992 resultados para Dominant process


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We investigated the responses of the ecologically dominant Antarctic phytoplankton species Phaeocystis antarctica (a prymnesiophyte) and Fragilariopsis cylindrus (a diatom) to a clustered matrix of three global change variables (CO2, mixed-layer depth, and temperature) under both iron (Fe)-replete and Fe-limited conditions based roughly on the Intergovernmental Panel on Climate Change (IPCC) A2 scenario: (1) Current conditions, 39 Pa (380 ppmv) CO2, 50 µmol photons/m**2/s light, and 2°C; (2) Year 2060, 61 Pa (600 ppmv) CO2, 100 µmol photons/m**2/s light, and 4°C; (3) Year 2100, 81 Pa (800 ppmv) CO2, 150 µmol photons/m**2/s light, and 6°C. The combined interactive effects of these global change variables and changing Fe availability on growth, primary production, and cell morphology are species specific. A competition experiment suggested that future conditions could lead to a shift away from P. antarctica and toward diatoms such as F. cylindrus. Along with decreases in diatom cell size and shifts from prymnesiophyte colonies to single cells under the future scenario, this could potentially lead to decreased carbon export to the deep ocean. Fe : C uptake ratios of both species increased under future conditions, suggesting phytoplankton of the Southern Ocean will increase their Fe requirements relative to carbon fixation. The interactive effects of Fe, light, CO2, and temperature on Antarctic phytoplankton need to be considered when predicting the future responses of biology and biogeochemistry in this region.

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Historically, the authority to conclude international treaties was exclusively exercised by administrative bodies (or the chief of state). However, recent studies pointed out that the present legislative bodies have come to play a more active role through ratification or the review of treaties in European and American countries. Harrington (2005) studied judicial reform in British dominions and criticized the past executive-dominant treaty-making process as a “democratic deficit” due to a fear that under this system the nation might be bound by international agreements for which a consensus had not been obtained. These studies indicated that people’s participation in the treaty-making process has increased on a global basis, but neither of them provides sufficient descriptive evidence regarding why and how such procedures were established. The present paper therefore attempts to solve these questions by analyzing the legislative and political process of the treaty-making procedure reform in Thailand’s 2007 constitution as a case study.

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Skeletal formation is a fundamental element of body patterning and is strictly regulated both temporally and spatially by a variety of molecules. Among these, retinoic acid (RA) has been shown to be involved in normal skeletal development. However, its pleiotropic effects have caused difficulty in identifying its crucial target cells and molecular mechanisms for each effect. Development of cartilage primordia is an important process in defining the skeletal structures. To address the role of RA in skeletal formation, we have generated mice expressing a dominant-negative retinoic acid receptor (RAR) in chondrogenic cells by using the type II collagen α1 promoter, and we have analyzed their phenotypes. These mice exhibited small cartilage primordia during development and retarded skeletal formation in both embryonic and postnatal periods. They also showed selective degeneration in their cervical vertebrae combined with homeotic transformations, but not in their extremities. The cervical phenotypes are reminiscent of phenotypes involving homeobox genes. We found that the expression of Hoxa-4 was indeed reduced in the cartilage primordia of cervical vertebrae of embryonic day 12.5 embryos. These observations demonstrate that endogenous RA acts directly on chondrogenic cells to promote skeletal growth in both embryonic and growing periods, and it regulates the proper formation of cervical vertebrae. Furthermore, RA apparently specifies the identities of the cervical vertebrae through the regulation of homeobox genes in the chondrogenic cells. Great similarities of the phenotypes between our mice and reported RAR knockout mice revealed that chondrogenic cells are a principal RA target during complex cascades of skeletal development.

