How to control market power of activity centres? A theoretical model showing the advantages of implementing competition within organizations

One important issue in firms’ governance is how to create incentives so that activity centres can become more efficient. In this paper, we first introduce an agency contract where the salary of the manager of an activity centre that produces an intermediate product is dependent of its performance. Secondly, we add competition within the organization. This latter point is new in the literature. We then develop a "static analysis" comparing a firm that has only one activity centre producing an intermediate product with another firm that has two activity centres producing the same intermediate product, in a context where the technology manifests increasing returns to scale. We conclude that the introduction of internal competition makes the firm globally more efficient, even though it cannot fully explore the existence of increasing returns to scale.Activity centres, internal market power, firm efficiency

Programa GENES - aplicativo computacional em estatística aplicada à genética

O principal objetivo do software GENES é ajudar pessoas que trabalham com análise genética e processamento de dados em programas de melhoramento, usando vários modelos biométricos. Este software tem várias janelas de ajuda que são muito amigáveis para o usuário. Mais informações sobre este programa estão disponíveis no livro "Programa GENES - Aplicativo Computacional em Genética e Estatística, 442. 1997". Pedidos de compra são bem-vindos no seguinte endereço: [email protected]. As cópias shareware do software GENES estão disponíveis em http://www.genetica.dbg.ufv.br.The main purpose of the GENES software is to help people working with genetic analysis and data processing in breeding programs, using several biometrics models. This software has several help windows that are very friendly to the user. More information about this program is available in the book "Programa GENES - Aplicativo Computacional em Genética e Estatística, 442. 1997". Purchase orders are welcome at the following address: [email protected]. Shareware copies of the GENES software are available at http://www.genetica.dbg.ufv.

Adaptability and stability of soybean genotypes recommended for Alto Paranaíba in Minas Gerais

The cultivation of soybean (Glycine max (L.) Merr.) stands out in the national and world scenario. Brazil, from different points of view, has a high productive capacity of this oilseed, which resulted in the classification of the country as the world's largest producer. The state of Minas Gerais is one of Brazil's agricultural granaries, and in soybean culture it is the sixth largest producing state. Thus, the objective was to evaluate the interaction genotypes x environments in soybean genotypes grown in Alto Paranaíba, Minas Gerais, and to identify genotypes with general response, those recommended for favorable or unfavorable environments through the different methodologies of adaptability and stability. Five experiments were conducted in the experimental block design, with four repetitions, in the 2020/2021 agricultural season, in which 14 soybean genotypes were analyzed by productivity, in kg ha-1. An individual analysis of variance was performed (for each environment) along with joint analysis of the experiments, average grouping test (for each environment), decomposition of the interaction between genotypes and pairs of environments and the adaptability and stability analyses were performed by the methods of Artificial Neural Networks, Lin and Binns modified by Carneiro and Centroid method. It was concluded that the interaction genotypes x environments was significant and between pairs of environments it was predominantly complex. The genotypes M5917IPRO, TMG7063IPRO and BMXFocoIPRO are recommended for general environment; the genotypes TMG2374IPRO and TMG7363RR are recommended for favorable environments; and the genotypes BS2606IPRO, TEC7849IPRO and BRS5980IPRO are recommended for unfavorable environments.The cultivation of soybean (Glycine max (L.) Merr.) stands out in the national and world scenario. Brazil, from different points of view, has a high productive capacity of this oilseed, which resulted in the classification of the country as the world's largest producer. The state of Minas Gerais is one of Brazil's agricultural granaries, and in soybean culture it is the sixth largest producing state. Thus, the objective was to evaluate the interaction genotypes x environments in soybean genotypes grown in Alto Paranaíba, Minas Gerais, and to identify genotypes with general response, those recommended for favorable or unfavorable environments through the different methodologies of adaptability and stability. Five experiments were conducted in the experimental block design, with four repetitions, in the 2020/2021 agricultural season, in which 14 soybean genotypes were analyzed by productivity, in kg ha-1. An individual analysis of variance was performed (for each environment) along with joint analysis of the experiments, average grouping test (for each environment), decomposition of the interaction between genotypes and pairs of environments and the adaptability and stability analyses were performed. It was concluded that the interaction genotypes x environments was significant and between pairs of environments it was predominantly complex, the genotypes M5917IPRO, TMG7063IPRO and BMXFocoIPRO are recommended for general environment, the genotypes TMG2374IPRO and TMG7363RR are recommended for favorable environments, and the genotypes BS2606IPRO, TEC7849IPRO and BRS5980IPRO are recommended for unfavorable environments

Diversidade genética de acessos de uvas de mesa baseada em caracteres morfoagronômicos

