Insights into the structural basis for zinc inhibition of the glycine receptor

Histidines 107 and 109 in the glycine receptor ( GlyR) alpha(1) subunit have previously been identified as determinants of the inhibitory zinc-binding site. Based on modeling of the GlyR alpha(1) subunit extracellular domain by homology to the acetylcholine-binding protein crystal structure, we hypothesized that inhibitory zinc is bound within the vestibule lumen at subunit interfaces, where it is ligated by His(107) from one subunit and His(109) from an adjacent subunit. This was tested by co-expressing alpha(1) subunits containing the H107A mutation with alpha(1) subunits containing the H109A mutation. Although sensitivity to zinc inhibition is markedly reduced when either mutation is individually incorporated into all five subunits, the GlyRs formed by the co-expression of H107A mutant subunits with H109A mutant subunits exhibited an inhibitory zinc sensitivity similar to that of the wild type alpha(1) homomeric GlyR. This constitutes strong evidence that inhibitory zinc is coordinated at the interface between adjacent alpha(1) subunits. No evidence was found for beta subunit involvement in the coordination of inhibitory zinc, indicating that a maximum of two zinc-binding sites per alpha(1)beta receptor is sufficient for maximal zinc inhibition. Our data also show that two zinc-binding sites are sufficient for significant inhibition of alpha(1) homomers. The binding of zinc at the interface between adjacent alpha(1) subunits could restrict intersubunit movements, providing a feasible mechanism for the inhibition of channel activation by zinc.

Structural characterization of respiratory syncytial virus fusion inhibitor escape mutants: homology model of the F protein and a syncytium formation assay

Respiratory syncytial virus (RSV) is a ubiquitous human pathogen and the leading cause of lower respiratory tract infections in infants. Infection of cells and subsequent formation of syncytia occur through membrane fusion mediated by the RSV fusion protein (RSV-F). A novel in vitro assay of recombinant RSV-F function has been devised and used to characterize a number of escape mutants for three known inhibitors of RSV-F that have been isolated. Homology modeling of the RSV-F structure has been carried out on the basis of a chimera derived from the crystal structures of the RSV-F core and a fragment from the orthologous fusion protein from Newcastle disease virus (NDV). The structure correlates well with the appearance of RSV-F in electron micrographs, and the residues identified as contributing to specific binding sites for several monoclonal antibodies are arranged in appropriate solvent-accessible clusters. The positions of the characterized resistance mutants in the model structure identify two promising regions for the design of fusion inhibitors. (C) 2003 Elsevier Science (USA). All rights reserved.

Comparative study of the radiation-induced grafting of styrene onto poly(tetrafluoroethylene-co-perfluoropropylvinyl ether) and polypropylene substrates. I: Kinetics and structural investigation

A comparative study has been made of the radiation grafting of styrene onto poly(tetrafluoroethylene-co-perfluoropropyl vinyl ether) (PFA) and polypropylene (PP) substrates, using the simultaneous irradiation method. Effects of grafting conditions such as monomer concentrations, type of solvent, dose rate and irradiation dose on the grafting yield were investigated. Under the same grafting conditions it was found that a higher degree of grafting of styrene was obtained using a mixture of dichloromethane/methanol solvents for PFA and methanol for PP and the degree of grafting was higher in PP than in PFA at all doses. However, the micro-Raman spectroscopy analysis of the graft revealed that, for the same degree of grafting, the penetration depth of the grafted polystyrene into the substrate was higher in PFA than in PP substrates. In both polymers the crystallinity was hardly affected by the grafting process and the degree of crystallinity decreased slightly with grafting dose. The dependence of the initial rate of grafting on the dose rate and the monomer concentration was found to be 0.6 and 1.4 order for PFA and 0.15 and 2.2 for PP, respectively. The degree of grafting increased with increasing radiation dose in both polymers. However, the grafting yield decreased with an increase in the dose rate. The increase in the overall grafting yield for PFA and PP was accompanied by a proportional increase in the penetration depth of the graft into the substrates. (C) 2003 Society of Chemical Industry.

