2,115 research outputs found

    Co-operation and economic relationship as determinants for competitiveness in the food sector: the Spanish wheat to bread chain

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    The objective of the paper is to investigate the impact of co-operation amongst stakeholders of the food chain on enterprise competitiveness. The analysis focuses on the Spanish wheat to bread chain. A theoretical model is developed which covers the main components that define competitiveness (profitability, turnover, market share, customer loyalty and product quality), quality supply chain relationship (trust, commitment and satisfaction) and the main factors explaining supply chain relationship (i.e. quality and frequency of the communication, personal bounds, etc.). The Spanish wheat to bread supply chain has been chosen to empirically test the model. This sector is very fragmented all along the chain, with a high number of wheat farmers, millers and bakers. Exchanges in the sector are mainly done in the open market but there is an increasing tendency to maintain stable relationships with suppliers to assure quality. Therefore, stakeholders in the wheat to bread chain are mainly using two types of economic relationships: “repeated market transactions” and “spot market” but the former is by far the most used. Based on data from a standardised survey with farmers, processors and retailers a structural equation modelling approach has been applied to empirically test the influence of relationship quality on stakeholders’ competitiveness in the Spanish wheat to bread chain. The main conclusion of the study is that, as the quality of the relationship in the Spanish wheat to bread chain improves the stakeholder’ competitiveness increases. The results also reveal that quality of the relationship in the Spanish wheat to bread chain is based on trust, satisfaction and commitment with buyers/sellers and strongly influenced by communication quality and quantity. In addition, the outcome shows that the quality of communication has an indirect positive effect on stakeholders’ competitiveness through the relationship quality. Finally, the only factor that will influence the quality of the relationship is the equal power distribution along the chain. Moreover, personal bounds positively influence the quality of communication in the bread Spanish supply chain.competitiveness, food, Spain, Agribusiness,

    Il profilo professionale del bibliotecario

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    Functional characterization of the nucleoporins Nup50 and Nup155 in postmitotic nuclear pore complex assembly

