New anallytic approximations based on the Magnus expansion

The Magnus expansion is a frequently used tool to get approximate analytic solutions of time-dependent linear ordinary differential equations and in particular the Schrödinger equation in quantum mechanics. However, the complexity of the expansion restricts its use in practice only to the first terms. Here we introduce new and more accurate analytic approximations based on the Magnus expansion involving only univariate integrals which also shares with the exact solution its main qualitative and geometric propertie

What Do We Know about Bullying in Schoolchildren with Disabilities? A Systematic Review of Recent Work

Bullying is a serious problem that particularly affects schoolchildren with disabilities. However, studies in this group have been carried out on smaller cohorts and the results obtained are, therefore, less representative and sometimes inconclusive. The purpose of this paper is to perform a systematic review of the work carried out in recent years, including the analysis of several variables related to the sample, the methodology applied and the type of bullying. The guidelines set down by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement were followed in three phases. The total sample consisted of 55 children who fulfilled the inclusion criteria. The results reveal that half the studies were conducted in cohorts of less than 250 schoolchildren and drew no distinctions between the different types of disabilities. Furthermore, there is no consensus regarding the methodology used, and no specialized instruments were used. Hardly any specific interventions have been performed into the type of bullying investigated, in which victimization is the predominant mode. We concluded that there is an urgent need to increase the number of studies, including a larger number of individuals and using specialized instruments, in order to obtain more solid results. Such studies will allow us to create specific prevention and intervention programs to address the bullying of schoolchildren with disabilities

La seca de encinas y alcornoques en Andalucía : decaimiento y enfermedad

El decaimiento forestal es una enfermedad de etiología compleja, resultado de la acción de un número variable de factores bióticos y abióticos que causan un deterioro gradual y general de los árboles afectados, hasta su muerte. Los factores implicados en el decaimiento de los Quercus en Andalucía son factores predisponentes de tipo selvícola, alteraciones climáticas como factor incitante, y plagas y enfermedades como factores contribuyentes. Entre las enfermedades implicadas en Seca de los Quercus destacan, por orden de importancia, la podredumbre radical causada por Phytophthora cinnamomi, los chancros de tronco y ramas causados por Botryosphaeria spp. y el chancro carbonoso causado por Biscogniauxia mediterranea. No obstante, las dos primeras enfermedades tienen una especial incidencia en distintas zonas de Andalucía de forma independiente, no asociadas al decaimiento. En el presente artículo se exponen las medidas de control disponibles contra estas enfermedades de los Quercus y se plantea la necesidad de disponer de un diagnóstico preciso en cada caso para abordar dicho control con garantías, ya que no cabe encontrar soluciones únicas que resulten eficaces con independencia de la naturaleza del problema._____________________________________The forestry decline is a complex disease, as a result of the action of a changeable number of biotic and abiotic factors that cause a gradual and general deterioration of the affected trees, until their death. The factors involved in the Quercus decline in Andalusia are predisposing factors like silvic, climatic alterations as inciting factor, and insect pest and diseases as contributing factors. Between the diseases involved in oak decline stand out, in order of importance, the root roting caused by Phytophthora cinnamomi, the chancres of trunk and branches caused by Botryosphaeria spp. and the charcoal canker caused by Biscogniauxia mediterranea. Nevertheless, the first two diseases have a special effect on different zones of Andalusia in different ways, not associated with the decay. In this article we expose the available tools of disease control. We emphasizes the need of having a precise diagnosis in every case to approach the control with guarantees, since there is no chance of finding only one efficient solution regardless of the nature of the problem

La "seca" de olivos jóvenes II: identificación y patogenicidad de los hongos asociados con podredumbres radicales

