Share the fame or share the blame? The reputational implications of partnerships

We use an adverse selection model to study the dynamics of firms' reputations when firms implement joint projects. We show that in contrast with projects implemented by a single firm, in the case of joint projects a firm's reputation does not necessarily increase following a success and does not necessarily decrease following a failure. We also study how reputation considerations affect firms ' decisions to participate in joint projects. We show that a high quality partner may not be preferable to a low quality partner, and that a high reputation partner is not necessarily preferable to a low reputation partner.

Differing phagocytic function of monocytes and neutrophils in Chagas' cardiopathy according to the presence or absence of congestive heart failure

We evaluated the in vitro phagocytic function and the production of microbicidal oxygen radicals by monocytes and neutrophils of 9 Chagas' heart disease subjects with heart failure and 9 without the syndrome in comparison with 11 healthy subjects, by assessing phagocytosis of Saccharomyces cerevisiae and NBT reduction by peripheral blood phagocytes. Phagocytic index of monocytes of chagasics without heart failure was significantly 6.7 and 10.6 times lower than those of controls and chagasics with the congestive syndrome, respectively, due to a lesser engagement in phagocytosis and to an inability of these cells to ingest particles. Neutrophils also show in chagasics without heart failure PI 11.2 and 19.8 times lower than that of controls and chagasics with heart failure, respectively. The percent of NBT reduction was normal and similar for the three groups. Balanced opposite effects of cardiovascular and immune disturbances may be acting in Chagas' disease subjects with heart failure paradoxically recovering the altered phagocytic function.

Primeiro relato de Lutzomyia cortelezzii (Brèthes, 1923) na cidade de Ilhéus, BA

A Lutzomyia cortelezzii foi encontrada na área urbana da cidade de Ilhéus, Bahia, Brasil. A aparição deste flebotomíneo em 100% das 288h de capturas no território ilheense é fato inédito. As coletas foram realizadas através de armadilhas luminosas tipo CDC, de dezembro/2003 a maio/2004, num total de 81 exemplares coletados.

Tendência temporal do tétano acidental no período de 1981 a 2004 em Pernambuco com avaliação do impacto da assistência em unidade de terapia intensiva sobre a letalidade

Apesar da redução na incidência de tétano acidental no Brasil, não houve queda significativa na letalidade. Nesta série de casos, comparamos a letalidade antes e após o estabelecimento padrão de manejo em unidade de terapia intensiva do paciente com tétano no Hospital Universitário Oswaldo Cruz, no período de 1981 a 2004. Em 24 anos, foram internados 1.971 pacientes e antes do manejo em Unidade de terapia intensiva a letalidade era de 35%. Durante 1997 foi instituída a unidade de terapia intensiva para assistência dos pacientes com tétano, e de 1998 a 2004, a letalidade caiu para 12,6%, OR= 0,27 (IC95%= 0,18- 0,39); p<0,001. Esta tendência foi evidenciada em todas as faixas etárias e em ambos os sexos. A centralização da assistência a esses pacientes em um único serviço especializado com Unidade de terapia intensiva de forma precoce, portanto, tem sido decisiva na redução da letalidade, por contar com a vasta experiência da equipe de saúde no manejo do tétano e melhor tratamento sintomático, antecipando as graves complicações da doença.

Urethral catheter removal 7 or 14 days after radical retropubic prostatectomy: clinical implications and complications in a randomized study

PURPOSE: To evaluate the hypothesis that a 7-day period of indwelling catheter after radical retropubic prostatectomy is effective and safe without the need of performing cystography. METHODS: In the period from January of 2000 to July of 2002, 73 patients underwent radical retropubic prostatectomy, and these patients were prospectively randomized in 2 groups: Group 1-37 patients who had the urethral catheter removed 7 days after the procedure, and Group 2-36 patients who had the catheter removed 14 days after the surgery. The 2 groups were similar, the surgeons and the technique were the same, and no cystography was performed to evaluate the presence of leaks. RESULTS: Two patients in Group 1 had bleeding and clot retention after having the catheter taken out in the seventh postoperative day and were managed by putting the catheter back in for 7 more days. Two patients in Group 2 developed bladder neck stricture and were treated by bladder neck incision with success. The continence rate was the same, with 2 cases of incontinence in each group. About 2 pads a day were used by the patients with incontinence. The average follow-up was 17.5 months (12-36 months). No urinary fistula, urinoma, or pelvic abscesses developed after catheter removal. Two patients were excluded from the analysis of this series: 1 died with a pulmonary embolus in the third postoperative day, and 1 developed a urinary suprapubic fistula before catheter withdrawal, which was maintained for 16 days. CONCLUSION: Withdrawal of the urethral catheter 7 days after radical retropubic prostatectomy, without performing cystography, has a low rate of short-term complications that are equivalent to withdrawal 14 days after the surgery.

