REVISION DE LA FAMILIA ROPALOMERIDAE (DIPTERA) EN MEXICO

A taxonomic revisión of the family Ropalomeridae is presented, based on the analysis of specimens from 14 States of México. R. latiforceps sp. nov. is described with specimens from México and Panamo, R. xanthops Williston is synonymized with Ropalomera femorata (Fabricius), and Lenkokroeberia chryserea Prado is recorded by the first time for the country. In addition, we provide new data on the distribution of Willistoniella pleuropunctata (Wiedemann), Kroeberia fuliginosa Lindner, and Mexicoa mexicana Steyskal. Distinguishing characters for all known genera and species are keyed and illustrated.Se hace un estudio taxonómico de la familia Ropalomendae basado en el análisis de material procedente de 14 estados de México. Se describe Ropalomera latiforceps sp. nov. con material de México y Panamá, R. xanthops Williston es sinonimizada con Ropalomera femorata (Fabricius), y por primera ocasión en el país se registra a Lenkokroeberia chryserea Prado. Además se provee nueva información sobre la distribución de Willistoniella pleuropunctata (Wiedemann), Kroeberia fuliginosa Lindner, y Mexicoa mexicana Steyskal. Los caracteres distintivos de cada una de las especies citadas son ilustrados y se anexa una clave para su separación

Ruby Xenocrystals in Dacite from Central Mexico

The occurrence of 1-2 cm in diameter, anhedral xenocrystals of red corundum (ruby) in a dacitic lava- flow from central Mexico -in the state of Hidalgo- has been recorded. Geochemically, this dacite nearly resembles adakitic rock (SiO2=63.73 66.64 wt %), with low alumina contents (Al2O3=14.38 14.93 wt %), sodium (Na2O=3.29 3.57wt %) and titanium (TiO2=0.55 0.60 wt %), slightly peraluminous (A/ CNK=1.04 1.17) and moderately potassic (K2O=1.90-2.04 wt %; K2O/Na2O=0.53-0.62), with rare earth spectra enriched in light-rare earth elements (La/Yb)N=9.71 10.98. The origin of the dacite is linked to the early geological evolution of the eastern sector of the Trans-Mexican Volcanic Belt (TMVB) during the Miocene, and its provenance could be a melt of a basaltic and pelitic-sediments slab and magmatic differentiation that generated adakitic magma. The gem-type corundum could have resulted after the addition of refractory products disaggregated from the Precambrian basement, carried, and transported to the surface by ascending magma

Análisis de la disponibilidad a pagar por carne de cerdo libre de antibióticos, un enfoque de Experimentos de Elección

Health issues and the production of differentiated foods influence the consumers' decisions and lead them to opt for products with particular organoleptic characteristics. The objective of this research was to estimate the preferences and willingness to pay for antibiotic-free pork in the municipality of Texcoco, State of Mexico, in order to determine the existence or absence of an incentive for the commercialization of antibiotic-free pork. The Discrete Choice Method of Experiments was used. The attributes considered in the design were: color, fat content, and presence of antibiotics. A survey of 196 consumers was carried out for this purpose. The results were analyzed with the NLOGIT 4.0 software, using a mixed logit model. The most valued attribute was antibiotic content, which means that respondents would be willing to pay an additional premium of $30.65 MXN/kg for antibiotic-free pork. It was found that the higher the income and the higher the frequency of pork consumption, the greater the willingness to pay an additional premium for antibiotic-free meat. A WTP of$5.78 MXN was determined for meat with normal fat, and of $3.73 MXN for red meat. Pork consumers in the eastern part of the State of Mexico would be willing to pay an additional premium for antibiotic-free pork and for such quality aspects as fat content and color.Los problemas de salud y la producción de alimentos diferenciados influyen en las decisiones de los consumidores y los orienta a optar por productos con características organolépticas particulares. El objetivo de esta investigación fue estimar las preferencias y disposición a pagar por carne de cerdo libre de antibióticos en el municipio de Texcoco, Estado de México, para determinar la existencia o no de un incentivo para la comercialización de carne de este tipo. Se utilizó el Método de Experimentos de Elección Discreta. Los atributos considerados en el diseño fueron: color, contenido de grasa y presencia de antibióticos. Para ello se aplicó una encuesta a 196 consumidores. Los resultados se analizaron con el software NLOGIT 4.0, mediante un modelo logit mixto. El atributo más valorado fue contenido de antibióticos, lo que significa que los entrevistados estarían dispuestos a pagar una prima adicional de$30.65 MXN/kg de carne de cerdo libre de antibióticos. Se encontró que, a mayor ingreso y a mayor frecuencia de consumo en carne de cerdo, mayor disposición a pagar una prima adicional por carne libre de antibióticos. Se determinó una DAP de $5.78 MXN por carne con grasa normal y de$3.73 MXN más por carne de color rojo. Los consumidores de carne de cerdo del oriente del Estado de México estarían dispuestos a pagar una prima adicional por carne de cerdo libre de antibióticos y aspectos de calidad como contenido de grasa y color

