Academic literature on the topic 'Non-existence result'
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Journal articles on the topic "Non-existence result"
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Wu, Mingzhu, and Zuodong Yang. "Existence and Non-Existence Result for Singular Quasilinear Elliptic Equations." Applied Mathematics 01, no. 05 (2010): 351–56. http://dx.doi.org/10.4236/am.2010.15046.
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Diening, Lars, and Michael Růžička. "An existence result for non-Newtonian fluids in non-regular domains." Discrete & Continuous Dynamical Systems - S 3, no. 2 (2010): 255–68. http://dx.doi.org/10.3934/dcdss.2010.3.255.
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Paoli, Laetitia. "An existence result for non-smooth vibro-impact problems." Journal of Differential Equations 211, no. 2 (April 2005): 247–81. http://dx.doi.org/10.1016/j.jde.2004.11.008.
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Kachmar, Ayman, and Mikael Persson. "A non-existence result for the Ginzburg–Landau equations." Comptes Rendus Mathematique 347, no. 21-22 (November 2009): 1261–64. http://dx.doi.org/10.1016/j.crma.2009.09.024.
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Mustafa, M. T. "A non-existence result for compact Einstein warped products." Journal of Physics A: Mathematical and General 38, no. 47 (November 9, 2005): L791—L793. http://dx.doi.org/10.1088/0305-4470/38/47/l01.
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De Beule, J., A. Hallez, and L. Storme. "A non-existence result on Cameron–Liebler line classes." Journal of Combinatorial Designs 16, no. 4 (2008): 342–49. http://dx.doi.org/10.1002/jcd.20164.
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Trabucho, L. "Non-linear bone remodelling: an existence and uniqueness result." Mathematical Methods in the Applied Sciences 23, no. 15 (2000): 1331–46. http://dx.doi.org/10.1002/1099-1476(200010)23:15<1331::aid-mma168>3.0.co;2-y.
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Paronetto, Fabio. "An existence result for evolution equations in non-cylindrical domains." Nonlinear Differential Equations and Applications NoDEA 20, no. 6 (March 14, 2013): 1723–40. http://dx.doi.org/10.1007/s00030-013-0227-0.
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Harker, Patrick T. "Existence of competitive equilibria via Smith's non-linear complementarity result." Economics Letters 19, no. 1 (January 1985): 1–4. http://dx.doi.org/10.1016/0165-1765(85)90090-4.
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Chen, Sitong, Binlin Zhang, and Xianhua Tang. "Existence and non-existence results for Kirchhoff-type problems with convolution nonlinearity." Advances in Nonlinear Analysis 9, no. 1 (September 20, 2018): 148–67. http://dx.doi.org/10.1515/anona-2018-0147.
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Abstract This paper is concerned with the following Kirchhoff-type problem with convolution nonlinearity: -\bigg{(}a+b\int_{\mathbb{R}^{3}}\lvert\nabla u|^{2}\,\mathrm{d}x\bigg{)}% \Delta u+V(x)u=(I_{\alpha}*F(u))f(u),\quad x\in{\mathbb{R}}^{3},\,u\in H^{1}(% \mathbb{R}^{3}), where {a,b>0} , {I_{\alpha}\colon\mathbb{R}^{3}\rightarrow\mathbb{R}} , with {\alpha\in(0,3)} , is the Riesz potential, {V\in\mathcal{C}(\mathbb{R}^{3},[0,\infty))} , {f\in\mathcal{C}(\mathbb{R},\mathbb{R})} and {F(t)\kern-1.0pt=\kern-1.0pt\int_{0}^{t}f(s)\,\mathrm{d}s} . By using variational and some new analytical techniques, we prove that the above problem admits ground state solutions under mild assumptions on V and f. Moreover, we give a non-existence result. In particular, our results extend and improve the existing ones, and fill a gap in the case where {f(u)=|u|^{q-2}u} , with {q\in(1+\alpha/3,2]} .
Dissertations / Theses on the topic "Non-existence result"
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Dereudre, David, and Sylvie Roelly. "Path-dependent infinite-dimensional SDE with non-regular drift : an existence result." Universität Potsdam, 2014. http://opus.kobv.de/ubp/volltexte/2014/7208/.
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We establish in this paper the existence of weak solutions of infinite-dimensional shift invariant stochastic differential equations driven by a Brownian term. The drift function is very general, in the sense that it is supposed to be neither small or continuous, nor Markov. On the initial law we only assume that it admits a finite specific entropy. Our result strongly improves the previous ones obtained for free dynamics with a small perturbative drift. The originality of our method leads in the use of the
specific entropy as a tightness tool and on a description of such stochastic differential equation as solution of a variational problem on the path space.
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Roelly, Sylvie, and Pra Paolo Dai. "An existence result for infinite-dimensional Brownian diffusions with non- regular and non Markovian drift." Universität Potsdam, 2004. http://opus.kobv.de/ubp/volltexte/2006/668/.
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We prove in this paper an existence result for infinite-dimensional stationary interactive Brownian diffusions. The interaction is supposed to be small in the norm ||.||∞ but otherwise is very general, being possibly non-regular and non-Markovian. Our method consists in using the characterization of such diffusions as space-time Gibbs fields so that we construct them by
space-time cluster expansions in the small coupling parameter.
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Ali, Zakaria Idriss. "Existence result for a class of stochastic quasilinear partial differential equations with non-standard growth." Diss., University of Pretoria, 2010. http://hdl.handle.net/2263/29519.
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In this dissertation, we investigate a very interesting class of quasi-linear stochastic partial differential equations. The main purpose of this article is to prove an existence result for such type of stochastic differential equations with non-standard growth conditions. The main difficulty in the present problem is that the existence cannot be easily retrieved from the well known results under Lipschitz type of growth conditions [42].Dissertation (MSc)--University of Pretoria, 2010.
Mathematics and Applied Mathematics
unrestricted
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ANSELLI, ANDREA. "PHI-CURVATURES, HARMONIC-EINSTEIN MANIFOLDS AND EINSTEIN-TYPE STRUCTURES." Doctoral thesis, Università degli Studi di Milano, 2020. http://hdl.handle.net/2434/703786.
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The aim of this thesis is to study the geometry of a Riemannian manifold M, with a special structure, called Einstein-type structure, depending on 3 real parameters, a smooth map phi into a target Riemannian manifold N, and a smooth function, called potential function, on M itself. We will occasionally let some of the parameters be smooth functions. The setting generalizes various previously studied situations:, Ricci solitons, almost Ricci-solitons, Ricci-harmonic solitons, quasi-Einstein manifolds and so on. By taking a constant potential function those structures reduces to harmonic-Einstein manifolds, that are a generalization of Einstein manifolds. The main ingredient of our analysis is the study of certain modified curvature tensors on M related to the map phi, called phi-curvatures, obtaining, for instance, their transformation laws under a conformal change of metric, and to develop a series of results for harmonic-Einstein manifolds that parallel those obtained for Einstein manifolds some times ago and also in the very recent literature. Einstein-type structures may be obtained, for some special values of the parameters involved, by a conformal deformation of a harmonic-Einstein manifold or even as the base of a warped product harmonic-Einstein manifold. The latter fact applies not only in the Riemannian but also in the Lorentzian setting and thus some Einstein-type structures are connected with solutions of the Einstein field equations, which are of particular interest in General Relativity. The main result of the thesis is the locally characterization, via a couple of integrability conditions and mild assumptions on the potential function, of Einstein-type structures with vanishing phi-Bach curvature (in the direction of the potential) as a warped product with harmonic-Einstein base and with an open real interval as fibre, extending in a very non trivial way a recent result for Bach flat Ricci solitons. Moreover the map phi depends only on the base of the warped product and not on the fibre . We also consider rigidity, triviality and non-existence results, both in the compact and non-compact cases. This is done via integral formulas and, in the non-compact case, via analytical tools, like the weak maximum principle and the classical results of Obata, Tashiro, Kanai.
