Structure, processing and midgut secretion of putative peritrophic membrane ancillary protein (PMAP) from Tenebrio molitor larvae

A cDNA coding for a Tenebrio molitor midgut protein named peritrophic membrane ancillary protein (PMAP) was cloned and sequenced. The complete cDNA codes for a protein of 595 amino acids with six insect-allergen-related-repeats that may be grouped in A (predicted globular)- and B (predicted nonglobular)-types forming an ABABAB structure. The PMAP-cDNA was expressed in Pichia pastoris and the recombinant protein (64 kDa) was purified to homogeneity and used to raise antibodies in rabbits. The specific antibody detected PMAP peptides (22 kDa) in the anterior and middle midgut tissue, luminal contents, peritrophic membrane and feces. These peptides derive from PMAP, as supported by mass spectrometry, and resemble those formed by the in vitro action of trypsin on recombinant PMAP. Both in vitro and in vivo PMAP processing seem to occur by attack of trypsin to susceptible bonds in the coils predicted to link AB pairs, thus releasing the putative functional AB structures. The AB-domain structure of PMAP is found in homologous proteins from several insect orders, except lepidopterans that have the apparently derived protein known as nitrile-specifier protein. Immunocytolocalization shows that PMAP is secreted by exocytosis and becomes entrapped in the glycocalyx, before being released into midgut contents. Circumstantial evidence suggests that PMAP-like proteins have a role in peritrophic membrane type 2 formation. (C) 2007 Elsevier Ltd. All rights reserved.

The influence of perhydroazepine and piperidine as further ancillary ligands on Ru-PPh(3)-based catalysts for ROMP of norbornene and norbornadiene

Polynorbornadiene and polynorbornene were synthesized via ring opening metathesis polymerization (ROMP) with [RuCl(2)(PPh(3))(2)(amine)] as catalyst precursors, amine = piperidine (1) or perhydroazepine (2) in the presence of 5 mu L of ethyl diazoacetate (EDA) ([monomer]/[Ru] = 5000; 40 degrees C with 1; 25 degrees C with 2). The effects of the solvent volume (2-8 mL of CHCl(3)) reaction time (5-120 min) and atmosphere type (argon and air) on the yields were investigated to observe the behavior of the two different precursors. Quantitative yields were obtained for 60 or 120 min regardless of the starting volumes, either in argon or air, with both Ru species. However, low yields were obtained for short times (5-30 min) when the reactions are performed with large volumes (6-8 mL). In argon, the yields were larger with 2, associated to a faster propagation reaction controlled by the Ru active species. In air, the yields were larger with 1, associated to a higher resistance to O(2) of the starting and propagating Ru species. The different activities between 1 and 2 are discussed considering the steric hindrance and electronic characteristics of the amines such as ancillary ligands and their arrangements with PPh(3) and Cl(-) ions in the metal centers. (c) 2009 Elsevier B.V. All rights reserved.

February 2009: Tax Time

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Education, preferences for leisure, and the optimal income tax schedule

Recent advances in dynamic Mirrlees economies have incorporated the treatment of human capital investments as an important dimension of government policy. This paper adds to this literature by considering a two period economy where agents are di erentiated by their preferences for leisure and their productivity, both private information. The fact that productivity is only learnt later in an agent's life introduces uncertainty to agent's savings and human capital choices and makes optimal the use of multi-period tie-ins in the mechanism that characterizes the government policy. We show that optimal policies are often interim ine cient and that the introduction of these ine ciencies may take the form of marginal tax rates on labor income of varying sign and educational policies that include the discouragement of human capital acquisition. With regards to implementation, state-dependent linear taxes implement optimal savings, while human capital policies may require labor income taxes that depend directly on agents' schooling.

