Hodge polynomials of some moduli spaces of Coherent Systems

When $k<n$, we study the coherent systems that come from a BGN extension in which the quotient bundle is strictly semistable. In this case we describe a stratification of the moduli space of coherent systems. We also describe the strata as complements of determinantal varieties and we prove that these are irreducible and smooth. These descriptions allow us to compute the Hodge polynomials of this moduli space in some cases. In particular, we give explicit computations for the cases in which $(n,d,k)=(3,d,1)$ and $d$ is even, obtaining from them the usual Poincar\'e polynomials.Comment: Formerly entitled: "A stratification of some moduli spaces of coherent systems on algebraic curves and their Hodge--Poincar\'e polynomials". The paper has been substantially shorten. Theorem 8.20 has been revised and corrected. Final version accepted for publication in International Journal of Mathematics. arXiv admin note: text overlap with arXiv:math/0407523 by other author

Yes, research can inform health policy; but can we bridge the 'Do-Knowing It's Been Done' gap?

Copyright @ 2011 Hanney and Gonzalez.Provisional Abstract: This editorial introduces a new Supplement in Health Research Policy and Systems and highlighs the importance of assessing the impact of health research by examining whether we can move from 'Know-Do' to 'Do-Knowing It's Been Done'This article is made available through the Brunel Open Access publishing fund

All downhill from the PhD? The typical impact trajectory of US academic careers

© 2020 The Authors. Published by MIT Press. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1162/qss_a_00072.Within academia, mature researchers tend to be more senior, but do they also tend to write higher impact articles? This article assesses long-term publishing (16+ years) United States (US) researchers, contrasting them with shorter-term publishing researchers (1, 6 or 10 years). A long-term US researcher is operationalised as having a first Scopus-indexed journal article in exactly 2001 and one in 2016-2019, with US main affiliations in their first and last articles. Researchers publishing in large teams (11+ authors) were excluded. The average field and year normalised citation impact of long- and shorter-term US researchers’ journal articles decreases over time relative to the national average, with especially large falls to the last articles published that may be at least partly due to a decline in self-citations. In many cases researchers start by publishing above US average citation impact research and end by publishing below US average citation impact research. Thus, research managers should not assume that senior researchers will usually write the highest impact papers

Estudio multicéntrico prospectivo observacional sobre implantes PIP® colocados en 12 años

A pesar de la controversia existente con los implantes PIP® (Poly Implant Prothèse, Francia) son pocos los estudios que existen al respecto, por lo que determinamos realizar un análisis multicéntrico en nuestro entorno para conocer las características y el comportamiento clínico de los mismos. Planteamos un estudio multicéntrico, prospectivo y observacional, en el que participaron 7 cirujanos plásticos certificados que durante un periodo de 12 años habían colocado implantes PIP®. Analizamos clínicamente y con ultrasonido mamario todas las pacientes que acudieron a revisión, recogimos todos los datos y cuantificamos los hallazgos en aquellas que se intervinieron quirúrgicamente para revisión de los implantes. Entre enero del 2012 y febrero del 2013 acudieron a consulta 184 pacientes de las 1.315 que habían sido operados entre 1998 y 2010 (14%), evaluando un total de 368 implantes. Solo 39 pacientes (21,2%) presentaban sintomatología. Mediante ultrasonido mamario, 322 implantes (87,5%) fueron informados como íntegros y 46 (12,5%) rotos. Del total de pacientes revisadas, 55 (30%) no se reoperaron por no tener datos de rotura, mientras que 129 pacientes (70%) decidieron operarse. De ellos, solo 46 presentaban datos de rotura ecográfica (36%). Durante la cirugía se encontraron 213 implantes íntegros (83%) y 45 implantes rotos (17, 8%). No se encontraron datos de malignidad en las piezas de biopsia tomadas de las cápsulas o en el líquido periprotésico; tampoco crecimiento bacteriano. El índice de rotura comprobada, 17,8%, fue mayor que el que presentan otros estudios pero que tienen tiempos de seguimiento más cortos. No se encontró irritación de tejidos o sintomatología mamaria en los implantes íntegros, ni datos de toxicidad en las cápsulas o en el líquido en los implantes rotos. En base a todo ello consideramos que no es mandatorio retirar los implantes PIP® como medida de rutina, sino hacerlo cuando exista evidencia o sospecha de rotura. Creemos que el ultrasonido mamario es un estudio altamente confiable para la evaluación de la integridad de estos implantes