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Wounding of endothelial cells is associated with altered direct intercellular communication. To determine whether gap junctional communication participates to the wound repair process, we have compared connexin (Cx) expression, cell-to-cell coupling and kinetics of wound repair in monolayer cultures of PymT-transformed mouse endothelial cells (clone bEnd.3) and in bEnd.3 cells expressing different dominant negative Cx inhibitors. In parental bEnd.3 cells, mechanical wounding increased expression of Cx43 and decreased expression of Cx37 at the site of injury, whereas Cx40 expression was unaffected. These wound-induced changes in Cx expression were associated with functional changes in cell-to-cell coupling, as assessed with different fluorescent tracers. Stable transfection with cDNAs encoding for the chimeric connexin 3243H7 or the fusion protein Cx43-βGal resulted in perturbed gap junctional communication between bEnd.3 cells under both basal and wounded conditions. The time required for complete repair of a defined wound within a confluent monolayer was increased by ∼50% in cells expressing the dominant negative Cx inhibitors, whereas other cell properties, such as proliferation rate, migration of single cells, cyst formation and extracellular proteolytic activity, were unaltered. These findings demonstrate that proper Cx expression is required for coordinated migration during repair of an endothelial wound.

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One of the key environmental concerns about shrimp farming is the discharge of waters with high levels of nutrients and suspended solids into adjacent waterways. In this paper we synthesize the results of our multidisciplinary research linking ecological processes in intensive shrimp ponds with their downstream impacts in tidal, mangrove-lined creeks. The incorporation of process measurements and bioindicators, in addition to water quality measurements, improved our understanding of the effect of shrimp farm discharges on the ecological health of the receiving water bodies. Changes in water quality parameters were an oversimplification of the ecological effects of water discharges, and use of key measures including primary production rates, phytoplankton responses to nutrients, community shifts in zooplankton and delta(15)N ratios in marine plants have the potential to provide more integrated and robust measures. Ultimately, reduction in nutrient discharges is most likely to ensure the future sustainability of the industry. (C) 2003 Elsevier Ltd. All rights reserved.

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Caveolins are a crucial component of caveolae but have also been localized to the Golgi complex, and, under some experimental conditions, to lipid bodies (LBs). The physiological relevance and dynamics of LB association remain unclear. We now show that endogenous caveolin-1 and caveolin-2 redistribute to LBs in lipid loaded A431 and FRT cells. Association with LBs is regulated and reversible; removal of fatty acids causes caveolin to rapidly leave the lipid body. We also show by subcellular fractionation, light and electron microscopy that during the first hours of liver regeneration, caveolins show a dramatic redistribution from the cell surface to the newly formed LBs. At later stages of the regeneration process (when LBs are still abundant), the levels of caveolins in LBs decrease dramatically. As a model system to study association of caveolins with LBs we have used brefeldin A (BFA). BFA causes rapid redistribution of endogenous caveolins to LBs and this association was reversed upon BFA washout. Finally, we have used a dominant negative LB-associated caveolin mutant (cav(DGV)) to study LB formation and to examine its effect on LB function. We now show that the cav(DGV) mutant inhibits microtubule-dependent LB motility and blocks the reversal of lipid accumulation in LBs.

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This paper examines the connected speech process described by Wells (1982b) as the T to R rule in the West Midlands speech variety associated with the Black Country. The T to R rule is well known as a linguistic marker of local varieties of the middle and far north of England. Less well understood is its position in the phonological systems of Midlands varieties. Varieties of the Midlands of England are underresearched in comparison with varieties of the north, and what is known about the application of the T to R rule in this transitional dialect area is correspondingly nebulous. This paper focuses on the Black Country area, and examines the possible outputs in the contexts which give rise to /t/ becoming [?] in local varieties of the north. I examine the written and spoken evidence which suggests that the T to R rule does indeed operate in the Black Country variety. My analysis focuses on possible phonetic outcomes of the T to R rule across time. In my conclusion, I discuss briefly the possibility that, lying on a bundle of isoglosses separating north from south, the variety of the Black Country reflects this in that a T to [?] rule, rather than a T to R rule, is the dominant output of this connected speech process in the Black Country.

