Does Opaqueness Make Equity Capital Expensive for Banks?

Bank managers often claim that equity is expensive, which contradicts the Modigliani-Miller irrelevance theorem. An opaque bank must signal its solvency by paying high and stable dividends in order to keep depositors tranquil. This signalling may require costly liquidations if the return on assets has been poor, but not paying the dividend might trigger a run. A strongly capitalized bank should keep substantial amounts of risk-free yet non-productive currency because the number of shares is high, which is costly. The dividend is informative of the state of the bank; rational depositors react to it.

Does uncertainty cause inertia in decision making? An experimental study of the role of regret aversion and indecisiveness

Previous research has shown that often there is clear inertia in individual decision making---that is, a tendency for decision makers to choose a status quo option. I conduct a laboratory experiment to investigate two potential determinants of inertia in uncertain environments: (i) regret aversion and (ii) ambiguity-driven indecisiveness. I use a between-subjects design with varying conditions to identify the effects of these two mechanisms on choice behavior. In each condition, participants choose between two simple real gambles, one of which is the status quo option. I find that inertia is quite large and that both mechanisms are equally important.

Risk, ambiguity, and diversification

Attitudes toward risk influence the decision to diversify among uncertain options. Yet, because in most situations the options are ambiguous, attitudes toward ambiguity may also play an important role. I conduct a laboratory experiment to investigate the effect of ambiguity on the decision to diversify. I find that diversification is more prevalent and more persistent under ambiguity than under risk. Moreover, excess diversification under ambiguity is driven by participants who stick with a status quo gamble when diversification among gambles is not feasible. This behavioral pattern cannot be accommodated by major theories of choice under ambiguity.

Unamuno sobre el hombre : naturaleza y cultura, vida trágica, en la educación.

Resumen del autor. Resumen en castellano y en inglés

"Pactionibus et stipulationibus". Contribución al estudio de la constitución de servidumbres prediales en el Derecho Romano clásico

Aquesta tesi doctoral té per objecte l'estudi de les "pactiones et stipulationes" com a mode de constitució inter vivos de les servituds predials, en el dret romà clàssic. La principal font que ens informa de la seva existència és Gai. 2, 31, segons la qual les pactiones et stipulationes serien el mecanisme generalment emprat per a la constitució de servituds i d'usdefruit a les províncies romanes. Aquest treball intenta ser una contribució a l'estudi d'aquest negoci constitutiu de drets reals, a partir d'una revisió de les fonts que s'allunyi de la tendència a considerar-les interpolades i ens permeti observar la intervenció del pretor en aquest camp, així com la precisa resposta dela jurisprudència clàssica, davant problemes com ara la trasnformació de les servituds en res incorporales i la progressiva decadència de la mancipatio i de la in iure cessio —agreujada per la impossibilitat d'adquisició d'aquests drets a través d'usucapio (lex Scribonia).

A study on the phylogeny and the ecology of ammonia-oxidizing bacteria using a new molecular marker based on the gene amoB

