Quantum fidelity and quantum phase transitions in matrix product states

Matrix product states, a key ingredient of numerical algorithms widely employed in the simulation of quantum spin chains, provide an intriguing tool for quantum phase transition engineering. At critical values of the control parameters on which their constituent matrices depend, singularities in the expectation values of certain observables can appear, in spite of the analyticity of the ground state energy. For this class of generalized quantum phase transitions we test the validity of the recently introduced fidelity approach, where the overlap modulus of ground states corresponding to slightly different parameters is considered. We discuss several examples, successfully identifying all the present transitions. We also study the finite size scaling of fidelity derivatives, pointing out its relevance in extracting critical exponents.Comment: 7 pages, 3 figure

Simulación de una Unidad Hospitalaria de Urgencias y su USO Potencial Para la Gestión

ResumenEn este trabajo se modeliza la Unidad de Urgencias del Hospital Ntra. Sra. del Pino como un sistema de colas y se diseñan y analizan mediante técnicas estadísticasde simulación con el lenguaje de programación SIMSCRIPT II.5 estructuras organizativas alternativas encaminadas a tres objetivos fundamentals: cómo se puede mejorar la eficiencia técnica de la Unidad a través de la reorganización y reasignación de la fuerza de trabajo actual; cómo reacciona el sistema ante cambios en las tasas de afluencia de los pacientes; y qué decisiones sobre asignación adicional de recursos serían más eficientes. Los cuellos de botella actuales son el Servicio de Clasificación, el Laboratorio de Analítica y el Servicio de Radiodiagnóstico, con tiempos medios de espera de 11, 31 y 12 minutos respectivamente. Algunos de los diseños alternativos pueden mejorar esta situación con un coste social que se cuantifica en el trabajo.SummaryWe developed a computer simulation model of Emergency Department Operations of the Hospital Ntra. Sra. del Pino as a queue system. We designed and analyzed alternative functional structures of the Department and their implications on resources organization and reallocation. We programmed the operations, relations and flows between the components of the system with the simulation language SIMSCRIPT II.5. We have designed alternative configurations to assess how technical efficiency could be improved through the reallocation of human resources; how the system react would to interarrival time of patients changes; and what decisions must be taken about resources allocation in order to improve efficiency. Triage, Emergency Laboratory and radiology have the maximum average waiting times (11,31 and 12 minutes, respectively). Some alternative organization patterns may improve this problem. Their social cost is also quantified in this work

Meaning-based attentional guidance as a function of foveal and task-related cognitive loads

Published online: 05 Jun 2018The depth of parafoveal word processing depends on the amount of cognitive resources available. Whether this principle applies to the parafoveal semantic processing of multiple words remains, however, controversial. This study therefore aimed at testing the impact of the amount of cognitive resources available on the parafoveal semantic processing of words, by manipulating the foveal and task-related cognitive loads. Participants searched for words in displays of three semantically related or unrelated words, one of which was presented in the centre of the screen and two within the parafovea. The nature of the task and the characteristics of the centred word were manipulated to vary respectively the load associated to the task and to the foveal load. Analyses revealed more first saccades toward the parafoveal semantic distractors when both loads were low. These results indicate that fast parafoveal semantic word processing is constrained by the availability of cognitive resources.This work was supported by Ministerio de Economía y Competitividad [grant number PSI2016-79624-P]; Direction Générale de l'Armement [grant number 2013.60.0019]

