Dividend Signaling and Unions

Dividend signaling models suggest that dividends are used to convey information about future earnings to investors. However, in a world where unions also receive these signals, managers are less inclined to send the signal in order to avoid the union capturing these future earnings through higher salaries. Using information from IRS 5500 Forms to measure firm level unionization, I found that the power of dividends as predictors of future earnings tends to be higher for non-unionized firms. Moreover, I use the variation at the state level in the adoption of right-to-work laws to overcome the possible endogeneity of unionization with an instrumental variables approach. The empirical results are robust to different specifications and time periodsDividends; Signaling; Unions

Corporate finance in general equilibrium models with incomplete markets: a survey

A Masters Thesis, presented as part of the requirements for the award of a Research Masters Degree in Economics from NOVA – School of Business and EconomicsThis is a survey of models of general equilibrium with incomplete markets and corporations. The intuition behind several of the difficulties that arise in these models is discussed. Interesting issues are pointed out also

Incorporación de nanotubos de carbono en estructuras metal-orgánicas para el almacenamiento de hidrógeno

209 páginas. Maestría en Ciencias e Ingeniería de Materiales.En nuestros días el almacenamiento de hidrógeno sigue siendo una limitante para aprovechar todo el potencial que tiene este recurso en producir energía limpia, en respuesta a ello, esta investigación se enfoca en la utilización de los nanotubos de carbono y las estructuras metal-orgánicas como alternativas, ya que ambos presentan excelentes capacidades de adsorción de hidrógeno. En esta tesis se propuso aprovechar dos de los materiales más prometedores tecnológicamente en la adsorción física de hidrógeno; los nanotubos de carbono y las estructuras metal-orgánicas, creando un material híbrido que logre acercarse a los requerimientos del Departamento de Energía de los Estados Unidos para su aplicación. Para lograrlo se sintetizaron por la vía solvotermal materiales compósitos basados en nanotubos de carbono incorporados in situ en MOFs(FeBTC, HKUST-1, y MOF-177). Este trabajo logró avances muy importantes en cuanto a la modificación de las MOFs mejorando sus propiedades texturales y morfológicas del material y así promover su aplicación tanto en procesos de adsorción como en otros campos de aplicación. En este proyecto de investigación se obtuvieron resultados muy interesantes en cuanto a las capacidades de adsorción de hidrógeno siendo 27.4 % mayores a los reportados en la literatura para la HKUST-1 y 54% para la MOF-177, también se logró observar mediante estudios de adsorción como el calor isostérico de adsorción aumenta cuando se le incorporan los nanotubos a las MOF, demostrando que la incorporación de estas nanoespecies crean nuevos sitios de mejor interacción. Además, la incorporación de estas nanoestructuras de carbono en todas las MOFs logró aumentar su estabilidad térmica hasta en 100°C para la FeBTC, lo cual abre una posibilidad para su utilización en otros campos como la catálisis y otras aplicaciones donde la estabilidad del material lo limitaba. Intentar explicar los resulados a nivel microscópico nos llevo a estudiar el comportamiento de una MOF (HKUST-1) mediante estudios teóricos de DFT en VASP, esto con el objetivo de entender como interactúan las moléculas del gas con las MOF y la posibilidad de que los NTC´s interactúen con está. Parte de la información obtenida de los estudios teóricos logró corroborar lo obtenido de los estudios de la adsorción de hidrógeno a presiones moderadas, utilizando el sistema de espectroscopia Raman in situ mediante el uso de una celda construida en nuestro laboratorio.The hydrogen storage is still a limiting factor to exploit the full potential of this resource in producing clean energy. In response, this research focuses on the use of carbon nanotubes and metal-organic frameworks as promising materials because they present excellent hydrogen adsorption capacities. In this thesis it was proposed to take advantage of two of the most technologically promising materials in the physical adsorption of hydrogen; Multi-walled carbon nanotubes and metal-organic frameworks, creating an composite material that archieves to gather the requirements published by Department of Energy for its application The incorporation of carbon nanotubes in the metal-organic frameworks will increase the adsorption capacity of the MOF. To achieve were synthetized by the solvotermal route composite materials based on carbon nanotubes incorporated in situ in MOFs (FeBTC, MOF-177 and HKUST-1). This work achieved very important advances in the modification of the MOFs improving its textural and morphological properties of the material, so that promote its application in both adsorption processes and other fields of application. In this research project, very interesting results were obtained in terms of hydrogen adsorption capacities, being 27.4% higher than those reported in the literature for HKUST-1 and 54% for MOF-177. It was also observed how the adsorption isosteric heat increases when the nanotubes are incorporated in the MOF, demonstrating that the incorporation of these nanospecies creates new sites of better interaction. On the other hand, the incorporation of carbon nanostructures in all MOFs to increase their thermal stability up to 100 ° C for FeBTC, which opens up a possibility for their use in other fields such as catalysis and other applications where the stability of material is limited. In the results at a microscopic level, we studied the behavior of a MOF (HKUST-1) through theoretical studies of DFT in VASP, with the aim of understanding how the gas molecules interact with the MOF and the possibility that NTC's interact with this. Part of the information obtained by the theoretical studies was corroborated through the studies of hydrogen adsorption at moderate pressures, using in situ Raman spectroscopy system by using a quartz cell constructed in our laboratory.Consejo Nacional de Ciencia y Tecnología (México)

