Weakly Lefschetz symplectic manifolds

The harmonic cohomology of a Donaldson symplectic submanifold and of an Auroux symplectic submanifold are compared with that of its ambient space. We also study symplectic manifolds satisfying a weakly Lefschetz property, that is, the $s$-Lefschetz propery. In particular, we consider the symplectic blow-ups of the complex projective space along weakly Lefschetz symplectic submanifolds. As an application we construct, for each even integer $s\geq 2$, compact symplectic manifolds which are $s$-Lefschetz but not $(s+1)$-Lefschetz.Comment: 22 pages; many improvements from previous versio

Symplectic resolutions, Lefschetz property and formality

We introduce a method to resolve a symplectic orbifold into a smooth symplectic manifold. Then we study how the formality and the Lefschetz property of the symplectic resolution are compared with that of the symplectic orbifold. We also study the formality of the symplectic blow-up of a symplectic orbifold along symplectic submanifolds disjoint from the orbifold singularities. This allows us to construct the first example of a simply connected compact symplectic manifold of dimension 8 which satisfies the Lefschetz property but is not formal, therefore giving a counter-example to a conjecture of Babenko and Taimanov.Comment: 21 pages, no figure

Poor performance of mutual funds in Spain. 1991-2007

Over the past 10 and 16 years, the average return on mutual funds in Spain was lower than the average return on government bonds at any term. Over the past 10 years, the average return on the funds was lower than inflation. In spite of these results, on December 31, 2007, 8,264,240 investors held 238.7 billion euros in the 2,907 mutual funds then in existence. During 2007, the number of shareholders fell by 555,569 and the value of their assets, by 6.1%. Only 30 of the 935 mutual funds with a 10-year history outperformed the benchmark and only two of them outperformed the overall index of the Madrid Stock Exchange (ITBM). If in the past 16 years every mutual fund had achieved the benchmark return for its category, the gain in value would have been 180 billion euros, instead of the actual figure of 80 billion euros. Total fees and other expenses for the period amounted to 34 billion euros.mutual funds; return to shareholders; benchmark; appreciation of the funds:

Performance analysis for lateral-line-inspired sensor arrays

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 2011The lateral line is a critical component of the fish sensory system, found to affect numerous aspects of behavior including maneuvering in complex fluid environments, schooling, prey tracking, and environment mapping. This sensory organ has no analog in modern ocean vehicles, despite its utility and ubiquity in nature, and could fill the gap left by sonar and vision systems in turbid cluttered environments. Yet, while the biological sensory system suggests the broad possibilities associated with such a sensor array, nearly nothing is known of the input processing and what information is available via the real lateral line. This thesis demonstrates and characterizes the ability of lateral-line-inspired linear pressure sensor arrays to perform two sensory tasks of relevance to biological and man-made underwater navigation systems, namely shape identification and vortex tracking. The ability of pressure sensor arrays to emulate the ”touch at a distance” feature of the lateral line, corresponding to the latter’s capability of identifying the shape of objects remotely, is examined with respect to moving cylinders of different cross sections. Using the pressure distribution on a small linear array, the position and size of a cylinder is tracked at various distances. The classification of cylinder shape is considered separately, using a large database of trials to identify two classification approaches: One based on differences in the mean flow, and one trained on a subset which utilizes information from the wake. The results indicate that it is in general possible to extract specific shape information from measurements on a linear pressure sensor array, and characterize the classes of shapes which are not distinguishable via this method. Identifying the vortices in a flow makes it possible to predict and optimize the performance of flapping foils, and to identify imminent stall in a control surface. Vortices in wakes also provide information about the object that generated the wake at distances much larger than the near-field pressure perturbations. Experimental studies in tracking a vortex pair and an individual vortex interacting with a flat plate demonstrate the ability to track vortices with a linear pressure sensor array from both small streamlined bodies and large flat bodies. Based on a theoretical analysis, the relationship between the necessary array parameters and the range of vortices of interest is established

The Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like Episode Syndrome-associated Human Mitochondrial tRNALeu(UUR) Mutation Causes Aminoacylation Deficiency and Concomitant Reduced Association of mRNA with Ribosomes

