Lyubeznik table of sequentially Cohen-Macaulay rings

We prove that sequentially Cohen-Macaulay rings in positive characteristic, as well as sequentially Cohen-Macaulay Stanley-Reisner rings in any characteristic, have trivial Lyubeznik table. Some other configurations of Lyubeznik tables are also provided depending on the deficiency modules of the ring.Comment: 9 pages, accepted in Communications in Algebr

Addendum to "Frobenius and Cartier algebras of Stanley-Reisner rings" [J. Algebra 358 (2012) 162-177]

We give a purely combinatorial characterization of complete Stanley-Reisner rings having principally generated (equivalently, finitely generated) Cartier algebras.Comment: The main result restated in a cleaner way. 5 pages, 2 figures. To appear in J. Algebr

Lyubeznik numbers of monomial ideals

We study Bass numbers of local cohomology modules supported on squarefree monomial ideals paying special attention to Lyubeznik numbers. We build a dictionary between local cohomology modules and minimal free resolutions that allow us to interpret Lyubeznik numbers as the obstruction to the acyclicity of the linear strands of the Alexander dual ideals. The methods we develop also help us to give a bound for the injective dimension of the local cohomology modules in terms of the dimension of the small support.Comment: 28 page

Database of historic ports and coastal sailing routes in England and Wales

This data paper presents a reconstruction of historical ports and coastal routes in England and Wales during the age of the sailing ship, ending at the beginning of the twentieth century. The dataset was created by an amalgamation of twenty different sources,including geographical data, primary sources and secondary literature. Ports found in historical documents were listed by year of appearance and georeferenced. Ports that appear in multiple sour-ces were listed only once. Coastal routes between ports were drawn based on navigation charts and bathymetry data, distinguishing five categories with different characteristics. Visibility from the coast was deduced from elevation rasters and lighthouse locations. Subsequently both ports and coastal routes were checked using topo-logical rules to ensure the connectivity of the network. The data is provided in shapefile format with all the attributes and can be analysed using Geographical Information Systems (GIS) for different types of geographical and historical studies

Generators of D-modules in positive characteristic

Let R be either a polynomial or a formal power series ring in a finite number of variables over a field k of characteristic p > 0 and let D be the ring of klinear differential operators of R. In this paper we prove that if f is a non-zero element of R then R[1/f], obtained from R by inverting f, is generated as a D-module by 1/f . This is very much in contrast to the characteristic zero situation where the corresponding statement is false (there the generation is governed by the roots of the Bernstein polynomial of f). In fact we prove analogs of the above result for a considerably wider class of rings R and a considerably wider class of D-modules.Comment: 15 pages. combines and extends the results of math.AC/0407464 and math.AC/0408124. to appear in Mathematical Research Letter

Measuring Technology Platforms impact with search data and web scraping

Resumen de la comunicación[EN] In recent years, European research policies and priorities in the agricultural sector have been developed through industry-based partnerships sponsored by the European Commission (EC). In 2004, the EC regulated a form of partnership called European Technology Platform (ETP) with the aim to define research agendas that would attract private investment. Monitoring the impact and performance of public policies, such as the implementation of ETPs, is basic for policy-makers. However, assessing the performance of ETPs frequently result into costly efforts given the current lack of indicators to monitor their variety of activities. In addition, since most ETPs have been set up recently it is difficult to assess their results, which are typically revealed after some time and take a considerable amount of time to be captured and processed with traditional methods such as surveys. In this study, we propose to assess the dynamics of ETPs through measures based on online information, given that it is fresh, available in real-time and is a publicly reflect of the activities of organizations. We firstly consider an ETP as an innovation intermediary and define its functions according to innovation literature. Then, we enumerate the particular activities within each function in which the ETP may be involved. To monitor such functions and activities, some indicators based on online data are proposed. This conceptual basis has been put into practice with a particular case study based on the agri-food technology platform “TP Organics”. Preliminary results show that the online-based indicators are able to measure the level of activity of the platform, if its scope is expanding or reducing, and how the importance of the different functions has evolved over time.Blazquez, D.; Domenech, J.; García Alvarez-Coque, JM. (2018). Measuring Technology Platforms impact with search data and web scraping. En 2nd International Conference on Advanced Reserach Methods and Analytics (CARMA 2018). Editorial Universitat Politècnica de València. 259-259. https://doi.org/10.4995/CARMA2018.2018.8363OCS25925

MPA network design based on graph network theory and emergent properties of larval dispersal

Despite the recognised effectiveness of networks of Marine Protected Areas (MPAs) as a biodiversity conservation instrument, nowadays MPA network design frequently disregards the importance of connectivity patterns. In the case of sedentary marine populations, connectivity stems not only from the stochastic nature of the physical environment that affects early-life stages dispersal, but also from the spawning stock attributes that affect the reproductive output (e.g., passive eggs and larvae) and its survivorship. Early-life stages are virtually impossible to track in the ocean. Therefore, numerical ocean current simulations coupled to egg and larval Lagrangian transport models remain the most common approach for the assessment of marine larval connectivity. Inferred larval connectivity may be different depending on the type of connectivity considered; consequently, the prioritisation of sites for marine populations' conservation might also differ. Here, we introduce a framework for evaluating and designing MPA networks based on the identification of connectivity hotspots using graph theoretic analysis. We use as a case of study a network of open-access areas and MPAs, off Mallorca Island (Spain), and test its effectiveness for the protection of the painted comber Serranus scriba. Outputs from network analysis are used to: (1) identify critical areas for improving overall larval connectivity; (2) assess the impact of species' biological parameters in network connectivity; and (3) explore alternative MPA configurations to improve average network connectivity. Results demonstrate the potential of graph theory to identify non-trivial egg/larval dispersal patterns and emerging collective properties of the MPA network which are relevant for increasing protection efficiency.Comment: 8 figures, 3 tables, 1 Supplementary material (including 4 table; 3 figures and supplementary methods

Hybrid benzidinium lead iodide perovskites with a 1D structure as photoinduced electron transfer photocatalysts

[EN] A hybrid benzidinium lead iodide perovskite (formula: PbI(3)benzidinium(0.5)) (3) with a 1D structure has been synthesized and characterized. The hybrid perovskite exhibits visible light (lambda > 450 nm) photocatalytic activity to promote the photoinduced electron transfer cis-to-trans isomerization of stilbene. The solid photocatalyst undergoes changes in the particle morphology, but maintains the crystallinity.Financial support from the Spanish Ministry of Economy and Competitiveness (Severo Ochoa, and CTQ2015-69563-CO2-R1) and the Generalitat Valenciana (Prometeo 2017/083) is gratefully acknowledged. Yong Peng also thanks the Universitat Politecnica de Valencia for a predoctoral scholarship.Peng, Y.; Albero-Sancho, J.; Alvarez, E.; García Gómez, H. (2019). Hybrid benzidinium lead iodide perovskites with a 1D structure as photoinduced electron transfer photocatalysts. Sustainable Energy & Fuels. 3(9):2356-2360. https://doi.org/10.1039/c9se00182dS235623603