979 resultados para APICAL-DOMINANCE


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Resumen tomado de la publicaci??n

Relevância:

20.00% 20.00%

Publicador:

Resumo:

L’éducation physique (EP) est considérée comme une discipline fortement caractérisée par le «faire». Ce sont des mouvements, des gestes, des techniques ou des tactiques en situation et leurs résultats qui sont évalués. C’est aussi à travers le «faire moteur» que majoritairement est pensé le processus d’apprentissage des élèves. Toutefois, si les actions motrices se trouvent au centre des préoccupations disciplinaires, les leçons d’éducation physique comportent toujours une part, parfois assez importante, des «moments à dominance verbale» (MàDV). Ces derniers renvoient aux phases de la séance durant lesquelles l’enseignant et/ou les élèves communiquent verbalement (des gestes ou des démonstrations peuvent accompagner la parole). Le temps dédié aux consignes initiales, le temps des régulations après une situation de jeu ou le temps des feed-back sont des exemples typiques

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An outdoor experiment was conducted to increase understanding of apical leaf necrosis in the presence of pathogen infection. Holcus lanatus seeds and Puccinia coronata spores were collected from two adjacent and otherwise similar habitats with differing long-term N fertilization levels. After inoculation, disease and necrosis dynamics were observed during the plant growing seasons of 2003 and 2006. In both years high nutrient availability resulted in earlier disease onset, a higher pathogen population growth rate, earlier physiological apical leaf necrosis onset and a reduced time between disease onset and apical leaf necrosis onset. Necrosis rate was shown to be independent of nutrient availability. The results showed that in these nutrient-rich habitats H. lanatus plants adopted necrosis mechanisms which wasted more nutrients. There was some indication that these necrosis mechanisms were subject to local selection pressures, but these results were not conclusive. The findings of this study are consistent with apical leaf necrosis being an evolved defence mechanism.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Apical leaf necrosis is a physiological process related to nitrogen (N) dynamics in the leaf. Pathogens use leaf nutrients and can thus accelerate this physiological apical necrosis. This process differs from necrosis occurring around pathogen lesions (lesion-induced necrosis), which is a direct result of the interaction between pathogen hyphae and leaf cells. This paper primarily concentrates on apical necrosis, only incorporating lesion-induced necrosis by necessity. The relationship between pathogen dynamics and physiological apical leaf necrosis is modelled through leaf nitrogen dynamics. The specific case of Puccinia triticina infections on Triticum aestivum flag leaves is studied. In the model, conversion of indirectly available N in the form of, for example, leaf cell proteins (N-2(t)) into directly available N (N-1(t), i.e. the form of N that can directly be used by either pathogen or plant sinks) results in apical necrosis. The model reproduces observed trends of disease severity, apical necrosis and green leaf area (GLA) and leaf N dynamics of uninfected and infected leaves. Decreasing the initial amount of directly available N results in earlier necrosis onset and longer necrosis duration. Decreasing the initial amount of indirectly available N, has no effect on necrosis onset and shortens necrosis duration. The model could be used to develop hypotheses on how the disease-GLA relation affects yield loss, which can be tested experimentally. Upon incorporation into crop simulation models, the model might provide a tool to more accurately estimate crop yield and effects of disease management strategies in crops sensitive to fungal pathogens.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this review we describe how concepts of shoot apical meristem function have developed over time. The role of the scientist is emphasized, as proposer, receiver and evaluator of ideas about the shoot apical meristem. Models have become increasingly popular over the last 250 years, and we consider their role. They provide valuable grounding for the development of hypotheses, but in addition they have a strong human element and their uptake relies on various degrees of persuasion. The most influential models are probably those that most data support, consolidating them as an insight into reality; but they also work by altering how we see meristems, re-directing us to influence the data we collect and the questions we consider meaningful.