On insurance markets with endogenous information acquisition: A robust mechanism design approach

Neste trabalho propomos a aplicação das noções de equilíbrio da recente literatura de desenho de mecanismo robusto com aquisição de informação endógena a um problema de divisão de risco entre dois agentes. Através deste exemplo somos capazes de motivar o uso desta noção de equilíbrio, assim como discutir os efeitos da introdu ção de uma restrição de participação que seja dependente da informação. A simplicidade do modelo nos permite caracterizar a possibilidade de implementar a alocação Pareto efiente em termos do custo de aquisição da informação. Além disso, mostramos que a precisão da informação pode ter um efeito negativo sobre a implementação da alocação efi ciente. Ao final, sao dados dois exemplos específicos de situações nas quais este modelo se aplica.

A monetary mechanism for sharing capital: Diamond and Dybvig meet Kiyotaki and Wright

A model is presented in which banks accept deposits of fiat money and intermediate capital. Alt though theories about the coexistence of money and credit are inherently difficult, the model offers a simple explanation for the dual role of financial institutions: Banks are well monitored, and can credibly allow fiat-money withdraws to whom needs its, thus qualifying to become safe brokers of idle capital. The model shares some features with those of Diamond and Dybvig (1983) and Kiyotaki and Wright (1989).

Global law in pieces fragmentation, regimes and pluralism

The idea that life undergoes a process of functional differentiation, and that, as a consequence, law becomes increasingly specialized – and maybe even transforms in its very nature – is now widespread. The specialized clusters of law or regulation are very often called regimes, in the international arena, international or transnational regimes. This paper deals, first, with three strong representations of international regimes and discusses some of their problems. It argues that, in order to make a good use of the category, it is necessary to keep in mind the differentiation between law and non-law in the wider context of governance. It then turns, firstly, to the notion of regimes as fragments of a unified and coherent public international law order and, secondly, as meeting points of regulations emerging from different legal orders as well as from other non-legal sources. Within public international law, regimes are seen as related to what is called the double fragmentation of that legal order. As clusters of regulation within a wider global regulatory order, regimes are put in relation to two types of legal or regulatory pluralism.

Convexity in multidimensional mechanism design

The present article initiates a systematic study of the behavior of a strictly increasing, C2 , utility function u(a), seen as a function of agents' types, a, when the set of types, A, is a compact, convex subset of iRm . When A is a m-dimensional rectangle it shows that there is a diffeomorphism of A such that the function U = u o H is strictly increasing, C2 , and strictly convexo Moreover, when A is a strictly convex leveI set of a nowhere singular function, there exists a change of coordinates H such that B = H-1(A) is a strictly convex set and U = u o H : B ~ iR is a strictly convex function, as long as a characteristic number of u is smaller than a characteristic number of A. Therefore, a utility function can be assumed convex in agents' types without loss of generality in a wide variety of economic environments.

A monetary mechanism for sharing capital: Diamond and Dybvig meet Kiyotaki and Wright

Historically, payment systems and capital intermediation interact. Friedman (1959), and many observers of bank instabilities, have ad- vocated separating depositary from credit institutions. His proposal meets today an ever-increasing provision of inside money, and a short- age of monetary models of bank intermediation. In this paper, we eval- uate the proposal from a new angle, with a model in which isolating a safe payments system from commercial intermediation undermines information complementarities in banking activities. Some features of the environment resemble the models in Diamond and Dybvig (1983), and Kiyotaki and Wright (1989).

The effects of a centralized college admission mechanism on migration and college enrollment: evidence from Brazil

No Brasil, a recente reformulação do Exame Nacional de Ensino Médio (ENEM) e a criação do Sistema de Seleção Unificada (SISU), um mecanismo de admissão centralizado que aloca os alunos às instituições, promoveram mudanças relevantes no Ensino Superior. Neste artigo, investigamos os efeitos da introdução do SISU na migração e evasão dos alunos ingressantes a partir dos dados do Censo de Educação Superior. Para tal, exploramos a variação temporal na adesão das instituições ao SISU e encontramos que a adoção do SISU está associada a um aumento da mobilidade entre municípios e entre estados dos alunos ingressantes em 3.8 pontos percentuais (p.p) e 1.6 p.p., respectivamente. Além disso, encontramos um aumento da evasão em 4.5 p.p. Nossos resultados indicam que custos associados à migração e comportamento estratégico são importantes determinantes da evasão dos alunos.