Structural variations and formation constants of first-row transition metal complexes of biologically active aroylhydrazones

Iron chelators of the 2-pyridinecarbaldehyde isonicotinoylhydrazone (HPCIH) class show high potential for the treatment of iron overload diseases. In the present study, selected first-row transition metal (from Mn to Zn) complexes with HPCIH and 2-pyridinecarbaldehyde (4'-aminobenzoyl)hydrazone (HPCAH) were synthesised and characterised. Crystallography reveals that HPCAH exclusively forms bis complexes with divalent transition metals, with each ligand coordinating meridionally through its pyridine-N, imine-N and carbonyl-O atoms, forming distorted octahedral cis-MN4O2 complexes. Complexes of HPCIH were more varied and unpredictable, with metal/ligand ratios of 1:1, 1:2, 2:2 and 3:2 obtained with different metal ions. The isonicotinoyl ring N-atom in HPCIH was found to be an effective ligand, and this resulted in the varied metal/ligand ratios observed. The formation constants of divalent metal complexes with HPCIH were determined by potentiometric titrations and the values obtained were consistent with similar tridentate ligands and with the Irving-Williams order. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).

Structural definition of the low-temperature phase transition of tris(ethane-1,2-diamine)zinc(II) dinitrate

The 93 K X-ray crystal structure of tris(ethane-1,2-diamine)zinc(II) dinitrate is reported. As predicted by the spectroscopic studies of other workers, there is a reversible phase transition of the structure at low temperature. We have determined this temperature to be 143 K. The structure at this temperature and below resembles that of the room temperature structure, except the crystallographic D-3 symmetry of the complex cation (296 K) is lowered to C-2 ( below 144 K) by subtle changes in cation-anion hydrogen bonding. No change in the conformation of the cation or its bond lengths and angles was found.

A yield architecture framework to explain adaptation of pearl millet to environmental stress

Functional knowledge of the physiological basis of crop adaptation to stress is a prerequisite for exploiting specific adaptation to stress environments in breeding programs. This paper presents an analysis of yield components for pearl millet, to explain the specific adaptation of local landraces to stress environments in Rajasthan, India. Six genotypes, ranging from high-tillering traditional landraces to low-tillering open-pollinated modern cultivars, were grown in 20 experiments, covering a range of nonstress and drought stress patterns. In each experiment, yield components (particle number, grain number, 100 grain mass) were measured separately for main shoots, basal tillers, and nodal tillers. Under optimum conditions, landraces had a significantly lower grain yield than the cultivars, but no significant differences were observed at yield levels around 1 ton ha(-1). This genotype x environment interaction for grain yield was due to a difference in yield strategy, where landraces aimed at minimising the risk of a crop failure under stress conditions, and modem cultivars aimed at maximising yield potential under optimum conditions. A key aspect of the adaptation of landraces was the small size of the main shoot panicle, as it minimised (1) the loss of productive tillers during stem elongation; (2) the delay in anthesis if mid-season drought occurs; and (3) the reduction in panicle productivity of the basal tillers under stress. In addition, a low investment in structural panicle weight, relative to vegetative crop growth rate, promoted the production of nodal tillers, providing a mechanism to compensate for reduced basal tiller productivity if stress occurred around anthesis. A low maximum 100 grain mass also ensured individual grain mass was little affected by environmental conditions. The strategy of the high-tillering landraces carries a yield penalty under optimum conditions, but is expected to minimise the risk of a crop failure, particularly if mid-season drought stress occurs. The yield architecture of low-tillering varieties, by contrast, will be suited to end-of-season drought stress, provided anthesis is early. Application of the above adaptation mechanisms into a breeding program could enable the identification of plant types that match the prevalent stress patterns in the target environments. (C) 2003 E.J. van Oosterom. Published by Elsevier Science B.V. All rights reserved.