Improving water solubility of natural antibacterials to inhibit important bacteria in meat products

AbstractThe use of natural antimicrobial compounds, such as cinnamic acid and its phenolic derivatives, may help prevent survival of Escherichia coli O157:H7 and other pathogenic bacteria in foods. The limitation of the widespread use of these acids is their low solubility in water systems. Therefore the objective of this work was to evaluate the impact of the concentration of soluble salts of hydroxycinnamic acids on the viability of E. coli O157:H7 and S. Gallinarum. The solubility enhancement of the compounds at pH 7 could bring important consequences, since, for instance, the majority of outbreaks involving E. coli O157:H7 have been caused by the ingestion of meat and lacteous derivatives that present nearly neutral pH. Also, experimental errors in the evaluation of inhibitory concentrations may be prevented, avoiding lack of solubility of phenolic acids and their tendency to precipitate during incubation of media. Morphological changes on ultrastructure of E. coli O157:H7 was analyzed using transmission electron microscopy. Sodium salts of ferulic and p-coumaric acids were prepared and tested against E. coli O157:H7 in concentrations of 0.2, 0.4, 0.6, 0.8 and 1% in trypticase soy medium at pH 7. A bacteriostatic and/or bactericidal effect was also concentration-dependent. A bactericidal effect was found at concentrations of 0.8 and 1%, a bacteriostatic effect at the intermediate concentration of 0.6%, and an almost normal growth at the lowest concentrations of 0.2 and 0.4% showing their potential to be used as pathogen inhibitors

Estado estructural actual del Reservorio “Los Gemelos” ubicado en el Cerro Pesqueda del distrito de Trujillo, provincia de Trujillo – departamento La Libertad, 2023

En la presente tesis titulada “Estado estructural actual del Reservorio “Los Gemelos” ubicado en el Cerro Pesqueda del distrito de Trujillo, provincia de Trujillo – departamento La Libertad, 2023” se realizó con el objetivo de determinar el estado estructural actual que presenta el Reservorio “Los Gemelos” ubicado en el Cerro Pesqueda y comprobar si dicho reservorio se encuentra o no en un óptimo estado estructural.Tesi

Patient analysis and case-control investigation for high-output ileostomy control with glucagon (PACIFHIC-G) like peptide-1 analogues: a case control study

Background: High ostomy losses (HOL) in the early postoperative (PO) period after an ileal resection are in an adaptation phase. After resection of the terminal ileum or proximal colon L cells are lost, this reduces the synthesis of glucagon-like peptide (GLP), its loss accelerates intestinal transit and gastric acid hypersecretion. An adequate adaptation phase is induced by enterotrophic hormones such as GLP. In this case control study, we performed an analysis of clinical outcomes with a conventional treatment compared with liraglutide intervention, a GLP-1 analogue. Methods: A single center, case-control study, from January 2021 to April 2023, patients had an ileal resection >20 cm, >18 years old, previously treated with loperamide 12 mg and omeprazole 80 mg, continued >1500 ml output at 48 hours PO, 30 patients where collected, 15 patients followed with a watch and wait approach and 15 patients treated 0.6 mcg of liraglutide every day for 8 weeks. Results: Clinical outcomes were followed for 6 months. Centimeters of resection had a statistically significant difference p<0.001 (control 20-180 cm vs. liraglutide 20-330 cm). Clinical outcomes with a significant difference where hospital length stay p<0.01 (control 4-133 days vs. 1-51 days) and hypovolemic shock p<0.05 (control 5 patients vs. 0 patients). Kaplan-Meier curve an 80% vs 100% 30 day survival rate in controls and liraglutide respectively. Conclusions: This is the first study with patients with HOL using liraglutide as an adaptation therapy. Patients had better clinical outcomes in mortality, length stay and hypovolemic shock

