52 resultados para Not drawn to scaleNone


Relevância:

100.00% 100.00%

Publicador:

Resumo:

At the end of 2008 the Convention on Cluster Munitions (CCM) that outlawed almost all types of cluster munitions was signed. It was the product of the so-called Oslo process, which had been set up two years earlier as a reaction to the failure to add a new protocol banning cluster munitions to the Convention on Certain Conventional Weapons (CCW). The position of the EU in these two processes was ambivalent: on the one hand it belonged to the strongest proponents for a new protocol within the CCW, but on the other hand the member states were in general not able to act jointly in the Oslo Process. According to this working paper especially the aspect of national security and the related relationship to the United States influenced the stances of many member states and complicated the formation of a common European position. There were common normative values of the EU detected, which played a role in the CCW, but they were only secondary to other interests of the member states.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The development, validation, comparison and evaluation of analytical methods for marine toxins rely on the availability of toxic material. Within the project JACUMAR PSP, our interest is mainly focused on autochthonous bivalve species with the toxic profile of Alexandrium minutum, since this is the principal species involved regionally in PSP outbreaks. Mussels and oysters were exposed during few days in the harbor of Vilanova i la Geltrú, to blooms reaching a maximum A. minutum concentration of 200,000 cells L-1 in 2008, and 40,000 and 800,000 cells L-1, in 2009. Mussels, oysters and clams were exposed to one bloom of 22,000 cells L-1 in the harbor of Cambrils in 2009. In all situations higher toxic levels analyzed by HPLC-FD with postcolumn oxidation were observed in mussels (i.e. 1,200-2,500 μg eq. STX kg-1) than in oysters (i.e. 60-800 μg eq. STX kg-1) exposed to the same bloom. Blooms with higher concentrations of A. minutum did not correspond to higher levels of PSP toxins in bivalves. These differences may be explained by differences in A. minutum population dynamics, toxin production or in the physiological state or behaviour of shellfish. These results confirm that mussels concentrate more PSP toxins from A. minutum than oysters and clams.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

