Use of Multiple Astrocytic Configurations within an Artificial Neuro-Astrocytic Network

[Abstract] The artificial neural networks used in a multitude of fields are achieving good results. However, these systems are inspired in the vision of classical neuroscience where neurons are the only elements that process information in the brain. Advances in neuroscience have shown that there is a type of glial cell called astrocytes that collaborate with neurons to process information. In this work, a connectionist system formed by neurons and artificial astrocytes is presented. The astrocytes can have different configurations to achieve a biologically more realistic behaviour. This work indicates that the use of different artificial astrocytes behaviours is beneficial.Xunta de Galicia; ED431G/01Xunta de Galicia; ED431D 2017/16Xunta de Galicia; ED431D 2017/23Ministerio de Economía y Competitividad; UNLC08-1E-002Ministerio de Economía y Competitividad; UNLC13-13-350

A Qualitative Inquiry Into the Role of Web-Based Collaboration Tools and Instructional Scaffolds in the Facilitation of Team Processes

Learning has expanded beyond take-home assignments and lectures. Team-based learning, for instance, supports the extended development of students by offering further education through collaborating with others. This type of learning develops teamwork skills that have become essential skills for students in today’s complex work environment. Furthermore, the use of online collaboration tools in virtual teams adds complexity to the collaboration process. This trend calls for valuable insights related to enhancing online team-based collaboration to ensure team success and learning. Scaffolds provide a promising approach because they support team processes online by providing guidance through the use of tools, activities and artifacts that enable virtual student teams to act as a team in a virtual environment. They effectively facilitate the achievement of goals for teams collaborating remotely. However, the extent and manner in which scaffolds actually support specific team processes such as planning, conflict management and coordination need more exploration. We conducted a qualitative study to explore how the use of information and communication technologies (ICT), activities and artifacts supported three types of team processes (transition, action, and interpersonal). In a semester long engineering project, student teams employed web-based collaboration tools and instructional scaffolds to support their collaborative processes. The scaffolds included training and access to a web-based application including a variety of collaboration tools (file repository, video conference, and discussion board) as well as guided collaborative activities (team profile, team building and team identity development, team charter, project plan and peer evaluation). Twenty five students participated voluntarily in one-on-one interview sessions. Interview transcripts were coded and analyzed through a loose qualitative research design to allow emergent constructs to unfold that are related to the research questions. Other sources of data such as records of online team activities, team charters, class update presentations, individual reflection activities and e-mail exchanges with the professor were also used to triangulate the analysis. The results show that the scaffolds supported all types of team processes. However, emergent constructs related to individual, team and organizational characteristics prevented some of the teams from using some of the scaffolds to support their team processes. These characteristics include lack of initiative, lack of writing skills, task orientation, lack of access to the tool, team turnover, teamwork skills, technology familiarity, and perceived ease of use. These findings support existing theories such as the sociotechnical theory (STS) and adaptive structuration theory (AST). Based on the findings, we identified research and practical implications as well as proposed strategies in the implementation of ICTs and instructional scaffolds in virtual teams

First Multiplatform Application for Pharmacies in Spain, Which Guides the Prescription of Probiotics According to Pathology

[Abstract] The study of the intestinal microbiota is one of the biggest challenges in the current clinical environment. In this context, probiotics have been a focus of interest to achieve the stability of the intestinal microbiota, due to probiotics’ key role in its regulation. The development of an automated system that allows practitioners to easily search for the optimal probiotic is the main objective of this study. Although it is true that there have been previous attempts of applications with this purpose, only authorized probiotics available in the countries of origin, Canada and the USA, were included. This event was a limitation when looking for those endorsed in other countries such as Spain. Thus, a system has been developed from free and multiplatform technologies that allow its use without any cost, finding, in a simple way, those probiotics that would be ideal for each pathology, either from a browser or from a cell phone.This work was supported by the “Collaborative Project in Genomic Data Integration (CICLOGEN)” PI17/01826 funded by the Carlos III Health Institute from the Spanish National plan for Scientific and Technical Research and Innovation 2013–2016, the European Regional Development Funds (ERDF)—“A way to build Europe.”, the General Directorate of Culture, Education and University Management of Xunta de Galicia (Ref. ED431D 2017/16), the “Galician Network for Colorectal Cancer Research” (Ref. ED431D 2017/23) and Competitive Reference Groups (Ref. ED431C 2018/49). The funding body did not have a role in the experimental design, data collection, analysis and interpretation, and writing of this manuscript. CITIC, as a Research Center accredited by Galician University System, is funded by “Consellería de Cultura, Educación e Universidades” of Xunta de Galicia, 80% co-financed by the ERDF Funds, ERDF Operational Programme Galicia 2014-2020, and the remaining 20% by “Secretaría Xeral de Universidades” (Grant ED431G 2019/01)Xunta de Galicia; ED431D 2017/16Xunta de Galicia; ED431D 2017/23Xunta de Galicia; ED431C 2018/49Xunta de Galicia; ED431G 2019/0