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Huang, Lirong. "Multiplicity results for some classes of Schrödinger-Poisson systems." Doctoral thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/12867.
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Doutoramento conjunto em Matemática - Matemática e Aplicações (PDMA)In this thesis, we study the existence and multiplicity of solutions of the following class of Schr odinger-Poisson systems: u + u + l(x) u = (x; u) in R3; = l(x)u2 in R3; where l 2 L2(R3) or l 2 L1(R3). And we consider that the nonlinearity satis es the following three kinds of cases: (i) a subcritical exponent with (x; u) = k(x)jujp2u + h(x)u (4 p < 2 ) under an inde nite case; (ii) a general inde nite nonlinearity with (x; u) = k(x)g(u) + h(x)u; (iii) a critical growth exponent with (x; u) = k(x)juj2 2u + h(x)jujq2u (2 q < 2 ). It is worth mentioning that the thesis contains three main innovations except overcoming several di culties, which are generated by the systems themselves. First, as an unknown referee said in his report, we are the rst authors concerning the existence of multiple positive solutions for Schr odinger- Poisson systems with an inde nite nonlinearity. Second, we nd an interesting phenomenon in Chapter 2 and Chapter 3 that we do not need the condition R R3 k(x)ep 1dx < 0 with an inde nite noncoercive case, where e1 is the rst eigenfunction of +id in H1(R3) with weight function h. A similar condition has been shown to be a su cient and necessary condition to the existence of positive solutions for semilinear elliptic equations with inde nite nonlinearity for a bounded domain (see e.g. Alama-Tarantello, Calc. Var. PDE 1 (1993), 439{475), or to be a su cient condition to the existence of positive solutions for semilinear elliptic equations with inde nite nonlinearity in RN (see e.g. Costa-Tehrani, Calc. Var. PDE 13 (2001), 159{189). Moreover, the process used in this case can be applied to study other aspects of the Schr odinger-Poisson systems and it gives a way to study the Kirchho system and quasilinear Schr odinger system. Finally, to get sign changing solutions in Chapter 5, we follow the spirit of Hirano-Shioji, Proc. Roy. Soc. Edinburgh Sect. A 137 (2007), 333, but the procedure is simpler than that they have proposed in their paper.
Nesta tese, estudamos a existência e a multiplicidade de soluções da seguinte classe de sistemas denominada de Schr odinger-Poisson: u + u + l(x) u = (x; u) in R3; = l(x)u2 in R3; onde l 2 L2(R3) ou l 2 L1(R3). Consideram-se não-linearidades que satisfazem um dos seguintes casos: (i) potências que envolvem um expoente sub-cr tico, da forma (x; u) = k(x)jujp2u + h(x)u, (4 p < 2 ), sendo k uma função com sinal indefinido e h uma função positiva; (ii) caso geral de uma não-linearidade indefi nida, da forma (x; u) = k(x)g(u) + h(x)u, sendo k uma função com sinal indefinido e h uma função positiva; (iii) potências que envolvem o expoente crí tico, da forma (x; u) = k(x)juj2 2u + h(x)jujq2u (2 q < 2 ). Convém salientar que esta tese tem três principais inovações, as quais ultrapassam dificuldades geradas pela natureza dos problemas estudados. Primeiro, como um relator anónimo referiu, este é o primeiro trabalho em que se trata a existência de várias soluções de sistemas de Schrödinger- Poisson com não-linearidade indefinida. Segundo, neste estudo encontrou-se um fen ómeno interessante, ver Capítulos 2 e 3, nomeadamente, não ser necess ária a condição R3 k(x)ep 1dx < 0 no caso indefinido e não-coercivo, sendo e1 a função associada ao primeiro valor próprio de + id em H1(R3) com peso h. Note-se que foi demonstrado que uma condi cão semelhante e condição necessária e suficiente na existência de solu cões positivas para equações elíticas semilineares com não-linearidades indefinidas em domínios limitados (ver e.g. Alama-Tarantello, Calc. Var. PDE 1 (1993), 439{475), ou ser uma condição suficiente na existência de soluções positivas para equações elíticas semilineares com não-linearidades indefinidas em RN (see e.g. Costa-Tehrani, Calc. Var. PDE 13 (2001), 159{189). Adicionalmente, o método utilizado pode ser utilizado para estudar outros aspetos dos sistemas de Schrodinger-Poisson, permite também estudar sistemas de Kirchho e sistemas de Schrodinger quasilineares. Por m, para obter soluções com mudança de sinal no Cap. 5, segue se a ideia de Hirano-Shioji, Proc. Roy. Soc. Edinburgh Sect. A 137 (2007), 333, mas o método utilizado é uma versão simplificada do método apresentado no artigo referido.
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Bruso, Keith Alvin. "Existence, uniqueness and blow-up results for non-linear wave equations." 1985. http://hdl.handle.net/2097/27403.
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Tiago, Jorge Filipe Duarte. "Existence results and applications for some non-linear optimal control problems." Doctoral thesis, 2009. http://hdl.handle.net/10451/1657.
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Tese de doutoramento, Matemática (Análise Matemática), 2010, Universidade de Lisboa, Faculdade de CiênciasOs resultados clássicos de existência, para problemas de controlo óptimo, governados por sistemas de equações diferenciais ordinárias, baseam-se em condições de convexidade que resultam frequentemente muito difíceis de verificar. Apresentamos uma abordagem geral para este problema, com base em várias relaxações do mesmo, na qual a convexidade surge de um modo inesperada. Isolamos uma condição suficiente, para a existência de soluções óptimas, que pode ser verificada em vários contextos. Podemos chegar a um resultado de existência para problemas vectoriais, com uma estrutura particular, proveniente de problemas de controlo e manobra deve veículos subaquáticos. Numa abordagem diferente, recuperamos técnicas clássicas baseadas na reformulação variacional, que nos permitem obter resultados de existência através da aplicação de teoremas para problemas variacionais, sem condições de convexidade. Em particular, provamos a existência de solução, no caso escalar, para problemas de controlo óptimo autónomos.Utilizamos o nosso resultado de existência, demonstrado para problemas de controlo óptimo com variáveis vectoriais, para provar a existência de solução para um problema de manobra de veículos subaquáticos. Para terminar, apresentamos algumas ideias para trabalho futuro. Propomos a implementação de um método numérico, baseado em direcções de descida mais rápida, para aproximar soluções de problemas de controlo óptimo vindos das aplicações. Mostramos resultados preliminares desta implementação, para alguns exemplos académicos.
Classical existence results for optimal control problems governed by systems of ordinary differential equations are based on typical convexity assumptions, which are quite often, very difficult to check. We present a general approach to prove existence of solutions for optimal control problems, based on several relaxations of the problem, where the convexity arises inan unexpected way. We isolate one sufficient condition for the existence of optimal solutions, which can be validated in various contexts. We end up with a main existence result for vector problems with a particular structure, motivated by underwater-vehicles-maneuvering problems. Alternatively, we recover the classical approach based on a purely variational reformulation, which can lead to existence results by using one existence theorems for variational problems without convexity assumptions. In particular we prove the existence of solution for autonomous scalar optimal control problems. Finally, we apply our existence result for vector state and control variables, to prove the local existence of solution for an optimal control problem describing the control of an underwater vehicle. Additionally to the main work described above, we introduce some ideas for future work. We propose to implement a numerical method, based on steepest descent directions, to approximate the solutions of realistic optimal control problems. Some preliminary results for academic examples are shown.
