A Multiscalar Global Drought Dataset: The SPEIbase: A New Gridded Product for the Analysis of Drought Variability and Impacts

A new multiscalar drought dataset, the SPEIbase, made available to the scientific and management community is presented. The multiscalar character of the dataset allows finding the most appropriate time scale of interest for a specific application, so potential uses of the dataset range over a wide variety of disciplines. The dataset (in three file formats) is distributed under an open license. Further work includes updating the dataset past December 2006, depending on the data availability.This work has been supported by the research projects CGL2008-01189/BTE and CGL2006-11619/HID, funded by the Spanish Commission of Science and Technology and FEDER; EUROGEOSS (FP7-ENV-2008-1-226487) and ACQWA (FP7-ENV-2007-1- 212250), funded by the VII Framework Programme of the European Commission; and “Las sequías climáticas en la cuenca del Ebro y su respuesta hidrológica” and “La nieve en el Pirineo aragonés: Distribución espacial y su respuesta a las condiciones climática,” funded by “Obra Social La Caixa” and the Aragón Government.Peer reviewe

Improving randomness characterization through Bayesian model selection

Nowadays random number generation plays an essential role in technology with important applications in areas ranging from cryptography, which lies at the core of current communication protocols, to Monte Carlo methods, and other probabilistic algorithms. In this context, a crucial scientific endeavour is to develop effective methods that allow the characterization of random number generators. However, commonly employed methods either lack formality (e.g. the NIST test suite), or are inapplicable in principle (e.g. the characterization derived from the Algorithmic Theory of Information (ATI)). In this letter we present a novel method based on Bayesian model selection, which is both rigorous and effective, for characterizing randomness in a bit sequence. We derive analytic expressions for a model's likelihood which is then used to compute its posterior probability distribution. Our method proves to be more rigorous than NIST's suite and the Borel-Normality criterion and its implementation is straightforward. We have applied our method to an experimental device based on the process of spontaneous parametric downconversion, implemented in our laboratory, to confirm that it behaves as a genuine quantum random number generator (QRNG). As our approach relies on Bayesian inference, which entails model generalizability, our scheme transcends individual sequence analysis, leading to a characterization of the source of the random sequences itself.Comment: 25 page

Habitat Characterization of Juvenile Atlantic Tarpon (Megalops atlanticus) in Isle of Youth, Cuba