This work deals with the identification of fungal isolates associated with root rot, the major factor included in the «drying and death syndrome» («seca») of young olive trees in Andalucía, southern Spain. Fungi associated with damping-off in olive tree nurseries were also identified. Several isolates from every fungal species were tested for pathogenicity in nursery plants and rooted cuttings of olive cultivar 'Picual'. Pathogenicity tests demonstrated that five fungal species -Cylindrocarpon destructans, Phytophthora megasperma, P. palmivora, Pythium irregulare and Sclerotium rolfsii- were clearly pathogenic to olive trees and reproduced symptoms of root rot and foliar wilting. Other fungal species associated with root rot of olive trees in the field or in the nurseries, including Fusarium acuminatum, F. eumartii, F. oxysporum, F. solani, Macrophomina phaseolina and Rhizoctonia solani, were weakly or not pathogenic. Pathogenicity of Phytophthora megasperma, P. palmivora and Pythium irregulare depended on soil water content, since isolates tested only caused extensive root rot and sudden plant death when the soil was continuously waterlogged. The high frequency of P. megasperma (part I) and its dependence for pathogenicity on soil water content suggest that this pathogen may play an important role in the well known sensitivity of young olive trees to «root asphyxiation».En este trabajo se han identificado los aislados fúngicos asociados a las podredumbres radiculares de olivo, el factor más importante incluido bajo la denominación genérica de «seca» de olivos jóvenes en Andalucía, así como los aislados asociados a la muerte de plántulas («damping-off») en viveros de olivo. La patogenicidad de aislados seleccionados de cada especie fúngica se evaluó en plantones y estaquillas enraizadas de olivo del cultivar «Picual», en condiciones parcialmente controladas. De todas las especies ensayadas, cinco mostraron claramente su patogenicidad en olivo: Cylindrocarpon destructans, Phytophthora megasperma, P. palmivora, Pythium irregulare y Sclerotium rolfsii, reproduciendo los síntomas de podredumbre radicular y marchitez foliar en las plantas inoculadas. Otras especies asociadas a podredumbres radiculares en campo y vivero {Fusarium acuminatum, F. eumartii, F. oxysporum, F. solani, Macrophomina phaseolina y Rhizoctonia solani) resultaron débilmente o nada patogénicas. La patogenicidad de Phytophthora megasperma, P. palmivora y Pythium irregulare resultó dependiente del contenido hídrico del suelo, ya que los aislados ensayados sólo causaron necrosis extensas del sistema radicular y muerte de las plantas inoculadas en condiciones de saturación continua del suelo. La elevada frecuencia de aislamiento de Phytophthora megasperma en suelos encharcados (parte I) y su dependencia patogénica del exceso de agua en el suelo sugieren que este hongo puede jugar un papel importante en la generalmente aceptada sensibilidad de los olivos jóvenes a la «asfixia radicular»

Overexpression of cytosolic group IVA phospholipase A2 protects cells from Ca2+ -dependent death

El pdf del artículo es la versión post-print.-- et al.The calcium ionophore ionomycin induces apoptosis-like events in the human embryonic kidney cell line at early times. Plasma membrane blebbing, mitochondrial depolarization, externalization of phosphatidylserine, and nuclear permeability changes can all be observed within 15 min of treatment. However, there is no activation of caspases or chromatin condensation. Expression of a fusion protein containing the enhanced green fluorescent protein (EGFP) and human cytosolic Group IVA phospholipase A2α (EGFP-cPLA 2α) in these cells prevents ionomycin-induced phosphatidylserine externalization and death. Cells expressing the cPLA 2α mutant D43N, which does not bind calcium, retain their susceptibility to ionomycin-induced cell death. Both nonexpressing and EGFP-D43N-cPLA2α-expressing human embryonic kidney cells can be spared from ionomycin-induced cell death by pretreating them with exogenous arachidonic acid. Moreover, during calcium overload, mitochondrial depolarization is significantly lower in the EGFP-cPLA2α- expressing cells than in cells expressing normal amounts of cPLA 2α. These results suggest that early cell death events promoted by an overload of calcium can be prevented by the presence of high levels of arachidonic acid. © 2006 by The American Society for Biochemistry and Molecular Biology, Inc.This work was supported in part by Grant BMC2001- 2244 from the Spanish Ministry of Science and Technology, Grants BFU2004-01886/BMC, SAF2004-04676, and SAF2004-01232 from the Spanish Ministry of Education and Science, and Red Brucella, Red Respira, and Red Temática de Investigación Cardiovascular, from the Instituto de Salud Carlos III.Peer Reviewe

Protocols of the EU bottom trawl survey of Flemish Cap

Methods and procedures used in the EU bottom trawl survey of Flemish Cap (NAFO Division 3M) are described in detail. The objectives of publicising these protocols are to achieve a better understanding of its results, and to contribute to the routines being unaltered

