Intrachain Energy Migration to Weak Charge-Transfer State in Polyfluorene End-Capped with Naphthalimide Derivative

Polyfluorene end-capped with N-(2-benzothiazole)-1 8-naphthalimide (PF-BNI) is a highly fluorescent material with fluorescence emission modulated by solvent polarity Its low energy excited state is assigned as a mixed configuration state between the singlet S(1) of the fluorene backbone (F) with the charge transfer (CI) of the end group BNI The triexponential fluorescence decays of PF-BNI were associated with fast energy migration to form an intrachain charge-transfer (ICCT) state polyfluorene backbone decay and ICCT deactivation Time-resolved fluorescence anisotropy exhibited biexponential relaxation with a fast component of 12-16 ps in addition to a slow one in the range 0 8-1 4 ns depending on the solvent showing that depolarization occurs from two different processes energy migration to form the ICCT state and slow rotational diffusion motion of end segments at a longer time Results from femtosecond transient absorption measurements agreed with anisotropy decay and showed a decay component of about 16 ps at 605 nm in PF BNI ascribed to the conversion of S(1) to the ICCT excited state From the ratio of asymptotic and initial amplitudes of the transient absorption measurement the efficiency of intrachain ICCT formation is estimated in 0 5 which means that on average, half of the excited state formed in a BNI-(F)(n)-BNI chain with n = 32 is converted to its low energy intrachain charge-transfer (ICCT) state

Performance Evaluation of Different PV-Array Configurations under Weak Light Conditions and Partial Shadings

The paper analyses empirical performance data of five commercial PV-plants in Germany. The purpose was on one side to investigate the weak light performance of the different PV-modules used. On the other hand it was to quantify and compare the shading losses of different PV-array configurations. The importance of this study relies on the fact that even if the behavior under weak light conditions or the shading losses might seem to be a relatively small percentage of the total yearly output; in projects where a performance guarantee is given, these variation can make the difference between meeting or not the conditions.When analyzing the data, a high dispersion was found. To reduce the optical losses and spectral effects, a series of data filters were applied based on the angle of incidence and absolute Air Mass. To compensate for the temperature effects and translate the values to STC (25°C), five different methods were assessed. At the end, the Procedure 2 of IEC 60891 was selected due to its relative simplicity, usage of mostly standard parameters found in datasheets, good accuracy even with missing values, and its potential to improve the results when the complete set of inputs is available.After analyzing the data, the weak light performance of the modules did not show a clear superiority of a certain technology or technology group over the others. Moreover, the uncertainties in the measurements restrictive the conclusiveness of the results.In the partial shading analysis, the landscape mounting of mc-Si PV-modules in free-field showed a significantly better performance than the portrait one. The cross-table string using CIGS modules did not proved the benefits expected and performed actually poorer than a regular one-string-per-table layout. Parallel substrings with CdTe showed a proper functioning and relatively low losses. Among the two product generations of CdTe analyzed, none showed a significantly better performance under partial shadings.

Feasible estimation of generalized linear mixed models (GLMM) with weak dependency between groups

This paper presents a two-step pseudo likelihood estimation technique for generalized linear mixed models with the random effects being correlated between groups. The core idea is to deal with the intractable integrals in the likelihood function by multivariate Taylor's approximation. The accuracy of the estimation technique is assessed in a Monte-Carlo study. An application of it with a binary response variable is presented using a real data set on credit defaults from two Swedish banks. Thanks to the use of two-step estimation technique, the proposed algorithm outperforms conventional pseudo likelihood algorithms in terms of computational time.

Transport and tourism : a weak symbiosis. An introduction to the special issue

“Tourism’s very existence depends on transport. Still, researchers in transportation and logistics do not show much interest in tourism whereas travel and tourism researchers pay more attention to accessibility than to transport.” These were the opening sentences of the call for papers for the TTRA European Chapter Conference “Transport and Tourism: Challenges, Issues and Conflicts” held in Rotterdam and Breda, The Netherlands from 22 to 24 April 2009.

