Trinuclear and tetranuclear adduct formation between sodium perchlorate and copper(II) complexes of salicylaldimine type ligands: structural characterization and theoretical investigation

The synthesis of two new sodium perchlorate adducts (1:2 and 1:3) with copper(II) "ligand-complexes'' is reported. One adduct is trinuclear [(CuL(1))(2)NaClO(4)] (1) and the other is tetranuclear [(CuL(2))(3)Na]ClO(4)center dot EtOH (2). The ligands are the tetradentate di-Schiff base of 1,3-propanediamines and salicylaldehyde (H(2)L(1)) or 2-hydroxyacetophenone (H(2)L(2)). Both complexes have been characterized by X-ray single crystal structure analyses. In both structures, the sodium cation has a six-coordinate distorted octahedral environment being bonded to four oxygen atoms from two Schiff-base complexes in addition to a chelated perchlorate anion in 1 and to six oxygen atoms from three Schiff-base complexes in 2. We have carried out a DFT theoretical study (RI-B97-D/def2-SVP level of theory) to compute and compare the formation energies of 1:2 and 1:3 adducts. The DFT study reveals that the latter is more stabilized than the former. The X-ray crystal structure of 1 shows that the packing of the trinuclear unit is controlled by unconventional C-H center dot center dot center dot O H-bonds and Cu(2+)-pi non-covalent interactions. These interactions explain the formation of 1 which is a priori disfavored with respect to 2.

The FunFOLD2 server for the prediction of protein-ligand interactions

The FunFOLD2 server is a new independent server that integrates our novel protein–ligand binding site and quality assessment protocols for the prediction of protein function (FN) from sequence via structure. Our guiding principles were, first, to provide a simple unified resource to make our function prediction software easily accessible to all via a simple web interface and, second, to produce integrated output for predictions that can be easily interpreted. The server provides a clean web interface so that results can be viewed on a single page and interpreted by non-experts at a glance. The output for the prediction is an image of the top predicted tertiary structure annotated to indicate putative ligand-binding site residues. The results page also includes a list of the most likely binding site residues and the types of predicted ligands and their frequencies in similar structures. The protein–ligand interactions can also be interactively visualized in 3D using the Jmol plug-in. The raw machine readable data are provided for developers, which comply with the Critical Assessment of Techniques for Protein Structure Prediction data standards for FN predictions. The FunFOLD2 webserver is freely available to all at the following web site: http://www.reading.ac.uk/bioinf/FunFOLD/FunFOLD_form_2_0.html.

Upland streamwater nitrate dynamics across decadal to sub-daily timescales: a case study of Plynlimon, Wales

Streamwater nitrate dynamics in the River Hafren, Plynlimon, mid-Wales were investigated over decadal to sub-daily timescales using a range of statistical techniques. Long-term data were derived from weekly grab samples (1984–2010) and high-frequency data from 7-hourly samples (2007–2009) both measured at two sites: a headwater stream draining moorland and a downstream site below plantation forest. This study is one of the first to analyse upland streamwater nitrate dynamics across such a wide range of timescales and report on the principal mechanisms identified. The data analysis provided no clear evidence that the long-term decline in streamwater nitrate concentrations was related to a decline in atmospheric deposition alone, because nitrogen deposition first increased and then decreased during the study period. Increased streamwater temperature and denitrification may also have contributed to the decline in stream nitrate concentrations, the former through increased N uptake rates and the latter resultant from increased dissolved organic carbon concentrations. Strong seasonal cycles, with concentration minimums in the summer, were driven by seasonal flow minimums and seasonal biological activity enhancing nitrate uptake. Complex diurnal dynamics were observed, with seasonal changes in phase and amplitude of the cycling, and the diurnal dynamics were variable along the river. At the moorland site, a regular daily cycle, with minimum concentrations in the early afternoon, corresponding with peak air temperatures, indicated the importance of instream biological processing. At the downstream site, the diurnal dynamics were a composite signal, resultant from advection, dispersion and nitrate processing in the soils of the lower catchment. The diurnal streamwater nitrate dynamics were also affected by drought conditions. Enhanced diurnal cycling in Spring 2007 was attributed to increased nitrate availability in the post-drought period as well as low flow rates and high temperatures over this period. The combination of high-frequency short-term measurements and long-term monitoring provides a powerful tool for increasing understanding of the controls of element fluxes and concentrations in surface waters.