La demència: una entitat infradiagnosticada

[cat]Actualment, la malaltia d’Alzheimer (MA) i altres demències existeixen com un continu que s’inicia en aquella fase en la qual el diagnòstic solament és possible amb l’ús dels biomarcadors, fins a una altra fase en la qual ja parlem d’estat de demència. Aquest curs insidiós comporta que avui en dia la demència sigui diagnosticada majoritàriament en aquest estat o, com a molt, en l’immediatament anterior, el deteriorament cognitiu lleu (DCL) (Alzheimer’s Association, 2017; Dubois et al., 2014). No obstant això, i justament en un moment en què la recerca evoluciona cap al diagnòstic precoç i preclínic, i en el qual pensàvem que la informatització de les històries clíniques i el fàcil accés a la formació i informació millorarien la identificació d’alguns processos amb molta prevalença, la demència com a tal continua greument infradetectada en el dia a dia de l’activitat assistencial (Canto, Bonis, Bryant, Castell i Otero, 2016). Aquesta epidèmia silenciosa fa vint anys que es denuncia (Larson, 1998). I mentre els biomarcadors fascinen els professionals i ben segur que en un futur seran més accessibles i ajudaran al diagnòstic de forma precisa i precoç (Sharma i Singh, 2016), ara com ara hem de recordar que la demència és un diagnòstic eminentment clínic i que en fase de demència escoltar el cuidador i observar el pacient, o fer ús dels principals tests de cribratge cognitiu, poden ser els millors elements per formular una sospita clínica des de l’atenció primària, al mateix temps que hem de saber que moltes demències no sempre s’inicien amb fallades de memòria i que els símptomes psiquiàtrics a determinades edats ens han de posar en guàrdia (Boise, Neal i Kaye, 2004; Ross et al., 1997). I tot això donant per fet que la idea que envelliment és igual a demència hauria de ser desterrada. I per als metges que treballen en l’àmbit hospitalari veurem la necessitat que incorporin la valoració de l’estat mental dels pacients ingressats com un signe vital i que considerin que la síndrome confusional aguda és un signe d’alerta o un factor de risc per a l’evolució posterior a demència (Witlox et al., 2010). Perquè l’objectiu final d’aquest capítol és visibilitzar que les dades epidemiològiques de la demència no quadren amb les dades clíniques, que la demència està infradiagnosticada ja des del primer nivell d’atenció, i que quan arriba al medi hospitalari, la síndrome confusional aguda és un bon signe d’alerta de demència que desgraciadament també costa ser identificat.[spa]Actualmente, la enfermedad de Alzheimer (MI) y otras demencias existen como un continuo que se inicia en aquella fase en la cual el diagnóstico solamente es posible con el uso de los biomarcadores, hasta otra fase en la cual ya hablamos de estado de demencia. Este curso insidioso comporta que hoy en día la demencia sea diagnosticada mayoritariamente en este estado o, como mucho, en el inmediatamente anterior, el deterioro cognitivo leve (DCL) (Alzheimer’s Association, 2017; Dubois et. al., 2014). Sin embargo, y justamente en un momento en que la investigación evoluciona hacia el diagnóstico precoz y preclínico, y en el cual pensábamos que la informatización de las historias clínicas y el fácil acceso a la formación e información mejorarían la identificación de algunos procesos con mucha prevalencia, la demencia como tal continúa gravemente infradetectada en el día a día de la actividad asistencial (Canto, Bonis, Bryant, Castillo y Otero, 2016). Esta epidemia silenciosa hace veinte años que se denuncia (Larson, 1998). Y mientras los biomarcadores fascinan los profesionales y bien seguro que en un futuro serán más accesibles y ayudarán al diagnóstico de forma precisa y precoz (Sharma y Singh, 2016), por ahora tenemos que recordar que la demencia es un diagnóstico eminentemente clínico y que en fase de demencia escuchar el cuidador y observar el paciente, o hacer uso de los principales tests de cribado cognitivo, pueden ser los mejores elementos para formular una sospecha clínica desde la atención primaria, al mismo tiempo que tenemos que saber que muchas demencias no siempre se inician con fallos de memoria y que los síntomas psiquiátricos a determinadas edades nos tienen que poner en guardia (Boise, Neal y Kaye, 2004; Ross et. al., 1997). Y todo esto dando por hecho que la idea que envejecimiento es igual a demencia tendría que ser desterrada. Y para los médicos que trabajan en el ámbito hospitalario veremos la necesidad que incorporen la valoración del estado mental de los pacientes ingresados como un signo vital y que consideren que el síndrome confusional agudo es un signo de alerta o un factor de riesgo para la evolución posterior a demencia (Witlox et. al., 2010). Porque el objetivo final de este capítulo es visibilizar que los datos epidemiológicos de la demencia no cuadran con los datos clínicos, que la demencia está infradiagnosticada ya desde el primer nivel de atención, y que cuando llega al medio hospitalario, el síndrome confusional agudo es un buen signo de alerta de demencia que desgraciadamente también cuesta ser identificado

