949 resultados para small structural changes
Resumo:
AbstractEffects of different β-glucan concentrations in maize flour on the properties of frozen maize tortillas were evaluated. Masa (dough), pre-cooked (PTs), frozen (FTs), thawed (TTs), and cooked tortillas (CTs) were made and analyzed. Moisture content of masa and tortillas significantly decreased as β-glucan concentration increased; however, the water absorption capacity (WAC), ice melting enthalpy, and frozen water in FTs increased. Texture and color of the masa, PTs, and CTs as well as sensory analysis showed differences only between tortillas with 0% and 4% β-glucans. β-glucans did not affect the texture of CTs. Soluble fiber increased by over threefold and fivefold in tortillas with 2% and 4% β-glucans, respectively, than in those without β-glucans. This result was consistent with the observed structural changes in tortillas, showing an increase in high-fiber aggregates with increasing β-glucan concentration. Tortillas with 2% β-glucans showed acceptable physicochemical, functional, and sensory properties, but over three times the soluble fiber. Therefore, it is possible to obtain frozen tortillas with high fiber content and increase their shelf life for subsequent cooking while maintaining good properties.
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Using an indicator of labor productivity, this paper aims to assess the contribution of structural changes in the Brazilian manufacturing and mining industries to productivity growth, during the 1970-2001 period. The conclusion is that: (i) there is no evidence to sustain that the Brazilian industry has definitely reversed the productivity growth rates slowdown trend; (ii) there is no clear evidence of a positive influence of the structural bonus; and (iii) job creation seems to be concentrated in low productivity growth sectors.
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This paper examines the post-War industrialization process in the Brazilian State of Minas Gerais, focusing on one of its desirable outcomes, namely the capacity to generate growth through the impact of strong input-output linkages. This process is placed into historical perspective considering the ideas that permeate the economic development debate throughout the period of analysis. Changes in the regional economic structure are assessed through the use of three input-output tables for the years of 1953, 1980 and 1995. By adopting the fields of influence methodology as the analytical core, it is shown that the efforts towards the creation of a more integrated regional economy have generated stronger influence of the targeted sectors (metal products, transportation equipment, chemical, and services). However, structural changes also contributed to strengthen leakage in the system originated in traditional economic activities.
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Growth and industrialization in Brazil. In this paper, based on the writings of Kaldor and his followers, we compare two phases of Brazilian economic growth, one showing fast growth rate and other with lack of growth. Our aim is to analyze the Brazilian economic behavior in the last 40 years, pointing out economic policy intervention, structural change, foreign trade and capital flows as determinants to account for gross product development path performance. Our aim is to shed some light on which is the potential rate of growth of the Brazilian economy nowadays, considering its historical growth path and recent structural changes in the industrial sector.
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This paper analyzes the Brazilian growth pattern during the post-liberalization period, emphasizing the structural links between finance and productive capital accumulation. The results indicate a finance-led growth regime in the period 2004-2008, under a very specific financialization process. The first part is a survey of the international literature, which defines the financialization concept and its relevance for understanding Brazilian economic problems. The next part provides a historical overview on the structural changes that made possible the development of financial-led regimes. The paper also applies an empirical analysis of some selected Brazilian macroeconomic indicators.
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Exchange rate regime and structural changes in the Brazilian manufacturing industry. This article proposes an analysis of the relationship between exchange rate regime and evolution of the Brazilian manufacturing industry during the period 1980-2008. Its main purpose is to detect the direction of the structural changes imposed by the new form of international insertion consolidated throughout the 1990s. The work also provides new empirical evidence regarding the assumptions of deindustrialization and "Dutch disease", which mark the current debate on the effects of the appreciation of real exchange rate in the Brazilian economy.
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Structural changes and labor market in Brazil. In the present article, we attempt to identify the sources of the changes in the labor schooling level in the three main sectors of the Brazilian economy: manufacturing, services and agriculture. It was verified that, despite the changes in the product and employment among sectors, mainly in the 1990s, the relative demands for qualified workers has not experimented significant changes. Moreover, in the periods in which schooling has increased more, the workers' wage has decreased more. This fact suggests that the increase in labor qualification was mainly due to the increase of this factor supply. The structural changes had contributed, in general, in a marginal and negative way to labor force level of qualification demand in all the three sectors.