The best infertility treatment for vasectomized men: assisted reproduction or vasectomy reversal?

In men with prior vasectomy, microsurgical reconstruction of the reproductive tract is more cost-effective than sperm retrieval with in vitro fertilization and intracytoplasmic sperm injection if the obstructive interval is less than 15 years and no female fertility risk factors are present. If epididymal obstruction is detected or advanced female age is present, the decision to use either microsurgical reconstruction or sperm retrieval with in vitro fertilization and intracytoplasmic sperm injection should be individualized. Sperm retrieval with in vitro fertilization and intracytoplasmic sperm injection is preferred to surgical treatment when female factors requiring in vitro fertilization are present or when the chance for success with sperm retrieval and intracytoplasmic sperm injection exceeds the chance for success with surgical treatment.

Modelos Mixtos-Aditivos Generalizados para el Estudio de Fenómenos Biológicos y Sociales Descriptos por Datos Agregados y/o Longitudinales. Generalized Mixed Additive Models for the Study of Biological and Social Phenomenons from Longitudinal and/or Aggregated Data.

Este proyecto propone extender y generalizar los procesos de estimación e inferencia de modelos aditivos generalizados multivariados para variables aleatorias no gaussianas, que describen comportamientos de fenómenos biológicos y sociales y cuyas representaciones originan series longitudinales y datos agregados (clusters). Se genera teniendo como objeto para las aplicaciones inmediatas, el desarrollo de metodología de modelación para la comprensión de procesos biológicos, ambientales y sociales de las áreas de Salud y las Ciencias Sociales, la condicionan la presencia de fenómenos específicos, como el de las enfermedades.Es así que el plan que se propone intenta estrechar la relación entre la Matemática Aplicada, desde un enfoque bajo incertidumbre y las Ciencias Biológicas y Sociales, en general, generando nuevas herramientas para poder analizar y explicar muchos problemas sobre los cuales tienen cada vez mas información experimental y/o observacional.Se propone, en forma secuencial, comenzando por variables aleatorias discretas (Yi, con función de varianza menor que una potencia par del valor esperado E(Y)) generar una clase unificada de modelos aditivos (paramétricos y no paramétricos) generalizados, la cual contenga como casos particulares a los modelos lineales generalizados, no lineales generalizados, los aditivos generalizados, los de media marginales generalizados (enfoques GEE1 -Liang y Zeger, 1986- y GEE2 -Zhao y Prentice, 1990; Zeger y Qaqish, 1992; Yan y Fine, 2004), iniciando una conexión con los modelos lineales mixtos generalizados para variables latentes (GLLAMM, Skrondal y Rabe-Hesketh, 2004), partiendo de estructuras de datos correlacionados. Esto permitirá definir distribuciones condicionales de las respuestas, dadas las covariables y las variables latentes y estimar ecuaciones estructurales para las VL, incluyendo regresiones de VL sobre las covariables y regresiones de VL sobre otras VL y modelos específicos para considerar jerarquías de variación ya reconocidas. Cómo definir modelos que consideren estructuras espaciales o temporales, de manera tal que permitan la presencia de factores jerárquicos, fijos o aleatorios, medidos con error como es el caso de las situaciones que se presentan en las Ciencias Sociales y en Epidemiología, es un desafío a nivel estadístico. Se proyecta esa forma secuencial para la construcción de metodología tanto de estimación como de inferencia, comenzando con variables aleatorias Poisson y Bernoulli, incluyendo los existentes MLG, hasta los actuales modelos generalizados jerárquicos, conextando con los GLLAMM, partiendo de estructuras de datos correlacionados. Esta familia de modelos se generará para estructuras de variables/vectores, covariables y componentes aleatorios jerárquicos que describan fenómenos de las Ciencias Sociales y la Epidemiología.

