How competition controls team production: The case of fishing firms

Under team production, those who monitor individual productivity are usually the only ones compensated with a residual that varies with the performance of the team. This pattern is efficient, as is shown by the prevalence of conventional firms, except for small teams and when specialized monitoring is ineffective. Profit sharing in repeated team production induces all team members to take disciplinary action against underperformers through switching and separation decisions, however. Such action provides effective self-enforcemnt when the markets for team members are competitive, even for large teams using specialized monitoring. The traditional share system of fishing firms shows that for this competition to provide powerful enough incentives the costs of switching teams and measuring team productivity must be bellow. Risk allocation may constrain the organizational design defined by the use of a share system. It does not account for its existence, however.Theory of the firm, team production, share contracts, profit sharing, remuneration systems, self-enforcement, fishing firms

Determinants of organizational form: Transaction costs and institutions in the European trucking industry

We explain why European trucking carriers are much smaller and rely more heavily on owner-operators (as opposed to employee drivers) than their US counterparts. Our analysis begins by ruling out differences in technology as the source of those disparities and confirms that standard hypotheses in organizational economics, which have been shown to explain the choice of organizational form in US industry, also apply in Europe. We then argue that the preference for subcontracting over vertical integration in Europe is the result of European institutions—particularly, labor regulation and tax laws—that increase the costs of vertical integration.Transaction costs, governance, hybrids, transportation

Quasi-integration in less-than-truckload trucking

This work studies the organization of less-than-truckload trucking from a contractual point of view. We show that the huge number of owner-operators working in the industry hides a much less fragmented reality. Most of those owner-operators are “quasi-integrated” in higher organizational structures. This hybrid form is generally more efficient than vertical integration because, in the Spanish institutional environment, it lessens serious moral hazard problems, related mainly to the use of the vehicles, and makes it possible to reach economies of scale and density. Empirical evidence suggests that what leads organizations to vertically integrate is not the presence of such economies but hold-up problems, related to the existence of specific assets. Finally, an international comparison hints that institutional constraints are able to explain differences in the evolution of vertical integration across countries.Hold-up, hybrids, institutions, moral hazard, vertical integration, trucking industry

Escuela, familia y comunidad: una propuesta para su integración

En el presente trabajo se realiza una revisión de las concepciones teóricas de la educación y la escuela que reconocen y justifican la integración de las familias y la comunidad en el ámbito escolar. Asimismo se profundiza en el estudio de la familia y sus características en la sociedad actual, para comprender la naturaleza de las relaciones con la escuela. A partir de todo ello se fundamenta una perspectiva de trabajo en el ámbito escolar que integra la escuela, las familias y la comunidad, para plantear finalmente unas consideraciones generales para la puesta en marcha de acciones o iniciativas conducentes a la superación de las barreras existentes entre la escuela y la familia.Grado en Educación Socia

Application of molecular techniques for identification and ennumeration of acetic acid bacteria

