635 research outputs found
An exploration of international challenges facing wine sector in Spain
International competitiveness of Spanish and European wines is faced by growing supply, decreasing domestic demand, declining public support, and rising competition from New World producers. Resolving the wine competitiveness crisis will require restructuring processes in production and innovative strategies in trade, particularly external trade. The purpose of this paper is to explore main current and future developments affecting the global wine market and their implications from a Spanish expert viewpoint. After identifying the world wine market’s main features and conditioning regulatory factors, a prospective analysis of international trade and its expected effects on export strategies of the Spanish wine operators is carried out, using a two-stage surveying process accomplished with a representative expert group from different professional backgrounds. Broadly, results indicate that while several tendencies experienced over the last decade will be maintained and/or intensified during the coming years, the major drivers of wine trade and competitiveness will increasingly relate to the role of emerging consumer countries, quality and demand-driven attributes, product differentiation and promotional marketing.wine markets, export prospects, export strategies, Spain., Agricultural and Food Policy,
Detecting Economic Regimes in France : a Qualitative Markov-Switching Indicator Using Mixed Frequency Data
This paper proposes an indicator for detecting business cycle turning points involving mixed frequency business survey unbalanced data. It is based on a hidden Markov-switching model and allows for the detection of regime changes in a given economy where information is displayed monthly and/or quarterly. Starting from Gregoir and Lenglart (2000) we propose an adaptable framework which can be applied to many situations involving monthly, bimonthly and quarterly data. The proposed methodology is applied to the French economy. Using balances from business survey, this indicator measures the probability of being in an accelerating or a decelerating phase referring to the output growth rate cycle. The index is confronted over the past with a reference dating based on the growth cycle of the French GDP estimated through a Christiano-Fitzgerald filter. By extracting information from business survey, our index exhibits quite clearly and timely regime changes in France. Moreover, the signal delivered by the indicator is mainly unrevised and available many quarters before the ex-post dating. Considering this adequacy with the reference dating over the past, the turning point index therefore provides an accurate signal on the current outlook.Business Cycle; Business Survey; Turning points; Markov Switching Indicator; Multifrequency Data
Simulación Fluido-Dinámica en CFD de un Radiador aplicado a la Automoción
El presente proyecto aborda el problema de simular en CFD (Computational Fluid Dynamics)
un radiador del ámbito de la automoción. Pero no un radiador cualquiera sino un radiador
aplicado en el sector de la automoción de competición.
Como información de partida se tiene un ensayo realizado en la empresa PENSKE Cars de Inglaterra dónde se han ensayado diferentes tipos de radiadores. Con los resultados de los
que se dispone de estos ensayos se basará una primera parte del proyecto que se basa en
analizar que variables de entrada son las mejores y que variables servirán para la
comprobación de los modelos de radiador simulados con CFD.
Una segunda parte del proyecto constará en simular con CFD diferentes tipos de modelos
diseñados para ver cual de ellos obtiene los mejores resultados. Para ello se utilizarán las
variables anteriormente seleccionadas. Así una vez hechas las simulaciones se será capaz
de ver si los modelos simulados son próximos a la realidad o no.
Con referencia a las simulaciones con CFD, éstas se harán en el espacio 3D ya que a decisión del autor del proyecto se cree que será de mucho más interés y relevancia que no un análisis en 2D.
También mencionar que los resultados que se obtienen en el proyecto se tratarán de forma cualitativa y no cuantitativa ya que el interés del proyecto es alcanzar unos resultados fiables
y que sean próximos a la realidad. La decisión de que los resultados se tomen de forma cualitativa viene dada por el fin del presente proyecto. Ya que la simulación posteriormente
se intentará introducir en una simulación global de un vehículo. Las variables de entrada no
se saben con exactitud, así que si se consigue un modelo que funcione correctamente podrá
ser introducido en la simulación global aún sin éste conseguir valores absolutos iguales a los
del ensayo real.
Una vez obtenido el modelo simulado, se modificará para intentar obtener los mejores
resultados posibles.