Bioprospecção de polissacarídeos sulfatados de macroalgas marinhas do litoral do Rio Grande do Norte: caracterização de uma heterofucana extraída da alga marron sargassum filipendula que induz apoptose em células hela

The coast of Rio Grande do Norte has more than 100 species of seaweed, mostly unexplored regarding their pharmacological potential. The sulfated polysaccharides (PS) are by far the more seaweed compounds studied, these present a range of biological properties, such as anticoagulant activity, anti-inflammatory, antitumor and antioxidant properties. In this study, we extract sulfated polysaccharide rich-extracts of eleven algae from the coast of Rio Grande do Norte (Dictyota cervicornis; Dictiopterys delicatula; Dictyota menstruallis; Dictyota mertensis; Sargassum filipendula; Spatoglossum schröederi; Gracilaria caudata; Caulerpa cupresoides; Caulerpa prolifera; Caulerpa sertularioides e Codim isthmocladum), and these were evaluated for the potential anticoagulant, antioxidant and antiproliferative. All polysaccharide extracts showed activity for anticoagulant, antioxidant and/or antiproliferative activity, especially D. delicatula and S. filipendula, which showed the most prominent pharmacological potential, thereby being chosen to have their sulfated polysaccharides extracted. By fractionating method were obtained six fractions rich in sulfated polysaccharides to the algae D. delicatula (DD-0,5V, DD-0, 7V, DD-1,0v, DD-1,3v, DD-1,5v and DD-2,0) and five fractions to the alga S. filipendula (SF-0,5V, SF-0,7V, SF-1,0v, SF-1,5v and SF-2,0v). For the anticoagulant assay only the fractions of D. delicatula showed activity, with emphasis on DD-1, 5v that presented the most prominent activity, with APTT ratio similar to clexane® at 0.1 mg/mL. When evaluated the antioxidant potential, all fractions showed potential in all tests (total antioxidant capacity, hydroxyl and superoxide radicals scavenging, ferrous chelation and reducing power), however, the ability to chelate iron ions appears as the main mechanism antioxidant of sulfated polysaccharides from seaweed. In antiproliferative assay, all heterofucanas showed dose-dependent activity for the inhibition of cell proliferation of HeLa, however, with the exception of SF-0,7V, SF- 1,0v and SF-1,5v, all fractions showed antiproliferative activity against MC3T3, a normal cell line. The heterofucana SF-1,5V had its antiproliferative mechanism of action evaluated. This heterofucan induces apoptosis in HeLa cells by a pathway caspase independent, promoting the release of apoptosis Inducing Factor (AIF) in the cytosol, which in turn induces chromatin condensation and DNA fragmentation into 50Kb fragments. These results are significant in that they provide a mechanistic framework for further exploring the use of SF-1.5v as a novel chemotherapeutics against human cervical cancer.

Structural and Biochemical Characterization of Peroxiredoxin Q beta from Xylella fastidiosa CATALYTIC MECHANISM and HIGH REACTIVITY

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

Mechanism of infection and colonization of Rhipicephalus sanguineus eggs by Mertarhizium anisopliae as revealed by scanning eletron microscopy and histopathology