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The synthesis, characterisation, X-ray single crystal structures and magnetic properties of three new basal-apical mu(2)-1,1-azide-bridged complexes [(CuLN3)-N-1](2) (1), [(CuLN3)-N-2](2) (2) and [(CuLN3)-N-3](2) (3) with very similar tridentate Schiff-base blocking ligands {HL1 = N-[2-(ethylamino) ethyl] salicylaldimine; HL2 = 7-(ethylamino)-4-methyl-5-azahept-3-en-2-one; HL3 = 7-amino-4-methyl-5-azaoct-3-en-2-one} have been reported [complex 1: monoclinic, P2(1)/c, a = 8.390(2), b = 7.512(2), c = 19.822(6) Angstrom, beta = 91.45(5)degrees; complex 2: monoclinic, P2(1)/c, a = 8.070(9), b = 9.787(12), c = 15.743(17) A, beta = 98.467(10)degrees; complex 3: monoclinic, P2(1)/n, a = 5.884(7), b = 16.147(18), c = 11.901(12) Angstrom, beta = 90.050(10)degrees]. The structures consist of neutral dinuclear entities resulting from the pairing of two mononuclear units through end-on azide bridges connecting an equatorial position of one copper centre to an axial position of the other, The copper ions adopt a (4+1) square-based geometry in all the complexes. In complex 2, there is no inter-dimer hydrogen-bonding. However, complexes 1 and 3 form two different supramolecular structures in which the dinuclear entities are linked by H-bonds giving one-dimensional systems. Variable temperature (300-2 K) magnetic-susceptibility measurements and magnetisation measurements at 2 K reveal that all three complexes have antiferromagnetic coupling. Magneto-structural correlations have been made taking into consideration both the azido bridging ligands and the existence of intermolecular hydrogen bonds. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The paper offers a new way to measure language ability in bilinguals, based on measures of lexical richness. The validity of proposed approach is tested in a variety of ways.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This chapter compares lexical diversity of French words used by Dutch-French bilinguals, English-French bilinguals and Flemish L2 learners of French.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper considers how the delivery of public leisure services in Britain has been affected by the imposition of Compulsory Competitive Tendering (CCT) on the management of facilities. In particular, it focuses on the changing relationship between the central and local levels of government, theorising a tripartite local response to CCT, incorporating local statism, post-Fordist rejection of CCT and post- Fordist compliance with the aims of the central administration. The paper then discusses the actual implementation of CCT, relating the theorised responses to those witnessed in practice. This results in the delineation of a continuum of stances, ranging from pragmatic forms of local statism, such as the protection of the former direct labour force, to centrist attempts to combine the ethics of socialism with the mechanics of the market, to an outright rejection of state organisation and control. The paper concludes that although legitimate attempts have been made to protect local services, the outcome of the CCT process has undoubtedly been the regeneration of public leisure provision away from its service roots towards a market model of provision.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Although much has been written about the effect on services of public sector restructuring, little is yet available on public leisure provision. This omission is addressed by considering how the delivery of public leisure services in Britain has been affected by the imposition of Compulsory Competitive Tendering (CCT). In particular, it focuses on the changing relationship between the central and local levels of government recognising, on the part of local government, a continuum of structural responses to central initiatives which have, in some cases, conspired to reduce the impact of CCT on public leisure provision. The paper concludes that although attempts have been made to protect local services, the outcome of the CCT process has been the regeneration of public leisure provision away from its service roots, but within an enduring ideological paradigm of conservative professionalism.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The 1991 decision of the European Commission on the Tetra Pak case was based on information which seemed to prove the firm's anti-competitive behavior. The Tetra Pak case is investigated here focusing on the meaning of multimarket dominance, using empirical techniques. We find that a more rigorous analysis of the data available would not confirm the Commission's assertions. That is, it cannot be concluded with certainty that the Commission was right to relate Tetra Pak's dominance in the aseptic sector to its market power in the non-aseptic sector. Our results suggest a general framework for the analysis of abusive transfer of market power across vertically or/and horizontally related markets.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper, the monetary policy independence of European nations in the years before European Economic and Monetary Union (EMU) is investigated using cointegration techniques. Daily data is used to assess pairwise relationships between individual EMU nations and ‘lead’ nation Germany, to assess the hypothesis that Germany was the dominant European nation prior to EMU. By and large our econometric investigations support this hypothesis, and lead us to conclude that the only European nation to lose monetary policy independence in the light of monetary union was Germany. Our results have important policy implications. Given that the loss of monetary policy independence is generally viewed as the main cost of monetary unification, our findings suggest a reconsideration of the costs and benefits of monetary integration. A country can only lose what it has, and in Europe the countries that joined EMU — spare Germany — apparently did not have much to lose, at least not in terms of monetary independence. Instead, they actually gained monetary policy influence by getting a seat in the ECB's governing council which is responsible for setting interest policy in the euro area.