Mudan??as organizacionais no processo de moderniza????o da Secretaria da Fazenda do Estado de Pernambuco

A partir de 1998, teve in??cio, na Secretaria da Fazenda do Estado de Pernambuco, o Programa de Moderniza????o Fazend??ria (Promofaz), que promoveu diversas mudan??as organizacionais, concentrando esfor??os em projetos estruturadores, incluindo investimentos no planejamento de tecnologia da informa????o (TI). Dentre os projetos de TI, destacou-se a elabora????o das arquiteturas de sistemas e tecnol??gicas. Neste trabalho, foi realizada uma revis??o dos processos organizacionais da moderniza????o fazend??ria, abrangendo aspectos de cultura, mudan??a e aprendizagem organizacionais, confrontados com referenciais hist??ricos e te??ricos, e maior enfoque na ??rea de tecnologia da informa????o. Apesar das dificuldades, o processo de informatiza????o tem provocado fortes impactos nos componentes culturais da institui????o. Sem a utiliza????o da tecnologia da informa????o como ferramenta, provavelmente n??o se implantariam os novos modelos de gest??o adotados pela Sefaz, mas se observou que a tecnologia, sozinha, n??o faz o milagre da mudan??a, sendo necess??rio todo um conjunto de esfor??os e um trabalho paralelo com outros fatores de mudan??a.

Política de segurança pública no Brasil contemporâneo : entre a segurança cidadã e a continuidade autoritária

O objeto de estudo dessa pesquisa é a política de segurança pública brasileira visando compreender o seu percurso ideológico e político no contexto de retomada e da consolidação da democracia no Brasil, após 21 anos de ditadura militar. Considerando o contexto no qual se verifica a existência de disputa política em torno da concepção de segurança pública, o objetivo geral deste trabalho é compreender a matriz estruturante da política de segurança pública no Brasil contemporâneo. Seu intuito visa responder à pergunta inicial e condutora do interesse que estrutura este trabalho, aqui apresentada nos seguintes termos: a política de segurança pública no Brasil após o restabelecimento das eleições diretas para a Presidência da República está em vias de transição, tendendo a assumir caráter democrático ou a força da tradição autoritária na cultura política brasileira tem-se garantido a sua continuidade neste campo da intervenção estatal? Ancoramos a nossa reflexão nas categorias teóricas de dominação, coerção e consenso no pensamento clássico de Hobbes, Marx, Weber e Gramsci, extraindo deles os elementos que nos auxiliam no entendimento da política de segurança pública brasileira. Para o estudo dessa política foi fundamental operarmos uma profunda revisão bibliográfica, especialmente para entender como a manutenção da ordem foi se desenhando no contexto brasileiro e como historicamente tem prevalecido um modelo de segurança pública marcado pelo autoritarismo. Entretanto, a partir da redemocratização brasileira há a emergência de outro paradigma para a política de segurança pública, a segurança cidadã, propondo, entre outras coisas, a reforma das instituições de segurança pública e a formação em direitos humanos nas instituições policiais. Para a análise do paradigma emergente de segurança, buscamos apoio no Programa Nacional dos Direitos Humanos e no Plano Nacional de Segurança Pública, documentos federais que representam a construção de uma nova intencionalidade para a segurança pública no Brasil. Finalmente, reconhecemos que, embora haja significativas reformas na segurança pública, tal política, diante da prevalência de um paradigma de segurança tradicional com fortes componentes autoritários, se encontra entre a segurança cidadã e a continuidade autoritária.