Defining the links between retail price strategies and price tactics

Retailers tend to become trapped in a price-promotion war where price issues are dealt with on a short-term basis, indicating almost solely tactical choices. Since price is the only part of the marketing mix providing direct revenues to the organisation, it should also be of strategic importance for the retailer. Not only in practice are price tactics often separated from pricing strategies, it is also the case in research where these are often studied in isolation from each other probably due to their individual complexity. This paper contributes to both the research area and practice by discussing these two complex areas together, and the essence of both strategy and tactics are defined. By considering the planning horizon for the retailer this paper further contributes by defining the links between price strategy and price tactic. The conclusion shows the importance of clearly establishing which analytical level is being analysed.

The BoP approach and its links to main related research fields: sense-making of the current discussion

A Base-da-Pirâmide (Base ofthePyramid- BoP) é referida na literatura como sendo o segmento sócio-econômico mais baixo em termos de paridade do poder de compra. Esse segmento encontrase geralmente excluído do sistema capitalista global. Esta tese analisa o tema BoP e discute dentro de um contexto sócio-econômico, como essa abordagem se relaciona com outras áreas de pesquisa, assim como a teoria do desenvolvimento internacional e a teoria de negócios internacionais. Estas duas teorias são identificadas como tendo uma relação mais forte com BoP. No que se segue, a abordagem BoP é incorporada nessas duas teorias com o objetivo de tornar este conceito mais claro e abrangente. Seguindo este raciocínio a abordagem BoP vem identificar contribuições no tocante a cada uma dessas abordagens teóricas. O argumento principal da tese é que a abordagem BoP é capaz de ligar essas duas teorias (teoria do desenvolvimento internacional e a teoria de negócios internacionais) em um só modelo teórico, mostrando assim que essas duas abordagens teóricas distintas podem na realidade serem complementares.

Wald tests for IV regression with weak instruments

This dissertation deals with the problem of making inference when there is weak identification in models of instrumental variables regression. More specifically we are interested in one-sided hypothesis testing for the coefficient of the endogenous variable when the instruments are weak. The focus is on the conditional tests based on likelihood ratio, score and Wald statistics. Theoretical and numerical work shows that the conditional t-test based on the two-stage least square (2SLS) estimator performs well even when instruments are weakly correlated with the endogenous variable. The conditional approach correct uniformly its size and when the population F-statistic is as small as two, its power is near the power envelopes for similar and non-similar tests. This finding is surprising considering the bad performance of the two-sided conditional t-tests found in Andrews, Moreira and Stock (2007). Given this counter intuitive result, we propose novel two-sided t-tests which are approximately unbiased and can perform as well as the conditional likelihood ratio (CLR) test of Moreira (2003).

Relações civis-militares e as leis de acesso a informação na América Latina e no Brasil

Na América Latina, um vasto legado de regimes militares tem contribuído para o fortalecimento de uma cultura de sigilo nos governos. Além da defesa da pátria contra a ameaça comunista, a maioria destes golpes se deveu a um senso de dever das Forças Armadas em preservar o Estado. Deste ponto de vista, os próprios militares seriam os mais qualificados para determinar quando e como intervir na ordem política interna. No entanto, justificar a intervenção militar na ordem política interna é sempre um empreendimento repleto de contradições e riscos graves para a liberdade. Este contexto levou os estudiosos e autoridades a repensarem o controle civil sobre os militares, e a redefinirem os papéis das forças armadas. Neste processo de consolidação da democracia, os militares ainda mantêm alguns poderes políticos e de veto dentro dos governos civis. O controle civil democrático das Forças Armadas na América Latina enfrenta a falta de incentivos políticos para os civis a se envolverem e se especializarem no assunto, já que não há ameaças internas, quer externas observadas. De fato, a região tem sido considerada como uma "zona de paz", onde os esforços diplomáticos prevaleceriam sobre conflitos armados. A promulgação de leis de acesso à informação pública (LAI) abre uma maneira inteiramente nova de escrutínio público – uma democracia monitorial, que afeta diretamente a autonomia militar e sua cultura organizacional. No estudo do surgimento e da força legal das LAI na América Latina, as relações entre civis e militares não foram consideradas em profundidade como um fator influente. Buscou-se traçar uma relação entre, por um lado, a existência de LAI, a data de aprovação da LAI e sua força geral e exceções, e por outro lado, as relações civis-militares na América Latina. Um número considerável de países suporta que as relações civis-militares influenciam a regulamentação das exceções e o momento em que a lei foi aprovada. Há uma tendência geral na América Latina a adotar LAI fracas na regulamentação de exceções. Também foi feito um estudo de caso do Brasil, país muito representativo da influência militar na política. Concluiu-se que as relações entre civis e militares no Brasil foram um fator de grande influência na aprovação final da LAI no país. Este estudo contribui para a construção de uma ponte entre as agendas de pesquisa de transparência e de relações civis-militares, com várias possibilidades de estudos de casos comparados.