Resumo:
Tämä työ käsittelee valkaistun ja valkaisemattoman sellumassan varastosäiliön tärinää ja värähtelyä. Värähtelyn seurauksena säiliön seinämän jäykisterenkaan hitsausliitokseen on syntynyt särö. Työn tavoitteena on selvittää, mikä johtaa särön syntyyn ja miten kestäväm-piä varastosäiliöitä voidaan rakentaa materiaali-, valmistus- tai rakennemuutoksien avulla. Työ alkoi tutkimalla rakennemateriaalina olevan duplex-teräksen mikrorakenteen ominai-suuksia, sekä sen hitsattavuutta ja seostamista kirjallisuustutkimuksena. Kirjallisuustutki-musta jatkettiin selvittämällä mahdollisia vaurion syntymekanismeja seinämän särölle. Työssä analysoitiin myös tehtaalla mitattuja värähtelyarvoja. Lopuksi laskettiin FE-analyysillä tyhjän varastosäiliön ominaismuodot ja -taajuudet moodianalyysillä, sekä selvi-tettiin harmonisella analyysillä pinnankorkeuden vaihtelun vaikutus siirtymävasteeseen ja kriittisiin värähtelytaajuuksiin. Varastosäiliöön kohdistuvaa värähtelyä ei ole mahdollista poistaa kokonaan, mutta väräh-telyn aiheuttamia seurauksia kyetään rajaamaan useilla keinoilla. Toimenpiteinä voivat olla ainakin seinämän materiaalin paksuuden lisääminen, jäykisteripojen lisääminen ja kriittisten sellun pinnankorkeuksien välttäminen. Kriittiseksi pinnankorkeudeksi havaittiin 40–45 %:n täyttöaste ja turvalliseksi korkeudeksi 35–38 %:n täyttöaste. Varastosäiliölle kriittisen ominaistaajuuden katsotaan syntyvän taajuuksilla 3,3–3,8 Hz ja 5,8–6,4 Hz. Sellumassa putoaa varastosäiliöön noin 2 Hz taajuudella.
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Human-Centered Design (HCD) is a well-recognized approach to the design of interactive computing systems that supports everyday and professional lives of people. To that end, the HCD approach put central emphasis on the explicit understanding of users and context of use by involving users throughout the entire design and development process. With mobile computing, the diversity of users as well as the variety in the spatial, temporal, and social settings of the context of use has notably expanded, which affect the effort of interaction designers to understand users and context of use. The emergence of the mobile apps era in 2008 as a result of structural changes in the mobile industry and the profound enhanced capabilities of mobile devices, further intensify the embeddedness of technology in the daily life of people and the challenges that interaction designers face to cost-efficiently understand users and context of use. Supporting interaction designers in this challenge requires understanding of their existing practice, rationality, and work environment. The main objective of this dissertation is to contribute to interaction design theories by generating understanding on the HCD practice of mobile systems in the mobile apps era, as well as to explain the rationality of interaction designers in attending to users and context of use. To achieve that, a literature study is carried out, followed by a mixed-methods research that combines multiple qualitative interview studies and a quantitative questionnaire study. The dissertation contributes new insights regarding the evolving HCD practice at an important time of transition from stationary computing to mobile computing. Firstly, a gap is identified between interaction design as practiced in research and in the industry regarding the involvement of users in context; whereas the utilization of field evaluations, i.e. in real-life environments, has become more common in academic projects, interaction designers in the industry still rely, by large, on lab evaluations. Secondly, the findings indicate on new aspects that can explain this gap and the rationality of interaction designers in the industry in attending to users and context; essentially, the professional-client relationship was found to inhibit the involvement of users, while the mental distance between practitioners and users as well as the perceived innovativeness of the designed system are suggested in explaining the inclination to study users in situ. Thirdly, the research contributes the first explanatory model on the relation between the organizational context and HCD; essentially, innovation-focused organizational strategies greatly affect the cost-effective usage of data on users and context of use. Last, the findings suggest a change in the nature of HCD in the mobile apps era, at least with universal consumer systems; evidently, the central attention on the explicit understanding of users and context of use shifts from an early requirements phase and continual activities during design and development to follow-up activities. That is, the main effort to understand users is by collecting data on their actual usage of the system, either before or after the system is deployed. The findings inform both researchers and practitioners in interaction design. In particular, the dissertation suggest on action research as a useful approach to support interaction designers and further inform theories on interaction design. With regard to the interaction design practice, the dissertation highlights strategies that encourage a more cost-effective user- and context-informed interaction design process. With the continual embeddedness of computing into people’s life, e.g. with wearable devices and connected car systems, the dissertation provides a timely and valuable view on the evolving humancentered design.