Fundação para a Ciência e Tecnologia (SFRH-BD-22107-2005), Programa Operacional Ciência e Inovaçao 2010
Books on the topic "Non-existence result"
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Amirell, Stefan, Hans Hägerdal, and Bruce Buchan, eds. Piracy in World History. NL Amsterdam: Amsterdam University Press, 2021. http://dx.doi.org/10.5117/9789463729215.
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In a modern global historical context, scholars have often regarded piracy as an essentially European concept which was inappropriately applied by the expanding European powers to the rest of the world, mainly for the purpose of furthering colonial forms of domination in the economic, political, military, legal and cultural spheres. By contrast, this edited volume highlights the relevance of both European and non-European understandings of piracy to the development of global maritime security and freedom of navigation. It explores the significance of ‘legal posturing’ on the part of those accused of piracy, as well as the existence of non-European laws and regulations regarding piracy and related forms of maritime violence in the early modern era. The authors in this volume highlight cases from various parts of the early-modern world, thereby explaining piracy as a global phenomenon.
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Anderson, Greg. Other Ways of Being Human. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780190886646.003.0007.
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To open Part Two (“The Many Real Worlds of the Past”), the book begins its ethical case for an ontological turn in history by establishing the past’s extraordinary ontological diversity. Drawing on a lengthy inventory of ethnographies and histories, the chapter adduces evidence for non-modern ontologies from a broad range of environments, including precolonial Mexico, India, Bali, and Polynesia, medieval Europe, Ming China, and the lifeworlds of various indigenous peoples in Amazonia, South East Asia, Melanesia, and Africa. The cumulative result is a panorama of ontological alterities, indicating wide historical variabilities in the essences and foundations of human existence, in the ways humans experience, say, personhood and subjectivity, kinship and sociality, materiality and ideality, mortality and rationality, humanity and divinity, and the sources, means, and ends of life itself. Yet the tools of our conventional historicism cannot account for these variabilities, since they all presuppose the truth of an ontology that prevails only in our capitalist modernity.
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Bakke, Monika, ed. Refugia. (Prze)trwanie transgatunkowych wspólnot miejskich /Refugia: The Survival of Urban Transspecies Communities. Adam Mickiewicz University Press, 2021. http://dx.doi.org/10.14746/amup.9788323239857.
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Refugia: The Survival of Urban Transspecies Communities encourages to us recognize the unexpected relations among species and to speculate about the possibility of their existence and development. It shows the need for care and support for multi-species urban communities by answering questions about the following: Which humans and non-humans may find refuge in the city? Under what conditions and to what extent? Are cities also becoming spaces of refuge for rare, endangered or endangered species and disappearing ecosystems? Can unwanted and underestimated life forms find refuge in the city, and how much compassion and hospitality do we have for them? Is it possible to be safe in the city without a place–home–shelter of one’s own? The book is the result of transdisciplinary research, including knowledge-producing artistic projects, whose research and communication methodology enable us to go beyond specialist circles. The book consists of two parts, the first of which, Refugia: The Transdisciplinary Practice of Curiosity, includes scientific texts focusing on various cases of interspecies relationships created in cities by human and non-human animals, plants, fungi, soil, architecture, etc. The second part of the book includes artistic statements in the form of visual documentation of projects created for the exhibition Refugia: Keep (Out of) These Places. The art presented here makes it possible to construct perspectives different from those generated in the field of humanities or sciences, but remaining in close contact with these fields.
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Løgstrup, K. E., Bjørn Rabjerg, and Robert Stern. The Ethical Demand. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780198855989.001.0001.
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This book concerns the nature and basis for the fundamental ethical relation between human beings. Beginning from the fundamental example of trust, it is argued that this relation arises from our interdependence and mutual vulnerability, which then gives us power over the lives of other people. It claimed that in this situation, there arises a demand to care for the other person. This demand is characterized as silent, radical, one-sided, and unfulfillable, as it cannot be satisfied by just doing what the other asks; requires us to act unselfishly; is non-reciprocal; and should not be experienced as a demand. As a result, the demand is distinguished from ordinary social norms, which lack these characteristics, though it is argued that there is a relation between these two levels, as legitimate social norms should ‘refract’ the ethical demand. It is also argued that in order to make sense of a demand of this sort, we must see ‘life as a gift’, rather than treating ourselves as the sovereign grounds for our own existence. In understanding the ethical demand in this way, it is suggested, we can make sense of Jesus’s proclamation to love our neighbour in purely human terms, though at the same time we may have to go beyond a scientific picture which operates with a clear distinction between fact and values, and treats determinism as a basis for rejecting moral responsibility.
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Cruft, Rowan. Human Rights, Ownership, and the Individual. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198793366.001.0001.
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What do we mean by rights, and can our use of the concept be justified? This book offers a partial vindication of the concept of a right, defending its use in relation to human rights while questioning it in relation to property. It starts with a new ‘Addressive’ account of the nature of rights as bringing together duty-bearer and right-holder first-personally—a theory which moves beyond and complements traditional Interest and Will Theories. This Addressive account implies that a right exists pre-institutionally (as a ‘natural’ or ‘moral’ right) only when a duty owes its existence predominantly to the right-holder’s good. On this basis, the book defends human rights law and practice as justifiably institutionalizing certain pre-legal moral rights held against other individuals and the state, including socio-economic rights. This defence proceeds independently of whichever conception of ‘the important human features’ (e.g. agency, capabilities, freedoms, interests, needs) one takes to underpin human rights—though it does depend on a distinction between individual and other goods. The book ends by arguing that for much property, conceiving the relevant duties in rights terms can mislead us into overlooking their foundation in the collective good. An alternative non-rights property system—broadly resembling modern markets but not conceived in terms of rights—is outlined. The result is a defence of the rights concept that is more supportive of human rights than many of their critics (from left or right) might expect, while pressing new doubts about much property as an individual right.
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Sharf, Robert H. Is Mindfulness Buddhist? (And Why It Matters). Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190495794.003.0010.
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Modern exponents of mindfulness meditation promote the therapeutic effects of “bare attention”—a sort of non-judgmental, non-discursive attending to the moment-to-moment flow of consciousness. This approach is arguably at odds with more traditional Theravāda Buddhist doctrine and meditative practice, but the cultivation of present-centered awareness is not without precedent in Buddhist history; similar innovations arose in medieval Chinese Zen (Chan) and Tibetan Dzogchen. These movements have several things in common. In each case the reforms were, in part, attempts to render Buddhist practice and insight accessible to laypeople unfamiliar with Buddhist philosophy and/or unwilling to adopt a renunciatory lifestyle. They also promised quick results. And finally, the innovations were met with suspicion and criticism from traditional Buddhist quarters. Those interested in the therapeutic effects of mindfulness and bare attention are often not aware of the existence, much less the content, of the controversies surrounding these practices in Asian Buddhist history.
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Baulieu, Laurent, John Iliopoulos, and Roland Sénéor. Supersymmetry, or the Defence of Scalars. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198788393.003.0027.
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The only fields of the Standard Model whose masses are not protected by a symmetry are the scalar fields. Supersymmetry is a symmetry between fermions and bosons which provides precisely such a protection mechanism. This chapter presents a comprehensive study of supersymmetric field theories. In particular, it is shown that they do not suffer from the phenomenon of gauge hierarchy. They have remarkable renormalisation properties and offer the most attractive framework to build a unified theory. The breaking of supersymmetry, both explicit and spontaneous, is studied in detail. The generalisation of electric-magnetic duality in supersymmetric theories yields non-perturbative results and the concept of twist makes possible the study of topological field theories. The supersymmetric extension of the Standard Model is shown to predict the existence of new elementary particles, whose phenomenological properties are analysed.