Defining the criteria for the evaluation of self-study multimedia language learning materials: do they facilitate or inhibit learner autonomy?

Durant els darrers anys, s’han publicat un gran nombre de materials multimèdia destinats a l’aprenentatge de llengües, la major part dels quals son CD-ROM dissenyats com a cursos per l’autoaprenentatge. Amb aquests materials, els alumnes poden treballar independentment sense l’assessorament d’un professor, i per aquest motiu s’ha afirmat que promouen i faciliten l’aprenentatge autònom. Aquesta relació, però, no es certa, com Phil Benson i Peter Voller 1997:10) han manifestat encertadament:(…) Such claims are often dubious, however, because of the limited range of options and roles offered to the learner. Nevertheless, technologies of education in the broadest sense can be considered to be either more or less supportive of autonomy. The question is what kind of criteria do we apply in evaluating them? En aquest article presentem una investigació conjunta on es defineixen els criteris que poden ser utilitzats per avaluar materials multimèdia en relació a la seva facilitat per permetre l’aprenentatge autònom. Aquests criteris son la base d’un qüestionari que s’ha emprat per avaluar una selecció de CD-ROM destinats a l’autoaprenentatge de llengües. La estructura d’aquest article és la següent: - Una introducció de l’estudi - Els criteris que s’han utilitzar per la creació del qüestionari - Els resultats generals de l’avaluació - Les conclusions que s’han extret i la seva importància pel disseny instructiu multimèdia

Marxism, social metabolism, and ecologically unequal exchange

Authors working on "industrial metabolism" or "social metabolism" look at the economy in terms of flows of energy and materials. Together with the ecological economists, they see the economy as a subsystem of a larger physical system. Marx and Engels followed with a few years’ delay many of the remarkable scientific and technical novelties of their time.

Wealth constraints, skill prices or networks: what determines emigrant selection?

The productive characteristics of migrating individuals, emigrant selection, affect welfare. The empirical estimation of the degree of selection suffers from a lack of complete and nationally representative data. This paper uses a new and better dataset to address both issues: the ENET (Mexican Labor Survey), which identifies emigrants right before they leave and allows a direct comparison to non-migrants. This dataset presents a relevant dichotomy: it shows on average negative selection for Mexican emigrants to the United States for the period 2000-2004 together with positive selection in Mexican emigration out of rural Mexico to the United States in the same period. Three theories that could explain this dichotomy are tested. Whereas higher skill prices in Mexico than in the US are enough to explain negative selection in urban Mexico, its combination with network effects and wealth constraints is required to account for positive selection in rural Mexico.

Inter-regional redistribution through infrastructure investment: tactical or programmatic?

In this paper we analyze the effects of both tactical and programmatic politics on the inter-regional allocation of infrastructure investment. We use a panel of data for the Spanish electoral districts during the period 1964-2004 to estimate an equation where investment depends both on economic and political variables. The results show that tactical politics do matter since, after controlling for economic traits, the districts with more ‘Political power’ still receive more investment. These districts are those where the incumbents’ Vote margin of victory/ defeat in the past election is low, where the Marginal seat price is low, where there is Partisan alignment between the executives at the central and regional layers of government, and where there are Pivotal regional parties which are influential in the formation of the central executive. However, the results also show that programmatic politics matter, since inter-regional redistribution (measured as the elasticity of investment to per capita income) is shown to increase with the arrival of the Democracy and EU Funds, with Left governments, and to decrease the higher is the correlation between a measure of ‘Political power’ and per capita income.

Clustering or scattering: the underlying reason for regulating distance among retail outlets

Concerns on the clustering of retail industries and professional services in main streets had traditionally been the public interest rationale for supporting distance regulations. Although many geographic restrictions have been suppressed, deregulation has hinged mostly upon the theory results on the natural tendency of outlets to differentiate spatially. Empirical evidence has so far offered mixed results. Using the case of deregulation of pharmacy establishment in a region of Spain, we empirically show how pharmacy locations scatter, and that there is not rationale for distance regulation apart from the underlying private interest of very few incumbents.