Application of molecular techniques for identification and enumeration of acetic acid bacteria:Los principales objetivos de la tesis son el desarrollo de técnicas de biología molecular rápidas y fiables para caracterizar bacterias acéticas.Las bacterias acéticas son las principales responsables del picado de los vinos y de la producción de vinagre. Sin embargo, existe un desconocimiento importante sobre su comportamiento y evolución. Las técnicas de enumeración y de identificación basadas en características fisico-químicas existentes son lentas y poco fiables mientras que las técnicas moleculares utilizadas son muy lentas y excesivamente caras y no son aplicables en un trabajo de rutina en el laboratorio ni adecuadas para una gran cantidad de muestras. En primer lugar se ha conseguido identificar a nivel de especie, mediante dos técnicas de biología molecular como son la PCR-RFLP del rDNA 16S y PCR-RFLP del rDNA 16S-23S ITS. Se lograron identificar todas las especies de bacterias acéticas existentes hasta el momento mediante la combinación de ambas técnicas. Estas técnicas se han utilizado también en estudios ecológicos.Se han desarrollado dos técnicas para la caracterización a nivel de cepa: ERIC- y REP-PCR. Estas técnicas han permitido la realización de estudios ecológicos en fermentaciones en distintas condiciones, permitiendo profundizar en el conocimiento de su comportamiento y desarrollo en fermentaciones vínicas. Se han desarrollado dos técnicas para la enumeración, real-time PCR y la detección nested-PCR respectivamente de bacterias acéticas. Estas técnicas presentan la ventaja de no tener que cultivar y por lo tanto de detectar la presencia de bacterias viables pero no cultivables, que han sido descritas dentro de las bacterias acéticas.Artículos en revistas internacionales:A González, N Hierro, M Poblet, N Rozès, A Mas, JM Guillamón: Application of molecular methods for the differentiation of acetic acid bacteria in a red wine fermentation Journal of Applied Microbiology, 96, 853-860, 2004A González, N Hierro, M Poblet, A Mas, JM Guillamón: Application of molecular methods to demonstrate species and strain evolution of acetic acid bacteria population during wine production. International Journal of Food Microbiology (en prensa), 2005. A González, JM Guillamón, A Mas, M Poblet: Application of molecular methods for routine identification of acetic acid bacteria. International Journal of Systematic and Evolutionary Microbiology (enviado).A. González, Núria Hierro, Montserrat Poblet, Albert Mas and José Manuel Guillamón. Enumeration and detection of acetic acid bacteria by real-time PCR and nested-PCR. FEMS Microbial Letters. (enviado).JM Guillamón, Hierro, N., A González, A Mas: New PCR-based methods for yeast identification. Journal of Applied Microbiology, 97, 792-801; 2004.Núria Hierro, Ángel González, Albert Mas, José Manuel Guillamón.(2005) Diversity and evolution of non-Saccharomyces yeast populations during wine fermentations: Efecto of grape ripeness and cold maceration. FEMS yeast research. (enviado).Artículos en revistas nacionales:A Mas, A González, N Hierro, M Poblet, N Rozès, JM Guillamón: Bacterias acéticas durante la fermentación vínica: Interacciones con otros microorganismos. Tecnología del vino, 11: 27-30, 2003.A Mas, N Hierro, JM Guillamón, A González, M Poblet, N Rozès: Nuevas técnicas de identificación, detección y cuantificación de levaduras de importancia en Enología. Tecnología del vino, 15, 65-70, 2004. Y. Quintero, A González, M Poblet, JM Guillamón, A Mas: Importancia de las bacterias acéticas en el vino. Enorigen, 1, 6-12, 2004Congresos y capítulos:A. González, M. Poblet, N. Rozés, JM. Guillamón, A. Mas. Desarrollo de técnicas moleculares de análisis de bacterias acéticas. Valencia, España. Gienol, 2001.A. González, N. Hierro, M. Poblet, N. Rozés, A. Mas, JM. Guillamón. Development of molécular techniques for the análisis of acetic acid bacteria. París, Francia. Xth international congress of Bacteriology and applied microbiology. 2002.J.M. Guillamón, A. González, M. Poblet, A. Mas. Development of molecular techniques for the analysis of acetic acid bacteria in winemaking. En: Yeast-Bacteria Interactions. Lallemand Tecnical Meetings, 10. Lallemand, S.A., 45-49, 2002.N. Hierro, A. González, N. Rozès, A. Mas, J.M. Guillamón: Nuevos métodos de identificación de levaduras basados en PCR. VII Jornadas Grupos de Investigación Enológica. Logroño.195-197, 2003Gonzalez, A.; Hierro, N.; Chiva, R.; Poblet, M.; Rozès, N.; Mas, A.; Guillamón, JM.: Dinámica poblacional de las bacterias acéticas en fermentaciones de vino tinto. VII Jornadas Grupos de Investigación Enológica. Logroño. 