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Italy is currently experiencing profound political change. One aspect of this change involves the decline in electoral support for the Italian Christian Democratic Party (DC) and the Italian Communist Party (PCI), now the Democratic Party of the Left (PDS). Signs of the electoral decline of both parties began to appear in the late 1970s and early 1980s and accelerated in the late 1980s and early 1990s. The pr imar y purpos e of th is thes is is to expla i n the electoral decline of the DC and PCI/PDS in the last decade. The central question being addressed in this thesis is the following: What factors contributed to the decline in electoral support for the DC and PCI? In addition, the thesis attempts to better comprehend the change in magni tude and direction of the Italian party system. The thesis examines the central question within an analytical framework that consists of models explaining electoral change in advanced industrial democracies and in Italy. A review of the literature on electoral change in Italy reveals three basic models: structural (socioeconomic and demographic factors), subcultural (the decline of the Catholic and Communist subcultures), and pol i tical (factors such as party strategy, and the crisis and collapse of communism in iv Eastern Europe and the former soviet Union and the end to the Cold War). Significant structural changes have occurred in Italy, but they do not invariably hurt or benefit either party. The Catholic and Communist subcultures have declined in size and strength, but only gradually. More importantly, the study discovers that the decline of communism and party strategy adversely affected the electoral performances of the DC and PC!. The basic conclusion is that political factors primarily and directly contributed to the decline in electoral support for both parties, while societal factors (structural and subcultural changes) played a secondary and indirect role. While societal factors do not contribute directly to the decline in electoral support for both parties, they do provide the context within which both parties operated. In addition, the Italian party system is becoming more fragmented and traditional political parties are losing electoral support to new political movements, such as the Lega Nord (LN-Northern League) and the Rete (Network). The growing importance of the North-South and centre-periphery cleavages suggests that the Italian party system, which is traditionally based on religious and ideological cleavages, may be changing.
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Two classes of compounds have been prepared and characterized as building blocks for chiral magnets and ferromagnetic conductors. In the fIrst project, the organic framework of a pentadentate, (N302) macro cycle has been synthetically modifIed to introduce phenyl substituents into its organic framework and the synthesis of four new [Fe(In(N302)(CN)2] complexes (I) - (IV) is presented. [Molecular diagram availble in pdf] This work represents the fIrst structural and magnetic studies of a family of spin crossover macrocycles that comprise of both structural and stereo-isomers. Magnetic susceptibility and Mossbauer data for the R,R-complex (I) is consistent with both a thermal and a light induced spin crossover transition. The X-ray data supports a change in geometry accompanying the thermal spin transition, from a high spin (HS) 7 -coordinate complex at room temperature to a low spin (LS) 5-coordinate complex at 100 K. The crystal structure ofthe racemic complex (III) reveals a HS, 7-coordinate complex at 200 K that undergoes no signifIcant structural changes on cooling. In contrast, the magnetic - susceptibility and Mossbauer data collected on a powder sample of the racemic complex are consistent with a LS complex. Finally, the meso complex (IV) was prepared and its structure and magnetic properties are consistent with a 5-coordinate LS complex that remains low spin, but undergoes conformational changes on cooling in solution. The chiral [Fe(H)(N302)(CN)2] macro cycle (I), together with its Mn(H) and Fe(H) derivatives have also been exploited as building blocks for the self-assembly of chiral magnets. In the second project, a synthetic route for the preparation of tetrathiafulvalene (TTF) donors covalently attached to a diisopropyl verdazyl radical via a cross conjugated pyridyl linker IS presented. Following this strategy, four new TTF-py- (diisopropyl)verdazyl radicals have been prepared and characterized (V) - (VIII) . [Molecular diagram available in pdf] The first (2:1) charge transfer complex ofa TTF-py-(diisopropyl)verdazyl radical donor and a TCNQ acceptor has been prepared and structurally characterized. The crystal packing shows that the donor and acceptor molecules are organized in a mixed stacking arrangement consistent with its insulating behaviour. EPR and magnetic susceptibility data support intramolecular ferromagnetic interactions between the TTF and the verdazyl radicals and antiferromagnetic interactions between TTF donors within a stack. In an attempt to increase the intramolecular exchange interaction between the two radicals, a TTF-x-(diisopropyl)verdazyl radical (IX) was prepared, where the two radicals are connected ia a conjugated divinylene linker. The neutral radical donors stack in a more favourable head-to-head arrangement but the bulky isopropyl groups prevent the donor radicals from stacking close enough together to facilitate good orbital overlap. [Molecular diagram available in pdf].