The conservation and characterization of grape (Vitis spp) genetic resources in germplasm banks have been the basis of its use in breeding programs that result in development of new cultivars. There are at least 10,000 grape cultivars kept in germplasm collection. The genetic diversity in 136 table grape accessions from the state of Bahia, Brazil, was evaluated. Continuous and discrete morphoagronomic traits were assessed. The clustering analysis by the Tocher otimization method resulted in 30 clusters (considering continuous morphoagronomic traits), and 9 clusters (taking into consideration multicategorical traits). There was no agreement between clusters obtained by both, continuous or discrete phenotypic descriptors, independent of the cluster method analysis used. A satisfactory genetic variability among the table grape accessions was observed.A conservação e caracterização dos recursos genéticos de videira (Vitis spp.) em bancos de germoplasma tem sido a base para a sua utilização nos programas de melhoramento, que resultam no desenvolvimento de novas cultivares, estimando-se a existência de pelo menos 10.000 cultivares de uva mantidos em coleções de germoplasma. Avaliou-se a diversidade genética presente em 136 acessos de uvas de mesa de uma coleção de germoplasma do estado da Bahia, com base em caraterísticas morfoagronômicas de variação contínua e discreta. A análise de agrupamento pelo método de Tocher resultou na formação de 30 grupos utilizando-se descritores morfo-agronômicos de variação contínua e 9 grupos, com base em caracteres multicategóricos. Não houve concordância entre os grupos obtidos pela análise de descritores fenotípicos contínuos e discretos, independente do método de agrupamento utilizado. Detectou-se a existência de variabilidade genética satisfatória entre os acessos de uvas de mesa da coleção

Validación de un laboratorio de neurosonología para la detección de patología carotídea estenosante.