Capital Intelectual: sua divulgação no setor bancário em Portugal

The importance of intangible resources has increased dramatically in recent years comparing to tangible ones. The economy in which we live is the result of competitive pressures that have imposed the implementation of business at an international level as well as a requirement in the application of sophisticated technologies that allow us to follow this fast evolution. In this age of information and innovation organizations will only survive if they are inserted in a global network of strategic relations, generically called as the network economy by Lev (2003). The service sector has stood out against the more traditional sectors of the economy. The intensive use of knowledge and a strong customer orientation created a new reality in today’s organizations: a growing importance attached to innovation, to the quality of products and services offered, to the information and communication technologies adopted, and to the creativity and particular abilities of human resources. The concept of intangible assets is more common in an accounting language and intellectual capital is most often applied in the context of management, being associated with a more comprehensive, multidimensional approach, representing all the knowledge that the institution owns and that it applies in the form of expertise, the creativity and organizational competencies that lead to innovation and to the sustained attainment of future economic benefits. An analysis of the scope of intellectual capital is fundamental to take more appropriate management decisions so that a more appropriate accounting treatment could be given by the accounting standardization organizations. This study intends to analyse the practices of information disclosure of the intellectual capital in the banking sector in Portugal, complementing the analysis of the disclosure of intangible assets in the context of accounting standards with the disclosure of intellectual capital in the context of organizational management. In particular, our main aims are to identify the extent of disclosure of intellectual capital made by banks in Portugal and also to identify the factors that determine such a disclosure. The disclosure in the context of accounting standards will be studied by checking the disclosure of intangible assets through the items listed in the International Accounting Standard 38 developed by the International Accounting Standards Board. The context of management was analysed by means of creating a voluntary disclosure index based on assumptions of the model Intellectus, developed by the Centro de Investigación sobre la Sociedad del Conocimiento – Instituto de Administración de Empresas (CIC-IADE) of the Universidad Autónoma of Madrid, and of the model Intellectual Capital Statement (made in Europe) (InCaS), both promoted by the European Commission and that we have adapted to the banking sector. When analysing the disclosure of intangible assets based on the context of accounting standards and the voluntary disclosure of intellectual capital, this study has tried to raise awareness about the importance of issuing reports on the intellectual capital as an alternative tool to take management decisions in the existing organizations and reflects the transparency and legitimacy that these institutions seek through a more extensive and more detailed information disclosure of their intellectual capital. Based on a complimentarily of economic theories, together with social and political theories, we tried to check the extent, evolution and tendencies of the compulsory disclosure of intangible assets and of the voluntary disclosure of the intellectual capital analysed in the period 2001-2011. Banks characteristics were also analysed in order to deduce those factors that determine or promote a larger disclosure in this sector. Based on these objectives, we adopted a longitudinal approach to explore the extent and the development of the disclosure of intangible assets as well as the factors that have determined it. Furthermore, we sought to assess the impact of the adoption of IAS 38 in the financial statements of the organizations in this sector. The disclosure index created on the basis of the disclosure requirements stated in IAS 38 from IASB was applied to the consolidated financial statements of the seventeen banks that rendered their statements in Portugal from 2001 to 2009. Since the information disclosed in the context of accounting standards may not have an important role as a management tool once it was not able to reflect what really contributes to the competitiveness and organizational growth, the voluntary disclosure of the intellectual capital was analysed according to the information obtained from the 2010 annual individual reports of the banks operating in Portugal in that year and from their respective websites in 2011. We tried to analyse the extent of the voluntary disclosure of the intellectual capital and of each of its components, human capital, structural capital and relational capital. The comparative analysis of their annual reports and their web pages allowed us to assess the incidence of the disclosure and discover what channel the banking sector focuses on when disclosing their intellectual capital. Also in this analysis the study of the disclosure determinants has allowed us to conclude about the influence of particular characteristics in the voluntary disclosure of the intellectual capital. The results of the analysis to the extent of the disclosure of intangible assets in the consolidated financial statements of the banking groups in Portugal in the period 2001-2009 have shown an average information disclosure of 0.24. This information disclosure evolved from an average value of 0.1940 in 2001 to 0.2778 in 2009. The