Tarpon is considered a ‘Vulnerable’ species by IUCN but is also a highly prized recreational species. It is reportedly abundant in Cuba and may be threatened by high levels of fishing pressure. However, the current knowledge about Tarpon habitat characteristics and ecology in Cuba is very poor, which limit any attempt for its management and conservation. Here we summarize abiotic characteristics of juvenile Tarpon habitats in Lanier Swamp, Isle of Youth, Cuba, which is a RAMSAR site and Faunal Refuge. Three locations in Lanier Swamp were sampled for juvenile Tarpon presence during 2015-2017: Colony Lagoon (CL), Punta Francés Lagoon (PFL) and San Pedro (SP) river system. Abiotic characteristics were sampled from these same sites in January 2017. The smallest Tarpon (~150 mm fork length (FL, n= 22) occurred at CL, characterized by shallower waters with extreme salinities (0.6 and 50.8), less connection with the sea, and more protection from sunlight. In contrast, larger juvenile Tarpon (~630 mm FL, n= 20) were captured at SP, the location with the greatest connectivity to the ocean and greatest depth (~353 cm). The main results suggest that water depth, salinity, sunlight exposure and spatial dimensions are important habitat characteristics. Additionally, this study demonstrates the importance of coastal mangroves as juvenile Tarpon habitat and highlights the potential of using Tarpon as an umbrella species with broader conservation benefits. This study is an important first step to understanding Tarpon habitat use patterns in Cuba and developing a comprehensive conservation plan. Resumen El sábalo es considerado especie ‘Vulnerable’ según la UICN, pero también es altamente apreciado en la pesca recreativa. Se ha registrado como una especie abundante en Cuba y pudiera estar amenazado por altos niveles de presión pesquera. Sin embargo, el conocimiento actual sobre los hábitats y la ecología del sábalo en Cuba es escaso, lo cual limita cualquier intento de manejo y conservación. En este estudio se describen las características abióticas de hábitats de sábalos juveniles en la Ciénaga de Lanier, Isla de la Juventud, Cuba; área que es sitio RAMSAR y Refugio de Fauna. Tres localidades en la Ciénaga de Lanier fueron muestreados para juveniles por la presencia de sábalos juveniles durante 2015-2017: Laguna Colony (CL), Laguna Punta Francés (PFL) y sistema rivereño San Pedro (SP). Se tomaron muestras de las características abióticas de estos mismos sitios en enero de 2017. Los sábalos más pequeños (~150 mm de longitud horquilla (LH, n= 22) habitaron sitios en CL menos profundos, con salinidades extremas (0,6 and 50,8), menos conectados con el mar, y más protegidos de la luz solar. Los sábalos juveniles más grandes (~630 mm LH, n= 20) fueron capturados en SP, la localidad con mayor conectividad con el mar y mayor profundidad (~353 cm). Los resultados encontrados sugieren que la profundidad del agua, salinidad, exposición solar y dimensión espacial, son importantes características del hábitat. Adicionalmente, se demuestra la importancia de los manglares como hábitats de sábalos juveniles y se resalta el potencial de emplear al sábalo como especie sombrilla con amplios beneficios en la conservación. Este estudio es una importante contribución para entender los patrones de uso del hábitat de los sábalos en Cuba y desarrollar un plan de conservación integral

Factors associated with hospitalisations in chronic conditions deemed avoidable: Ecological study in the Spanish healthcare system

Objectives: Potentially avoidable hospitalisations have been used as a proxy for primary care quality. We aimed to analyse the ecological association between contextual and systemic factors featured in the Spanish healthcare system and the variation in potentially avoidable hospitalisations for a number of chronic conditions. Methods: A cross-section ecological study based on the linkage of administrative data sources from virtually all healthcare areas (n=202) and autonomous communities (n=16) composing the Spanish National Health System was performed. Potentially avoidable hospitalisations in chronic conditions were defined using the Spanish validation of the Agency for Health Research and Quality (AHRQ) preventable quality indicators. Using 2012 data, the ecological association between potentially avoidable hospitalisations and factors featuring healthcare areas and autonomous communities was tested using multilevel negative binomial regression. Results: In 2012, 151 468 admissions were flagged as potentially avoidable in Spain. After adjusting for differences in age, sex and burden of disease, the only variable associated with the outcome was hospitalisation intensity for any cause in previous years (incidence risk ratio 1.19 (95% CI 1.13 to 1.26)). The autonomous community of residence explained a negligible part of the residual unexplained variation (variance 0.01 (SE 0.008)). Primary care supply and activity did not show any association. Conclusions: The findings suggest that the variation in potentially avoidable hospitalisations in chronic conditions at the healthcare area level is a reflection of how intensively hospitals are used in a healthcare area for any cause, rather than of primary care characteristics. Whether other non-studied features at the healthcare area level or primary care level could explain the observed variation remains uncertain

The SPEIbase: A new gridded product for the analysis of drought variability and drought impacts

22 Pag., 17 Fig.The SPEIbase is a global SPEI dataset at time scales from 1 to 48 months with a spatial resolution of 0.5° for the period 1901-2006. It is based on the CRU TS3 dataset, the most complete and up-to-date source of gridded temperature and precipitation data for the entire World. It is also based on the same grid and time structure. Monthly temperature data was used to compute the ET0 based on the approximation of Thornthwaite (1948). Overview of the talk: 1. The SPEI: motivation, advantages 2. The SPEIbase: methodology, data sources, distribution 3. Examples of use 4. Data distributionPeer reviewe