Disposición a pagar por carne de cerdo sin antibióticos en el Estado de México

Pork represents the second source of protein in Mexico due to the multiple benefits of its consumption. However, several studies link the indiscriminate use of antibiotics with public health problems. This study aimed to know the willingness to pay for antibiotic-free pork with the contingent valuation method (CV). Questionnaires were applied to 156 consumers in eastern State of Mexico and the data were analyzed with a binomial logit model. It was found on average, a willingness to pay a premium of 16.34% ($17.81 MXN kg-1) as a markup price. The most representative variables were premium amount, age, number of dependents in household, income and frequency of consumption. The results indicated that there is a potential market for differentiated antibiotic-free pork meat, so that consumers are willing to pay a premium per kg of 16.34$17.81 kg-1) como sobreprecio. Las variables más representativas fueron monto de la prima, edad, número de dependientes en el hogar, ingreso y frecuencia de consumo. Los resultados indicaron que existe un mercado potencial para carne de cerdo diferenciada libre de antibióticos y que los consumidores están dispuestos a pagar una prima por kg 16.34% adicional al precio de la carne convencional

The Use of Bioinformatic Tools in Symbiosis and Co-Evolution Studies

Through millions of years, the multicellular organisms have coexisted and coevolved with the surrounding microorganisms, in an almost symbiotic relationship forming a complex entity known as holobiont. The composition and functions of these microbial communities were limited during many years to only a mere fraction, due to the use of culture-based techniques. The advent of molecular-based techniques allowed the identification of uncultured organisms in a culture-free manner. In recent years, the development of next generation sequencing techniques have allowed the high-throughput study of microbial communities allowing the identification and classification of otherwise uncultured microorganisms in a given environment, tissue or host through metagenomics. The next generation sequencing techniques have been used in the functional study of microbial assemblages and were able to identify the role of the microorganisms in biogeochemical cycles, pathogenic processes, metabolism and development, through metatranscriptomics. Taken together, the next generation sequencing based-studies have shown the existence of a complex metabolic network in different hosts and environments, with the microbial communities. This chapter will focus in different available bioinformatic tools that are suitable to study symbiosis and coevolution processes in a given sample

Designing bioactive porous titanium interfaces to balance mechanical properties and in vitro cells behavior towards increased osseointegration

