Irregular hypergeometric D-modules

We study the irregularity of hypergeometric D-modules $\mathcal{M}_A (\beta )$ via the explicit construction of Gevrey series solutions along coordinate subspaces in $X =\mathbb{C}^n$. As a consequence, we prove that along coordinate hyperplanes the combinatorial characterization of the slopes of $\mathcal{M}_A (\beta)$ given by M. Schulze and U. Walther in [21] still holds without any assumption on the matrix A. We also provide a lower bound for the dimensions of the spaces of Gevrey solutions along coordinate subspaces in terms of volumes of polytopes and prove the equality for very generic parameters. Holomorphic solutions outside the singular locus of $\mathcal{M}_A (\beta)$ can be understood as Gevrey solutions of order one along X at generic points and so they are included as a particular case.Comment: 41 pages; references, Remark 7.2. and 4 figures added; some comments changed; corrected typo

Characteristic cycles and Gevrey series solutions of AA-hypergeometric systems

We compute the $L$-characteristic cycle of an $A$-hypergeometric system and higher Euler-Koszul homology modules of the toric ring. We also prove upper semicontinuity results about the multiplicities in these cycles and apply our results to analyze the behavior of Gevrey solution spaces of the system.Comment: 22 page

The Rhythm of our Lives. Aesthetic Perspectives East & West

The leading approach to everyday aesthetics for the past few decades has departed from analytic philosophical grounds, generating some tensions or dichotomies regarding its foundational cornerstones: the ordinary vs. extraordinary character of everyday aesthetic experience, contextual familiarity vs. strangeness, object vs. processual orientation, etc. Although John Dewey has been widely acclaimed as a sort of foundational figure for this burgueoning sub-discipline of aesthetics, maybe not enough emphasis has been laid on his very different pragmatist approach. In this regard, his reliance on Hegelian cum Darwinian premises might allow for a connection with other branches of continental as well as Asian philosophies, from which also some research on everyday aesthetics has been made. It is from this wider ontological framework that the notion of rhythm could be vindicated as a pivotal aspect of the aesthetic dimension of our everyday lives. Dewey deals extensively with it in Art as Experience, conceiving it as a sort of pattern of accomplished experiences, accounting also for his naturalistic approach and art and life continuity thesis. On the other hand, neo-pragmatist exponent Richard Shusterman, among others, has posited links of connection between Pragmatist aesthetics and East-Asian philosophies. Particularly, Dewey’s resonances with Asian philosophies have been studied, with a preeminence on the notions of harmony and rhythm. This paper will depart from the analysis of the notion of rhythm in Dewey’s philosophy, trying to hint at some possible developments of its implications. Particularly, it will expand on some East Asian paralelisms to his philosophy, trying to link them with the notion of rhythm as an epitomizing ground for the conjunction of the extraordinary (art) and the ordinary (life).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

The Poetic Dimension of Everyday Aesthetic Appreciation. Perspectives from East-Asian Cultures

As Yuriko Saito, one of the main exponents of everyday aesthetics holds, East-Asian cultures have long established a deep link between artistic practices and everyday life, transforming apparently mundane practices such as having a cup o ftea with cakes into a highly ritualized form of art (cha-no-yu) and allowing us to enjoy the fleeting moment. The tea ceremony example is grounded, as this paper aims at showing, on a whole East-Asian worldview (as exemplfieied in Confucianism, Daoism and Zen Buddhism philosophies) whereby aesthetic appreciation is deeply pervaded by a poetic feeling, mainly consisting in the interactive harmony or attunement established with the particular circumstances of one’s own life due precisely to its fleeting and evanescent nature. To accomplish this, savouring and perceiving the uniqueness ingrained in every single human experience, the adequate attitude is the poetic one, due to its holistic and non-discriminative nature. Having as its focus everyday life, or simply put, life as such in its specificity, traditional artistic practices in East-Asia as the arts of the brush, garden design or utilitarian crafts such as pottery, become means of revealing what, due to its closeness, lies hidden in ordinary experience. Utilitarian arts are, in this sense, a priviledged way of conveying this end due precisely to its practical link with ordinary existence, preventing the eventual arousal of a purely formal and detached apprehension. The only coherent way to develop this awareness of the extraordinary in the ordinary, to use Leddy’s expression, is through the main feature of all poetic qualities: indirect allusion and subdued reference so that what is close at hand may shine in a different light. Particularly, in association with Japanese Zen Buddhism, where the rootedness of aesthetics in the ordinary is stronger, it has frequently adopted the form of restraint, contention, reserve, or, as Saito puts it, “insufficiency”. This paper aims at showing with the help of a few examples how this difuse poetic attitude, so prevalent in Traditional East-Asian contexts, is required not only in standardized art practices, but also in a wider aesthetic level of awareness of our ordinary experiences. In order to justify these claims, it will refer first to the ideal of harmony or poetic resonance in Chinese aesthetics and then it will refer to some concrete Japanese aesthetic categories inspired by Zen Buddhism, such as mono-no-aware, sabi, wabi, or yugen