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Work in the area of molecule-based magnetic and/or conducting materials is presented in two projects. The first project describes the use of 4,4’-bipyridine as a scaffold for the preparation of a new family of tetracarboxamide ligands. Four new ligands I-III have been prepared and characterized and the coordination chemistry of these ligands is presented. This project was then extended to exploit 4,4’-bipyridine as a covalent linker between two N3O2 macrocyles. In this respect, three dimeric macrocycles have been prepared IV-VI. Substitution of the labile axial ligands of the Co(II) complex IV by [Fe(CN)6]4- afforded the self-assembly of the 1-D polymeric chain {[Co(N3O2)H2O]2Fe(CN)6}n•3H2O that has been structurally and magnetically characterized. Magnetic studies on the Fe(II) complexes V and VI indicate that they undergo incomplete spin crossover transitions in the solid state. Strategies for the preparation of chiral spin crossover N3O2 macrocycles are discussed and the synthesis of the novel chiral Fe(II) macrocyclic complex VII is reported. Magnetic susceptibility and Mössbauer studies reveal that this complex undergoes a gradual spin crossover in the solid state with no thermal hysteresis. Variable temperature X-ray diffraction studies on single crystals of VII reveal interesting structural changes in the coordination geometry of the macrocycle accompanying its SCO transition. The second project reports the synthesis and characterization of a new family of tetrathiafulvalene derivatives VIII – XII, where a heterocyclic chelating ligand is appended to a TTF donor via an imine linker. The coordination chemistries of these ligands with M(hfac)2.H2O (M( = Co, Ni, Mn, Cu) have been explored and the structural and magnetic properties of these complexes are described.
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Des modèles de dysfonction érectile (DE) ont été développés et étudiés chez le rat. Cependant, peu de choses sont connues dans certains modèles présentant des facteurs de risque de la DE, en l’occurrence le rat soumis à une diète riche en glucose, le rat avec une restriction de croissance intra-utérine (RCIU) et le rat avec l’infusion continue de l’angiotensine (Ang) II en ce qui concerne l’évaluation de la fonction érectile in vivo. C’est ainsi que nous nous sommes proposés cette étude. La fonction érectile a été mesurée par la stimulation électrique du nerf caverneux à des cohortes de rats mâles Sprague-Dawley de différents âges comme suit: 1) des rats jeunes de 12 semaines d’âge, adultes reproducteurs à la retraite d’environ 30 semaines d’âge et des rats de 27 et 29 semaines soumis à une diète riche en glucose par l’eau de breuvage (10%) à court (1 semaine), moyen (6 semaines) et long (12 ou 13 semaines) termes; 2) des rats jeunes âgés de 12 semaines recevant une infusion soit de l’Ang II (200ng/kg/min) soit de la saline par mini-pompes osmotiques sous-cutanées pendant 1 et 2 semaines; et 3) des rats adultes âgés de 36 semaines avec une RCIU. La fonction érectile a été représentée par des courbes de variations de pression intracaverneuse (PIC) et d’aire sous la courbe (ASC) normalisées avec la pression artérielle moyenne (PAM) en réponse à la stimulation nerveuse à différents volts. À la fin des expériences, les animaux ont été sacrifiés, le sang recueilli pour le dosage de la glycémie et de l’insulinémie; le pénis, l’aorte thoracique et le cœur prélevés à des fins d’analyses protéique et histologique. La diète riche en glucose à court terme a eu un effet néfaste sur la fonction érectile chez le jeune rat mais bénéfique chez le rat adulte reproducteur; de même que pour les études à long terme, la diète riche en glucose a amélioré ou renversé la DE associée au vieillissement. Les rats avec RCIU ont exhibé une baisse très significative de la fonction érectile. Ces détériorations ou améliorations de la fonction érectile avec le glucose ou dans la RCIU ont été principalement associées à des modifications de l’expression de l’Akt, en plus d’une augmentation de l’insuline sérique dans les groupes avec le glucose. L’Ang II a entraîné une baisse de la fonction érectile, statistiquement très significative après 1 semaine et maintenue après 2 semaines de traitement, sans causer des changements morphologiques au cœur et à l’aorte thoracique. En conclusion : l’atteinte du système érectile se fait précocement dans les complications cardiovasculaires liées à l’activation du SRA, l’implication de l’Akt dans la modulation de la fonction érectile dépend de type de vieillissement et de la diète, le RCIU est un facteur de risque pour la DE.
