Corporate Demand for Liquidity

This paper proposes a theory of corporate liquidity demand and provides new evidence on corporate cash policies. Firms have access to valuable investment opportunities, but potentially cannot fund them with the use of external finance. Firms that are financially unconstrained can undertake all positive NPV projects regardless of their cash position, so their cash positions are irrelevant. In contrast, firms facing financial constraints have an optimal cash position determined by the value of today's investments relative to the expected value of future investments. The model predicts that constrained firms will save a positive fraction of incremental cash flows, while unconstrained firms will not. We also consider the impact of Jensen (1986) style overinvestment on the model's equilibrium, and derive conditions under which overinvestment affects corporate cash policies. We test the model's implications on a large sample of publicly-traded manufacturing firms over the 1981-2000 period, and find that firms classified as financially constrained save a positive fraction of their cash flows, while firms classified as unconstrained do not. Moreover, constrained firms save a higher fraction of cash inflows during recessions. These results are robust to the use of alternative proxies for financial constraints, and to several changes in the empirical specification. We also find weak evidence consistent with our agency-based model of corporate liquidity.

Corporate Financial and Investment Policies when Future Financing is not Frictionless

Much of corporate finance is concerned with the impact of financing constraints on firms. However, the literature on financing constraints largely ignores the intertemporal implications of those constraints; in particular, how future financing constraints affect current investment decisions. We present a model in which future financing constraints lead firms to have a current preference for investments with shorter payback periods, investments with less risk, and investments that utilize more liquid/pledgeable assets. The model has a host of implications in different areas of corporate finance, including firms' capital budgeting rules, risk-taking behavior, capital structure choices, hedging strategies, and cash management policies. We show how a number of patterns reported in the empirical literature can be reconciled and interpreted in light of the intertemporal optimization problem firms solve when they face costly external financing. For example, contrary to Jensen and Meckling (1976), we show that firms may reduce rather than increase risk when leverage increases exogenously. Furthermore, firms in economies with less developed financial markets will not only take different quantities of investment, but will also take different kinds of investment (safer, short-term projects that are potentially less profitable). We also point out to several predictions that have not been empirically examined. For example, our model predicts that investment safety and liquidity are complementary: constrained firms are specially likely to distort the risk profile of their most liquid investments.

Targeting Drp1 and mitochondrial fission for therapeutic immune modulation

Mitochondria are dynamic organelles whose processes of fusion and fission are tightly regulated by specialized proteins, known as mitochondria-shaping proteins. Among them, Drp1 is the main pro-fission protein and its activity is tightly regulated to ensure a strict control over mitochondria shape according to the cell needs. In the recent years, mitochondrial dynamics emerged as a new player in the regulation of fundamental processes during T cell life. Indeed, the morphology of mitochondria directly regulates T cell differentiation, this by affecting the engagment of alternative metabolic routes upon activation. Further, Drp1-dependent mitochondrial fission sustains both T cell clonal expansion and T cell migration and invasivness. By this review, we aim at discussing the most recent findings about the roles played by the Drp1-dependent mitochondrial fission in T cells, and at highlighting how its pharmacological modulation could open the way to future therapeutic approaches to modulate T cell response

Corporate Demand for Liquidity

This paper proposes a theory of corporate liquidity demand and provides new evidence on corporate cash policies. Firms have access to valuable investment opportunities, but potentially cannot fund them with the use of external finance. Firms that are financially unconstrained can undertake all positive NPV projects regardless of their cash position, so their cash positions are irrelevant. In contrast, firms facing financial constraints have an optimal cash position determined by the value of today’s investments relative to the expected value of future investments. The model predicts that constrained firms will save a positive fraction of incremental cash flows, while unconstrained firms will not. We also consider the impact of Jensen (1986) style overinvestment on the model’s equilibrium, and derive conditions under which overinvestment affects corporate cash policies. We test the model’s implications on a large sample of publicly-traded manufacturing firms over the 1981-2000 period, and find that firms classified as financially constrained save a positive fraction of their cash flows, while firms classified as unconstrained do not. Moreover, constrained firms save a higher fraction of cash inflows during recessions. These results are robust to the use of alternative proxies for financial constraints, and to several changes in the empirical specification. We also find weak evidence consistent with our agency-based model of corporate liquidity

Compactly Supported Wavelets Derived From Legendre Polynomials: Spherical Harmonic Wavelets