Comparison of interplanetary signatures of streamers and pseudostreamers

If the source of the slow solar wind is a web comprising pseudostreamer belts connected to the streamer belt, then one expects the properties of interplanetary pseudostreamer flows to be similar to those of streamer flows. That expectation is tested with data from the slow wind preceding stream interfaces in stream interaction regions at 1 AU, where the interfaces separate what was originally slow and fast wind. Pseudostreamer cases were separated from streamer cases with the aid of the streamer identification tool developed by Owens et al. (2013), and superposed epoch analysis was performed to compare the patterns of a number of plasma and composition parameters. The results reveal that pseudostreamer flows have all of the slow-wind characteristics of streamer flows except that they are slightly less pronounced than streamer characteristics when compared to fast wind. The results are consistent with the concept that the solar wind displays a continuum of dynamic states rather than only slow and fast states.

Networks and plant disease management: concepts and applications

A network is a natural structure with which to describe many aspects of a plant pathosystem. The article seeks to set out in a nonmathematical way some of the network concepts that promise to be useful in managing plant disease. The field has been stimulated by developments designed to help understand and manage animal and human disease, as well as by technical infrastructures, such as the internet. It overlaps partly with landscape ecology. The study of networks has helped identify likely ways to reduce flow of disease in traded plants, to find the best sites to monitor as warning sites for annually reinvading disease, and to understand the fundamentals of how a pathogen spreads in different structures. A tension between the free flow of goods or species down communication channels and free flow of pathogens down the same pathways is highlighted.

First-principles study of the inversion thermodynamics and electronic structure of FeM2X4 (thio)spinels (M = Cr, Mn, Co, Ni; X = O, S)

FeM2X4 spinels, where M is a transition metal and X is oxygen or sulfur, are candidate materials for spin filters, one of the key devices in spintronics. We present here a computational study of the inversion thermodynamics and the electronic structure of these (thio)spinels for M = Cr, Mn, Co, Ni, using calculations based on the density functional theory with on-site Hubbard corrections (DFT+U). The analysis of the configurational free energies shows that different behaviour is expected for the equilibrium cation distributions in these structures: FeCr2X4 and FeMn2S4 are fully normal, FeNi2X4 and FeCo2S4 are intermediate, and FeCo2O4 and FeMn2O4 are fully inverted. We have analyzed the role played by the size of the ions and by the crystal field stabilization effects in determining the equilibrium inversion degree. We also discuss how the electronic and magnetic structure of these spinels is modified by the degree of inversion, assuming that this could be varied from the equilibrium value. We have obtained electronic densities of states for the completely normal and completely inverse cation distribution of each compound. FeCr2X4, FeMn2X4, FeCo2O4 and FeNi2O4 are half-metals in the ferrimagnetic state when Fe is in tetrahedral positions. When M is filling the tetrahedral positions, the Cr-containing compounds and FeMn2O4 are half-metallic systems, while the Co and Ni spinels are insulators. The Co and Ni sulfide counterparts are metallic for any inversion degree together with the inverse FeMn2S4. Our calculations suggest that the spin filtering properties of the FeM2X4 (thio)spinels could be modified via the control of the cation distribution through variations in the synthesis conditions.

Hybrid materials through linkage of chalcogenide tetrahedral clusters

Tetrahedral chalcogenide clusters, with their well-defined molecular structures and interesting properties, are attractive building blocks for hybrid materials, in which porosity may be integrated with electronic or optical properties. Linkage of tetrahedral clusters often occurs through bridging chalcogenolate ligands, and results in extended structures of inorganic connectivity. However, linkage of tetrahedral clusters via organic ligands is also possible and a number of coordination polymers have already been reported. Recent advances on the synthesis and crystal structures of extended hybrid structures based on tetrahedral clusters are described here.

Modelling primary producer interaction and composition: an example of a UK lowland river

Nutrient enrichment and drought conditions are major threats to lowland rivers causing ecosystem degradation and composition changes in plant communities. The controls on primary producer composition in chalk rivers are investigated using a new model and existing data from the River Frome (UK) to explore abiotic and biotic interactions. The growth and interaction of four primary producer functional groups (suspended algae, macrophytes, epiphytes, sediment biofilm) were successfully linked with flow, nutrients (N, P), light and water temperature such that the modelled biomass dynamics of the four groups matched that of the observed. Simulated growth of suspended algae was limited mainly by the residence time of the river rather than in-stream phosphorus concentrations. The simulated growth of the fixed vegetation (macrophytes, epiphytes, sediment biofilm) was overwhelmingly controlled by incoming solar radiation and light attenuation in the water column. Nutrients and grazing have little control when compared to the other physical controls in the simulations. A number of environmental threshold values were identified in the model simulations for the different producer types. The simulation results highlighted the importance of the pelagic–benthic interactions within the River Frome and indicated that process interaction defined the behaviour of the primary producers, rather than a single, dominant driver. The model simulations pose interesting questions to be considered in the next iteration of field- and laboratory based studies.