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    The nucleus encloses the genetic material of the cell. Contact and exchange between the nuclear and cytoplasmic compartments are tightly regulated by nuclear pore complexes (NPCs), huge multimeric protein complexes that span the double nuclear envelope. These must ensure specific and timely regulated access to the nucleus to all the factors required for its correct development and maintenance. In order to be able to do so, NPCs must form in a tightly regulated fashion, producing transport-competent complexes as a result. The formation of the pores occurs in two different stages of the cell cycle, during interphase and after mitosis. During these stages, the pores are likely assembled by distinct pathways, due to the differences existing in morphology at these moments of the life of the cell. A deeper understanding of the mechanism of interaction of factors involved in NPC formation, which is far to be complete, will contribute to unravel one of the biggest, most complex cellular events. In the course of my PhD, I analyzed interactions and ordered recruitment of nucleoporins. In vitro nuclear assembly using Xenopus egg extracts revealed that a small component of NPCs, nucleoporin Nup50, is required at the early stages of postmitotic NPC assembly. Nup50 is a small nucleoplasmic nucleoporin known to be required for nuclear import. I have identified two distinct sites on the protein that are important for its postmitotic function, each of them dispensable if the other is functional, but required if the other is mutated or compromised. Interestingly, Nup50 binds the NPC assembly initiator MEL28/ELYS; in spite of this, I proved that their interaction is not required for postmitotic NPC assembly, and that they probably perform redundant functions. Additionally, I have studied the role of the domains of nucleoporin Nup155. Nup155 is a membrane binding protein required for postmitotic NPC assembly at a later step than Nup50. It contains an N-terminal domain, which arranges as a beta-propeller fold in its tertiary structure, and a C-terminal domain, which folds as a alfa-solenoid. Depletion of Nup155 causes failure by Xenopus egg extracts to form nuclear pore complexes and a closed nuclear envelope in vitro. Nup155 contains a membrane-binding region within its N-terminal. In vitro nuclear assembly using Xenopus egg extracts show that this membrane binding activity is required at the end of mitosis, as a mutant of Nup155 full length construct affecting the residues involved in membrane binding was not able to replace the endogenous protein in Nup155 depleted extracts to a comparable level with the Nup155 wildtype. Moreover, addback of an N-terminal truncation of Nup155, containing the membrane binding domain, was able to restore nuclear envelope, but not nuclear pore complex assembly. The work further indicates that Nup155 is found in a closed conformation in solution. Its binding site for Nup53 is found in the N-terminal, but it is partially blocked by its C-terminal, that prevents arranging of the optimal surface contact. Nup93 is required for the conformational change to happen: when Nup93 binds Nup53, the contact surface between Nup53 and Nup155 is optimized and, in this context, Nup93 can localize to the nascent pore and further recruits the Nup-62 complex.Der Zellkern umschließt das genetische Material der Zelle. Kontakt und Austausch zwischen den nuklearen und zytoplasmatischen Kompartimenten werden durch Kernporenkomplexe (NPCs) vermittelt. NPCs sind riesige multimere Proteinkomplexe, die in die Kernhülle integriert sind. Dafür müssen sich NPCs präzise und wohl-geordnet zu transportkompetenten Komplexe aufbauen. Die Bildung der Poren erfolgt in zwei verschiedenen Stadien des Zellzyklus: in der Interphase und nach der Mitose. Während diesen Stadien werden die Poren wahrscheinlich aufgrund morphologischer Unterschiede der Zellarchitektur auf unterschiedlichen Wegen zusammengebaut. Ein tieferes Verständnis des Mechanismus der Interaktion von NPC-bildenden Faktoren könnte dazu beitragen, einen der größten und komplexesten zellulären Vorgänge zu entschlüsseln. Im Laufe meiner Promotion analysierte ich Interaktionen und die geordnete Rekrutierung von Kernporenproteinen. In-vitro-Zusammenbau des Zellkerns unter Verwendung von Xenopus-Eiextrakten ergab, dass eine Komponente der NPCs, das Kernporenprotein Nup50, in den frühen Stadien der postmitotischen NPC-Bildung erforderlich ist. Nup50 ist ein kleines nukleoplasmatisches Kernporenprotein, von dem bekannt ist, dass es für den Kernimport erforderlich ist. Ich habe zwei verschiedene Stellen in Nup50 identifiziert, die zusammen für die postmitotische Funktion wichtig sind. Beide Stellen sind entbehrlich, wenn die andere funktional ist, aber erforderlich, wenn die jeweils andere Stelle mutiert oder kompromittiert ist. Ich konnte außerdem zeigen, dass Nup50 den Initiator des NPC-Aufbaus, MEL28 / ELYS, bindet, aber diese Interaktion nicht für die postmitotische NPC-Bildung erforderlich ist. Darüber hinaus habe ich die Rolle der Domänen des Kernporenproteins Nup155 erforscht. Nup155 ist ein membranbindendes Protein, das für die postmitotische NPC-Bildung in einem späteren Schritt als Nup50 erforderlich ist. Es enthält eine N-terminale Domäne, die als beta-Propeller in ihrer Tertiärstruktur angeordnet ist, und eine C-terminale Domäne, die sich als alfa-Solenoid faltet. Durch Depletion von Nup155 können Xenopus-Eiextrakte in vitro nicht mehr Kernporenkomplexe und eine geschlossenen Kernhülle bilden. Nup155 enthält eine membranbindende Region innenhalb ihres N-Terminals. In-Vitro-Zellkernrekonstitutionen unter Verwendung von Xenopus-Eiextrakten zeigen, dass diese Membranbindungsaktivität am Ende der Mitose erforderlich ist, da eine Mutante des Nup155 Proteins, die nicht mehr an Membranen binden kann, nicht in der Lage war, das endogene Protein in Nup155-depletierten Extrakten zu ersetzen. Allerdings war das Hinzufügen von Nup155, welches am C-Terminus gekürzt wurde, in der Lage, die Kernhülle wiederherzustellen, aber nicht den Kernporenkomplex zu bilden. Diese Arbeit zeigt weiter, dass Nup155 in Lösung in einer geschlossenen Konformation gefunden werden kann. Die Bindungsstelle für Nup53 befindet sich am N-Terminus, ist aber teilweise durch den C-Terminus blockiert, was den optimalen Oberflächenkontakt der beiden Proteine verhindert. Nup93 ist erforderlich für die Konformationsänderung: Wenn Nup93 Nup53 bindet, wird die Kontaktfläche zwischen Nup53 und Nup155 optimiert und in diesem Zusammenhang kann sich Nup93 an die naszierenden Pore lokalisieren und den Nup-62-Komplex rekrutieren