average value is 0.8286 if it is only considered the disclosure of the intangible assets that the banks possessed. The evolution of this index means an increase in the average disclosure from 0.7852 in 2001 to 0.8788 in 2009. From the first results that are related to the extent of the disclosure of intangible assets in the financial statements, we can verify that the banking groups present a low disclosure level of these resources. However, when considering the disclosure of only the intangible assets that each institution owns, the disclosure level appears to be in compliance with the disclosure requirements for this sector. An evolution in the disclosure of intangible assets for the period considered was confirmed, showing an increase in the information disclosure of intangible assets in 2005, the year in which the accounting rules for intangible assets changed. The analysis that focused on the disclosure in the context of management tried to understand the extent, the incidence and the determinants of the voluntary information disclosure of intellectual capital in the annual reports of 2010 and on their web pages in 2011, studying the 32 banks operating in Portugal in this period. The average voluntary disclosure of the intellectual capital in the 2010 annual reports is 0.4342 while that in web pages is 0.2907. A review of the components of the intellectual capital allowed us to assess the importance that the banks confer to each of these components. The data obtained show that the relational capital, and more specifically the business capital, is the most disclosed component by banks in Portugal both in the annual reports and in their institutional web pages, followed by the structural capital and, finally, by the human capital. The disclosure of the human capital and the structural capital is higher in the annual reports than that in the websites, while the relational capital is more disclosed in the websites than in the annual reports. The results have also shown that the banks make a complementary use of both sources when disclosing information about their structural capital and relational capital but they do not show any information about their human capital in their websites. We tried to prove the influence of factors that could determine the accounting disclosure and the voluntary disclosure of the intellectual capital in this sector. The change in the IASB accounting rules as from January 1st 2005 gave a greater disclosure of accounting information of intangible assets in the financial statements of banks. The bank size and corporate governance measures have statistically proved to have an influence on the extent of the accounting disclosure of intangible assets and on the voluntary disclosure of the intellectual capital. Economic and financial variables such as profitability, operating efficiency or solvency were not determinants of information disclosure. The instability that the banking sector has experienced in economic and financial indicators in recent years as a result of the global financial markets imbalance has worsen indicators such as profitability, efficiency and solvency and caused major discrepancies in the economic situation between banks in Portugal. This empirical analysis has contributed to confront the disclosure required by accounting rules performed in the financial statements of organizations with that performed in the main disclosure media which is available for entities and which is increasingly requested in the process of taking management decisions. It also allowed us to verify whether there is homogeneity between institutions in the fulfilment of the requirements for information disclosure of intangible assets. However, as for voluntary disclosure of intellectual capital, there are large disparities in the disclosure extent between organizations. Regardless of this sector specific characteristics, the voluntary disclosure of intellectual capital made by banks in Portugal follows the trends in other sectors and the practices adopted in other countries, namely regarding the amount of information disclosed, the incidence of the disclosure on the indicators of relational capital and the importance of variables such as size as determinants of disclosure of intellectual capital. For a further knowledge in this field, we created a specific index for the banking sector, considering appropriate indicators for an incisive, comprehensive analysis in order to consider the most relevant indicators of intellectual capital components. Besides, confronting the analysis of disclosure in the context of accounting standards with the study of voluntary disclosure brought a new analysis approach to the research on intellectual capital disclosure. With this study, we have also intended to raise greater awareness of the need for harmonization in the intellectual capital disclosure on the part of the regulatory banking authority by means of a demanding, consistent and transparent report of intellectual capital with simple, clear, objective indicators so that those interested in disclosing intellectual capital information in the organizations in this sector may obtain more harmonized and comparable information. A research on the disclosure quality of intellectual capital, together with the application of other analysis methodologies in this sector, might be a promising approach for future research. Applying the voluntary disclosure index to the same sector in other countries may also contribute to the knowledge of disclosure practices in different geographical environments. We highlight the relevance of further studies contributing to the harmonization and consistency in the presentation of an intellectual capital report so as to enable organizations to disclose the resources that contribute most to their competitiveness and growth.