L'agricultura i la industrialització han causat un augment significatiu del nombre d'ambients rics en amoni. La presència de compostos nitrogenats redueix la qualitat de l'aigua, causant problemes de toxicitat, deteriorant el medi ambient i fins i tot afectant la salut humana. En conseqüència, la nitrificació s'ha convertit en un procés global que afecta al cicle del nitrogen a la biosfera. Els bacteris oxidadors d'amoni (AOB) són els responsables de l'oxidació de l'amoni a nitrit, i juguen un paper essencial en el cicle del nitrogen. Els primers oxidadors d'amoni foren aïllats a finals del segle XIX, però la lentitud del seu creixement i les dificultats per cultivar-los feren que fins als anys 80, amb els primers estudis emprant el gen 16SrDNA, no s'assolís un coneixement complert d'aquest grup bacterià. Actualment les bases de dades contenen multitud d'entrades amb seqüències corresponents a AOB. L'objectiu d'aquest treball era trobar, desenvolupar i avaluar eines útils i fiables per a l'estudi dels AOB en mostres ambientals. En aquest treball primer descrivim la utilització de la hibridació in situ amb fluorescència (FISH), mitjançant l'aplicació de sondes amb diana en el 16SrRNA dels AOB. La FISH ens va permetre detectar i recomptar aquest grup bacterià; no obstant, aquest mètode no permetia la detecció de noves seqüències, pel que es necessitava una nova eina. Amb aquesta intenció vam aplicar la seqüència de la sonda Nso1225 en una PCR. El fet d'amplificar específicament un fragment del 16SrDNA dels AOB va suposar el desenvolupament d'una nova eina molecular que permetia detectar la presència i diversitat d'aquests bacteris en ambients naturals. Malgrat tot, algunes seqüències pertanyents a bacteris no oxidadors d'amoni del subgrup β dels proteobacteris, eren també obtingudes amb aquesta tècnica. Així mateix, un dels inconvenients de l'ús del 16SrDNA com a marcador és la impossibilitat de detectar simultàniament els AOB que pertanyen als subgrups β i γ dels proteobacteris. El gen amoA, que codifica per la subunitat A de l'enzim amoni monooxigenasa (AMO), era aleshores àmpliament utilitzat com a marcador per a la detecció dels AOB. En aquest treball també descrivim la utilització d'aquest marcador en mostres procedents d'un reactor SBR. Aquest marcador ens va permetre identificar seqüències de AOB en la mostra, però la necessitat de detectar amoA mitjançant clonatge fa que l'ús d'aquest marcador requereixi massa temps per a la seva utilització com a eina en estudis d'ecologia microbiana amb moltes mostres. Per altra banda, alguns autors han assenyalat l'obtenció de seqüències de no AOB en utilitzar amoA en un protocol de PCR-DGGE. Amb la finalitat d'obtenir una eina ràpida i rigorosa per detectar i identificar els AOB, vam desenvolupar un joc nou d'oligonucleòtids amb diana en el gen amoB, que codifica per a la subunitat transmembrana de l'enzim AMO. Aquest gen ha demostrat ser un bon marcador molecular pels AOB, oferint, sense tenir en compte afiliacions filogenètiques, una elevada especificitat, sensibilitat i fiabilitat. En aquest treball també presentem una anàlisi de RT-PCR basada en la detecció del gen amoB per a la quantificació del gènere Nitrosococcus. El nou joc d'oligonucleòtids dissenyat permet una enumeració altament específica i sensible de tots els γ-Nitrosococcus coneguts. Finalment, vam realitzar un estudi poligènic, comparant i avaluant els marcadors amoA, amoB i 16SrDNA, i vàrem construir un arbre filogenètic combinat. Com a resultat concloem que amoB és un marcador adequat per a la detecció i identificació dels AOB en mostres ambientals, proporcionant alhora agrupacions consistents en fer inferències filogenètiques. Per altra banda, la seqüència sencera del gen 16S rDNA és indicada com a marcador en estudis amb finalitats taxonòmiques i filogenètiques en treballar amb cultius purs de AOB.

A importância da marca no Turismo : o Rebranding do Sana Sesimbra Hotel 4****

A dinâmica do mercado actual em constante mutação torna-o cada vez mais exigente, obrigando as empresas a acompanhar de forma constante todas estas mudanças rápidas e muitas vezes inesperadas. É neste contexto que a questão do valor da marca se torna essencial para as organizações. De forma a criar uma imagem positiva na mente dos consumidores é necessária uma gestão rigorosa da marca, cabendo aos gestores a responsabilidade de criar uma estratégia de posicionamento tendo como base a oferta de um benefício junto de todos os seus públicos-alvo, cumprindo sempre uma promessa. A marca é assim um sinal que pode representar um benefício ou uma missão de determinada empresa, distinguindo os seus produtos e serviços das empresas concorrentes. A presente dissertação expõe a concepção de um projecto real de desenvolvimento e implementação de uma estratégia de reposicionamento levada a cabo por uma organização ligada à hotelaria, tendo como objectivo a sua avaliação crítica. Esta será analisada através de apoio bibliográfico sobre a temática assim como através de entrevistas realizadas aos responsáveis do grupo e documentos por eles fornecidos. De forma a contornar a limitação do estudo sobre a impossibilidade de reunir dados primários por conta da autora, colaboradora na empresa em estudo, será analisado um site através do qual se poderá observar o grau de satisfação dos clientes antes e depois da implementação da nova estratégia. Este estudo permitirá concluir se a implementação está a ser realizada de forma correcta e de que forma poderão ser corrigidas posteriormente as anomalias ou melhorados alguns aspectos.

Natureza Humana em Thomas Hobbes e Hans Morgenthau

O artigo discute a conceção de natureza humana presente na obra de Hans Morgenthau (1904-1980) a partir de seu clássico. A Política entre as Nações: a luta pelo poder e pela Paz, debatendo o seu papel para o conjunto de sua teoria. Aqui se discutem as diferenças entre esta conceção de Morgenthau e a de Thomas Hobbes, na qual se inspira, e as consequências disso para a relação entre Estado, sociedade e entre os próprios Estados na esfera internacional. Discute também a ligação dessa ontologia para o campo das relações internacionais, ligando ao debate da impossibilidade do Estado Mundial e sobre o fenómeno do equilíbrio de poder, na esferadoméstica e no cenário internacional.