    When more is less: the effect of multiple health and nutritional labels in food product choice

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    Consumers are facing increasing information on health and nutritional aspects of foods, an important source of which is that presented in food packages. Prior research has identified that this information is positively valued, but the effect of multiple information items simultaneously is not so well understood. A choice experiment has been conducted to identify the effect of multiple health and nutrition information sources in two products which represent both a healthy and less-healthy food (pork Frankfurt sausages and plain yoghurt respectively). Results show that although highly heterogeneous, preferences seem to positively value individual information items and negatively value the presence of more than one item, specially if the item is a health claim. Premiums consumers are willing to pay represent a significant percentage of retail price, specially for the less healthy food product which also faces lower retails prices.Nutritional information, nutritional claims, health claims, Consumer/Household Economics, Food Consumption/Nutrition/Food Safety,

    IDENTIFYING CONSUMER VALUATION PATTERNS OF ALTERNATIVE NUTRITION AND HEALTH LABELS COMBINATIONS: EVIDENCE FROM SPAIN

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    The provision of nutrition and health information on food labels is increasing as an industry and regulation answer to the growing consumer concern with diet-health relationships. Prior research has shown that the presence of this information on food labels is valued by consumers; however there is still no clear pattern on which labelling options are more valued and how different consumers value the different options. This paper analyses the results of a choice experiment conducted to identify the effect of multiple health and nutrition information sources on consumer food choice, taking into account preference heterogeneity using a latent class approach. Results show that different consumer groups can be identified with clearly distinguishable valuation and behavioural patterns. A minority of consumers attaches high WTP to the provision of additional information in the nutrition facts panel, however this is not show for a vast majority who value claims. Moreover, not taking into account this preference heterogeneity can lead to policies that do not maximize consumer welfare. Based on the characteristics of consumers identified in each group, recommendations are made as to how both industry and public administration can move forward with the development of nutritional labelling guidelines or policies.Nutrition facts panel, latent class, choice experiments, consumer, interactions, health claims, nutrition claims, Consumer/Household Economics, Food Consumption/Nutrition/Food Safety, Health Economics and Policy,

    Nakon EC8: novi talijanski propisi za protupotresnu gradnju

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    The 2002 Molise earthquake, which was defined by seismologists as a normal event in the geodynamics of the Italian peninsula but had an international resonance due to the collapse of a primary school, triggered a series of research initiatives in earthquake engineering and significant modifications to building codes in Italy. The modifications were completed at the beginning of 2008 with the release of a new comprehensive building code for Italy. This document was mainly inspired by Eurocode, but it contains some changes and improvements. In this paper, comments are made on three specific parts of the new code: definition of seismic action, analysis of liquefaction and analysis of slope stability. For the first part, seismic action is defined based on a recent careful study of the seismic hazard in Italy. For liquefaction analysis, some developments are given, keeping the same structure used in Eurocode. Finally, for slope stability, improvements are introduced to avoid overestimation of pseudostatic forces in conventional analyses.Iako su potres u pokrajini Molize, koji se dogodio 2002. godine, seizmolozi kategorizirali kao uobičajenu geodinamičku pojavu na talijanskom poluotoku, on je imao veliki odjek u javnosti jer je prouzročio rušenje jedne osnovne škole. Taj je događaj u Italiji inicirao mnoga istraživanja u području potresnog inženjerstva i značajne izmjene zakona o gradnji. Te su izmjene dovršene početkom 2008. godine, kada je obznanjen novi, detaljno razrađen, talijanski zakon o protupotresnoj gradnji. Taj je zakon izrađen po uzoru na Eurokod, ali donosi i neke novine i unaprje|enja. Iz tog se zakona u ovom članku komentiraju: definicija seizmičkog opterećenja, te analize potencijala likvefakcije i stabilnosti kosina. Seizmičko je opterećenje određeno na temelju nedavnih detaljnih studija seizmičkog hazarda na području Italije. Što se tiče likvefakcije, prikazane su neke novine u odnosu na Eurokod. Konačno, u vezi stabilnosti kosina unesene su izmjene u odnosu na Eurokod da se izbjegnu prevelike pseudostatičke sile u konvencionalnim analizama stabilnosti
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