Finalizado el proyecto se habrá conseguido un modelo de simulación de un radiador que simula el comportamiento real. Y cumpliendo así con uno de los objetivos del proyecto, poder incorporar la simulación obtenida en una simulación global de un coche de carreras de LeMans – Serie LMP1
La reestructuración de los mercados mundiales de alimentos y materias primas
Me voy a referir en esta ponencia a los mercados de las materias primas agrarias, y básicamente al mercado de los cereales, piedra angular de todos los mercados de materias primas agrarias y alimentos, debido a su influencia en el resto de los mercados agrarios, en las oleaginosas través de complejas relaciones de sustitución en la producción y el consumo, y directamente en los productos ganaderos, al ser parte fundamental de la alimentación animal. Hasta hace muy poco hablar agricultura en la Unión Europea y particularmente en España inevitablemente nos llevaba a referirnos a su escasa competitividad y a los peligros de abandono de la actividad en la medida en que se avanzase hacia una desconexión del apoyo público y a una disminución de la protección. Hoy en día este discurso, no tan lejano, parece ciencia ficción y desde hace 5 años asistimos a un resurgir de la agricultura, al menos en el discurso político. La situación del mercado mundial de los alimentos en los últimos tiempos ha estado condicionada por la evolución de los precios, con una tendencia al alza que pocos esperaban, y todos los organismos internacionales, gobiernos nacionales y centros de investigación se afanan en estudiar abordando las causas que explican su evolución y perspectivas, y los efectos que esta situación esta causando. A pesar de que en los últimos meses esta tendencia se ha suavizado y se han podido constatar descensos importantes en los precios, debido al descenso de la demanda, aumentos esperados en la producción y disminución de los costes de la energía, muchas de estas causas siguen vigentes, por lo que todas las previsiones apuntan a que los precios se mantendrán elevados en comparación con los niveles histórico
Spacetime geometry from canonical spherical gravity
We study covariant models for vacuum spherical gravity within a canonical
setting. Starting from a general ansatz, we derive the most general family of
Hamiltonian constraints that are quadratic in first-order and linear in
second-order spatial derivatives of the triad variables, and obey certain
specific covariance conditions. These conditions ensure that the dynamics
generated by such family univocally defines a spacetime geometry, independently
of gauge or coordinates choices. This analysis generalizes the Hamiltonian
constraint of general relativity, though keeping intact the covariance of the
theory, and leads to a rich variety of new geometries. We find that the
resulting geometries depend on seven free functions of one scalar variable, and
we study their generic features. By construction, there are no propagating
degrees of freedom in the theory. However, we also show that it is possible to
add matter to the system by simply following the usual minimal-coupling
prescription, which leads to novel models to describe dynamical scenarios
Nonsingular collapse of a spherical dust cloud
We provide a covariant framework to study singularity-free
Lema\^itre-Tolman-Bondi spacetimes with effective corrections motivated by loop
quantum gravity. We show that, as in general relativity, physically reasonable
energy distributions lead to a contraction of the dust shells. However,
quantum-gravity effects eventually stop the collapse, the dust smoothly bounces
back, and no gravitational singularity is generated. This model is constructed
by deforming the Hamiltonian constraint of general relativity with the
condition that the hypersurface deformation algebra is closed. In addition,
under the gauge transformations generated by the deformed constraints, the
structure function of the algebra changes adequately, so that it can be
interpreted as the inverse spatial metric. Therefore, the model is completely
covariant in the sense that gauge transformations in phase space simply
correspond to coordinate changes in spacetime. However, in the construction of
the metric, we point out a specific freedom of considering a conformal factor,
which we use to obtain a family of singularity-free spacetimes associated to
the modified model.Comment: 1 figure. Small clarifications and a brief comparison with previous
related models. Version matching the published pape
Adapting the wine industry in China to climate change: Challenges and opportunities
Recently, China has become an exciting wine consumer market and one of the most important wine producers. China?s domestic wine industry is in the enviable position of contributing approximately 70 % of the total wine consumed with a 1.36 billion population market and the second largest world economy. Current studies of the Chinese wine industry are mostly focused on the wine market. However, global climate change, which affects the quantity, quality and distribution of wine, will have a strong impact on the Chinese domestic wine industry. In this paper, we characterize the impact of climate change in China and establish policy, financial, technical, institutional and collaborative adaptation strategies for the Chinese wine industry