Characterization of heat tolerance in wheat cultivars and effects on production components

Abstract: There is a need for heat tolerant wheat cultivars adapted to the expansion of cultivation areas in warmer regions due to the high demand of this cereal for human consumption. The objective of this study was to evaluate the effect of high temperatures on grain yield and yield components of wheat and characterize heat tolerant wheat genotypes at different development stages. The genotypes were evaluated in the field with and without heat stress. High temperatures reduced the number of spikelets per spike (21%), number of grains per spike (39%), number of grains per spikelet (23%), 1000-grain weight (27%) and grain yield (79%). Cultivars MGS 1 Aliança, Embrapa 42, IAC 24-Tucuruí and IAC 364-Tucuruí III are the most tolerant to heat stress between the stages double ridge and terminal spikelet; MGS 1 Aliança, BRS 264, IAC 24-Tucuruí, IAC 364-Tucuruí III and VI 98053, between meiosis and anthesis; and BRS 254, IAC-24-Tucuruí, IAC-364-Tucuruí III and VI 98053, between anthesis and physiological maturity. High temperatures reduce grain yield and yield components. The number of grains per spike is the most reduced component under heat stress. The genotypes differed in tolerance to heat stress in different developmental stages.

Effect of spatial arrangement on the production components and yield of sunflower

ABSTRACT The sunflower plant is an oilseed crop that has aroused a great interest in the Brazilian and international scenery especillay because of the possibility of using its oil for biodiesel production. The objective of this study was to evaluate productivity and yield components of Embrapa 122 sunflower according to the spatial arrangement. Treatments were arranged in 4 x 4 factorial arrangement, which are the four spacings between rows (0.30; 0.50; 0.70 and 0.90 m) and four sowing densities (30,000; 45,000; 60,000 and 75,000 plants ha-1). The experiment was carried out in a complete randomized block design with four replications. The experiments were conducted in the experimental area of the Plant Science Department in Fortaleza, State of Ceará-Brazil and on the Curu Vale Experimental Farm in Pentecoste, State of Ceará-Brazil. Productivity and the following production components were analyzed in the end of the crop cycle: harvested capitula, capitulum diameter, capitulum mass, achene mass per capitulum, mass of 100 achenes, achenes per capitulum, harvest index and oil content in the achenes. The experiments were analyzed jointly in relation to the cropping area and the data submitted to analysis of variance and quantitative factors tested by polynomial regression. The variables, spacing, density and cropping area did not interact with these variables and the spatial arrangement of the plants affected only the components. The cropping area influences the productive behavior of sunflower Embrapa 122. The spatial arrangement of the plants of sunflower of variety Embrapa 122 influences yield components but does not affect productivity.

An optimal level of technology reliance on foreign partners in a global sourcing partnership: components procurement, technology management and market performance

Existing studies on global sourcing strategy have implicitly adopted a cJosed-systems perspective in which sourcing activities are managed within a multinational company across national boundaries. Produd and process innovations and components procurement that are jointly managed by a consortium of cooperating firms have not been examined. In this paper, we empiricallyexamine the issues concerning sourcing partnerships in an open-systems perspective. Findings suggest that even in a sourcing partnership arrangement with a foreign supplier, the principal firm's ability to procure and control the supply of major components has a positive bearing on its market performance.

CAUSE-FIT, POSITIVE ATTITUDES AND BEHAVIORS WITHIN HYBRID COLOMBIAN ORGANIZATIONS

ABSTRACTSocially oriented ventures have provided livelihoods and social recognition to disadvantaged communities in different corners of the world. In some cases, these ventures are the result of Corporate Social Responsibility (CSR) programs. In Latin America, this type of undertaking has responded positively to unmet social needs. The social cause drives these organizations and their human resources and they give high value to organizational cause-fit. This paper presents empirical evidence of the effects of perceived cause-fit on several worker attitudes and behaviors. Psychological contract theory was adopted as theoretical background. Employees working in a hybrid (for-profit/socially oriented) Colombian organization created by a CSR program participated in the survey. Data provided by 218 employees were analyzed using PLS structural equation modeling. The results suggest the ideological components of the employee-employer relationship predict positive attitudes and cooperative organizational behaviors towards hybrid organizations.

Modification of MOR by desilication treatments: Structural, textural and acidic characterization

The effect of several desilication experimental parameters (base concentration, temperature and time) on the characteristics of MOR zeolite was studied. The samples were characterized by X-ray diffraction, Al-27 and Si-29 MAS-NMR, chemical analysis, and FTIR (framework vibration region). The textural characterization was made by N-2 adsorption and the acidity was evaluated by pyridine adsorption followed by FTIR and by the catalytic model reaction of n-heptane cracking. The alkaline treatments promoted the Si extraction from the zeolite framework, without considerable loss of crystallinity and, as it was envisaged, an important increase of the mesoporous structure was attained. A linear correlation between the number of framework Si per unit cell. N-Si and the asymmetric stretching wavenumber, nu(i), was observed. The acidity characterization shows that the desilicated samples exhibit practically the same acid properties than the parent HMOR zeolite. The optimum desilication conditions were those used to obtain sample M/0.2/85/2, i.e., sample treated with 0.2 M NaOH solution at 85 degrees C for 2 h.