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Amirell, Stefan Eklöf, Hans Hägerdal, and Bruce Buchan, eds. Piracy in World History. Amsterdam University Press, 2021. http://dx.doi.org/10.1017/9789048544950.
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In a modern global historical context, scholars have often regarded piracy as an essentially European concept which was inappropriately applied by the expanding European powers to the rest of the world, mainly for the purpose of furthering colonial forms of domination in the economic, political, military, legal and cultural spheres. By contrast, this edited volume highlights the relevance of both European and non-European understandings of piracy to the development of global maritime security and freedom of navigation. It explores the significance of 'legal posturing' on the part of those accused of piracy, as well as the existence of non-European laws and regulations regarding piracy and related forms of maritime violence in the early modern era. The authors in this volume highlight cases from various parts of the early-modern world, thereby explaining piracy as a global phenomenon.
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Priest, Graham. Logic: A Very Short Introduction. Oxford University Press, 2017. http://dx.doi.org/10.1093/actrade/9780198811701.001.0001.
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Logic is often perceived as having little to do with the rest of philosophy, and even less to do with real life. Logic: A Very Short Introduction shows how wrong this conception is. It explores the philosophical roots of the subject, explaining how modern formal logic deals with issues ranging from the existence of God and the reality of time to paradoxes of probability and decision theory. Along the way, the basics of formal logic are explained in simple, non-technical terms, showing that logic is a powerful and exciting part of modern philosophy. It also covers the subjects of algorithms and axioms, and proofs in mathematics.
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Shengelia, Revaz. Modern Economics. Universal, Georgia, 2021. http://dx.doi.org/10.36962/rsme012021.
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Economy and mankind are inextricably interlinked. Just as the economy or the production of material wealth is unimaginable without a man, so human existence and development are impossible without the wealth created in the economy. Shortly, both the goal and the means of achieving and realization of the economy are still the human resources. People have long ago noticed that it was the economy that created livelihoods, and the delays in their production led to the catastrophic events such as hunger, poverty, civil wars, social upheavals, revolutions, moral degeneration, and more. Therefore, the special interest of people in understanding the regulatory framework of the functioning of the economy has existed and exists in all historical epochs [A. Sisvadze. Economic theory. Part One. 2006y. p. 22]. The system of economic disciplines studies economy or economic activities of a society. All of them are based on science, which is currently called economic theory in the post-socialist space (the science of economics, the principles of economics or modern economics), and in most countries of the world - predominantly in the Greek-Latin manner - economics. The title of the present book is also Modern Economics. Economics (economic theory) is the science that studies the efficient use of limited resources to produce and distribute goods and services in order to satisfy as much as possible the unlimited needs and demands of the society. More simply, economics is the science of choice and how society manages its limited resources. Moreover, it should be emphasized that economics (economic theory) studies only the distribution, exchange and consumption of the economic wealth (food, beverages, clothing, housing, machine tools, computers, services, etc.), the production of which is possible and limited. And the wealth that exists indefinitely: no economic relations are formed in the production and distribution of solar energy, air, and the like. This current book is the second complete updated edition of the challenges of the modern global economy in the context of the coronary crisis, taking into account some of the priority directions of the country's development. Its purpose is to help students and interested readers gain a thorough knowledge of economics and show them how this knowledge can be applied pragmatically (professionally) in professional activities or in everyday life. To achieve this goal, this textbook, which consists of two parts and tests, discusses in simple and clear language issues such as: the essence of economics as a science, reasons for origin, purpose, tasks, usefulness and functions; Basic principles, problems and peculiarities of economics in different economic systems; Needs and demand, the essence of economic resources, types and limitations; Interaction, mobility, interchangeability and efficient use of economic resources. The essence and types of wealth; The essence, types and models of the economic system; The interaction of households and firms in the market of resources and products; Market mechanism and its elements - demand, supply and price; Demand and supply elasticity; Production costs and the ways to reduce them; Forms of the market - perfect and incomplete competition markets and their peculiarities; Markets for Production Factors and factor incomes; The essence of macroeconomics, causes and importance of origin; The essence and calculation of key macroeconomic indicators (gross national product, gross domestic product, net national product, national income, etc.); Macroeconomic stability and instability, unemployment, inflation and anti-inflationary policies; State regulation of the economy and economic policy; Monetary and fiscal policy; Income and standard of living; Economic Growth; The Corona Pandemic as a Defect and Effect of Globalization; National Economic Problems and New Opportunities for Development in the conditions of the Coronary Crisis; The Socio-economic problems of moral obsolescence in digital technologies; Education and creativity are the main solution way to overcome the economic crisis caused by the coronavirus; Positive and negative effects of tourism in Georgia; Formation of the middle class as a contributing factor to the development of tourism in Georgia; Corporate culture in Georgian travel companies, etc. The axiomatic truth is that economics is the union of people in constant interaction. Given that the behavior of the economy reflects the behavior of the people who make up the economy, after clarifying the essence of the economy, we move on to the analysis of the four principles of individual decision-making. Furtermore, the book describes how people make independent decisions. The key to making an individual decision is that people have to choose from alternative options, that the value of any action is measured by the value of what must be given or what must be given up to get something, that the rational, smart people make decisions based on the comparison of the marginal costs and marginal returns (benefits), and that people behave accordingly to stimuli. Afterwards, the need for human interaction is then analyzed and substantiated. If a person is isolated, he will have to take care of his own food, clothes, shoes, his own house and so on. In the case of such a closed economy and universalization of labor, firstly, its productivity will be low and, secondly, it will be able to consume only what it produces. It is clear that human productivity will be higher and more profitable as a result of labor specialization and the opportunity to trade with others. Indeed, trade allows each person to specialize, to engage in the activities that are most successful, be it agriculture, sewing or construction, and to buy more diverse goods and services from others at a relatively lower price. The key to such human interactions is that trade is mutually beneficial; That markets are usually the good means of coordination between people and that the government can improve the results of market functioning if the market reveals weakness or the results of market functioning are not fair. Moroever, it also shows how the economy works as a whole. In particular, it is argued that productivity is a key determinant of living standards, that an increase in the money supply is a major source of inflation, and that one of the main impediments to avoiding inflation is the existence of an alternative between inflation and unemployment in the short term, that the inflation decrease causes the temporary decline in unemployement and vice versa. The Understanding creatively of all above mentioned issues, we think, will help the reader to develop market economy-appropriate thinking and rational economic-commercial-financial behaviors, to be more competitive in the domestic and international labor markets, and thus to ensure both their own prosperity and the functioning of the country's economy. How he/she copes with the tasks, it is up to the individual reader to decide. At the same time, we will receive all the smart useful advices with a sense of gratitude and will take it into account in the further work. We also would like to thank the editor and reviewers of the books. Finally, there are many things changing, so it is very important to realize that the XXI century has come: 1. The century of the new economy; 2. Age of Knowledge; 3. Age of Information and economic activities are changing in term of innovations. 1. Why is the 21st century the century of the new economy? Because for this period the economic resources, especially non-productive, non-recoverable ones (oil, natural gas, coal, etc.) are becoming increasingly limited. According to the World Energy Council, there are currently 43 years of gas and oil reserves left in the world (see “New Commersant 2007 # 2, p. 16). Under such conditions, sustainable growth of real gross domestic product (GDP) and maximum satisfaction of uncertain needs should be achieved not through the use of more land, labor and capital (extensification), but through more efficient use of available resources (intensification) or innovative economy. And economics, as it was said, is the science of finding the ways about the more effective usage of the limited resources. At the same time, with the sustainable growth and development of the economy, the present needs must be met in a way that does not deprive future generations of the opportunity to meet their needs; 2. Why is the 21st century the age of knowledge? Because in a modern economy, it is not land (natural resources), labor and capital that is crucial, but knowledge. Modern production, its factors and products are not time-consuming and capital-intensive, but science-intensive, knowledge-intensive. The good example of this is a Japanese enterprise (firm) where the production process is going on but people are almost invisible, also, the result of such production (Japanese product) is a miniature or a sample of how to get the maximum result at the lowest cost; 3. Why is the 21st century the age of information? Because the efficient functioning of the modern economy, the effective organization of the material and personal factors of production largely depend on the right governance decision. The right governance decision requires prompt and accurate information. Gone are the days when the main means of transport was a sailing ship, the main form of data processing was pencil and paper, and the main means of transmitting information was sending letters through a postman on horseback. By the modern transport infrastructure (highways, railways, ships, regular domestic and international flights, oil and gas pipelines, etc.), the movement of goods, services and labor resoucres has been significantly accelerated, while through the modern means of communication (mobile phone, internet, other) the information is spreading rapidly globally, which seems to have "shrunk" the world and made it a single large country. The Authors of the book: Ushangi Samadashvili, Doctor of Economic Sciences, Associate Professor of Ivane Javakhishvili Tbilisi State University - Introduction, Chapters - 1, 2, 3, 4, 5, 6, 9, 10, 11,12, 15,16, 17.1,18 , Tests, Revaz Shengelia, Doctor of Economics, Professor of Georgian Technical University, Chapters_7, 8, 13. 14, 17.2, 17.4; Zhuzhuna Tsiklauri - Doctor of Economics, Professor of Georgian Technical University - Chapters 13.6, 13.7,17.2, 17.3, 18. We also thank the editor and reviewers of the book.