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The development of strategy remains a debate for academics and a concern for practitioners. Published research has focused on producing models for strategy development and on studying how strategy is developed in organisations. The Operational Research literature has highlighted the importance of considering complexity within strategic decision making; but little has been done to link strategy development with complexity theories, despite organisations and organisational environments becoming increasingly more complex. We review the dominant streams of strategy development and complexity theories. Our theoretical investigation results in the first conceptual framework which links an established Strategic Operational Research model, the Strategy Development Process model, with complexity via Complex Adaptive Systems theory. We present preliminary findings from the use of this conceptual framework applied to a longitudinal, in-depth case study, to demonstrate the advantages of using this integrated conceptual model. Our research shows that the conceptual model proposed provides rich data and allows for a more holistic examination of the strategy development process. © 2012 Operational Research Society Ltd. All rights reserved.

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This article analyses language insertion as a bilingual communicative practice, applying a functional, speaker-focused approach to the study of sociolinguistics and language contact. The article is based on a study of contact phenomena in a formerly diglossic region in Northern Germany, where the previously spoken language – Low German – is in the process of being replaced by the dominant standard variety, German. It examines regional publications in order to establish the linguistic techniques by which Low German elements are incorporated into the Standard German texts and the communicative purposes that they serve. The paper concludes that in the process of language shift an emblematic repertoire from Low German is created which can be applied into the dominant contact language, German, for specific communicative purposes.

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The purpose of this study was to explore postmodern identity in the work of Chuck Palahniuk. The characters within Palahniuk's text Invisible Monsters realize the manner in which identity is a construct, and their response is to oppose and redefine it. In my research, I looked at how postmodern identity is defined by some of the leading critical thinkers in the field, and then I applied their thought to Palahniuk's characters. I showed how these characters come to understand the process by which society defines them, and with that realization, they oppose its totalizing definitions. The characters deconstruct the natural attitudes society has towards identity, and they reveal that it is in some way possible to create a unique identity that is not easily definable by the ruling discourse. I concluded that his attention to identity highlights Palahniuk's concern for the place, identity, and influence of his generation.

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This thesis defends the position that the Eastern Orthodoxy has the potential to develop, on the basis of its core concepts and doctrines, a new political theology that is participatory, personalist and universalist. This participatory political theology, as I name it, endorses modern democracy and the values of civic engagement. It enhances the process of democracy-building and consolidation in the SEE countries through cultivating the ethos of participation and concern with the common good among and the recognition of the dignity and freedom of the person. This political-theological model is developed while analyzing critically the traditional models of church-state relations (the symphonia model corresponding to the medieval empire and the Christian nation model corresponding to the nation-state) as being instrumentalized to serve the political goals of non-democratic regimes. The participatory political-theological model is seen as corresponding to the conditions of the constitutional democratic state. The research is justified by the fact the Eastern Orthodoxy has been a dominant religiouscultural force in the European South East for centuries, thus playing a significant role in the process of creation of the medieval and modern statehood of the SEE countries. The analysis employs comparative constitutional perspectives on democratic transition and consolidation in the SEE region with the theoretical approaches of political theology and Eastern Orthodox theology. The conceptual basis for the political-theological synthesis is found in the concept and doctrines of the Eastern Orthodoxy (theosis and synergy, ecclesia and Eucharist, conciliarity and catholicity, economy and eschatology) which emphasize the participatory, personalist and communal dimensions of the Orthodox faith and practice. The paradigms of revealing the political-theological potential of these concepts are the Eucharistic ecclesiology and the concept of divine-human communion as defining the body of Orthodox theology. The thesis argues that with its ethos of openness and engagement the participatory political theology presupposes political systems that are democratic, inclusive, and participatory, respecting the rights and the dignity of the person. The political theology developed here calls for a transformation and change of democratic systems towards better realization of their personalist and participatory commitments. In the context of the SEE countries the participatory political theology addresses the challenges posed by alternative authoritarian political theologies practiced in neighboring regions.