Finiteness theorems for matroid complexes with prescribed topology

It is known that there are finitely many simplicial complexes (up to isomorphism) with a given number of vertices. Translating to the language of $h$-vectors, there are finitely many simplicial complexes of bounded dimension with $h_1=k$ for any natural number $k$. In this paper we study the question at the other end of the $h$-vector: Are there only finitely many $(d-1)$-dimensional simplicial complexes with $h_d=k$ for any given $k$? The answer is no if we consider general complexes, but when focus on three cases coming from matroids: (i) independence complexes, (ii) broken circuit complexes, and (iii) order complexes of geometric lattices. We prove the answer is yes in cases (i) and (iii) and conjecture it is also true in case (ii).Comment: to appear in European Journal of Combinatoric

IMPLICATIONS OF CAPITAL-INTENSIVE DEVELOPMENT INTERVENTIONS FOR COMMUNAL RESOURCE OWNERS: THE CASE OF COMMUNAL FARMERS IN ECUADOR

The introduction in Ecuador of a primary irrigation infrastructure into a communal setting where land users did not fully control the land and had effectively no access to credit, produced a sell off of nearly all irrigable lands. The change in land reservation prices between buyers and sellers is analyzed.Land Economics/Use,

The topology of the external activity complex of a matroid

We prove that the external activity complex $\textrm{Act}_<(M)$ of a matroid is shellable. In fact, we show that every linear extension of LasVergnas's external/internal order $<_{ext/int}$ on $M$ provides a shelling of $\textrm{Act}_<(M)$. We also show that every linear extension of LasVergnas's internal order $<_{int}$ on $M$ provides a shelling of the independence complex $IN(M)$. As a corollary, $\textrm{Act}_<(M)$ and $M$ have the same $h$-vector. We prove that, after removing its cone points, the external activity complex is contractible if $M$ contains $U_{3,1}$ as a minor, and a sphere otherwise.Comment: Comments are welcom

Delimitación de los perímetros de protección de pozos mediante las técnicas numéricas y el método analítico, acuífero Margarita, Cuba

La popularidad de los perímetros de protección de pozos como herramienta importante en la protección de las aguas subterráneas para el consumo humano, incluyendo por supuesto las aguas minerales embotelladas, a aumentado considerablemente en los últimos años, viéndose reflejada en numerosos documentos de diverso alcance, destacándose frecuentemente que no todos los métodos de delimitación de perímetros de protección de pozos dan resultados satisfactorios. En este sentido, el objetivo principal del presente trabajo fue, delimitar de la forma más precisa posible, el perímetro de protección alrededor de una importante fuente de agua mineral para embotellar, ubicada en el acuífero Margarita, región central de Cuba. En la delimitación se utilizaron dos de los métodos de más amplio uso internacional, el analítico, en cuatro de sus variantes y el numérico, mediante el modelo VisualMODFLOW. Se muestra como bajo las condiciones analizadas (acuíferos heterogéneos, anisotrópicos y de extensión local), los resultados entre ambos métodos pueden diferir en más del 100%, siendo varias las causas que provocan tales diferencias, entre las que destacan, la influencia de la recarga por las precipitaciones y el aporte de agua subterránea de las partes del acuífero que se ubican por debajo de la máxima profundidad del pozo. Se presenta además un mapa de gestión de los recursos hídricos subterráneos del área de estudio, donde se establece como y donde deben explotarse los recursos de aguas subterráneas, sin que se afecte las dimensiones calculadas del perímetro de protección, ni el caudal de explotación del pozo de mayor importancia. Finalmente, se proponen adecuaciones en las variantes utilizadas del método analítico, las cuales pueden mejorar considerablemente los resultados alcanzados bajo las condiciones hidrogeológicas analizadas. De cualquier forma, se subraya las grandes limitaciones que presenta el método analítico para delimitar los perímetros de protección de pozos en las condiciones analizadas y las potencialidades ilimitadas que para este fin, poseen los modelos numéricos

Exploring the managerial intuition and knowledge of managers in Mexico\u27s \u3ci\u3emaquiladora\u3c/i\u3e industry