Margin squeeze: an above cost predatory pricing approach

We provide a new legal perspective for the antitrust analysis of margin squeeze conducts. Building on recent economic analysis, we explain why margin squeeze conducts should solely be evaluated under adjusted predatory pricing standards. The adjustment corresponds to an increase in the cost benchmark used in the predatory pricing test by including opportunity costs due to missed upstream sales. This can reduce both the risks of false-positives and false-negatives in margin squeeze cases. We justify this approach by explaining why classic arguments against above-cost predatory pricing typically do not hold in vertical structures where margin squeezes take place and by presenting case law evidence supporting this adjustment. Our approach can help to reconcile the divergent US and EU antitrust stances on margin squeeze.

Nonlinear Schrodinger equation with chaotic, random, and nonperiodic nonlinearity

In this Letter we deal with a nonlinear Schrodinger equation with chaotic, random, and nonperiodic cubic nonlinearity. Our goal is to study the soliton evolution, with the strength of the nonlinearity perturbed in the space and time coordinates and to check its robustness under these conditions. Here we show that the chaotic perturbation is more effective in destroying the soliton behavior, when compared with random or nonperiodic perturbation. For a real system, the perturbation can be related to, e.g., impurities in crystalline structures, or coupling to a thermal reservoir which, on the average, enhances the nonlinearity. We also discuss the relevance of such random perturbations to the dynamics of Bose-Einstein condensates and their collective excitations and transport. (C) 2010 Elsevier B.V. All rights reserved.

Equivalent Circuits and Nanoplasmonics

We show how a circuit analysis, used widely in electrical engineering, finds application to problems of light wave injection and transport in subwavelength structures in the optical frequency range. Lumped circuit and transmission-line analysis may prove helpful in the design of plasmonic devices with standard, functional properties.

A percepção da idéia de justiça em um contexto de mudanças organizacionais.

This thesis aims to analyse the perception of justice in the day-to-day of the corporations, when organizational changes take the place therein. The context of the corporation which is focused herein derives from the globalization of the Brazilian market of telecommunications which has been started in the 90`s. Two substantial changes have occurred in the period of only ten years. What happens in the day-to-day of the corporations in those moments, when a deep change in their structures is operated? Which is the impact of such change in the working hours and in the internal relations? Those questions have been relevant to and have motivated the perfomance of the survey. It has been developed with twenty employees of the ¿Z¿ corporation, who are based in the city of Rio de Janeiro and who have been heard. Such different interviews with the employees have reached thirty hours. After the completion of the due analysis of the contents of the survey, this thesis sustains that the organizational practices of the ¿Z¿ corporation do not adhere to modernization and, therefore lead the perception of the unfair. This thesis wishes to contribute to the field of the organizational studies, with an interpretation of the data that have been compiled in a given moment, about a corporation.

O processo de modernização dos Tribunais de Contas no contexto da reforma do estado no Brasil

Os tribunais de contas, embora sejam órgãos tradicionais na administração pública com raízes remotas ligadas à própria criação do Estado Moderno, passam hoje por intensas modificações em sua estrutura operacional e formas de atuação. O presente trabalho tem o objetivo de analisar o processo de modernização dos tribunais de contas estaduais e municipais do país no contexto da reforma do Estado brasileiro. A primeira parte dessa dissertação apresenta uma radiografia da situação atual dos TC¿s, apontando as principais características diferenciadoras desses órgãos em relação à sua capacidade operacional e ao desempenho de suas funções constitucionais. A segunda parte apresenta um balanço das principais iniciativas de aperfeiçoamento organizacional que podem ser verificadas nas estruturas dos TC¿s mais recentemente, dando destaque para as inovações de ouvidoria, sistemas informatizados de controle e escolas de contas.