La meva incorporació al grup de recerca del Prof. McCammon (University of California San Diego) en qualitat d’investigador post doctoral amb una beca Beatriu de Pinós, va tenir lloc el passat 1 de desembre de 2010; on vaig dur a terme les meves tasques de recerca fins al darrer 1 d’abril de 2012. El Prof. McCammon és un referent mundial en l’aplicació de simulacions de dinàmica molecular (MD) en sistemes biològics d’interès humà. La contribució més important del Prof. McCammon en la simulació de sistemes biològics és el desenvolupament del mètode de dinàmiques moleculars accelerades (AMD). Les simulacions MD convencionals, les quals estan limitades a l’escala de temps del nanosegon (~10-9s), no son adients per l’estudi de sistemes biològics rellevants a escales de temps mes llargues (μs, ms...). AMD permet explorar fenòmens moleculars poc freqüents però que son clau per l’enteniment de molts sistemes biològics; fenòmens que no podrien ser observats d’un altre manera. Durant la meva estada a la “University of California San Diego”, vaig treballar en diferent aplicacions de les simulacions AMD, incloent fotoquímica i disseny de fàrmacs per ordinador. Concretament, primer vaig desenvolupar amb èxit una combinació dels mètodes AMD i simulacions Car-Parrinello per millorar l’exploració de camins de desactivació (interseccions còniques) en reaccions químiques fotoactivades. En segon lloc, vaig aplicar tècniques estadístiques (Replica Exchange) amb AMD en la descripció d’interaccions proteïna-lligand. Finalment, vaig dur a terme un estudi de disseny de fàrmacs per ordinador en la proteïna-G Rho (involucrada en el desenvolupament de càncer humà) combinant anàlisis estructurals i simulacions AMD. Els projectes en els quals he participat han estat publicats (o estan encara en procés de revisió) en diferents revistes científiques, i han estat presentats en diferents congressos internacionals. La memòria inclosa a continuació conté més detalls de cada projecte esmentat.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The “one-gene, one-protein” rule, coined by Beadle and Tatum, has been fundamental to molecular biology. The rule implies that the genetic complexity of an organism depends essentially on its gene number. The discovery, however, that alternative gene splicing and transcription are widespread phenomena dramatically altered our understanding of the genetic complexity of higher eukaryotic organisms; in these, a limited number of genes may potentially encode a much larger number of proteins. Here we investigate yet another phenomenon that may contribute to generate additional protein diversity. Indeed, by relying on both computational and experimental analysis, we estimate that at least 4%–5% of the tandem gene pairs in the human genome can be eventually transcribed into a single RNA sequence encoding a putative chimeric protein. While the functional significance of most of these chimeric transcripts remains to be determined, we provide strong evidence that this phenomenon does not correspond to mere technical artifacts and that it is a common mechanism with the potential of generating hundreds of additional proteins in the human genome.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Stress can cause damage and atrophy of neurons in the hippocampus by deregulating the expression of neurotrophic factors that promote neuronal plasticity. The endocannabinoid system represents a physiological substrate involved in neuroprotection at both cellular and emotional levels. The lack of CB1 receptor alters neuronal plasticity and originates an anxiety-like phenotype in mice. In the present study, CB1 knockout mice exhibited an augmented response to stress revealed by the increased despair behavior and corticosterone levels showed in the tail suspension test and decreased brain derived neurotrophic factor (BDNF) levels in the hippocampus. Interestingly, local administration of BDNF in the hippocampus reversed the increased despair behavior of CB1 knockout mice, confirming the crucial role played by BDNF on the emotional impairment of these mutants. The neurotrophic deficiency seems to be specific for BDNF since no differences were found in the levels of NGF and NT-3, two additional neurotrophic factors. Moreover, BDNF impairment is not related to the activity of its specific receptor TrkB or the activity of the transcription factor CREB. These results suggest that the lack of CB1 receptor originates an enhanced response to stress and neuronal plasticity by decreasing BDNF levels in the hippocampus that lead to impairment in the responses to emotional disturbances.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study analyses the determinants of the rate of temporary employment in various OECD countries using both macro-level data drawn from the OECD and EUROSTAT databases, as well as micro-level data drawn from the 8th wave of the European Household Panel. Comparative analysis is set out to test different explanations originally formulated for the Spanish case. The evidence suggests that the overall distribution of temporary employment in advanced economies does not seem to be explicable by the characteristics of national productive structures. This evidence seems at odds with previous interpretations based on segmentation theories. As an alternative explanation, two types of supply-side factors are tested: crowding-out effects and educational gaps in the workforce. The former seems non significant, whilst the effects of the latter disappear after controlling for the levels of institutional protection in standard employment during the 1980s. Multivariate analysis shows that only this latter institutional variable, together with the degree of coordinated centralisation of the collective bargaining system, seem to have a significant impact on the distribution of temporary employment in the countries examined. On the basis of this observation, an explanation of the very high levels of temporary employment observed in Spain is proposed. This explanation is consistent with both country-specific and comparative evidence.