O presente trabalho teve como objetivo verificar a forma de penetração do fungo Metarhizium anisopliae em ovos do carrapato Rhipicephalus sanguineus, assim como as lesões infringidas no interior do ovo. A aderência e penetração do fungo foram estudadas por meio da microscopia eletrônica de varredura e a ação do fungo nos tecidos internos avaliada em secções histológicas convencionais. Para observação destes eventos, realizaram-se infecções experimentais em 11 grupos de ovos do R. sanguineus contendo 25 mg cada. Os ovos foram banhados durante 3 minutos, sob agitação manual, em suspensão com concentração de 10(8) conídios/mL. Nos grupos controle o banho foi realizado apenas no veículo da suspensão. Os ovos foram processados para análise histopatológica e microscopia eletrônica de varredura nos seguintes tempos após a infecção: 1 e 18h, e um, dois, três, quatro, cinco, seis, sete, nove e onze dias. Observou-se grande germinação de conídios em 67% dos ovos 18h após a inoculação e o fungo penetrou em 92,6% dos ovos 5 dias após a infecção. A extrusão do patógeno ocorreu em 87% dos ovos 7 dias após a infecção, chegando a 100% no 9º dia. Nas análises histopatológicas não foram observadas lesões dignas de nota, porem deve-se ressaltar que houve significativa redução (53,9%) na eclosão a partir dos ovos infectados.

EFFICIENCY of PNEUMATIC and HORIZONTAL PERFORATED DISK METER MECHANISM IN CORN NO-TILLAGE SEEDERS IN SOIL WITH DIFFERENT MOBILIZATION REPORTS

This work objectified to evaluate the efficiency of two meter mechanism of corn seeds when submitted to different forward speed and soil management system during the non-tillage seeding. It was used a factorial design in randomized blocks. The factors whose effects were examined were related to the seeders with pneumatic and horizontal disk meter mechanisms for the distribution of the seeds, to the set tractor-seeder forward speeds (4.4; 8.0 and 9.8 km h(-1)), and to the soil management system considering the corn no-tillage seeding over minimum tillage with chisel plow and the no-tillage system for the seeding of oat culture (Avena strigosa Schreb). It was verified that the forward speed didn't influence the initial and final stands of plants but it interfered in the regularity of longitudinal distribution of plants. The smallest speed provided the largest percentile of normal spacing between plants. The pneumatic meter mechanism presented better performance than the horizontal disk perforated in the longitudinal distribution of plants. About corn productivity aspect it's indifferent the recommendation of use for pneumatic and perforated horizontal disk meter mechanism of seeds.

Mechanism of anticlastogenicity of Agaricus blazei Murill mushroom organic extracts in wild type CHO (K-1) and repair deficient (xrs5) cells by chromosome aberration and sister chromatid exchange assays

Agaricus blazei Murill is a medicinal mushroom native to Brazil. The present work assessed the clastogenic and anticlastogenic potential of organic extracts (ethanol and chloroform/methanol) from the lineage AB97/11 in chinese hamster CHO-K-1 (wild type) and CHO-xrs5 (repair deficient) cells using the chromosome aberration (CA) and sister chromatid exchange (SCE) assays. In these experimental conditions were observed: (a) anticlastogenic effect at concentrations of 0.06 and 0.09% of the EtOH extract and at the 0.03 and 0.06% concentrations of the C/MetOH extract in CHO-K-1; (b) absence of protector effect on CHO-xrs5 cells; and (c) absence of protector effect in the SCE assay. These results indicate that organic extracts of A. blazei lineage AB97/11 present bio-antimutagenic type protective activity. (C) 2003 Elsevier B.V. B.V. All rights reserved.

Mechanism and control of Genipa americana seed germination

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Interaction mechanism of poly (o-ethoxyaniline) and collagen blends

Blend films of poly (o-ethoxyaniline) (POEA) and collagen were fabricated by casting under optimized conditions and characterized by Raman scattering and UV-vis absorption spectroscopies. The UV-vis spectra showed that the addition of collagen in the aqueous solution of POEA promotes a dedoping of the POEA. This effect was also observed for the blend films as supported by Raman scattering and a mechanism for the chemical interaction between POEA-collagen is proposed. The influences of different percentage of collagen as well as the pH of stock solutions during the fabrication process of the blend films were also investigated. It was found that the preparation method plays an important role in the flexibility and freestanding properties of the films. Complementary, the surface morphology was studied by atomic force microscopy and the conductivity by dc measurements. (C) 2003 Elsevier Ltd. All rights reserved.