Decision-making has been a subject of interest for management scholars since the scientific management era (Wren, 1994). Brockmann and Simmonds (1997) and Guinipero, Dawley and Anthony (1999) studied the link between managerial decision-making and tacit knowledge in the effort to identify important cognitive elements in the day-to-day decision-making processes of firm managers. Despite their bold and innovative aims, however, Brockmann et al. (1997) and Guinipero et al. (1999) were weakened by their fundamental assumption that tacit knowledge is synonymous to intuition, and by inconsistencies in their research goals and methods. This dissertation addresses these shortcomings. The contributions of this research to the realm of management studies are as follows; first, it extends the studies by Brockmann et al. (1997) and Guinipero et al. (1999) to an international setting by surveying managers in Mexico\u27s maquiladora industry to explore the link between intuition and tacit managerial know-how. The second valuable contribution of this study is that it tests the link between managerial know-how and intuition and the number of promotions, gender and the geographical proximity of maquiladora managers to the border; these variables have been theoretically linked in the literature but have yet to be tested empirically. Third, this study adds Mexico to the growing roll of test countries for two long-standing and oft-utilized surveys by Wagner and Sternberg (1991) and Parikh et al. (1994) used for assessing tacit knowledge and intuition. These survey instruments have been applied in fifteen countries in five continents, yet have never been tested in the largest Spanish speaking culture in the world. It stands to reason that by testing Mexican nationals, the universality of these surveys could be greatly enhanced

How continuous-like processes improve affordability for viral vaccines - Example of LAIV

Designing a continuous process for a life viral vaccine could be seen useless, and challenging, as the virus infection will kill the cell substrate after 2-5 days of infection. From the technical perspective, chaining the operations of cell culture under perfusion and viral production, clarification and capture / concentration is an efficient option to setup a small scale continuous automated process to manufacture massive amounts of viral vaccines. We will show how beneficial it can be in terms of process development, manufacturing simplicity, capital expenditure and cost of production. Also, we will show how this approach can help producers of viral vaccines to produce at very low cost even for segmented markets for which small amounts of multiple vaccines are needed

Y el Madrid, Qué, ¿Otra Vez Campeón de Europa? ¿No? /And Real Madrid Once Again European Champion, Right? Spanish architecture and CIAM debates from 1953 to 1959

In August 11 1956 José Luis Sert opened the Dubrovnik CIAM 10 meeting with his speech on The Future of CIAM. Just two months earlier, June 13, the Real Madrid Football Club won the European Cup in Paris. It was the first European Cup as such and the first of the many trophies won by the Spanish club. This, of course, is an anecdote, but a fairly informative one. That a Spanish and exiled architect opened the CIAM 10 strongly contrasted with one of the few international events starred by Francoist Spain: winning the European cup. This is an oblique way of saying that CIAM debates were far from being a concern in the Spanish theoretical and professional architecture milieu in the 1950s. Spanish architects were starting to incorporate the basic trends of post-war modernism to their designs at this time, and the American and European modern architecture slowly began to filter, but they were far from being involved in the heated 1956 CIAM debate. However, one Spanish architect, José Antonio Coderch entered CIAM, following Sert’s suggestions, ready to participate as a Team 10 member in the 1959 Otterlo schwanengesang, and for sure some of the preoccupations that occupied CIAM also concerned the Spaniards. This paper recounts how in this brief period, say between 1953 and 1959 with the key middle date of 1956, the contemporary CIAM debates obliquely entered the previously isolated Spain, and how Spanish architects caught up (if so) with post-war modernism and its criticism at the same time.info:eu-repo/semantics/publishedVersio

Improving edge finite element assembly for geophysical electromagnetic modelling on shared-memory architectures

This work presents a set of node-level optimizations to perform the assembly of edge finite element matrices that arise in 3D geophysical electromagnetic modelling on shared-memory architectures. Firstly, we describe the traditional and sequential assembly approach. Secondly, we depict our vectorized and shared-memory strategy which does not require any low level instructions because it is based on an interpreted programming language, namely, Python. As a result, we obtained a simple parallel-vectorized algorithm whose runtime performance is considerably better than sequential version. The set of optimizations have been included to the work-flow of the Parallel Edge-based Tool for Geophysical Electromagnetic Modelling (PETGEM) which is developed as open-source at the Barcelona Supercomputing Center. Finally, we present numerical results for a set of tests in order to illustrate the performance of our strategy.This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 644202. The research leading to these results has received funding from the European Union's Horizon 2020 Programme (2014-2020) and from Brazilian Ministry of Science, Technology and Innovation through Rede Nacional de Pesquisa (RNP) under the HPC4E Project (www.hpc4e.eu), grant agreement No. 689772. Authors gratefully acknowledge the support from the Mexican National Council for Science and Technology (CONACYT). All numerical tests were performed on the MareNostrum supercomputer of the Barcelona Supercomputing Center - Centro Nacional de Supercomputación (www.bsc.es).Peer ReviewedPostprint (author's final draft