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Business organisations are excellent representations of what in physics and mathematics are designated "chaotic" systems. Because a culture of innovation will be vital for organisational survival in the 21st century, the present paper proposes that viewing organisations in terms of "complexity theory" may assist leaders in fine-tuning managerial philosophies that provide orderly management emphasizing stability within a culture of organised chaos, for it is on the "boundary of chaos" that the greatest creativity occurs. It is argued that 21st century companies, as chaotic social systems, will no longer be effectively managed by rigid objectives (MBO) nor by instructions (MBI). Their capacity for self-organisation will be derived essentially from how their members accept a shared set of values or principles for action (MBV). Complexity theory deals with systems that show complex structures in time or space, often hiding simple deterministic rules. This theory holds that once these rules are found, it is possible to make effective predictions and even to control the apparent complexity. The state of chaos that self-organises, thanks to the appearance of the "strange attractor", is the ideal basis for creativity and innovation in the company. In this self-organised state of chaos, members are not confined to narrow roles, and gradually develop their capacity for differentiation and relationships, growing continuously toward their maximum potential contribution to the efficiency of the organisation. In this way, values act as organisers or "attractors" of disorder, which in the theory of chaos are equations represented by unusually regular geometric configurations that predict the long-term behaviour of complex systems. In business organisations (as in all kinds of social systems) the starting principles end up as the final principles in the long term. An attractor is a model representation of the behavioral results of a system. The attractor is not a force of attraction or a goal-oriented presence in the system; it simply depicts where the system is headed based on its rules of motion. Thus, in a culture that cultivates or shares values of autonomy, responsibility, independence, innovation, creativity, and proaction, the risk of short-term chaos is mitigated by an overall long-term sense of direction. A more suitable approach to manage the internal and external complexities that organisations are currently confronting is to alter their dominant culture under the principles of MBV.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In principle, a country can not endure negative genuine savings for longperiods of time without experiencing declining consumption. Nevertheless,theoreticians envisage two alternatives to explain how an exporter ofnon-renewable natural resources could experience permanent negativegenuine savings and still ensure sustainability. The first one allegesthat the capital gains arising from the expected improvement in theterms of trade would suffice to compensate for the negative savings ofthe resource exporter. The second alternative points at technologicalchange as a way to avoid economic collapse. This paper uses the dataof Venezuela and Mexico to empirically test the first of these twohypotheses. The results presented here prove that the terms oftrade do not suffice to compensate the depletion of oil reservesin these two open economies.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We test whether outside experts have information not available to insiders by usingthe voting record of the Bank of England's Monetary Policy Committee. Memberswith more private information should vote more often against conventional wisdom,which we measure as the average belief of market economists about future interest rates. We find evidence that external members indeed have information notavailable to internals, but also use a quasi-natural experiment to show they mayexaggerate their expertise to obtain reappointment. This implies that an optimalcommittee, even outside monetary policy, should potentially include outsiders, butneeds to manage career concerns.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A new algorithm called the parameterized expectations approach(PEA) for solving dynamic stochastic models under rational expectationsis developed and its advantages and disadvantages are discussed. Thisalgorithm can, in principle, approximate the true equilibrium arbitrarilywell. Also, this algorithm works from the Euler equations, so that theequilibrium does not have to be cast in the form of a planner's problem.Monte--Carlo integration and the absence of grids on the state variables,cause the computation costs not to go up exponentially when the numberof state variables or the exogenous shocks in the economy increase. \\As an application we analyze an asset pricing model with endogenousproduction. We analyze its implications for time dependence of volatilityof stock returns and the term structure of interest rates. We argue thatthis model can generate hump--shaped term structures.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper proposes a model of financial markets and corporate finance,with asymmetric information and no taxes, where equity issues, Bankdebt and Bond financing may all co-exist in equilibrium. The paperemphasizes the relationship Banking aspect of financial intermediation:firms turn to banks as a source of investment mainly because banks aregood at helping them through times of financial distress. The debtrestructuring service that banks may offer, however, is costly. Therefore,the firms which do not expect to be financially distressed prefer toobtain a cheaper market source of funding through bond or equity issues.This explains why bank lending and bond financing may co-exist inequilibrium. The reason why firms or banks also issue equity in our modelis simply to avoid bankruptcy. Banks have the additional motive that theyneed to satisfy minimum capital adequacy requeriments. Several types ofequilibria are possible, one of which has all the main characteristics ofa "credit crunch". This multiplicity implies that the channels of monetarypolicy may depend on the type of equilibrium that prevails, leadingsometimes to support a "credit view" and other times the classical "moneyview".