Book chapters on the topic "Non-existence result"
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Benguria, Rafael, and Soledad Benguria. "A non-existence result for a generalized radial Brezis–Nirenberg problem." In Partial Differential Equations, Spectral Theory, and Mathematical Physics, 1–15. Zuerich, Switzerland: European Mathematical Society Publishing House, 2021. http://dx.doi.org/10.4171/ecr/18-1/1.
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Seberry, Jennifer. "Some Algebraic and Combinatorial Non-existence Results." In Orthogonal Designs, 7–17. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-59032-5_2.
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Gramlich, Ralf, and Hendrik Van Maldeghem. "Epimorphisms of Generalized Polygons, Part 2: Some Existence and Non-Existence Results." In Developments in Mathematics, 177–200. Boston, MA: Springer US, 2001. http://dx.doi.org/10.1007/978-1-4613-0283-4_12.
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Mascolo, Elvira. "Existence results for non convex problems of the calculus of variations." In Calculus of Variations and Partial Differential Equations, 201–7. Berlin, Heidelberg: Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/bfb0082897.
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van den Eede, G., and D. Plan. "Integration of Co-Extra Results in EU Tools for Traceability." In Genetically Modified and Non-Genetically Modified Food Supply Chains: Co-Existence and Traceability, 491–520. Oxford, UK: Wiley-Blackwell, 2012. http://dx.doi.org/10.1002/9781118373781.ch26.
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Bazin, V., C. Guillopé, and J. C. Saut. "Some Existence and Stability Results for Non-Isothermal Flows of Viscoelastic Fluids." In Fluid Mechanics and Its Applications, 73–84. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0191-2_6.
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Cannarsa, Piermarco, and Vincenzo Vespri. "Existence and uniqueness results for a non linear stochastic partial differential equation." In Lecture Notes in Mathematics, 1–24. Berlin, Heidelberg: Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/bfb0072880.
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Bohanec, M., Y. Bertheau, C. Brera, K. Gruden, A. Holst-Jensen, E. J. Kok, B. Lécroart, et al. "The Co-Extra Decision Support System: A Model-Based Integration of Project Results." In Genetically Modified and Non-Genetically Modified Food Supply Chains: Co-Existence and Traceability, 459–89. Oxford, UK: Wiley-Blackwell, 2012. http://dx.doi.org/10.1002/9781118373781.ch25.
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Hilal, K., K. Guida, L. Ibnelazyz, and M. Oukessou. "Existence Results for an Impulsive Fractional Integro-Differential Equations with a Non-compact Semigroup." In Recent Advances in Intuitionistic Fuzzy Logic Systems, 191–211. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-02155-9_16.
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Gastaldi, F. "Existence Results for Minima of Non-Coercive Funtionals and Applications to Unilateral Problems in Elasticity." In Unilateral Problems in Structural Analysis — 2, 139–50. Vienna: Springer Vienna, 1987. http://dx.doi.org/10.1007/978-3-7091-2967-8_9.
Full textConference papers on the topic "Non-existence result"
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محمد عزيز, ايناس. "Non Recognition in contemporary sociology theories." In Peacebuilding and Genocide Prevention. University of Human Development, 2021. http://dx.doi.org/10.21928/uhdicpgp/12.
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" When studying the social issues associated with the relations of mutual recognition between oneself and the other, in which our disregard for any position or perception of the nature of this relationship leads to the denial of its existence in social life, the human self is not complete without the other as a complementary partner of its existence and its continuation in a social medium chosen by man as an object that can not live isolated alone from the children of his race, nor was he able to establish a positive lasting relationship with his other partner but subjected the human being to his brother man, and the result of this relationship The negativity of images of violence, conflict, domination and domination, which made the search for the sources behind the lack of self-recognition of the other individual or group, especially in societies of pluralism and cultural diversity as a feature that can be considered universal, to form the focus of theories and studies carried out by philosophers, sociologists, economists and psychologists through which they identified the main sources leading to denial or non-recognition of the other. "
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Usha, R., and I. Mohammed Rizwan Sadiq. "Weakly Nonlinear Stability Analysis of a Non-Uniformly Heated Non-Newtonian Falling Film." In ASME/JSME 2007 5th Joint Fluids Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/fedsm2007-37201.
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A thin liquid layer of a non-Newtonian film falling down an inclined plane that is subjected to non-uniform heating has been considered. The temperature of the inclined plane is assumed to be linearly distributed and the case when the temperature gradient is positive or negative is investigated. The film flow is influenced by gravity, mean surface-tension and thermocapillary force acting along the free surface. The coupling of thermocapillary instability and surface-wave instabilities is studied for two-dimensional disturbances. A non-linear evolution equation is derived by applying the long-wave theory and the equation governs the evolution of a power-law film flowing down an inclined plane. The linear stability analysis shows that the film flow system is stable when the plate temperature is decreasing in the downstream direction while it is less stable for increasing temperature along the plate. Weakly non-linear stability analysis using the method of multiple scales has been investigated and this leads to a secular equation of the Ginzburg-Landau type. The analysis shows that both supercritical stability and subcritical instability are possible for the film flow system. The results indicate the existence of finite-amplitude waves and the threshold amplitude and non-linear speed of these waves are influenced by thermocapillarity. The results for the dilatant as well as pseudoplastic fluids are obtained and it is observed that the result for the Newtonian model agrees with the available literature report. The influence of non-uniform heating of the film flow system on the stability of the system is compared with the stability of the corresponding uniformly heated film flow system.