204 - 206. 2003.A. González, N. Hierro, M. Poblet, N. Rozés, A. Mas, JM. Guillamón. Population dynamics of acetic acid bacteria during red wine fermentations. 1st FEMS congress of European microbiologists. Lubiana, Eslovenia, 2003.N. Hierro, A. González, A. Mas, JM Guillamón. New PCR-based methods for yeast identification. Ponencia. Budapest, Hungría. ISSY 2003J.M. Guillamón, A. González, N. Hierro, N. Rozès, A. Mas, M. Poblet: Técnicas de identificación de bacterias acéticas. En: Primeras Jornadas de I+D+i en la Elaboración de Vinagres de vino. URV-CeRTA. 9-16, 2003.A. González, N. Hierro, M. Poblet, A. Mas, N. Rozès, J.M. Guillamón Bacterias acéticas durante la fermentación vínica. En: Primeras Jornadas de I+D+i en la Elaboración de Vinagres de vino. URV-CeRTA. 25-30, 2003.JM Guillamón, A González, M Poblet, A Mas: I microorganismi dell'Aceto Balsamico. Modena. 2004A. González, N. Hierro, M. Poblet, JM. Guillamón, A. Mas. Quantification of acetic acid bacteria in wine and vinegar samples using rt-PCR. Badajoz, España. BioMicroWorld 2005.J.M. Guillamón, A. González, M. Poblet, A. Mas: Molecualr techniques of identification and quantification of acetic acid bacteria. Vinegars and Acetic Acid Bacteria International Symposium. Reggio Emilia, 2005.A. Mas, A. González, J.M. Guillamón, M. Poblet: Acetic acid bacteria population dynamics during wine fermentation. Vinegars and Acetic Acid Bacteria International Symposium. Reggio Emilia, 2005.F. Barja, A. González, M. Mesa, M. Macías, D. Cantero. Molecular and morphological characterization of acetic acid bacteria from industrial fermenters of wine vinegar production. Vinegars and Acetic Acid Bacteria International Symposium. Reggio Emilia, 2005.A. González, N. Hierro, M. Poblet, JM. Guillamón, A. Mas. Quantitative-PCR for rapid detection of acetic acid bacteria. Vinegars and Acetic Acid Bacteria International Symposium. Reggio Emilia, 2005.N. Hierro, A. González, N. Rozés, A. Mas, JM. Guillamón. PCR-cuantitativa para la detección y cuantificación de levaduras vínicas. Palencia, España. Gienol, 2005.A. González, N. Hierro, M. Poblet, JM. Guillamón, A. Mas. Evolución de la población de las cepas de bacterias acéticas durante la fermentación alcohólica. Palencia, España. Gienol, 2005.Application of molecular techniques for identification and enumeration of acetic acid bacteria:The main objectives of the present thesis is the development of fast and reliable molecular techniques for the identification and characterization of acetic acid bacteria.Acetic acid bacteria are the main responsible of the acetification of the wines and of the Viniegra production. However, there is an important lack of knowledge about their behaviour and evolution through the different processes they are involved. The techniques of enumeration and identification based on their chemo-taxonomic properties are tedious and not reliable meanwhile molecular techniques already used are slow, tedious, very expensive and not useful for routine analysis of big amounts of samples in the laboratory.We have been able to identify at species level, with two molecular techniques such as PCR-RFLP del rDNA 16S and PCR-RFLP del rDNA 16S-23S ITS. We were able to identify all the described acetic acid bacteria species with the combination of the two techniques. Those, have also been used in ecological studies in wine.We have developed two techniques for the characterization of aceic acid bacteria at strain level: ERIC- and REP-PCR. Those techniques have allowed us the development of ecological studies in wine fermentations in different condition, allowing us to improve our knowledge about these bacteria behaviour and development through the wine fermentations.We have developed two techniques for the enumeration, real-time PCR and for the detection, nested-PCR respectively of acetic acid bacteria. Those techniques allow us not to plate the samples before the analysis, therefore they allow the detection of the viable but non-culturable cells, already describes inside the acetic acid bacteria