Yet another reason to tax goods

The optimal taxation of goods, labor and capital income is considered in a two period model where: i) private information changes through time; ii) savings are not observed, and; iii) savings a§ect preferences conditional on the realization of types. The simultaneous appearance of these three elements cause optimal commodity taxes to depend on o§-equilibrium savings. As a consequence, separability no longer su¢ ces for the uniform taxation prescription of Atkinson and Stiglitz (AS) to obtain. If preferences are homothetic AS is partially restored: taxes are uniform within periods, however, future consumption is taxed at a higher rate than current consumption.

Ideological changes and tax structure: Latin American countries during the nineties

Sabatini (2002) and Roberts and Wibbles (1999) Pointed Out That Voters in Latin American Countries are no Longer Choosing According to Their Ideological Preferences. Ashworth and Heyndels (2002) Showed That the Tax Choice In Oecd Countries Does not Follow the Ideological Pattern of Party Preferences. the Most Robust Result of This Work Shows That the Tax Choice in Latin American Countries Still Depends on This Ideological Preference. We Also Verified That Changes in the Tax Structure Depend on Changes Both in the Tax Burden and the Openness of the Economy

Estratégias para a superação de problemas locais à Vila do Abraão e sua relação com o desenvolvimento sustentável do turismo

This study evaluates how the interaction among organizations located in Vila do Abraão, in Ilha Grande, Rio de Janeiro State, has contributed to the sustainability of this locality. An analysis of the island¿s local problems showed that firms informality and solid waste management practices were bringing damaging consequences to the island, and that this local productive arrangement (APL) has been able to collectively find solutions to such issues. These solutions basically encompassed: a) choosing estrategies the lead to a self-sustained model and not traditional way dependent on tax benefits; b) recognizing that the solutions to these problems involved the common action of public and private sectors and the civil society, and that various artifices should be used to establish such cooperation; c) the presence of actors outside the APL who played an important role in overcoming the problems of the cluster; d) using transparent legal instruments that defined the rights and obligations of each party and e) tripartite social entrepreneurship actions through NGOs to help solve problems common to the whole island.

The effects of tax incentives for small firms on employment levels

This paper will examine the effects of tax incentives for small businesses on employment level evaluating a program with this purpose implemented in Brazil in the 1990s. We first develop a theoretical framework which guides both the de nition of the parameters of interest and their identi cation. Selection problems both into the treatment group and into the data sample are tackled by combining fixed effects methods and regression discontinuity design on alternative sub-samples of a longitudinal database of manufacturing firms. The results show that on the one hand the size composition of the treated fi rms may be changed due to the survival of some smaller firms that would have exited had it not been eligible to the program. On the other hand, the treated firms who do not depend on the program to survive do employ more workers.

Nota fiscal eletrônica reduz custos para o contribuinte?

O presente trabalho tem por objetivo investigar se a adoção de documentos eletrônicos, uma realidade cuja obrigatoriedade é crescente no Brasil, é acompanhada por uma redução nos custos de conformidade das empresas. O autor buscou o referencial teórico em várias áreas do conhecimento: no Direito Tributário e no Direito Civil, na Matemática Aplicada, na Tecnologia da Informação e, por fim, na Contabilidade. Do Direito Civil vieram os conceitos de documento, que juntamente com conceitos de Matemática e de Teoria da Informação permitem construir a noção de Documento Eletrônico. Do Direito Tributário vieram as noções relativas aos tributos no ordenamento brasileiro, e as suas obrigações associadas (principal e acessórias). Da Contabilidade buscaram-se as definições de custos de conformidade e de transação, de forma que se pudesse avaliar quanto custa para uma empresa ser conforme com as obrigações tributárias acessórias brasileiras, especialmente no que tange ao uso de documentos fiscais eletrônicos. O estudo foi circunscrito na Nota Fiscal Eletrônica, que no Brasil deve ser utilizada em operações de circulação de mercadorias em substituição à Nota Fiscal Modelo 1 ou 1-A, documento tradicional que existe há décadas no Brasil. Buscaram-se informações quantitativas com empresas brasileiras, e a conclusão final é que existem evidências que justificam a afirmação de que o uso de documentos eletrônicos é mais barato que o uso de documentos em papel, mediante a comparação entre os custos de transação associados com a Nota Fiscal Modelo 1 ou 1-A e com a Nota Fiscal Eletrônica.