INTRODUCCIÓN. Se entiende por ictus isquémico el trastorno circulatorio cerebral por oclusión arterial que altera, transitoria o definitivamente, el funcionamiento de una o varias partes del encéfalo. La detección de estenosis arterial cervical o intracraneal constituye uno de los aspectos más relevantes en su estudio, al explicar un 35% del total de eventos en nuestro medio (le siguen el origen cardio-embólico - 20% - y el microangiopático - 18% -). Desde los años 60, la velocimetría Doppler se ha convertido, por su aplicabilidad y precisión, en la técnica de elección para la primera aproximación al diagnóstico de esta patología. Aunque la patología carotídea cervical grave es la que puede suponer una mayor modificación de la actitud terapéutica en un primer momento (condicionando la indicación de cirugía), el estudio neurosonológico completo debe incluir también la valoración hemodinámica de las arterias intracraneales y, si es pertinente, un comentario sobre el patrón global del espectro Doppler (que en ocasiones permite sugerir la presencia de microangiopatía cerebral difusa). Expertos acreditados en la técnica y sociedades científicas afines están de acuerdo en la necesidad de que cada laboratorio, al tener sus propias peculiaridades, lleve a cabo un trabajo de validación de sus resultados. Sin embargo, hasta la fecha de la presente tesis, el número de estudios de validación publicados e indexados en Medline con autoría en instituciones de nuestro país es escaso: cuatro para estenosis carotídea cervical, dos para estenosis de arterias intracraneales, y ninguno para la detección de microangiopatía. En este último caso, sólo existen trabajos foráneos y, a diferencia de lo que ocurre con las estenosis cervicales e intracraneales, ninguno ha conseguido encontrar un punto de corte con aplicabilidad clínica. JUSTIFICACIÓN. Tres pilares fundamentan este trabajo. 1) La necesidad de rigor científico en el ámbito asistencial (representada en la recomendación de las sociedades de validar cada laboratorio). 2) La conveniencia de actualización científica en la materia (los trabajos de velocimetría Doppler son ya antiguos en su mayoría, y fueron realizados con equipos ahora obsoletos). Y 3) La existencia de un vacío en el conocimiento médico: Por un lado, es notoria la escasez de trabajos que consideren simultáneamente la hemodinámica de la arteria carótida cervical y de las arterias intracraneales en la elaboración final del juicio diagnóstico. Por otra parte, es constatable la total ausencia de estudios que demuestren la utilidad de la técnica del estudio neurosonológico como soporte complementario en el diagnóstico etiológico de microangiopatía de un evento isquémico agudo cerebral. HIPÓTESIS Y OBJETIVOS. - Hipótesis: El examen Doppler ciego cervical y transcraneal simultáneo, e interpretado en el conjunto de sus hallazgos por un neurólogo experto acreditado en la técnica, constituye una herramienta diagnóstica, cuanto menos, tan fiable como el examen dúplex-Doppler cervical aislado, de competencia radiológica en nuestro medio, para la detección de estenosis carotídea grave. Y proporciona datos adicionales de alto valor diagnóstico en patología vascular cerebral. - Objetivo principal: Validar la competencia diagnóstica de la técnica Doppler cervical y transcraneal realizada en el Laboratorio de Neurosonología de la Unidad de Patología Vascular Cerebral del Hospital Universitario Virgen de la Victoria, como screening de estenosis cervical grave, enfrentándolo al dúplex-Doppler habitualmente utilizado en el centro, dependiente del servicio de radiología, con tal fin. - Objetivos secundarios: 1) Determinar si el conjunto de parámetros considerados en el estudio incrementan la rentabilidad diagnóstica como técnica de screening para la detección de estenosis arterial de repercusión cerebral, no sólo proporcionando datos fiables de arteria carótida interna cervical, sino adicionalmente de arterias intracraneales y lecho microvascular. Y 2) Determinar si la realización del screening neurovascular por parte del neurólogo conlleva precocidad diagnóstica respecto a la dependencia de radiología para el mismo, esto es, si reduce el intervalo de tiempo entre el evento isquémico cerebral agudo que lo motiva, y la detección o exclusión de estenosis arterial de repercusión cerebral. MATERIAL Y MÉTODOS. Se diseñó un estudio descriptivo observacional de evaluación de pruebas diagnósticas. Se compararon los resultados obtenidos mediante la técnica integrada Doppler carotideo y transcraneal realizada en el Laboratorio de Neurosonología de la Unidad de Patología Vascular Cerebral del Hospital Universitario Virgen de la Victoria, con los proporcionados por la técnica dúplex-Doppler carotideo, dependiente del servicio de radiología, y considerada de referencia para el screening de estenosis carotídea significativa en dicho centro. Sobre los datos recopilados, se planteó la realización de un análisis con la herramienta SPSS. RESULTADOS. N = 228 pacientes. Se determinó como resultado principal, para el Doppler ciego en la detección de estenosis carotídea > 70%, una sensibilidad y especificidad del 96% y el 100% respectivamente. Para el dúplex, los resultados equivalentes fueron 87% y 94%. En la detección de estenosis intracraneal por Doppler, esos parámetros puntuaron 78% y 98%, también respectivamente. El estudio dúplex (radiológico) no incluía ese dato. En cuanto al estudio de microangiopatía cerebral por Doppler, se encontró una correlación visual entre la puntuación Fazekas y la resistividad difusa (medida como IP ó IR). Ambos parámetros se comportaban como un buen predictor diagnóstico de etiología microangiopática del evento, con un área bajo la curva de 0.78 (Fazekas) y 0.70 (igual para IP e IR), respectivamente. Se seleccionaron como puntos de corte óptimos IP = 0,96 para screening (sensibilidad 96%), así como IP = 1,46 para confirmación (especificidad 89%) de dicha etiología. CONCLUSIONES. Las más relevantes son: 1. El examen Doppler ciego cervical y transcraneal queda validado como herramienta diagnóstica fiable para la detección de estenosis carotídea grave cervical. 2. Demostramos que la inclusión del Doppler transcraneal en la interpretación de los hallazgos cervicales mejora los resultados obtenidos por el dúplex, actualmente la técnica de cribaje estándar. 3. El estudio Doppler efectuado por el laboratorio de neurosonología demuestra una utilidad adicional como técnica de screening de estenosis arterial intracraneal y de microangiopatía cerebral. 4. Los contenidos técnicos, científicos, clínicos y económicos de este trabajo, señalan la necesidad de consolidar los laboratorios de neurosonología en todo hospital de tercer nivel, por su fiabilidad y premura diagnósticas al servicio del paciente, y por la optimización de los recursos económicos disponibles

Comparison of direct and indirect selection processes and selection indices in Eucalyptus grandis

Utilizando experimentos que envolviam famílias de meios-irmãos de Eucalyptus grandis, em seis locais, onde foram anotados dados de circunferência à altura do peito (CAP), altura de plantas (ALT), incidência de ferrugem (FER), incidência de cancro (CAN) e número de árvores normais por parcela (NAR), foram comparadas as metodologias de seleções direta e indireta e índices de seleção (clássico e de Pesek e Baker) com relação às características avaliadas. As seleções direta e indireta não apresentaram distribuição de ganhos genéticos esperados adequada aos propósitos do presente trabalho. O índice clássico e o de Pesek e Baker apresentaram distribuição de ganhos genéticos esperados mais equilibrada.This study used data from six experiments with half-sib families of Eucalyptus grandis, carried out at six localities, to evaluate the following traits: circumference at breast height (CAP), plant height (ALT), rust incidence (FER), canker incidence (CAN) and number of normal trees per plot (NAR). The direct and indirect selection methodologies were compared with the selection indices (classic and Pesek and Baker method) using all the traits. Neither selection method yielded the expected distribution of genetic gains. Both the classic and Pesek and Baker's indices produced a more suitable distribution of expected genetic gains