International involvement of smes: the impact of ownership

This paper analyses the relation between SME ownership and international involvement. With a wide sample of Spanish firms, from 1991 to 1999, we test the following hypotheses. Family SMEs results in lower involvement in international markets, due to difficult access to necessary strategic resources. SMEs with another company as a large-block shareholder will be more involved internationally, as they do have access more strategic resources. Likewise, when another company invests in a family SME, international involvement increases

Graphene Based Poly(Vinyl Alcohol) Nanocomposites Prepared by In Situ Green Reduction of Graphene Oxide by Ascorbic Acid: Influence of Graphene Content and Glycerol Plasticizer on Properties

The enhanced properties of polymer nanocomposites as compared with pure polymers are only achieved in the presence of well-dispersed nanofillers and strong interfacial adhesion. In this study, we report the preparation of nanocomposite films based on poly(vinyl alcohol) (PVA) filled with well dispersed graphene sheets (GS) by in situ reduction of graphene oxide (GO) dispersed in PVA solution using ascorbic acid (L-AA) as environmentally friendly reductant. The combined effect of GS content and glycerol as plasticizer on the structure, thermal, mechanical, water absorption, and water barrier properties of PVA/GS nanocomposite films is studied for the first time. Higher glass transition temperature, lower crystallinity, melting, and crystallization temperature, higher mechanical properties, and remarkable improvement in the thermal stability compared to neat PVA are obtained as a result of strong interfacial interactions between GS and PVA by hydrogen bonding. PVA/GS composite film prepared by ex situ process is more brittle than its in situ prepared counterpart. The presence of GS improves the water barrier and water resistance properties of nanocomposite films by decreasing water vapor permeability and water absorption of PVA. This work demonstrates that the tailoring of PVA/GS nanocomposite properties is enabled by controlling GS and glycerol content. The new developed materials, particularly those containing plasticizer, could be potential carriers for transdermal drug delivery.SAIOTEK 2013 S-PE13UN004 Basque Governmen

Impacts of fire, fire-fighting chemicals and post-fire stabilisation techniques on the soil-plant system

Forest fires, as well as fire-fighting chemicals, greatly affect the soil-plant system causing vegetation loss, alterations of soil properties and nutrient losses through volatilization, leaching and erosion. Soil recovery after fires depends on the regeneration of the vegetation cover, which protects the soil and prevents erosion. Fire-fighting chemicals contain compounds potentially toxic for plants and soil organisms, and thus their use might hamper the regeneration of burnt ecosystems. In high severity fires and steep areas, natural revegetation can be delayed due to seed bank destruction and soil erosion, being paramount to adopt, as soon as possible, post-fire stabilization techniques. Straw mulching is very effective in reducing post-fire erosion, but it is necessary to optimize this technique because its costs and the availability of straw hinder its application on a regional scale. Moreover, even though it is well known that fires greatly affect the N cycle, there is not much information about the effects of straw mulching on gross N fluxes. The aims of this thesis are: 1) to assess how fire and three fire-fighting chemicals affect the soil-plant system in the long term (10 years); 2) to optimize the use of post-fire straw mulching, so it is economically viable, and to assess the effects of its application on the soil-plant system; 3) to evaluate the effects fire, fire severity and straw mulching on gross N fluxes