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L’arthrose (OA) est une maladie articulaire dégénérative à l’étiologie complexe et diverse. Les travaux de ces dernières années ont démontré que l’OA est une pathologie affectant tous les tissus de l’articulation incluant le cartilage, la membrane synoviale et l’os sous-chondral. L’OA se traduit par une déstructuration et une perte de fonctionnalité de l’articulation, et est principalement caractérisée par une perte de cartilage articulaire. L’inflammation de la membrane synoviale joue un rôle déterminant dans la progression de l’OA, toutefois elle serait secondaire à la dégradation du cartilage. De plus, l’os sous-chondral est également le siège de nombreuses transformations lors de l’OA. Il est fortement suggéré que ces changements ne correspondent pas seulement à une conséquence, mais pourraient être une cause du développement de l’OA impliquant une communication entre ce tissu et le cartilage. Il est maintenant bien établi que les voies inflammatoires et cataboliques jouent un rôle crucial dans l’OA. C’est pourquoi, nous avons étudié l’implication d’une nouvelle famille de récepteurs membranaires, les PARs, et plus particulièrement le PAR-2 dans les voies physiopathologiques de l’OA. Notre hypothèse est que l’activation de PAR-2 au cours de l’OA est un phénomène majeur du développement/progression de la maladie faisant du récepteur PAR-2 un candidat privilégié pour le développement de nouvelles approches thérapeutiques ciblant non seulement le cartilage mais aussi l’os sous-chondral. Pour cette étude, nous avons travaillé in vitro avec des chondrocytes (Cr) et des ostéoblastes (Ob) OA respectivement du cartilage et de l’os sous-chondral du condyle fémoral humain. Nos résultats ont démontré que PAR-2 était plus exprimé dans les Cr et les Ob OA que dans les cellules normales. Par ailleurs, PAR-2 est régulé positivement par certains facteurs retrouvés au cours de l’OA comme l’IL-1β, le TNF-α et le TGF-β dans les Cr OA, et par l’IL-1β, le TNF-α et la PGE2 dans les Ob OA. De plus, les principaux facteurs cataboliques et inflammatoires, soit la MMP-1, la MMP-13 et la COX-2 sont produits en quantité plus élevée suite à l’activation du récepteur dans le cartilage OA. De même, l’activation de PAR-2 dans les Ob OA conduit à une production accrue de facteurs pro-résorptifs tels que RANKL, l’IL-6, la MMP-1 et la MMP-9, et à l’augmentation de l’activité pro-résorptive de ces cellules. En outre, dans les deux types tissulaires étudiés, l’activation de PAR-2 augmente l’activité de certaines protéines de la famille des MAPKinases comme Erk1/2, p38 et JNK. Finalement, nous avons conclu notre étude en employant un modèle in vivo d’OA induite chez la souris sauvage et déficiente pour le gène PAR-2. Nos résultats ont démontré que l’absence d’expression et de production de PAR-2 influençait le processus inflammatoire et les changements structuraux affectant à la fois le cartilage et l’os sous-chondral, conduisant à un ralentissement du développement de l’OA. Nos travaux de recherche ont donc permis de montrer que le récepteur PAR-2 est un élément majeur du processus OA en agissant sur les voies cataboliques et inflammatoires du cartilage, et sur le remodelage tissulaire de l’os sous-chondral. Mots-clés : Arthrose, chondrocyte, cartilage, ostéoblaste, os sous-chondral, PAR-2, MMPs, COX, ILs, RANKL, résorption osseuse, MAPKinase, catabolisme, inflammation
Resumo:
L’Écosse du XVIIIe siècle connaît de grands changements qui seront à l’aune des transformations socio-économiques sous-tendant sa Révolution industrielle. L’historiographie sur le sujet est divisée entre deux visions du développement – nommées pour le bienfait de cette étude traditionnelle et révisionniste – à savoir si ces transformations valident la notion d’une « révolution agraire ». Cette étude propose une recension de ces deux courants et propose d’appliquer leur analyse sur une région circonscrite, l’Aberdeenshire. À l’aide de l’Old Statistical Account, source majeure pour l’étude de l’histoire moderne écossaise, nous tenterons de démontrer que le caractère particulier du développement des régions ne correspond pas à l’application des conclusions nationales. Nous accorderons une attention spéciale à la propriété foncière, à l’impact des enclosures et à la temporalité des changements. De par ses spécificités, et son retard de modernisation agraire et agricole, nous croyons que la région suit le schéma dressé par les historiens révisionnistes, c.-à-d. des changements structurels s’étendant sur un temps long et ne s’inscrivant pas directement dans la période 1755-1815, traditionnellement désignée comme « révolution agraire ». Il s’agirait plutôt d’une adaptation partielle et originale des nouvelles idées mises de l’avant par les protagonistes de la modernisation.