Portfolio Substitution and the Revenue Cost of Exempting State and Local Government Interest Payments from Federal Income Tax

This paper explores how alternative assumptions about household portfolio behavior affect estimates of the revenue cost of excluding state and local government interest payments from the federal income tax base. Standard tax expenditure estimates assume that current holders of tax-exempt bonds would replace their holdings of tax-exempt bonds with taxable bonds if the tax exemption were eliminated. We consider a number of alternative possible portfolio responses. Because taxable bonds are among the most heavily taxed assets, assuming that investors holding tax-exempt bonds would otherwise hold taxable bonds yields a larger estimate of the revenue cost of tax exemption than many alternative assumptions. Based on data from the 2004 Survey of Consumer Finances, we estimate that the revenue cost of tax exemption under the "taxable bond substitution hypothesis" is $14.2 billion, compared with$10.1 billion if corporate stock replaces tax-exempt bonds in household portfolios, and $7.9 billion if investors distribute their tax-exempt bond holdings in proportion to the other assets currently in their portfolios. We also explore the revenue effects of capping the dollar amount of tax-exempt interest per tax return and of limiting tax-exempt interest as a fraction of AGI.

Dividend Signaling and Unions

Dividend signaling models suggest that dividends are used to convey information about future earnings to investors. However, in a world where unions also receive these signals, managers are less inclined to send the signal in order to avoid the union capturing these future earnings through higher salaries. Using information from IRS 5500 Forms to measure firm level unionization, I found that the power of dividends as predictors of future earnings tends to be higher for non-unionized firms. Moreover, I use the variation at the state level in the adoption of right-to-work laws to overcome the possible endogeneity of unionization with an instrumental variables approach. The empirical results are robust to different specifications and time period

Tax Incentives and Business Investment: New Evidence from Mexico

This paper provides new evidence on the response of business investment to tax incentives. I use the variation provided by recent reforms to the Mexican corporate tax system, including the elimination and reintroduction of accelerated depreciation allowances applicable to investment undertaken outside the three main Mexican metropolitan areas. I show that investment is very sensitive to changes in tax variables and interest rates, with an estimated elasticity of investment with respect to the user cost around -2.0. The results are robust to different specifications and instrumental variables approaches. The large elasticity is shown to be the result of the large cross sectional variation in the user cost of capital and also a product of the small open economy nature of the Mexican economy. In particular, large investment responses of plants owned by multinational firms and a elasticity of imported assets considerably larger than that of domestically purchased goods. Furthermore, the use of panel data at the establishment level allows me to identify the discrete nature of investment decisions and to show that the capital accumulation pattern is consistent with nonconvex adjustment costs and irreversibilities, similar to those found for the US. Thus, the large elasticity compared to US estimates cannot be attributed to differences in adjustment costs. Finally, I provide evidence that the large investment response is not an artifact of misreporting or tax evasion since the elasticity of investment in other assets such as transportation equipment and land, which is harder to misreport, is also high

Efecto del potencial redox en la oxidación anaerobia de compuestos fenólicos por un lodo desnitrificante