Singularity resolution by holonomy corrections: Spherical charged black holes in cosmological backgrounds
We study spherical charged black holes in the presence of a cosmological
constant with corrections motivated by the theory of loop quantum gravity. The
effective theory is constructed at the Hamiltonian level by introducing certain
correction terms under the condition that the modified constraints form a
closed algebra. The corresponding metric tensor is then carefully constructed
ensuring that the covariance of the theory is respected, that is, in such a way
that different gauge choices on phase space simply correspond to different
charts of the same spacetime solution. The resulting geometry is characterized
by four parameters: the three usual ones that appear in the general
relativistic limit (describing the mass, the charge, and the cosmological
constant), as well as a polymerization parameter, which encodes the
quantum-gravity corrections. Contrary to general relativity, where this family
of solutions is generically singular, in this effective model the presence of
the singularity depends on the values of the parameters. The specific ranges of
values that define the family of singularity-free spacetimes are explicitly
found, and their global structure is analyzed. In particular, the mass and the
cosmological constant need to be nonnegative to provide a nonsingular geometry,
while there can only be a bounded, relatively small, amount of charge. These
conditions are suited for any known spherical astrophysical black hole in the
de Sitter cosmological background, and thus this model provides a globally
regular description for them.Comment: Minor corrections performed. Version matching the published paper. 38
pages, 10 figures, 6 appendice
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Miniature transposable sequences are frequently mobilized in the bacterial plant pathogen Pseudomonas syringae pv. phaseolicola
Mobile genetic elements are widespread in Pseudomonas syringae, and often associate with virulence genes. Genome
reannotation of the model bean pathogen P. syringae pv. phaseolicola 1448A identified seventeen types of insertion
sequences and two miniature inverted-repeat transposable elements (MITEs) with a biased distribution, representing 2.8%
of the chromosome, 25.8% of the 132-kb virulence plasmid and 2.7% of the 52-kb plasmid. Employing an entrapment vector
containing sacB, we estimated that transposition frequency oscillated between 2.661025 and 1.161026, depending on the
clone, although it was stable for each clone after consecutive transfers in culture media. Transposition frequency was similar
for bacteria grown in rich or minimal media, and from cells recovered from compatible and incompatible plant hosts,
indicating that growth conditions do not influence transposition in strain 1448A. Most of the entrapped insertions
contained a full-length IS801 element, with the remaining insertions corresponding to sequences smaller than any
transposable element identified in strain 1448A, and collectively identified as miniature sequences. From these, fragments
of 229, 360 and 679-nt of the right end of IS801 ended in a consensus tetranucleotide and likely resulted from one-ended
transposition of IS801. An average 0.7% of the insertions analyzed consisted of IS801 carrying a fragment of variable size
from gene PSPPH_0008/PSPPH_0017, showing that IS801 can mobilize DNA in vivo. Retrospective analysis of complete
plasmids and genomes of P. syringae suggests, however, that most fragments of IS801 are likely the result of reorganizations
rather than one-ended transpositions, and that this element might preferentially contribute to genome flexibility by
generating homologous regions of recombination. A further miniature sequence previously found to affect host range
specificity and virulence, designated MITEPsy1 (100-nt), represented an average 2.4% of the total number of insertions
entrapped in sacB, demonstrating for the first time the mobilization of a MITE in bacteria
Precios hedónicos para vinos de Ribera del Duero y Navarra en el mercado estadounidense
El sector del vino se enfrenta a nuevas oportunidades de mercado, debido a la creciente liberalización comercial, a las que hay que unir recientes retos: una mayor competencia con nuevos actores y el descenso del consumo en los países productores tradicionales. Por ello, optar por decisiones estratégicas de comercialización acertadas puede impulsar una presencia sostenible en los mercados internacionales. En este marco, se ha procedido a determinar la función de precios hedónicos para los vinos de las categorías popular Premium y super Premium de las denominaciones de origen de Ribera del Duero y de Navarra para el mercado de Estados Unidos. Cinco atributos de estos vinos han resultado tener impacto sobre el precio en mayor o menor medida: nota de calidad, origen, año de cosecha, grado de envejecimiento y tamaño de la bodega. Se discuten, finalmente, las implicaciones de mercado para productores y comercializadores
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