The pathogenetic mechanism of the mitochondrial tRNALeu(UUR) A3243G transition associated with the mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome has been investigated in transmitochondrial cell lines constructed by transfer of mutant mitochondrial DNA (mtDNA)-carrying mitochondria from three genetically unrelated MELAS patients or of isogenic wild-type mtDNA-carrying organelles into human mtDNA-less cells. An in vivo footprinting analysis of the mtDNA segment within the tRNALeu(UUR) gene that binds the transcription termination factor failed to reveal any difference in occupancy of sites or qualitative interaction with the protein between mutant and wild-type mtDNAs. Cell lines nearly homoplasmic for the mutation exhibited a strong (70-75%) reduction in the level of aminoacylated tRNALeu(UUR) and a decrease in mitochondrial protein synthesis rate. The latter, however, did not show any significant correlation between synthesis defect of the individual polypeptides and number or proportion of UUR codons in their mRNAs, suggesting that another step, other than elongation, may be affected. Sedimentation analysis in sucrose gradient showed a reduction in size of the mitochondrial polysomes, while the distribution of the two rRNA components and of the mRNAs revealed decreased association of mRNA with ribosomes and, in the most affected cell line, pronounced degradation of the mRNA associated with slowly sedimenting structures. Therefore, several lines of evidence indicate that the protein synthesis defect in A3243G MELAS mutation-carrying cells is mainly due to a reduced association of mRNA with ribosomes, possibly as a consequence of the tRNALeu(UUR) aminoacylation defect

Measurement of Social Capital and Growth: an Economic Methodology

This paper develops a measure of social capital based on economic relationships and analyzes its effects on growth. Investment in social capital is modeled by using the conceptual framework for measuring physical capital services. The measure of social capital depends on expectations of income, its investment cost, inequality in society, the density of trust networks, the size of the social network and the rate of depreciation of social capital. With this methodology a database is constructed for 23 OECD countries covering the period 1970-2001 and the positive effect of social capital on economic growth is tested.Social capital, Investment, Social networks, Economic Growth

Rentabilidad y creación de valor de 136 empresas españolas en el primer semestre de 2009 y en 2008

En el primer semestre de 2009, la rentabilidad de la bolsa española fue 6,9% y 81 empresas (entre 136) tuvieron rentabilidad positiva. Considerando conjuntamente los años 2008 y 2009, sólo 4 empresas (Funespaña, CAF, Viscofán y Tecnocom) tuvieron rentabilidad positiva. La destrucción de valor para los accionistas de las 136 empresas fue ¿5 millardos en el semestre (¿420 millardos en 2008). El descenso de 2008-9 ha sido similar a los de 2002, 1947 y 1956; y menor que el de 1973-82. Se muestra un hecho preocupante: el aumento de la rentabilidad adicional que los inversores internacionales exigen a los bonos del Estado español con respecto a los emitidos por el Estado alemán. Este diferencial fue prácticamente cero en 2003-2006 y aumentó sustancialmente en 2008 y 2009. El último anexo contiene algunos apuntes sobre la "crisis".Creación de valor; Rentabilidad para accionistas; Capitalización bursátil;

Rentabilidad de los fondos de pensiones en España. 1991-2008

En los últimos 3, 5 y 10 años, la rentabilidad promedio de los planes de pensiones fue sensiblemente inferior a la inflación y a la inversión en bonos del estado a cualquier plazo. Ninguno de los fondos de pensiones del sistema individual con 15 años de historia tuvo una rentabilidad superior a la del bono español a 10 años. Sólo 12 de los 587 planes con 10 años de historia y 2 de los 1520 planes con 5 años de historia tuvieron una rentabilidad superior al Índice de la Bolsa de Madrid. El 31 de diciembre de 2008, 10,6 millones de partícipes tenían un patrimonio de ¿78,5 millardos en 3.293 planes de pensiones. El decepcionante resultado global de los fondos se debe a las elevadas comisiones, a la composición de la cartera y a la gestión activa. Las comisiones de los fondos en 2008 fueron ¿1 millardo. El resultado global de los fondos no justifica en absoluto la discriminación fiscal a favor de los mismos. En muchos casos, los inversores perdieron la desgravación fiscal con la que el Estado les indujo a invertir en fondos de pensiones en menos de 5 años (vía comisiones e ineficiencias en inversión y gestión). Parece obvio que el Estado tiene alguna responsabilidad en las pérdidas que millones de contribuyentes han sufrido y siguen sufriendo.fondo pensiones; fondo inversión; rentabilidad partícipes; benchmark;