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Ge, Bing, Shu-sheng Zang, Peiqing Guo, and Yin-shen Tian. "Experimental Study of Nitrogen Dilution Effects on a Double-Swirled Non-Premixed Syngas Burner." In ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-68929.
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The development of integrated, coal-gasification combined cycle (IGCC) systems provides cost-effective and environmentally sound options for meeting future coal-utilizing power generation needs in the world. The combustion of gasified coal fuel significantly influences overall performance of IGCC power generation. This study focuses on investigating the nitrogen dilution effects on a double-swirled non-premixed syngas flame. As the references, investigations on the H2 and CO double-swirled flames with N2 dilution are presented. Planar laser-induced fluorescence (PLIF) of OH-radical measurement is adopted to identify main reaction zones and burnt gas regions. Together with temperature and emission measurement during exhaust section, some important characteristics of the syngas flame are overall investigated. Experimental result shows that syngas flame root near the burner exit demonstrates double flame front structure. The existence of N2 expands the flame opening angle and enlarges the main reaction zone, and it may lead to lower NO emission and higher CO emission in exhaust gas.
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Charfeddine, Lanouar, and Karim Barkat. "Do Oil and Gas Revenues promote Economic Diversification in Qatar?" In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2020. http://dx.doi.org/10.29117/quarfe.2020.0048.
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The aim of this paper is to explore the short- and long-term asymmetric impact of oil prices shocks and oil and gas revenues changes on the total real GDP, and the level of economic diversification of the Qatar economy. To this end, two econometric approaches have been used: (1) the A-B structural vector autoregressive (AB − SVARX) model with exogenous variables where four different asymmetric oil prices and oil and gas revenues measures have been employed, and (2) the nonlinear autoregressive distributed lag (NARDL) model. The results show that, in the short-run, the responses of both total real GDP and non-oil real GDP to negative shocks on real oil prices and real oil and gas revenues are higher than the impact of positive shocks, indicating evidence for the existence of asymmetric impact of shocks in the short-run. However, the results suggest that the impact of shocks do not last more than three quarters. This evidence for the existence of asymmetric behavior is also confirmed by the NARDL analysis, which shows that, in the long run, positive oil prices shocks and oil and gas revenues changes have higher impact on the two proxies of economic activity than negative changes do. A result that confirms the resilience of the Qatar economy to negative shocks and the positive role played by the energy sector in improving the Qatar economic diversification degree. Finally, the results show that the non-oil sector is completely resilient to negative shocks in the long run as the impact of negative shocks are insignificant on the non-oil real GDP. Several policies aimed to improve the level of economic diversification of the country and delink the government revenues from oil and gas revenues are proposed and discussed.
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MINHÓS, F. M., and I. SANTOS. "EXISTENCE AND NON-EXISTENCE RESULTS FOR TWO-POINT BOUNDARY VALUE PROBLEMS OF HIGHER ORDER." In Proceedings of the International Conference on Differential Equations. WORLD SCIENTIFIC, 2005. http://dx.doi.org/10.1142/9789812702067_0032.
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Krylov, Slava, Shimon Seretensky, and David Schreiber. "Pull-In Behavior of Electrostatically Actuated Multistable Microstructures." In ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/detc2007-35552.
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We present an analysis of the electromechanical behavior and stability of a capacitive-based Micro Electro Mechanical Systems (MEMS) device with non-monotonous stiffness-deflection dependence. As an example, we consider a flexible initially curved double clamped micro beam actuated by a distributed electrostatic force. Since the system exhibits both mechanical snap-through buckling and electrostatic pull-in instability, the equilibrium curve has two bifurcation points implying the existence of multiple equilibrium configurations. The multistability phenomenon described in the present work is a result of interaction between mechanical and electrostatic nonlinearities of the system and differs from the electrostatic pull-in based bistability and mechanical bistability associated with the snap-through buckling. The governing equations of the geometrically nonlinear curved Euler-Bernoulli beam are formulated in the framework of the shallow arch approximation. Actuating force is calculated using second order perturbation solution of the Laplace equation for an electric potential. A coupled electro mechanical model is built by the Rayleigh-Ritz method with linear undamped eigenmodes of a straight beam as base functions. After verification of the model results, we analyze the influence of initial geometry of the beam on the location (in terms of actuation voltage and deflections) of the critical points on the bifurcation diagram. It was found that for snap-through to take place, the initial elevation of the beam should be larger than a certain value whereas the existence of electrical pull-in instability is unconditional. In addition, the stable relative deflection of a curved beam is larger than of initially straight beam. Based on the model results, we present an example of a multistable actuator design. Devices of various configurations were fabricated of single crystal silicon using deep reactive ion etching and the existence of multiple stable states and multiple instability points was demonstrated experimentally.
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Yoshida, Hiroyuki, Horiguchi Naoki, Ayako Ono, Hajime Furuichi, and Kenichi Katono. "Numerical Simulation of Annular Dispersed Flow in Simplified Subchannel of Light Water Cooled Fast Reactor RBWR." In 2022 29th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/icone29-91630.
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Abstract About the boiling transition (BT) that determines the maximum thermal output of the BWR, it is considered that the spacers have significant effects on the occurrence of BT. In the light water cooled fast reactor: RBWR, thermal-hydraulics conditions are more severe than the current BWR. Then, the effect of the spacer on BT should be sufficiently utilized in the RBWR. The RBWR is still in the design stage, therefore is not reasonable to determine the shape of the spacer by evaluation only for large-scale tests. In the occurrence of BT, it is considered that the two-phase flow pattern is the annular dispersed flow, and we want to evaluate the effects of spacer shape on annular dispersed flow in RBWR subchannels. This research uses the detailed two-phase flow simulation code TPFIT to simulate annular dispersed flow in RBWR subchannels. As the first step of this research, we performed numerical simulations of annular dispersed flow in the simplified subchannel of RBWR. We used a circular tube with the same hydraulic diameter as the RBWR subchannel to consider the basic effects of spacer on the annular dispersed flow. In this paper, we describe the result of numerical simulation. In addition, we evaluated droplets’ size and velocity based on simulation results for the spacer’s existence and non-existence cases.
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Zhang, Wei, and Qi-liang Wu. "Multi-Pulse Chaotic Dynamics of Four-Dimensional Non-Autonomous Nonlinear System for a Truss Core Sandwich Plate." In ASME 2014 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/detc2014-34133.
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In this paper, an extended high-dimensional Melnikov method is used to investigate global and chaotic dynamics of a simply supported 3D-kagome truss core sandwich plate subjected to the transverse and the in-plane excitations. Based on the motion equation derived by Zhang and the method of multiple scales, the averaged equation is obtained for the case of principal parametric resonance and 1:2 sub-harmonic resonance for the first-order mode and primary resonance for the second-order mode. From the averaged equation obtained, the system is simplified to a three order standard form with a double zero and a pair of pure imaginary eigenvalues by using the theory of normal form. Then, the extended Melnikov method is utilized to investigate the Shilnikov-type multi-pulse heteroclinic bifurcations and existence of chaos. The analysis of the extended Melnikov method demonstrates that there exist the Shilnikov-type multi-pulse heteroclinic bifurcations and chaos in the four-dimensional non-autonomous nonlinear system. Finally, the results of numerical simulations also show that for the nonlinear system of simply supported 3D-kagome truss core sandwich plate with the transverse and the in-plane excitations, the Shilnikov-type multi-pulse motion of chaos can happen and further verify the result of theoretical analysis.