En el presente trabajo se explora el efecto de la adición de tres quinonas: menadiona, alizarina y antraquinona-2,6-disulfonato, a diferentes concentraciones (0 a 2 mM), en el proceso desnitrificante con p-cresol. Los resultados muestran que cuando se adicionó menadiona, se afectó la eficiencia de consumo de substratos principalmente. En todos los casos los rendimientos para nitrógeno molecular y carbono inorgánico se mantuvieron alrededor de 0.9. En presencia de alizarina y menadiona, en comparación con los controles sin quinonas, las velocidades específicas de consumo para nitrato y p-cresol decrecieron en un 40 y 90 % respectivamente. El inoculo previamente expuesto a las quinonas fue utilizado en ensayos de recuperabilidad de la actividad desnitrificante usando p-cresol y acetato como fuentes de carbono. Para los inóculos que estuvieron expuestos a la antraquinona-2,6-disulfonato y a la alizarina, la actividad desnitrificante fue totalmente recuperada con ambas fuentes de carbono. Sin embargo, el lodo expuesto a diferentes concentraciones de menadiona casi no recuperó su actividad. En un intento en tratar de entender los mecanismos involucrados por medio de los cuales las quinonas participan en el proceso desnitrificante, se encontró que la menadiona y la alizarina presentan efectos inhibitorios muy marcados en el proceso desnitrificante, mientras que la antraquinona-2,6- disulfonato no presentó efecto alguno. Los resultados sugieren que la menadiona modifica el sistema de transporte de substratos y la alizarina afecta algunas enzimas desnitrificantes mediante la formación de complejos con el molibdeno. Un modelo basado en los potenciales de óxido-reducción de la ruta desnitrificante y la primera parte de la oxidación de p-cresol, sugiere que los efectos observados por la adición de quinonas parecen estar más asociados a propiedades estructurales de las moléculas de quinona e hidrofobicidad, que a su capacidad de óxido-reducción. Para entender mejor el papel que juega el potencial de óxido-reducción de las quinonas en la desnitrificación organotrófíca, se estudió el efecto de tres potenciales eléctricos (PE), correspondientes a los potenciales de óxido reducción de cada una de las quinonas ensayadas (-187 mV, -279 mV y +104 mV). Se observó que el inoculo desnitrificante tuvo la capacidad de oxidar el p-cresol con la aplicación de los tres EP, en ausencia de cualquier aceptor final de electrones, incluyendo el nitrato. Sin embargo, a cualquiera de los EP ensayados, el lodo fue incapaz de desnitrificar en ausencia de algún donador de electrones. En el proceso desnitrificante con p-cresol, la aplicación de los EP, provocó el desacoplamiento de los procesos oxidativo y reductivo, favoreciendo la oxidación de materia orgánica por encima de la reducción de nitrato. Adicionalmente se observaron efectos a nivel de ruta bioquímica. A potenciales de - 279mV y +104mV, el consumo de nitrato y nitrito se afectó, así como, la transformación de p-hidroxibenzoato. Aunque, a -187 mV, parece solo haber efectos a nivel de transporte de substratos. Se presenta evidencia de que la aplicación de los diferentes EP, tiene efectos característicos sobre el proceso desnitrificante, que no son comparables entre sí. Lo anterior confirma que el potencial de óxido-reducción de las quinonas no es quien gobierna los efectos observados por la adición de menadiona, alizarina y antraquinona-2,6- disulfonato en el proceso desnitrificante con p - cresol.Denitrification using p-cresol as electron source was studied in the presence of three quinones, menadione, alizarine and anthraqui none-2,6-disulfonate, at different molar concentrations (O to 2 mM). Results showed that substrates consumption efficiency was mainly affected when menadione was present. In all cases the yield for N 2 and inorganic carbon values remained around 0.9. In pr esence of alizarine and menadione specific consumption rates for p-cresol and nitrate decreased 40% and 90% (for both substrates), compared to controls not exposed to quinones. The sludge previously exposed to quinones was submitted to recovering denitrifying studies using acetate and p-cresol. After exposing to anthraquinone-2,6-disulfonate and alizarine with p-cresol and acetate, the metabolic activity of denitrifying sludge was completely recovered, but previous exposition at any menadione concentration resulted in a very low metabolic recuperation. An attempt in elucidating the underlying mechanisms in which the quinones function in the denitrification, shown that menadione and alizarine can have a marked inhibitory effect on denitrifying process and AQDS no effect at all. The results suggested that menadione modify the transport system and alizarine affected some denitrifying enzymes by complexing the molybdenum. A model based on oxido-reduction potentials of the enzymes implied in denitrifying pathway and p-cresol oxidation suggested that the effect of quinones on the denitrification process appears to be more associated to quinone moiety structural properties and hydrophobicity than to their oxidative-reductive capacity. In order to better understand the effect of oxido-reduction potential of quinone s in organotrophic denitr ification, the effect of the application of three electric potentials (EP) (-187 mV, -279 mV and +104 mV) on a denitrifying process was explored. It was observ ed that the denitrifying sludge was able to support the oxidation of p-cresol with the application of the EP in the absence of nitrate, but it was unable to drive the denitrification without an electron donor. On denitrification, the applied EP uncoupled the oxidative from the reductive process, favoring the p-cresol oxidation over the production of N 2 -Additionally effects at biochemical level were observed. At potentials of -279 and +104 mV, the nitrate and nitrite consumption was affected as well as the transformation of p- hydroxybenzoate. However, at -187 mV, effects seemed to occur only on transport of substrates. Evidence that denitrification had very characteristic and different physiological behaviors for each EP assayed are presented, confirming that the oxido-reduction potential of the quinones is not who governs the effects observed on the organogtrophic denitrifying process with p-cresol