Titanium implant failures are mainly related to stress shielding phenomenon and the poor cell interaction with host bone tissue. The development of bioactive and biomimetic Ti scaffolds for bone regeneration remains a challenge which needs the design of Ti implants with enhanced osseointegration. In this context, 4 types of titanium samples were fabricated using conventional powder metallurgy, fully dense, dense etched, porous Ti, and porous etched Ti. Porous samples were manufactured by space holder technique, using ammonium bicarbonate particles as spacer in three different ranges of particle size (100–200 μm, 250–355 μm and 355–500 μm). Substrates were chemically etched by immersion in fluorhydric acid at different times (125 and 625 s) and subsequently, were characterized from a micro-structural, topographical and mechanical point of view. Etched surfaces showed an additional roughness preferentially located inside pores. In vitro tests showed that all substrates were biocompatible (80% of cell viability), confirming cell adhesion of premioblastic cells. Similarly, osteoblast showed similar cell proliferation rates at 4 days, however, higher cell metabolic activity was observed in fully dense and dense etched surfaces at 7 days. In contrast, a significant increase of alkaline phosphatase enzyme expression was observed in porous and porous etched samples compared to control surfaces (dense and dense etched), noticing the suitable surface modification parameters (porosity and roughness) to improve cell differentiation. Furthermore, the presence of pores and rough surfaces of porous Ti substrates remarkably decreased macrophage activation reducing the M1 phenotype polarization as well M1 cell marker expression. Thus, a successful surface modification of porous Ti scaffolds has been performed towards a reduction on stress shielding phenomenon and enhancement of bone osseointegration, achieving a biomechanical and biofunctional equilibrium.Ministry of Economy and Competitiveness of Spain grant MAT2015-71284-PJunta de Andalucía – FEDER (Spain) Project Ref. P12-TEP-140

Características del poder y la rentabilidad en las empresas familiares jiennenses: teoría de agencia versus dirección estratégica

El objetivo de este trabajo es el análisis, bajo los argumentos de la Teoría de Agencia y la Dirección Estratégica, del tipo de estructura de poder que es más ventajoso para la empresa familiar andaluza; esto es, aquella independiente que permite controlar y vigilar el comportamiento oportunista desarrollado por los directivos, o por el contrario, la de naturaleza dual que otorga discreción y poder al propietario de la empresa familiar. Para ello, tras revisar la literatura correspondiente, se plantean tres hipótesis cuyo contraste se efectúa sobre una muestra de 856 empresas familiares jiennenses.The main purpose of this paper is to analyze, under the arguments of Agency Theory and Strategic Management, what type of power structure is more advantageous for the family business and its proprietors, one independent that allows to control the manager´s opportunist behavior, or other dual that grants discretion and power to the president of the family business. For it, after revising the corresponding literature, three hypotheses are formulated and tested on a sample of 856 family business

OBTENCIÓN DEL MÁXIMO ANCHO DE BANDA PARA LA ADQUISICIÓN Y RECONSTRUCCIÓN DE SEÑALES ANALÓGICAS CON LA TARJETA SPARTAN 3E

ResumenEn este trabajo se presenta un sistema en el cual se obtiene el máximo ancho de banda posible para la adquisición y reconstrucción de señales analógicas en la tarjeta de desarrollo Spartan-3E del fabricante Xilinx, utilizando los convertidores que contiene dicha tarjeta, tanto el ADC como el DAC. El sistema está desarrollado en VHDL empleando el concepto de máquina de estados finitos (FSM) y el administrador digital de reloj (DCM) incluido en el FPGA de la tarjeta. En aplicaciones tales como procesamiento digital de señales en tiempo real, comunicaciones digitales y control digital, por mencionar algunas, es muy importante tener un ancho de banda considerable en el sistema. El valor máximo obtenido para el ancho de banda del sistema fue de 161 kHz.Palabras Claves: ADC, ancho de banda, DAC, FPGA, Spartan-3E.OBTAINING THE MAXIMUM BANDWIDTH FOR THE ACQUISITION AND RECONSTRUCTION OF ANALOGUE SIGNALS WITH THE SPARTAN 3E CARDAbstractThis paper presents a system in which the maximum bandwidth possible for the acquisition and reconstruction of analog signals is obtained in the Spartan-3E development board of the Xilinx manufacturer, using the converters contained in this board, both the ADC and The DAC. The system is developed in VHDL using the concept of finite state machine (FSM) and the digital clock manager (DCM) included in the FPGA. In applications such as digital processing of real-time signals, digital communications and digital control, to mention a few, it is very important to have a considerable bandwidth in the system. The maximum value obtained for the system bandwidth was 161 kHz.Keywords: ADC, bandwith, DAC, FPGA, Spartan-3E