densitometry (SBDens) for the performance and report of the bone mineral density testing. These positions were obtained by consensus in a meeting at São Paulo in 2006. SBDens positions were supported by other scientific societies described in the text