Making Neural QA as Simple as Possible but not Simpler

Recent development of large-scale question answering (QA) datasets triggered a substantial amount of research into end-to-end neural architectures for QA. Increasingly complex systems have been conceived without comparison to simpler neural baseline systems that would justify their complexity. In this work, we propose a simple heuristic that guides the development of neural baseline systems for the extractive QA task. We find that there are two ingredients necessary for building a high-performing neural QA system: first, the awareness of question words while processing the context and second, a composition function that goes beyond simple bag-of-words modeling, such as recurrent neural networks. Our results show that FastQA, a system that meets these two requirements, can achieve very competitive performance compared with existing models. We argue that this surprising finding puts results of previous systems and the complexity of recent QA datasets into perspective

Juvenile handling rescues autism-related effects of prenatal exposure to valproic acid

Environmental factors acting on young animals affect neurodevelopmental trajectories and impact adult brain function and behavior. Psychiatric disorders may be caused or worsen by environmental factors, but early interventions can improve performance. Understanding the possible mechanisms acting upon the developing brain could help identify etiological factors of psychiatric disorders and enable advancement of effective therapies. Research has focused on the long-lasting effects of environmental factors acting during the perinatal period, therefore little is known about the impact of these factors at later ages when neurodevelopmental pathologies such as autism spectrum disorder (ASD) are usually diagnosed. Here we show that handling mice during the juvenile period can rescue a range of behavioral and cellular effects of prenatal valproic acid (VPA) exposure. VPA-exposed animals show reduced sociability and increased repetitive behaviors, along with other autism-related endophenotypes such as increased immobility in the forced swim test and increased neuronal activity in the piriform cortex (Pir). Our results demonstrate that briefly handling mice every other day between postnatal days 22 and 34 can largely rescue these phenotypes. This effect can also be observed when animals are analyzed across tests using an “autism” factor, which also discriminates between animals with high and low Pir neuron activity. Thus, we identified a juvenile developmental window when environmental factors can determine adult autism-related behavior. In addition, our results have broader implications on behavioral neuroscience, as they highlight the importance of adequate experimental design and control of behavioral experiments involving treating or testing young animals.Fil: Seiffe, Araceli. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; ArgentinaFil: Ramírez, Mauro Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; ArgentinaFil: Sempé, Lucas. Queen Margaret University Edinburgh; Reino UnidoFil: Depino, Amaicha Mara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentin

Hypomyelination and oligodendroglial alterations in a mouse model of autism spectrum disorder

Autism spectrum disorders (ASDs) are neuropsychiatric diseases characterized by impaired social interaction, communication deficits, and repetitive and stereotyped behaviors. ASD etiology is unknown, and both genetic and environmental causes have been proposed. Different brain structures are believed to play a role in ASD-related behaviors, including medial prefrontal cortex (mPFC), hippocampus, piriform cortex (Pir), basolateral amygdala (BLA) and Cerebellum. Compelling evidence suggests a link between white matter modifications and ASD symptoms in patients. Besides, an hypomyelination of the mPFC has been associated in rodents to social behavior impairment, one of the main symptoms of ASD. However, a comparative analysis of myelination as well as oligodendroglial (OL)-lineage cells in brain regions associated to social behaviors in animal models of ASD has not been performed so far. Here, we investigated whether OL-lineage cells and myelination are altered in a murine model of ASD induced by the prenatal exposure to valproic acid (VPA). We showed an hypomyelination in the BLA and Pir of adult VPA-exposed mice. These results were accompanied by a decrease in the number of OL-lineage cells and of mature OLs in the Pir, in addition to the mPFC, where myelination presented no alterations. In these regions the number of oligodendrocyte progenitors (OPCs) remained unaltered. Likewise, activation of histone deacetylases (HDACs) on OL-lineage cells in adulthood showed no differences. Overall, our results reveal OL-lineage cell alterations and hypomyelination as neuropathological hallmarks of ASD that have been overlooked so far.Fil: Graciarena, Mariana. Inserm; Francia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Seiffe, Araceli. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; ArgentinaFil: Nait Oumesmar, Brahim. Inserm; FranciaFil: Depino, Amaicha Mara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; Argentin

Early estradiol exposure masculinizes disease-relevant behaviors in female mice

Most psychiatric disorders show a sex bias in incidence, symptomatology, and/or response to treatment. Males are more susceptible to neurodevelopmental disorders including autism spectrum disorder and attention-deficit activity disorder, while women are more prone to major depressive disorder and anxiety disorders after puberty. A striking difference between males and females in humans and other mammals is that males undergo a process of brain masculinization due to the early exposure to gonadal hormones. In rodents, this developmental organization of the brain is essential for adult males to express the appropriate sexual behaviors in the presence of a receptive female. Our goal was to determine whether this process of brain masculinization influences behaviors relevant to psychiatric disorders. To this aim, we studied sex differences and the effect of neonatal 17β-estradiol benzoate treatment of female mice on different disease-relevant behaviors. Our analysis includes postnatal behavior, juvenile play, and adult tests for sociability, repetitive behaviors, anxiety, and depression. Our results show that the sex differences observed in exploration, repetitive behaviors, and depression-related behaviors are largely reduced when females are neonatally treated with 17β-estradiol benzoate. These results suggest a role of neonatal sex steroids in the development of disease-relevant behaviors and provide evidence supporting a role for perinatal exposure to estrogens and androgens on the development and manifestation of psychiatric disorders.Fil: Seiffe, Araceli. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Ramirez, Mauro Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Barrios, Claudio Dario. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Albarrán, María Milagros. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Depino, Amaicha Mara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentin

Las potestades de la administración en la contratación pública. Un estudio comparado de la perspectiva de la república dominicana y el reino de España, en relación con los modificados contractuales

The present investigation addresses the interesting subject of contractual modifications in public procurement, an issue that is currently very much in vogue and that permeates a multiplicity of disciplines, within which they are found; law, engineering, economics, sociology, and other sciences. This research is a work of comparative law, analyzes the European legal framework, relying the jurisprudence of the Court of Justice of the European Union that has notoriously influenced the European Directives 2014/23/UE y 2014/24/UE and the Spanish law of public procurement regulated by Law 9/2017 of Public Sector Contracts and Dominican law under Law 340/06 on Purchases and Contracts for Goods, Services, Works and Concessions and the regulation of application of the law contained in Decree No. 543-12, and incipient jurisprudence that begins to consolidate in the law of the Dominican Republic. At the same time, as a work of comparative law, it also brings up important jurisprudential decisions of the French State Council, whose doctrine constitutes an important reference in the Dominican Republic. The present investigation places the Dominican Republic in the international context, in the light of the various trade agreements that it has signed, in particular, DR CAFTA, the Economic Association Agreement (EPA) better known as EPA among the ACP countries and the European Union and recently the establishment of commercial relations with the People's Republic of China, all of the above, justifies the relevance of this work, which runs in an almost homogeneous world with regard to public procurement, which must be analyzed in the framework of a global administrative law and similar general principles, in the context of complex regulations in its drafting, which hinders legal certainty. Finally, the planning and some jurisprudential tendencies in the Council of State of Colombia and the systems of checks and balances regarding contractual modifications are analyzed, in the case of European law and Dominican law of public procurement.La presente investigación aborda el interesante tema de los modificados contractuales en la contratación pública, tema que, se encuentra muy en boga actualmente y que permea una multiplicidad de disciplinas, dentro de las cuales se encuentran; el derecho, la ingeniería, la economía, la sociología, y otras ciencias. Esta investigación es un trabajo de derecho comparado, analiza el marco legal Europeo, entronizando en la jurisprudencia del Tribunal de Justicia de la Unión Europea que notoriamente ha influido en las Directivas Europeas 2014/23/UE y 2014/24/UE y el derecho español de la contratación pública regulado por la Ley 9/2017 de Contratos del Sector Público y el derecho dominicano al amparo de la ley 340/06 sobre Compras y Contrataciones de Bienes, Servicios, Obras y Concesiones y el reglamento de aplicación de la ley contenido en Decreto No. 543-12, y la jurisprudencia incipiente que comienza a consolidarse en el derecho dominicano. Al mismo tiempo, como labor de derecho comparado, trae también a colación importantes decisiones jurisprudenciales del Consejo de Estado Francés, cuya doctrina constituye un importante referente en República Dominicana. La presente investigación sitúa a la República Dominicana en el contexto internacional, a la luz de los diversos tratados comerciales que ha suscrito la misma, en especial, el DR CAFTA, el Acuerdo de Asociación Económica (AAE) mejor conocido como EPA entre los países ACP y la Unión Europea y recientemente el establecimiento de relaciones comerciales con la República Popular China, todo lo expuesto, justifica la pertinencia de este trabajo, que discurre en un mundo casi homogéneo en lo que respecta la contratación pública, que se debe analizar en el marco de un derecho administrativo global y unos principios generales análogos, en el contexto de normativas complejas en su redacción, que dificulta la seguridad jurídica. Finalmente, se analiza la planificación y algunas tendencias jurisprudenciales en el Consejo de Estado de Colombia y los sistemas de pesos y contrapesos en materia de modificados contractuales, en el caso del derecho europeo y el derecho dominicano de la contratación públic

Influence of Slow Surface States on Effective Lifetime Measurements

AbstractIn a recent work, the effect of surface states following a change of the Fermi level with a characteristic relaxation time τrelax on transient effective charge carrier lifetime measurements has been described. The working condition for solar cells, however, is a steady-state low-injection at the passivated surface. In the work presented here, the effect of such surface states in steady-state low-injection conditions is discussed and the considerations are compared with quasi-steady-state lifetime measurements on a sample exhibiting such surface states. Careful comparison of transient and quasi-steady-state lifetime measurements leads to an evaluation of the characteristic relaxation time of the surface traps

Surface texturing for crystalline silicon wafers with wafer thickness down to 100 µm

In the photovoltaic industry light trapping by front and rear side texturing is an increasing important issue with decreasing wafer thickness down to 100 µm for saving costs. In this study the impact of backside texturing by application of the Linear Microwave Plasma (LMP) technique in a SF6/O2 plasma chemistry has been investigated. The textured surfaces have been characterized in terms of statistical roughness parameters and the scatter angle distribution function using atomic force microscopy (AFM). Moreover, the reflection and transmission have been determined using an integrating sphere setup. In addition reflection, transmission and absorption have been investigated for the dielectric passivation system which consists of a-SiNx:H front side passivation and AlOx-SiOx rear surface passivation as well as for the multiple layer system which consists of the dielectric passivation system including an aluminium rear side metallization corresponding to the complete solar cell