Quality assurance mechanisms in agrifood: The case of the Spanish fresh meat sector

The largest fresh meat brand names in Spain are analyzed here to study how quality is signaled in agribusiness and how the underlying quality -assurance organizations work. Results show, first, that organizational form varies according to the specialization of the brand name. Publicly-controlled brand names are grounded on market contracting with individual producers, providing stronger incentives. In contrast, private brands rely more on hierarchy, taking advantage of its superiority in solving specific coordination problems. Second, the seemingly redundant coexistence of several quality indicators for a given product is explained in efficiency terms. Multiple brands are shown to be complementary, given their specialization in guaranteeing different attributes of the product.Quality assurance, co-branding, agriculture, vertical integration, contracts

A modular CMOS analog fuzzy controller

The low/medium precision required for many fuzzy applications makes analog circuits natural candidates to design fuzzy chips with optimum speed/power figures. This paper presents a sixteen rules-two inputs analog fuzzy controller in a CMOS 1 /spl mu/m single-poly technology based on building blocks implementations previously proposed by the authors (1995). However, such building blocks are rearranged here to get a highly modular architecture organized from two high level blocks: the label block and the rule block. In addition, sharing of membership function circuits allows a compact design with low area and power consumption and its highly modular architecture will permit to increase the number of inputs and rules in future chips with hardly design effort. The paper includes measurements from a silicon prototype of the controller

CMOS design of adaptive fuzzy ASICs using mixed-signal circuits

Analog circuits are natural candidates to design fuzzy chips with optimum speed/power figures for precision up to about 1%. This paper presents a methodology and circuit blocks to realize fuzzy controllers in the form of analog CMOS chips. These chips can be made to adapt their function through electrical control. The proposed design methodology emphasizes modularity and simplicity at the circuit level - prerequisites to increasing processor complexity and operation speed. The paper include measurements from a silicon prototype of a fuzzy controller chip in CMOS 1.5 /spl mu/m single-poly technology

A multiplexed mixed-signal fuzzy architecture

Analog circuits provide better area/power efficiency than their digital counterparts for low-medium precision requirements. This limit in precision as well as the lack of design tools when compared to the digital approach, imposes a limit of complexity, hence fuzzy analog controllers are usually oriented to fast low-power systems with low-medium complexity. The paper presents a strategy to preserve most of the advantages of an analog implementation, while allowing a notorious increment of the system complexity. Such strategy consists in implementing a reduced number of rules, those that really determine the output in a lattice controller, which we call analog core, then this core is dynamically programmed to perform the computation related to a specific rule set. The data to program the analog core are stored in a memory, and constitutes the whole knowledge base in a kind of virtual rule set. HSPICE simulations from an exemplary controller are shown to illustrate the viability of the proposal

Neuro-fuzzy chip to handle complex tasks with analog performance

This Paper presents a mixed-signal neuro-fuzzy controller chip which, in terms of power consumption, input-output delay and precision performs as a fully analog implementation. However, it has much larger complexity than its purely analog counterparts. This combination of performance and complexity is achieved through the use of a mixed-signal architecture consisting of a programmable analog core of reduced complexity, and a strategy, and the associated mixed-signal circuitry, to cover the whole input space through the dynamic programming of this core [1]. Since errors and delays are proportional to the reduced number of fuzzy rules included in the analog core, they are much smaller than in the case where the whole rule set is implemented by analog circuitry. Also, the area and the power consumption of the new architecture are smaller than those of its purely analog counterparts simply because most rules are implemented through programming. The Paper presents a set of building blocks associated to this architecture, and gives results for an exemplary prototype. This prototype, called MFCON, has been realized in a CMOS 0.7μm standard technology. It has two inputs, implements 64 rules and features 500ns of input to output delay with 16mW of power consumption. Results from the chip in a control application with a DC motor are also provided