Análise crítica do cyberslacking nas estruturas organizacionais

A Internet é um hoje um instrumento fenomenal de pesquisa e informação, e rapidamente entrou na vida das pessoas. Sua utilização proporciona uma sensação de liberdade e descobertas. Este estudo pretende discorrer sobre o entrada da Internet nas organizações e um fenômeno decorrente chamado "Cyberslackíng', que passou a designar o uso de equipamentos e sistemas informáticos dispostos pelo empregador para fins particulares, no ambiente de trabalho. A pesquisa foi conduzida com executivos das empresas da cidade de Curitiba-Paraná, que possuíam formação universitária e tinham acesso à Internet tanto nos escritórios como nas respectivas residências. O ponto central do trabalho foi identificar se a entrada da Internet nas organizações alterou as estruturas e as formas de controle sobre o trabalho. Posicionou-se a Internet no ambiente de trabalho, as empresas e respectivas estruturas organizacionais inseridas no regime de produção. A proposta do trabalho consistiu em realizar uma análise crítica sobre o tema. Nesse sentido, apresenta-se uma revisão de literatura fundamentada nos autores da Escola de Frankfurt, tendo sido avaliadas as estruturas organizacionais, a racionalidade do comportamento do trabalhador, a questão dos controles e autoridade. Também foi estudado o novo modelo de organização do trabalho pós-fordistas e como o trabalhador foi conduzido para se tornar cada vez mais conectado às empresas. Analisaram-se a influência das novas tecnologias sobre as estruturas de trabalho e as adequações adotadas pelo capital após sua introdução nestes ambientes e, principalmente, a questão dos controles exercidos sobre os trabalhadores e os aspectos legais envolvidos neste novo paradigma de trabalho. Conclui-se que as organizações já vêm se adaptando às mudanças econômicas mundiais e também tecnológicas ao longo dos anos, criando novos mecanismos de controle sobre o trabalho, envolvendo os trabalhadores dentro dos sistemas e se aproveitando de fatores externos como o nível de desemprego, aliado à racionalidade do trabalhador, para garantir maior produtividade e eficiência.O cyberslackíng foi condenado pelos próprios trabalhadores devido aos riscos que pode apresentar ao sistema de informação das empresas e, conseqüentemente, ao seu trabalho, mas é considerado um instrumento de fuga para as pressões do sistema impostos pelo capital.

A gestão de pessoas em centros de serviços compartilhados no Brasil: um estudo sobre a percepção dos gestores e empregados operacionais

Os estudos da área de Administração se concentraram em compreender as atividades core das organizações, de forma que os esforços para se entender as atividades de staff e a maneira pela qual elas podem agregar valor foram menos exploradas. Assim, estruturas organizacionais como os centros de serviços compartilhados (CSCs) se apresentam não apenas como uma oportunidade de estudo, mas também como uma demanda da área, dada a expansão desse modelo de prestação de serviços de atividades de staff dos grandes grupos organizacionais. Diante desse contexto, existe um ambiente específico de trabalho que pouco se aprofundou em relação à área de Recursos Humanos (RH), sendo importante, portanto, entender quais são as percepções dos funcionários de CSCs (analistas e gestores) diante das práticas e características organizacionais relacionadas com a Gestão de Pessoas. Assim sendo, o objetivo do presente estudo é verificar como se configuram as características e práticas que se relacionam à Gestão de Pessoas nos CSCs, a partir das percepções de seus gestores e analistas. Embasando-se na literatura sobre as características dos CSCs, atrelada à gestão de pessoas nesse tipo de estrutura e da Administração Estratégica de RH, estruturou-se o arcabouço teórico do estudo e definiram-se as categorias de análise. Por meio de um estudo de caso, quatro CSCs instalados no Brasil foram abordados, sendo entrevistadas 44 pessoas (sete gestores e 37 analistas operacionais). Os resultados apontaram categorias específicas aos CSCs fossem levantadas: gerência de linha, desenvolvimento profissional e responsabilidade dos analistas, sentimento de inferioridade, estratégias de retenção de empregados, diversidade interna, formação de centro de excelência. Concluiu-se que os CSC requerem um departamento de Gestão de Pessoas específico para seus empregados internos para atender as especificidades do CSC; deve haver cuidado em aplicação de modelos rígidos internamente porque os CSCs maduros são diversificados; que os CSCs são centros de excelência para conhecimentos operacionais; os gerentes de linha poderiam ser mais bem treinados para melhorar seus relacionamentos com os analistas.