Rail Infrastructure Pricing For Intercity Passenger Services In Europe: Possible Impacts On The Railways Competitive Framework

At the beginning of the 90’s, the European Union initiated a railways reform with the aim to face the decline of railway transport, as well as to increase railway competitiveness and interoperability at European scale. The First Railway Package of this reform focused on the split between infrastructure management and operation and, therefore, on the establishment of pricing systems. Due to lack of straight definition, the application of the Directives on infrastructure charges in the different European countries has given rise to a large spectrum of charging systems. It is a direct consequence of the differences in the charging philosophies (MC –marginal cost, MC+ - marginal cost with mark-ups, FC –Full Cost recovery, etc.), the charging types (single tariff, two-parts tariff) and the parameters (or variables) chosen for defining the amount of the charge in each particular case. This paper analyses the rail infrastructure charges in 23 European countries from the point of view of the parameters used for defining them. The analysis deepens the knowledge of qualitative differences between these countries’ pricing structure. Furthermore, it analyses its consequences in the total amount of the charge to be paid by passenger services running through links considered to be the best national railways relations in each one of the countries studied. Concerning the qualitative analysis, forty-six different types of variables were identified for the whole of the systems analysed. With regard to the quantitative field,calculations reveal that infrastructure charges range from 14,6 €/train-km to 0,6 €/train-km for “comparable” national links. The last part of this paper discusses the weight of those fares for the use of infrastructure for intercity rail passenger services with regard to its competitor mode. Results from an analysis of 100 national and international links allow drawing some conclusions on the possible impacts of railway infrastructure pricing on the railways competitive framework in Europe.Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

Rail Infrastructure Pricing For Intercity Passenger Services In Europe: Possible Impacts On The Railways Competitive Framework

At the beginning of the 90’s, the European Union initiated a railways reform with the aim to face the decline of railway transport, as well as to increase railway competitiveness and interoperability at European scale. The First Railway Package of this reform focused on the split between infrastructure management and operation and, therefore, on the establishment of pricing systems. Due to lack of straight definition, the application of the Directives on infrastructure charges in the different European countries has given rise to a large spectrum of charging systems. It is a direct consequence of the differences in the charging philosophies (MC –marginal cost, MC+ - marginal cost with mark-ups, FC –Full Cost recovery, etc.), the charging types (single tariff, two-parts tariff) and the parameters (or variables) chosen for defining the amount of the charge in each particular case. This paper analyses the rail infrastructure charges in 23 European countries from the point of view of the parameters used for defining them. The analysis deepens the knowledge of qualitative differences between these countries’ pricing structure. Furthermore, it analyses its consequences in the total amount of the charge to be paid by passenger services running through links considered to be the best national railways relations in each one of the countries studied. Concerning the qualitative analysis, forty-six different types of variables were identified for the whole of the systems analysed. With regard to the quantitative field,calculations reveal that infrastructure charges range from 14,6 €/train-km to 0,6 €/train-km for “comparable” national links. The last part of this paper discusses the weight of those fares for the use of infrastructure for intercity rail passenger services with regard to its competitor mode. Results from an analysis of 100 national and international links allow drawing some conclusions on the possible impacts of railway infrastructure pricing on the railways competitive framework in Europe.Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

The interplay of phonology and orthography in visual cognate word recognition: an ERP study

This study examined the role of phonological and orthographic overlap in the recognition of cognate words by recording electrophysiological and behavioral data. One hundred and ninety-two words were selected: 96 cognate words listed according to their phonological and orthographic overlap vs. 96 noncognate words. Twenty-four proficient European Portuguese-English bilinguals performed a silent reading task with a masked priming paradigm. The results showed that phonology interacts with semantic activation at N400 modulations. Phonological priming effects were dependent on the orthographic overlap of cognate words. Thus, the distinctive processing of cognate words seems to be due to their cross-linguistic similarity, which is consistent with a localist connectionist account on cognate representation and processing.The research reported in this paper wasfunded by FCT (Foundation for Science and Technology), by NSRF (National Strategic Reference Framework), by COMPETE (Operational Agenda for Competitiveness Factors), a program created by the EU as part of the European Regional Development Fund (ERDF), (PTDC/PSI-PCO/104671/2008) and by the Spanish Ministry of Education and Science (PSI2009–12616) and Plan E