Jorge Carrera Andrade, poeta del hombre (Estudios)

El autor lee a Carrera Andrade como un creador surgido en el quiebre de los presupuestos, ideologías y esperanzas del siglo XIX e inicios del XX, más plagado de incertidumbres que de certezas. Acaso el rasgo autobiográfico de su poesía, y su apego a una temática múltiple –no apartada nunca del desciframiento de los sentidos de lo pequeño– han oscurecido la intención del autor de reflexionar sobre la condición y el destino del hombre moderno. Cercano al existencialismo, en tanto filosofía develadora de la fragilidad y soledad humanas, de la futilidad de sus construcciones intelectuales, Carrera fue testigo –en un siglo de confrontaciones– «de la fealdad triunfante y la libertad encadenada». El poeta describe tres atributos definitorios del hombre moderno: soledad, imposibilidad de ser libre, y su condición de desterrado. Plantea Carrera que estas condiciones ontológicas de soledad y de ser prisionero no se agotarían en el hombre, sino que conformarían también a otros seres y objetos del universo. El destierro aludiría no solo a la condición literal del exiliado, sino también a la ausencia de un hogar espiritual, aunque, en relación a este punto, parece arribar a una cierta conciliación mediante la idea de que es posible trascender la finitud del individuo en la pervivencia de la humanidad entera –destino común el del «hombre planetario», cantado por el poeta a pesar de su soledad y sus prisiones.

La historia de Nay y Sinar de Jorge Isaacs y Sab de Gertrudis Gómez de Avellaneda: un contrapunto (Dossier: Novela, historia y nación en América Latina)

En este texto el autor se propone cotejar la historia de Nay y Sinar incluida en la novela María, de Jorge Isaacs (1867), con la de Bernabé en Sab (publicada en Madrid en 1841), de Gertrudis Gómez de Avellaneda. Esta exploración busca, por un lado, crear un contrapunto de ambos textos, por otro lado, se propone pasar revista a temas como la construcción de lo masculino en los dos textos, la posición antiesclavista de las mismas y Madre Natura como antagonista y coadyuvante de los protagonistas. Para cerrar este trabajo el autor aplicará un par de ideas de Benedict Anderson intentando explicar lo siguiente: los personajes de Isaacs y Gómez de Avellaneda provienen de una comunidad imaginada perdida y se ven en la imposibilidad de reproducir en un contexto diferente los límites de ese reino que ya no existe o que quizá no existió, por ser parte de la imaginación comunitaria.

Unimodality of wave amplitude in the northern Hemisphere

A novel statistic for local wave amplitude of the 500-hPa geopotential height field is introduced. The statistic uses a Hilbert transform to define a longitudinal wave envelope and dynamical latitude weighting to define the latitudes of interest. Here it is used to detect the existence, or otherwise, of multimodality in its distribution function. The empirical distribution function for the 1960-2000 period is close to a Weibull distribution with shape parameters between 2 and 3. There is substantial interdecadal variability but no apparent local multimodality or bimodality. The zonally averaged wave amplitude, akin to the more usual wave amplitude index, is close to being normally distributed. This is consistent with the central limit theorem, which applies to the construction of the wave amplitude index. For the period 1960-70 it is found that there is apparent bimodality in this index. However, the different amplitudes are realized at different longitudes, so there is no bimodality at any single longitude. As a corollary, it is found that many commonly used statistics to detect multimodality in atmospheric fields potentially satisfy the assumptions underlying the central limit theorem and therefore can only show approximately normal distributions. The author concludes that these techniques may therefore be suboptimal to detect any multimodality.

Beurling zeta functions, generalised primes, and fractal membranes

We study generalised prime systems P (1 < p(1) <= p(2) <= ..., with p(j) is an element of R tending to infinity) and the associated Beurling zeta function zeta p(s) = Pi(infinity)(j=1)(1 - p(j)(-s))(-1). Under appropriate assumptions, we establish various analytic properties of zeta p(s), including its analytic continuation, and we characterise the existence of a suitable generalised functional equation. In particular, we examine the relationship between a counterpart of the Prime Number Theorem (with error term) and the properties of the analytic continuation of zeta p(s). Further we study 'well-behaved' g-prime systems, namely, systems for which both the prime and integer counting function are asymptotically well-behaved. Finally, we show that there exists a natural correspondence between generalised prime systems and suitable orders on N-2. Some of the above results are relevant to the second author's theory of 'fractal membranes', whose spectral partition functions are given by Beurling-type zeta functions, as well as to joint work of that author and R. Nest on zeta functions attached to quasicrystals.