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Heliodoro, Paula, Rui Dias, and Paulo Alexandre. "FINANCIAL CONTAGION BETWEEN THE US AND EMERGING MARKETS: COVID-19 PANDEMIC CASE." In 4th International Scientific Conference – EMAN 2020 – Economics and Management: How to Cope With Disrupted Times. Association of Economists and Managers of the Balkans, Belgrade, Serbia, 2020. http://dx.doi.org/10.31410/eman.s.p.2020.1.
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To realise how crises are disseminated is relevant for policy makers and regulators in order to take appropriate measures to prevent or contain the propagation of crises. This study aims to analysis the financial contagion in the six main markets of Latin America (Argentina, Brazil, Chile, Colombia, Mexico and Peru) and the USA, in the period 2015-2020. Different approaches have been undertaken to carry out this analysis in order to consider the following research question, namely whether: (i) the global pandemic covid19 has accentuated the contagion between Latin American financial markets and the US? The results of the autocorrelation tests are totally coincident with those obtained by the BDS test. The rejection of the null hypothesis, i.i.d., can be explained, among other factors, by the existence of autocorrelation or by the existence of heteroscedasticity in the stock market index series, in which case the rejection of the null hypothesis is explained by non-linear dependence on data, with the exception of the Argentine market. However, significant levels of contagion were expected to occur between these regional markets and the US as a result of the global pandemic (Covid-19), which did not happen. These results may indicate the implementation of efficient diversification strategies. The authors consider that the results achieved are relevance for investors who seek opportunities in these stock markets, as well as for policy makers to carry out institutional reforms in order to increase the efficiency of stock markets and promote the sustainable growth of financial markets.
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Vadasz, Johnathan J., and Joseph E. A. Roy-Aikins. "Sudden and Smooth Transitions to Weak Turbulence in Porous Media Convection." In ASME 2003 Heat Transfer Summer Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/ht2003-47379.
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The fundamental understanding of the transition from laminar to turbulent convection in porous media is far from being conclusive. In isothermal flow in porous media no experiments identifying the three dimensional nature of a transition from the Darcy regime, via an inertia dominated regime, towards turbulence are available. In particular this detailed description of turbulence is missing in the problem of porous media convection where an additional non-linear interaction appears as a result of the coupling between the equations governing the fluid flow and the energy equation. The latter can typically cause a transition to a non-steady and non-periodic regime (referred to as weak turbulent) at much lower values of the parameter controlling the flow, when compared to the corresponding isothermal system. The present paper identifies the conditions for sudden and smooth transitions. In addition it attempts to address the question related to the reason for the subcritical transition to weak turbulence and the existence of a range of values of the porous media Rayleigh number over which the transition occurs, i.e. the Lorenz attractor.
Reports on the topic "Non-existence result"
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Oliynyk, Kateryna, and Matteo Ciantia. Application of a finite deformation multiplicative plasticity model with non-local hardening to the simulation of CPTu tests in a structured soil. University of Dundee, December 2021. http://dx.doi.org/10.20933/100001230.
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In this paper an isotropic hardening elastoplastic constitutive model for structured soils is applied to the simulation of a standard CPTu test in a saturated soft structured clay. To allow for the extreme deformations experienced by the soil during the penetration process, the model is formulated in a fully geometric non-linear setting, based on: i) the multiplicative decomposition of the deformation gradient into an elastic and a plastic part; and, ii) on the existence of a free energy function to define the elastic behaviour of the soil. The model is equipped with two bonding-related internal variables which provide a macroscopic description of the effects of clay structure. Suitable hardening laws are employed to describe the structure degradation associated to plastic deformations. The strain-softening associated to bond degradation usually leads to strain localization and consequent formation of shear bands, whose thickness is dependent on the characteristics of the microstructure (e.g, the average grain size). Standard local constitutive models are incapable of correctly capturing this phenomenon due to the lack of an internal length scale. To overcome this limitation, the model is framed using a non-local approach by adopting volume averaged values for the internal state variables. The size of the neighbourhood over which the averaging is performed (characteristic length) is a material constant related to the microstructure which controls the shear band thickness. This extension of the model has proven effective in regularizing the pathological mesh dependence of classical finite element solutions in the post-localization regime. The results of numerical simulations, conducted for different soil permeabilities and bond strengths, show that the model captures the development of plastic deformations induced by the advancement of the cone tip; the destructuration of the clay associated with such plastic deformations; the space and time evolution of pore water pressure as the cone tip advances. The possibility of modelling the CPTu tests in a rational and computationally efficient way opens a promising new perspective for their interpretation in geotechnical site investigations.
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Morrison, Mark, Joshuah Miron, Edward A. Bayer, and Raphael Lamed. Molecular Analysis of Cellulosome Organization in Ruminococcus Albus and Fibrobacter Intestinalis for Optimization of Fiber Digestibility in Ruminants. United States Department of Agriculture, March 2004. http://dx.doi.org/10.32747/2004.7586475.bard.
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Improving plant cell wall (fiber) degradation remains one of the highest priority research goals for all ruminant enterprises dependent on forages, hay, silage, or other fibrous byproducts as energy sources, because it governs the provision of energy-yielding nutrients to the host animal. Although the predominant species of microbes responsible for ruminal fiber degradation are culturable, the enzymology and genetics underpinning the process are poorly defined. In that context, there were two broad objectives for this proposal. The first objective was to identify the key cellulosomal components in Ruminococcus albus and to characterize their structural features as well as regulation of their expression, in response to polysaccharides and (or) P AA/PPA. The second objective was to evaluate the similarities in the structure and architecture of cellulosomal components between R. albus and other ruminal and non-ruminal cellulolytic bacteria. The cooperation among the investigators resulted in the identification of two glycoside hydrolases rate-limiting to cellulose degradation by Ruminococcus albus (Cel48A and CeI9B) and our demonstration that these enzymes possess a novel modular architecture specific to this bacterium (Devillard et al. 2004). We have now shown that the novel X-domains in Cel48A and Cel9B represent a new type of carbohydrate binding module, and the enzymes are not part of a ceiluiosome-like complex (CBM37, Xu et al. 2004). Both Cel48A and Cel9B are conditionally expressed in response to P AA/PPA, explaining why cellulose degradation in this bacterium is affected by the availability of these compounds, but additional studies have shown for the first time that neither PAA nor PPA influence xylan degradation by R. albus (Reveneau et al. 2003). Additionally, the R. albus genome sequencing project, led by the PI. Morrison, has supported our identification of many dockerin containing proteins. However, the identification of gene(s) encoding a scaffoldin has been more elusive, and recombinant proteins encoding candidate cohesin modules are now being used in Israel to verify the existence of dockerin-cohesin interactions and cellulosome production by R. albus. The Israeli partners have also conducted virtually all of the studies specific to the second Objective of the proposal. Comparative blotting studies have been conducted using specific antibodies prepare against purified recombinant cohesins and X-domains, derived from cellulosomal scaffoldins of R. flavefaciens 17, a Clostridium thermocellum mutant-preabsorbed antibody preparation, or against CbpC (fimbrial protein) of R. albus 8. The data also suggest that additional cellulolytic bacteria including Fibrobacter succinogenes S85, F. intestinalis DR7 and Butyrivibrio fibrisolvens Dl may also employ cellulosomal modules similar to those of R. flavefaciens 17. Collectively, our work during the grant period has shown that R. albus and other ruminal bacteria employ several novel mechanisms for their adhesion to plant surfaces, and produce both cellulosomal and non-cellulosomal forms of glycoside hydrolases underpinning plant fiber degradation. These improvements in our mechanistic understanding of bacterial adhesion and enzyme regulation now offers the potential to: i) optimize ruminal and hindgut conditions by dietary additives to maximize fiber degradation (e.g. by the addition of select enzymes or PAA/PPA); ii) identify plant-borne influences on adhesion and fiber-degradation, which might be overcome (or improved) by conventional breeding or transgenic plant technologies and; iii) engineer or select microbes with improved adhesion capabilities, cellulosome assembly and fiber degradation. The potential benefits associated with this research proposal are likely to be realized in the medium term (5-10 years).