Sacrifice and efficiency of the income tax schedule

We investigate the efficiency of equal sacrifice tax schedules in an economy which primitives are exactly those in Mirrlees (1971): a continuum of individuals with identical preferences defined over consumption and leisure who differ with respect to their labor market productivity. Using a separable specification for preferences we derive the minimum equal sacrifice allocation and recover the tax schedule that implements it. The separable specification allows us to use the methodology developed by Werning (2007b) to check whether the schedule is efficient, that is, whether there is no alternative tax schedule that raises more revenue while delivering less utility to no one. We find that inefficiency does not arise for most parametrizations we use to approximate the US economy. For the few cases for which inefficiency does arise, it does so only for very high levels of income and marginal tax rates.

Tax filing choices for the household under separable spheres bargaining

If household choices can be rationalized by the maximization of a well defined utility function, allowing spouses to file individually or jointly is equivalent to offering the envelope of the two tax schedules. If, instead, household ’preferences’ are constantly being redefined through bargaining, the option to file separately may affect outcomes even if it is never chosen. We use Lundberg and Pollak’s (1993) separate spheres bargaining model to assess the impact of filing options on the outcomes of primary and secondary earners. Threat points of the household’s bargain are given for each spouse by the utility that he or she attains as a follower of a counter-factual off-equilibrium Stackelberg game played by the couple. For a benchmark tax system which treats a couple’s average taxable income as if it were that of a single individual, we prove that if choices are not at kinks, allowing couples to choose whether to file jointly or individually usually benefits the secondary earner. In our numeric exercises this is also the case when choices are at kinks as well. These findings are, however, quite sensitive to the details of the tax system, as made evident by the examination of an alternative tax system.

On the efficiency of equal sacrifice income tax schedules

In an economy which primitives are exactly those in Mirrlees (1971), we investigate the efficiency of labor income tax schedules derived under the equal sacrifice principle. Starting from a given government revenue level, we use Werning’s (2007b) approach to assess whether there is an alternative tax schedule to the one derived under the equal sacrifice principle that raises more revenue while delivering less utility to no one. For our preferred parametrizations of the problem we find that inefficiency only arises at very high levels of income. We also show how the multipliers of the Pareto problem may be extracted from the data and used to find the implicit marginal social weights associated with each level of income.

Taxing hard-to-tax markets

Tax enforcement costs constrain the government s ability to observe economic transactions, giving rise to hard-to-tax (HTT) markets. In these markets transactions are untaxed and consumers are better o¤ than in taxed markets. This paper studies a novel approach to combat evasion in HTT markets: consumer auditing, which rewards consumers for re- questing transaction receipts. We develop a Hotelling-type spatial model of sales taxation to analyze the welfare and distributional e¤ects of the implementation of this policy. We and that consumer auditing allows for a lower tax rate and greater provision of the public good in the economy. We show that this policy not only can enhance welfare, but also equalize utilities of consumers across markets

The effects of small firm tax incentives on employment levels

This paper aims to evaluate the impact on employment growth of a tax incentive program targeting Brazilian manufacturing small businesses (SIMPLES). This evaluation is conducted for two distinct periods: for the year 1997, when the program was first implemented, and for the year 1999, when the eligibility rule was modified to allow the eligibility of a broader group of firms. The evaluation takes into account two distinct channels through which the charted effects operate. The first is the employment variation in the firms that became eligible for the incentives, and the second is the change in the survival probability experienced by the same group of firms. Moreover, each of these channels can be activated either by the tax reduction dimension of the program or by its dimension of red tape simplification. Our results identify positive effects on employment growth for the tax incentive program only in the dimension of red tape simplification and its effects on the 1997 sample.