Computational analysis of the interaction between transcription factors and the predicted secreted proteome of the yeast Kluyveromyces lactis

<p>Abstract</p> <p>Background</p> <p>Protein secretion is a cell translocation process of major biological and technological significance. The secretion and downstream processing of proteins by recombinant cells is of great commercial interest. The yeast <it>Kluyveromyces lactis </it>is considered a promising host for heterologous protein production. Because yeasts naturally do not secrete as many proteins as filamentous fungi, they can produce secreted recombinant proteins with few contaminants in the medium. An ideal system to address the secretion of a desired protein could be exploited among the native proteins in certain physiological conditions. By applying algorithms to the completed <it>K. lactis </it>genome sequence, such a system could be selected. To this end, we predicted protein subcellular locations and correlated the resulting extracellular secretome with the transcription factors that modulate the cellular response to a particular environmental stimulus.</p> <p>Results</p> <p>To explore the potential <it>Kluyveromyces lactis </it>extracellular secretome, four computational prediction algorithms were applied to 5076 predicted <it>K. lactis </it>proteins from the genome database. SignalP v3 identified 418 proteins with N-terminal signal peptides. From these 418 proteins, the Phobius algorithm predicted that 176 proteins have no transmembrane domains, and the big-PI Predictor identified 150 proteins as having no glycosylphosphatidylinositol (GPI) modification sites. WoLF PSORT predicted that the <it>K. lactis </it>secretome consists of 109 putative proteins, excluding subcellular targeting. The transcription regulators of the putative extracellular proteins were investigated by searching for DNA binding sites in their putative promoters. The conditions to favor expression were obtained by searching Gene Ontology terms and using graph theory.</p> <p>Conclusion</p> <p>A public database of <it>K. lactis </it>secreted proteins and their transcription factors are presented. It consists of 109 ORFs and 23 transcription factors. A graph created from this database shows 134 nodes and 884 edges, suggesting a vast number of relationships to be validated experimentally. Most of the transcription factors are related to responses to stress such as drug, acid and heat resistance, as well as nitrogen limitation, and may be useful for inducing maximal expression of potential extracellular proteins.</p

Linkage analysis between dominant and co-dominant makers in full-sib families of out-breeding species

As high-throughput genomic tools, such as the DNA microarray platform, have lead to the development of novel genotyping procedures, such as Diversity Arrays Technology (DArT) and Single Nucleotide Polymorphisms (SNPs), it is likely that, in the future, high density linkage maps will be constructed from both dominant and co-dominant markers. Recently, a strictly genetic approach was described for estimating recombination frequency (r) between co-dominant markers in full-sib families. The complete set of maximum likelihood estimators for r in full-sib families was almost obtained, but unfortunately, one particular configuration involving dominant markers, segregating in a 3:1 ratio and co-dominant markers, was not considered. Here we add nine further estimators to the previously published set, thereby making it possible to cover all combinations of molecular markers with two to four alleles (without epistasis) in a full-sib family. This includes segregation in one or both parents, dominance and all linkage phase configurations

Half a century of studying adaptability and stability in maize and soybean in Brazil

The study of adaptability and stability underlies the cultivar recommendation process for all crops. There is a considerable number of statistical methods available for this purpose, but little is known about their actual adoption by the Brazilian scientific community. The objective of this study was to carry out a systematic review of the scientific literature on the adaptability and stability methods used in maize and soybean in Brazil from scientific articles published between 1970 and 2017 in Brazilian journals. Article searches were carried out in journals indexed through the SciELO database. The articles were classified according to the year of publication and the adaptability and stability methods used. We also evaluated the pattern of association between methods. We found 113 articles on adaptability and stability in maize and soybean, in which 21 methods were listed. The most commonly used method was the Eberhart and Russell methodology. The Cruz, Torres, and Vencovsky along with the AMMI methods were also widely used. The number of articles using most methods decreased in the current decade, except for the GGE Biplot, MHPRVG, and Centroid methods. In studies with more than one method, the methods were more likely to be used together with the Eberhart and Russell methodology. Adaptability and stability in maize and soybean have been widely studied over the last several decades in Brazil, although the number of publications on this subject has decreased over this time period