A new family of wavelets is introduced, which is associated with Legendre polynomials. These wavelets, termed spherical harmonic or Legendre wavelets, possess compact support. The method for the wavelet construction is derived from the association of ordinary second order differential equations with multiresolution filters. The low-pass filter associated with Legendre multiresolution analysis is a linear phase finite impulse response filter (FIR).Comment: 6 pages, 6 figures, 1 table In: Computational Methods in Circuits and Systems Applications, WSEAS press, pp.211-215, 2003. ISBN: 960-8052-88-

Fourier Eigenfunctions, Uncertainty Gabor Principle and Isoresolution Wavelets

Shape-invariant signals under Fourier transform are investigated leading to a class of eigenfunctions for the Fourier operator. The classical uncertainty Gabor-Heisenberg principle is revisited and the concept of isoresolution in joint time-frequency analysis is introduced. It is shown that any Fourier eigenfunction achieve isoresolution. It is shown that an isoresolution wavelet can be derived from each known wavelet family by a suitable scaling.Comment: 6 pages, XX Simp\'osio Bras. de Telecomunica\c{c}\~oes, Rio de Janeiro, Brazil, 2003. Fixed typo

Plantio de leguminosas arbóreas para produção de moirões vivos e construção de cercas ecológicas.

Os diferentes modelos de cercas utilizados nas propriedades rurais do Brasil. Justificativas para o uso de cercas de moirões vivos. Benefícios e vantagens do uso de leguminosas arbóreas na construção de cercas ecológicas. Custos de implantação mais baixos. Geração de produtos econômicos. Efeito estético, paisagístico e abrigo para os animais. Benefícios ecológicos. Fixação biológica de nitrogênio (FBN) associada às plantas. Aporte de biomassa e efeito sobre as forrageiras herbáceas. Uso como forragem. Durabilidade. Outros usos. Limitações para a adoção de leguminosas na construção de cercas ecológicas. Conhecendo a leguminosa arbórea Gliricidia sepium (Jacq.). Steud. Descrição botânica e características da espécie. Hsitórico e distribuição geográfica. Adaptação ambiental. Possibilidades para o Brasil. O uso da Gliricidia sepium como moirão vivo. Banco da multiplicação e produção de estacas de gliricidia. Construção das cercas ecológicas. Implantação da cerca. Fixação do arame. Manejo e tratos culturais. Composição química e descrição mineralógica da Gliricidia sepium. Produção de biomassa. Constituição química e influência na fertilidade do solo. Proteína bruta e digestibilidade in vitro. Outras espécies vegetais utilizadas na construção de cercas ecológicas. Leguminosas do gênero Erythrina. Utilização de outras espécies de leguminosas na cosntrução de cercas ecológicas. Espécies de outras famílias recomendadas para a implantação de cercas ecológicas. Análise sócio-econômica do uso de moirões vivos na construção de cercas ecológicas. Análise econômica da implantação e utilização dos diferentes modelos de cercas. Comercialização de estacas e moirões vivos. O ambiente de marketing do moirão vivo em relação à outros produtos utilizados na construção de cercas.bitstream/item/111693/1/CNPAB-SIST.-DE-PROD.-3-05.pd

Recuperação de voçorocas em áreas rurais.

Como recuperar uma voçoroca a baixo custo? Atividades necessárias antes da implantação das estratégias de controle de erosão. Implantação de estratégias físicas de controle da erosão. Determinação da declividade da área; Com nível retangular; Cálculo da distância entre os terraços; Demarcação e locação dos terraços; Com instrumentos alternativos; Com nível óptico; Determinação do escoamento superficial (Q); Dimensionamento das estruturas físicas; Terraços; Bacias de retenção; Paliçadas; Considerações sobre a forma da encosta ou morro; Revegetação de voçorocas com leguminosas arbóreas inoculadas com microrganismos; Por que utilizar espécies leguminosas? Quais espécies plantar? Preparo e plantio das mudas no campo; Custos de recuperação de uma voçoroca; Eficiência da metodologia de recuperação de voçorocas.bitstream/item/111696/1/CNPAB-Recuperacao-de-vocorocas-em-areas-rurais-SP.-06.pdfAutores: Roriz Luciano Machado, Alexander Silva de Resende, Eduardo Francia Carneiro Campello, Carlos Eduardo Gabriel Menezes, Caetano Marciano de Souza, Avílio Antônio Franco