Supply chain turbulence: the impact of a mid-range event in multi-tier, multi-dimension supply chains

Nota: A autora agradece à Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) pela concessão de bolsa de estudos para o desenvolvimento deste projeto de pesquisa.

Links hipertextuais na comunicação científica: análise webométrica dos sítios acadêmicos latino-americanos em ciências sociais

VANTI, Nadia. Links hipertextuais na comunicação científica: análise webométrica dos sítios acadêmicos latino-americanos em Ciências Sociais. Porto Alegre, 2007. 292 f. Tese (Doutorado em Comunicação e Informação) – Universidade Federal do Rio Grande do Sul. Porto Alegre, 2007.

Por trás de links, sempre existem pessoas: o anonimato como fator de pertencimento no uso de redes sociais on-line em projetos educacionais

The thesis investigated how social networks online that allows anonymous postings can be used by teachers and students to promote the meeting between the sexual education and the needs and expectations of young people face a crosscutting theme, remarkably a taboo. It needs teaching strategies more efficient than those traditionally defended. With this experience, found in a short course about sexuality and health, we sought to go beyond the use of social networks for social entertainment, showing they can be an field that favors the process of teaching and learning. The research was based on the convergence of the communication concepts from Paulo Frere and another from Jürgen Habermas, as well as the philosophical concepts of utopia, ideology and dialectic are interrelated not only among themselves, but also inside an education field. Methodologically in this thesis, we adopted the category of qualitative research; the method is a combination of case study with action research. The technique was the use of questionnaires, data collection was in attendance and the types of data were primary. Finally, we present, then, the idea the communication is not in the middle, but in the trusty relationship established between the interlocutors. In this way, we can think when a student has met their need to be able answer his questions about sex with their teacher through an online social network that allows anonymity and through which the student knows who responds is their teacher, but the teacher can not distinguish the identity of his students, this dialogic relationship serves to get claims of the validity that are characterized as potential communicative action

Weak phenotypic reversion of ivermectin resistance in a field resistant isolate of Haemonchus contortus by verapamil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

An interaction between two RNA binding proteins, Nab2 and Pub1, links mRNA Processing/Export and mRNA stability

mRNA stability is modulated by elements in the mRNA transcript and their cognate RNA binding proteins. Poly(U) binding protein 1 (Pub1) is a cytoplasmic Saccharomyces cerevisiae mRNA binding protein that stabilizes transcripts containing AU-rich elements (AREs) or stabilizer elements (STEs). In a yeast two-hybrid screen, we identified nuclear poly(A) binding protein 2 (Nab2) as being a Pub1-interacting protein. Nab2 is an essential nucleocytoplasmic shuttling mRNA binding protein that regulates poly(A) tail length and mRNA export. The interaction between Pub1 and Nab2 was confirmed by copurification and in vitro binding assays. The interaction is mediated by the Nab2 zinc finger domain. Analysis of the functional link between these proteins reveals that Nab2, like Pub1, can modulate the stability of specific mRNA transcripts. The half-life of the RPS16B transcript, an ARE-like sequence-containing Pub1 target, is decreased in both nab2-1 and nab2-67 mutants. In contrast, GCN4, an STE-containing Pub1 target, is not affected. Similar results were obtained for other ARE- and STE-containing Pub1 target transcripts. Further analysis reveals that the ARE-like sequence is necessary for Nab2-mediated transcript stabilization. These results suggest that Nab2 functions together with Pub1 to modulate mRNA stability and strengthen a model where nuclear events are coupled to the control of mRNA turnover in the cytoplasm.