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Christopher, David A., and Avihai Danon. Plant Adaptation to Light Stress: Genetic Regulatory Mechanisms. United States Department of Agriculture, May 2004. http://dx.doi.org/10.32747/2004.7586534.bard.
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Original Objectives: 1. Purify and biochemically characterize RB60 orthologs in higher plant chloroplasts; 2. Clone the gene(s) encoding plant RB60 orthologs and determine their structure and expression; 3. Manipulate the expression of RB60; 4. Assay the effects of altered RB60 expression on thylakoid biogenesis and photosynthetic function in plants exposed to different light conditions. In addition, we also examined the gene structure and expression of RB60 orthologs in the non-vascular plant, Physcomitrella patens and cloned the poly(A)-binding protein orthologue (43 kDa RB47-like protein). This protein is believed to a partner that interacts with RB60 to bind to the psbA5' UTR. Thus, to obtain a comprehensive view of RB60 function requires analysis of its biochemical partners such as RB43. Background & Achievements: High levels of sunlight reduce photosynthesis in plants by damaging the photo system II reaction center (PSII) subunits, such as D1 (encoded by the chloroplast tpsbAgene). When the rate of D1 synthesis is less than the rate of photo damage, photo inhibition occurs and plant growth is decreased. Plants use light-activated translation and enhanced psbAmRNA stability to maintain D1 synthesis and replace the photo damaged 01. Despite the importance to photosynthetic capacity, these mechanisms are poorly understood in plants. One intriguing model derived from the algal chloroplast system, Chlamydomonas, implicates the role of three proteins (RB60, RB47, RB38) that bind to the psbAmRNA 5' untranslated leader (5' UTR) in the light to activate translation or enhance mRNA stability. RB60 is the key enzyme, protein D1sulfide isomerase (Pill), that regulates the psbA-RN :Binding proteins (RB's) by way of light-mediated redox potentials generated by the photosystems. However, proteins with these functions have not been described from higher plants. We provided compelling evidence for the existence of RB60, RB47 and RB38 orthologs in the vascular plant, Arabidopsis. Using gel mobility shift, Rnase protection and UV-crosslinking assays, we have shown that a dithiol redox mechanism which resembles a Pill (RB60) activity regulates the interaction of 43- and 30-kDa proteins with a thermolabile stem-loop in the 5' UTR of the psbAmRNA from Arabidopsis. We discovered, in Arabidopsis, the PD1 gene family consists of II members that differ in polypeptide length from 361 to 566 amino acids, presence of signal peptides, KDEL motifs, and the number and positions of thioredoxin domains. PD1's catalyze the reversible formation an disomerization of disulfide bonds necessary for the proper folding, assembly, activity, and secretion of numerous enzymes and structural proteins. PD1's have also evolved novel cellular redox functions, as single enzymes and as subunits of protein complexes in organelles. We provide evidence that at least one Pill is localized to the chloroplast. We have used PDI-specific polyclonal and monoclonal antisera to characterize the PD1 (55 kDa) in the chloroplast that is unevenly distributed between the stroma and pellet (containing membranes, DNA, polysomes, starch), being three-fold more abundant in the pellet phase. PD1-55 levels increase with light intensity and it assembles into a high molecular weight complex of ~230 kDa as determined on native blue gels. In vitro translation of all 11 different Pill's followed by microsomal membrane processing reactions were used to differentiate among PD1's localized in the endoplasmic reticulum or other organelles. These results will provide.1e insights into redox regulatory mechanisms involved in adaptation of the photosynthetic apparatus to light stress. Elucidating the genetic mechanisms and factors regulating chloroplast photosynthetic genes is important for developing strategies to improve photosynthetic efficiency, crop productivity and adaptation to high light environments.
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Reisch, Bruce, Avichai Perl, Julie Kikkert, Ruth Ben-Arie, and Rachel Gollop. Use of Anti-Fungal Gene Synergisms for Improved Foliar and Fruit Disease Tolerance in Transgenic Grapes. United States Department of Agriculture, August 2002. http://dx.doi.org/10.32747/2002.7575292.bard.
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Original objectives . 1. Test anti-fungal gene products for activity against Uncinula necator, Aspergillus niger, Rhizopus stolonifer and Botrytis cinerea. 2. For Agrobacterium transformation, design appropriate vectors with gene combinations. 3. Use biolistic bombardment and Agrobacterium for transformation of important cultivars. 4. Characterize gene expression in transformants, as well as level of powdery mildew and Botrytis resistance in foliage of transformed plants. Background The production of new grape cultivars by conventional breeding is a complex and time-consuming process. Transferring individual traits via single genes into elite cultivars was proposed as a viable strategy, especially for vegetatively propagated crops such as grapevines. The availability of effective genetic transformation procedures, the existence of genes able to reduce pathogen stress, and improved in vitro culture methods for grapes, were combined to serve the objective of this proposal. Effective deployment of resistance genes would reduce production costs and increase crop quality, and several such genes and combinations were used in this project. Progress The efficacy of two-way combinations of Trichoderma endochitinase (CHIT42), synthetic peptide ESF12 and resveratrol upon the control of growth of Botrytis cinerea and Penicillium digitatum were evaluated in vitro. All pairwise interactions were additive but not synergistic. Per objective 2, suitable vectors with important gene combinations for Agrobacterium transformation were designed. In addition, multiple gene co-transformation by particle bombardment was also tested successfully. In New York, transformation work focused on cultivars Chardonnay and Merlot, while the technology in Israel was extended to 41B, R. 110, Prime, Italia, Gamay, Chardonnay and Velika. Transgenic plant production is summarized in the appendix. Among plants developed in Israel, endochitinase expression was assayed via the MuchT assay using material just 1-5 days after co-cultivation. Plants of cv. Sugraone carrying the gene coding for ESF12, a short anti-fungal lytic peptide under the control of the double 358 promoter, were produced. Leaf extracts of two plants showed inhibition zones that developed within 48 h indicating the inhibitory effect of the leaf extracts on the six species of bacteria. X fastidiosa, the causal organism of Pierce's disease, was very sensitive to leaf extracts from ESF12 transformed plants. Further work is needed to verify the agricultural utility of ESF12 transformants. In New York, some transformants were resistant to powdery mildew and Botrytis fruit rot. Major conclusions, solutions, achievements and implications The following scientific achievements resulted from this cooperative BARD project: 1. Development and improvement of embryogenesis and tissue culture manipulation in grape, while extending these procedures to several agriculturally important cultivars both in Israel and USA. 2. Development and improvement of novel transformation procedures while developing transformation techniques for grape and other recalcitrant species. 3. Production of transgenic grapevines, characterization of transformed vines while studying the expression patterns of a marker gene under the control of different promoter as the 35S CaMV in different part of the plants including flowers and fruits. 4. Expression of anti-fungal genes in grape: establishment of transgenic plants and evaluation of gene expression. Development of techniques to insert multiple genes. 5. Isolation of novel grape specific promoter to control the expression of future antimicrobial genes. It is of great importance to report that significant progress was made in not only the development of transgenic grapevines, but also in the evaluation of their potential for increased resistance to disease as compared with the non engineered cultivar. In several cases, increased disease resistance was observed. More research and development is still needed before a product can be commercialized, yet our project lays a framework for further investigations.