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Business organisations are excellent representations of what in physics and mathematics are designated "chaotic" systems. Because a culture of innovation will be vital for organisational survival in the 21st century, the present paper proposes that viewing organisations in terms of "complexity theory" may assist leaders in fine-tuning managerial philosophies that provide orderly management emphasizing stability within a culture of organised chaos, for it is on the "boundary of chaos" that the greatest creativity occurs. It is argued that 21st century companies, as chaotic social systems, will no longer be effectively managed by rigid objectives (MBO) nor by instructions (MBI). Their capacity for self-organisation will be derived essentially from how their members accept a shared set of values or principles for action (MBV). Complexity theory deals with systems that show complex structures in time or space, often hiding simple deterministic rules. This theory holds that once these rules are found, it is possible to make effective predictions and even to control the apparent complexity. The state of chaos that self-organises, thanks to the appearance of the "strange attractor", is the ideal basis for creativity and innovation in the company. In this self-organised state of chaos, members are not confined to narrow roles, and gradually develop their capacity for differentiation and relationships, growing continuously toward their maximum potential contribution to the efficiency of the organisation. In this way, values act as organisers or "attractors" of disorder, which in the theory of chaos are equations represented by unusually regular geometric configurations that predict the long-term behaviour of complex systems. In business organisations (as in all kinds of social systems) the starting principles end up as the final principles in the long term. An attractor is a model representation of the behavioral results of a system. The attractor is not a force of attraction or a goal-oriented presence in the system; it simply depicts where the system is headed based on its rules of motion. Thus, in a culture that cultivates or shares values of autonomy, responsibility, independence, innovation, creativity, and proaction, the risk of short-term chaos is mitigated by an overall long-term sense of direction. A more suitable approach to manage the internal and external complexities that organisations are currently confronting is to alter their dominant culture under the principles of MBV.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The goal of this paper is to estimate time-varying covariance matrices.Since the covariance matrix of financial returns is known to changethrough time and is an essential ingredient in risk measurement, portfolioselection, and tests of asset pricing models, this is a very importantproblem in practice. Our model of choice is the Diagonal-Vech version ofthe Multivariate GARCH(1,1) model. The problem is that the estimation ofthe general Diagonal-Vech model model is numerically infeasible indimensions higher than 5. The common approach is to estimate more restrictive models which are tractable but may not conform to the data. Our contributionis to propose an alternative estimation method that is numerically feasible,produces positive semi-definite conditional covariance matrices, and doesnot impose unrealistic a priori restrictions. We provide an empiricalapplication in the context of international stock markets, comparing thenew estimator to a number of existing ones.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We examine the conditions under which competitive equilibria can beobtained as the limit, when the number of strategic traders getslarge, of Nash equilibria in economies with asymmetric informationon agents' effort and possibly imperfect observability of agents'trades. Convergence always occur when either effort is publiclyobserved (no matter what is the information available tointermediaries on agents' trades); or effort is private informationbut agents' trades are perfectly observed; or no information at allis available on agents' trades. On the other hand, when eachintermediary can observe its trades with an agent, but not theagent's trades with other intermediaries, the (Nash) equilibriawith strategic intermediaries do not converge to any of thecompetitive equilibria, for an open set of economies. The source ofthe difficulties for convergence is the combination of asymmetricinformation and the restrictions on the observability of tradeswhich prevent the formation of exclusive contractual relationshipsand generate barriers to entry in the markets for contracts.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The proposal to work on this final project came after several discussions held with Dr. Elzbieta Malinowski Gadja, who in 2008 published the book entitled Advanced Data Warehouse Design: From Conventional to Spatial and Temporal Applications (Data-Centric Systems and Applications). The project was carried out under the technical supervision of Dr. Malinowski and the direct beneficiary was the University of Costa Rica (UCR) where Dr. Malinowski is a professor at the Department of Computer Science and Informatics. The purpose of this project was twofold: First, to translate chapter III of said book with the intention of generating educational material for the use of the UCR and, second, to venture in the field of technical translation related to data warehouse. For the first component, the goal was to generate a final product that would eventually serve as an educational tool for the post-graduate courses of the UCR. For the second component, this project allowed me to acquire new skills and put into practice techniques that have helped me not only to perfom better in my current job as an Assistant Translator of the Inter-American BAnk (IDB), but also to use them in similar projects. The process was lenggthy and required torough research and constant communication with the author. The investigation focused on the search of terms and definitions to prepare the glossary, which was the basis to start the translation project. The translation process itself was carried out by phases, so that comments and corrections by the author could be taken into account in subsequent stages. Later, based on the glossary and the translated text, illustrations had been created in the Visio software were translated. In addition to the technical revision by the author, professor Carme Mangiron was in charge of revising the non-technical text. The result was a high-quality document that is currently used as reference and study material by the Department of Computer Science and Informatics of Costa Rica.