Force constants and dipole moment derivatives of molecules from perturbed Hartree-Fock calculations II. Applications to limited basis set SCF-MO wavefunctions

The perturbed Hartree–Fock theory developed in the preceding paper is applied to LiH, BH, and HF, using limited basis‐set SCF–MO wavefunctions derived by previous workers. The calculated values for the force constant ke and the dipole‐moment derivative μ(1) are (experimental values in parentheses): LiH, ke  =  1.618(1.026)mdyn/Å,μ(1)  =  −18.77(−2.0±0.3)D/ÅBH,ke  =  5.199(3.032)mdyn/Å,μ(1)  =  −1.03(−)D/Å;HF,ke  =  12.90(9.651)mdyn/Å,μ(1)  =  −2.15(+1.50)D/Å. The values of the force on the proton were calculated exactly and according to the Hellmann–Feynman theorem in each case, and the discrepancies show that none of the wavefunctions used are close to the Hartree–Fock limit, so that the large errors in ke and μ(1) are not surprising. However no difficulties arose in the perturbed Hartree–Fock calculation, so that the application of the theory to more accurate wavefunctions appears quite feasible.

Molecular inventory of faecal microflora in patients with Crohn's disease

Intestinal microbial community is involved in the pathogenesis of Crohn's disease, but knowledge of its potential abnormalities has been limited by the impossibility to grow many dominant intestinal bacteria. Using sequence analysis of randomly cloned bacterial 16S ribosomal DNA, the dominant faecal species from four Crolin's disease patients and four controls were compared. Whereas marked inter-individual differences were observed in the faecal microflora of patients, three remained distantly related to controls on the basis of their operational taxonomic unit composition. Bacteroides vidgatus and closely related organisms represented the only molecular species shared by all patients and exhibited an unusually high rate of occurrence. Escherichia coli clones were isolated only in two patients with ileocolonic Crohn's disease. Moreover, numerous clones belonged to phylogenetic groups or species that are commonly not dominant in the faecal microflora of healthy subjects: Pectinatus, Sutterella, Verritcomicrobium, Fusobacterium, Clostridium disporicum, clostridium glycolicum, Clostridium ramosum, Clostridium innocuum and Clostridium perfringens. (C) 2004 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.

A statistical mechanical approach for the computation of the climatic response to general forcings

The climate belongs to the class of non-equilibrium forced and dissipative systems, for which most results of quasi-equilibrium statistical mechanics, including the fluctuation-dissipation theorem, do not apply. In this paper we show for the first time how the Ruelle linear response theory, developed for studying rigorously the impact of perturbations on general observables of non-equilibrium statistical mechanical systems, can be applied with great success to analyze the climatic response to general forcings. The crucial value of the Ruelle theory lies in the fact that it allows to compute the response of the system in terms of expectation values of explicit and computable functions of the phase space averaged over the invariant measure of the unperturbed state. We choose as test bed a classical version of the Lorenz 96 model, which, in spite of its simplicity, has a well-recognized prototypical value as it is a spatially extended one-dimensional model and presents the basic ingredients, such as dissipation, advection and the presence of an external forcing, of the actual atmosphere. We recapitulate the main aspects of the general response theory and propose some new general results. We then analyze the frequency dependence of the response of both local and global observables to perturbations having localized as well as global spatial patterns. We derive analytically several properties of the corresponding susceptibilities, such as asymptotic behavior, validity of Kramers-Kronig relations, and sum rules, whose main ingredient is the causality principle. We show that all the coefficients of the leading asymptotic expansions as well as the integral constraints can be written as linear function of parameters that describe the unperturbed properties of the system, such as its average energy. Some newly obtained empirical closure equations for such parameters allow to define such properties as an explicit function of the unperturbed forcing parameter alone for a general class of chaotic Lorenz 96 models. We then verify the theoretical predictions from the outputs of the simulations up to a high degree of precision. The theory is used to explain differences in the response of local and global observables, to define the intensive properties of the system, which do not depend on the spatial resolution of the Lorenz 96 model, and to generalize the concept of climate sensitivity to all time scales. We also show how to reconstruct the linear Green function, which maps perturbations of general time patterns into changes in the expectation value of the considered observable for finite as well as infinite time. Finally, we propose a simple yet general methodology to study general Climate Change problems on virtually any time scale by resorting to only well selected simulations, and by taking full advantage of ensemble methods. The specific case of globally averaged surface temperature response to a general pattern of change of the CO2 concentration is discussed. We believe that the proposed approach may constitute a mathematically rigorous and practically very effective way to approach the problem of climate sensitivity, climate prediction, and climate change from a radically new perspective.