Exploring the temporal dynamics of speech production with EEG and group ICA

Speech production is a complex skill whose neural implementation relies on a large number of different regions in the brain. How neural activity in these different regions varies as a function of time during the production of speech remains poorly understood. Previous MEG studies on this topic have concluded that activity proceeds from posterior to anterior regions of the brain in a sequential manner. Here we tested this claim using the EEG technique. Specifically, participants performed a picture naming task while their naming latencies and scalp potentials were recorded. We performed group temporal Independent Component Analysis (group tICA) to obtain temporally independent component timecourses and their corresponding topographic maps. We identified fifteen components whose estimated neural sources were located in various areas of the brain. The trial-by-trial component timecourses were predictive of the naming latency, implying their involvement in the task. Crucially, we computed the degree of concurrent activity of each component timecourse to test whether activity was sequential or parallel. Our results revealed that these fifteen distinct neural sources exhibit largely concurrent activity during speech production. These results suggest that speech production relies on neural activity that takes place in parallel networks of distributed neural sources

Different processes lead to similar patterns: a test of codivergence and the role of sea level and climate changes in shaping a southern temperate freshwater assemblage

<p>Abstract</p> <p>Background</p> <p>Understanding how freshwater assemblages have been formed and maintained is a fundamental goal in evolutionary and ecological disciplines. Here we use a historical approach to test the hypothesis of codivergence in three clades of the Chilean freshwater species assemblage. Molecular studies of freshwater crabs (<it>Aegla</it>: Aeglidae: Anomura) and catfish (<it>Trichomycterus arealatus</it>: Trichomycteridae: Teleostei) exhibited similar levels of genetic divergences of mitochondrial lineages between species of crabs and phylogroups of the catfish, suggesting a shared evolutionary history among the three clades in this species assemblage.</p> <p>Results</p> <p>A phylogeny was constructed for <it>Trichomycterus areolatus </it>under the following best-fit molecular models of evolution GTR + I + R, HKY + I, and HKY for cytochrome <it>b</it>, growth hormone, and rag 1 respectively. A GTR + I + R model provided the best fit for both 28S and mitochondrial loci and was used to construct both <it>Aegla </it>phylogenies. Three different diversification models were observed and the three groups arose during different time periods, from 2.25 to 5.05 million years ago (Ma). Cladogenesis within <it>Trichomycterus areolatus </it>was initiated roughly 2.25 Ma (Late Pliocene - Early Pleistocene) some 1.7 - 2.8 million years after the basal divergences observed in both <it>Aegla </it>clades. These results reject the hypothesis of codivergence.</p> <p>Conclusions</p> <p>The similar genetic distances between terminal sister-lineages observed in these select taxa from the freshwater Chilean species assemblage were formed by different processes occurring over the last ~5.0 Ma. Dramatic changes in historic sea levels documented in the region appear to have independently shaped the evolutionary history of each group. Our study illustrates the important role that history plays in shaping a species assemblage and argues against assuming similar patterns equal a shared evolutionary history.</p

El desbalance glomérulo-tubular en la fisiopatología de la hipertensión arterial asociada al bajo peso al nacer

La hipertensión arterial constituye un problema de salud mundial. Quedan sin esclarecer mecanismos fisiopatogénicos en su aparición. Se ha asociado el bajo peso al nacer por crecimiento intrauterino retardado con la hipertensión en la edad adulta, relacionado con nefrogénesis incompleta. El desarrollo de hipertensión en ratas, provocando hipertrofia tubular proximal, indica que el desbalance entre las funciones glomerular y tubular genera incapacidad excretora del riñón y esta podría existir en el daño renal del bajo peso. Con el objetivo de valorar la posible implicación del desbalance glomérulo-tubular a preponderancia tubular en los mecanismos fisiopatológicos renales descritos en la hipertensión asociada al crecimiento intrauterino retardado, se utilizaron métodos teóricos. El cuerpo teórico elaborado se fundamentó en datos consultados en revistas científicas.Se concluye queel estado de desbalance glomérulo-tubular con preponderancia tubular, ha sido poco estudiado en relación con el desarrollo de la hipertensión en estos sujetos. Este fenómeno no se reconoce, hasta el momento, como una «anormalidad» renal, que puede constituir un mecanismo hipertensógeno primario.Palabras clave: Desbalance glomérulo-tubular, bajo peso al nacer, crecimiento intrauterino retardado, hipertensión arterial, riñón, fisiopatología renal de la hipertensión arterial.</p

A set of PCR-based markers for management of a library of Solanum lycopersicoides introgression lines

[EN] A collection of introgression lines (ILs) of Solanum lycopersicoides Dunal in the genetic background of cultivated tomato (S. lycopersicum L.) is a valuable tool for tomato breeding. Efficient management of the collection requires the use of molecular markers. The objective of this work was to identify polymerase chain reaction (PCR)-based markers that were polymorphic between the parents of the ILs, namely ‘VF36’ and ‘LA2951’. In total, 81 primer pairs were tested on genomic DNA from both parents. Genomic DNA of the inter-specific hybrid between the two parents, from which the IL collection had been derived, was also tested. The markers used were either cleaved amplified polymorphic sequence (CAPS) markers or were derived from a set of conserved orthologous genes. In both cases, the markers had been mapped in tomato and described in the SOL Genomics Network. Forty-seven of the markers tested produced a single PCR product in ‘VF36’ and ‘LA2951’. Eleven markers revealed polymorphisms as differences in band-sizes between the two parents. At least one restriction enzyme that generated polymorphism was identified in 29 of the remaining 36 markers. Among other applications, some of these markers have been used to identify plants carrying a target DNA fragment among segregating generations, or to delimit the length of an introgressed sequenceThis research was financed by the Ministerio de Educacion y Ciencia and Ministerio de Ciencia e Innovacion, Madrid, Spain (Projects Nos. AGL2008-05114 and AGL2011-30083).Peiró Barber, RM.; Díez Niclós, MJTDJ.; Pérez De Castro, AM. (2015). A set of PCR-based markers for management of a library of Solanum lycopersicoides introgression lines. The Journal of Horticultural Science and Biotechnology. 90(3):279-284. https://doi.org/10.1080/14620316.2015.11513183S279284903Díez, M. J. and Nuez, F. (2008). Tomato. In:Handbook of Plant Breeding. (Prohens, J. and Nuez F., Eds.). Springer, New York, NY, USA, 249–323.Pérez-De-Castro, A., Díez, M. J. and Nuez, F. (2011). Evaluation of a subset ofSolanum lycopersicoidesintrogression lines for resistance to Tomato yellow leaf curl disease. In:Proceedings of the XVII Eucarpia Meeting Group - Tomato. Málaga, Spain. 17.Soler, S., Belmonte, I., Aramburu, J., Galipienso, L., López, C., Sifres, A., Pérez-De-Castro, A. and Díez, M. J. (2012). Identificación de una fuente de tolerancia al ToMV en una colección de líneas de introgresión derivada deSolanum lycopersicoidesLA2951. In:Proceedings of the XVI Congreso de la Sociedad Española de Fitopatología, Málaga, Spain. 221

A further cost for the sicker sex? Evidence for male-biased parasite-induced vulnerability to predation

Males are typically the sicker sex. Data from multiple taxa indicate that they are more likely to be infected with parasites, and are less ‘tolerant’, or less able to mitigate the fitness costs of a given infection, than females. One cost of infection for many animals is an increased probability of being captured by a predator. A clear, hitherto untested, prediction is therefore that this parasite-induced vulnerability to predation is more pronounced among males than females. We tested this prediction in the sexually size dimorphic guppy, Poecilia reticulata, in which females are typically larger than males. We either sham or experimentally infected guppies with Gyrodactylus turnbulli, elicited their escape response using an established protocol and measured the distance they covered during 60 ms. To discriminate between the effects of body size and those of other inherent sex differences, we size-matched fish across treatment groups. Infection with G. turnbulli reduced the distance covered during the escape response of small adults by 20.1%, whereas that of large fish was unaffected. This result implies that parasite-induced vulnerability to predation is male-biased in the wild: although there was no difference in escape response between our experimentally size-matched groups of males and females, males are significantly smaller across natural guppy populations. These results are consistent with Bateman’s principle for immunity: natural selection for larger body sizes and longevity in females seems to have resulted in the evolution of increased infection tolerance. We discuss the potential implications of male-biased parasite-induced vulnerability for the evolutionary ecology of this host-parasite interaction in natural communities