Probiotic: First Prescriptive Application of Probiotics in Spain

[Abstract] The study of the intestinal microbiota is one of the greatest challenges in today’s clinical environment. Thus, probiotics have been established as a focus for its stability, as they play a key role in its regulation. The development of an automated technique that allows the practitioners the smooth search for the optimal probiotic is postulated as the main objective of this study. Despite the existence of previous attempts at applications for this purpose, they have only been carried out for the countries of origin, preventing them from being used in others such as Spain. Therefore, a system has been developed with open, multi-platform, and free technologies, which manages to locate the optimal probiotic for each pathology.Xunta de Galicia; ED431G/01Xunta de Galicia; ED431D 2017/16Xunta de Galicia; ED431D 2017/2

Mode coupling of Schwarzschild perturbations: Ringdown frequencies

Within linearized perturbation theory, black holes decay to their final stationary state through the well-known spectrum of quasinormal modes. Here we numerically study whether nonlinearities change this picture. For that purpose we study the ringdown frequencies of gauge-invariant second-order gravitational perturbations induced by self-coupling of linearized perturbations of Schwarzschild black holes. We do so through high-accuracy simulations in the time domain of first and second-order Regge-Wheeler-Zerilli type equations, for a variety of initial data sets. We consider first-order even-parity $(\ell=2,m=\pm 2)$ perturbations and odd-parity $(\ell=2,m=0)$ ones, and all the multipoles that they generate through self-coupling. For all of them and all the initial data sets considered we find that ---in contrast to previous predictions in the literature--- the numerical decay frequencies of second-order perturbations are the same ones of linearized theory, and we explain the observed behavior. This would indicate, in particular, that when modeling or searching for ringdown gravitational waves, appropriately including the standard quasinormal modes already takes into account nonlinear effects

Improved outer boundary conditions for Einstein's field equations

In a recent article, we constructed a hierarchy B_L of outer boundary conditions for Einstein's field equations with the property that, for a spherical outer boundary, it is perfectly absorbing for linearized gravitational radiation up to a given angular momentum number L. In this article, we generalize B_2 so that it can be applied to fairly general foliations of spacetime by space-like hypersurfaces and general outer boundary shapes and further, we improve B_2 in two steps: (i) we give a local boundary condition C_2 which is perfectly absorbing including first order contributions in 2M/R of curvature corrections for quadrupolar waves (where M is the mass of the spacetime and R is a typical radius of the outer boundary) and which significantly reduces spurious reflections due to backscatter, and (ii) we give a non-local boundary condition D_2 which is exact when first order corrections in 2M/R for both curvature and backscatter are considered, for quadrupolar radiation.Comment: accepted Class. Quant. Grav. numerical relativity special issue; 17 pages and 1 figur

Human and Helicobacter Pylori Coevolution Shapes the Risk of Gastric Disease

Helicobacter pylori is the principal cause of gastric cancer, the second leading cause of cancer mortality worldwide. However, H. pylori prevalence generally does not predict cancer incidence. To determine whether coevolution between host and pathogen influences disease risk, we examined the association between the severity of gastric lesions and patterns of genomic variation in matched human and H. pylori samples. Patients were recruited from two geographically distinct Colombian populations with significantly different incidences of gastric cancer, but virtually identical prevalence of H. pylori infection. All H. pylori isolates contained the genetic signatures of multiple ancestries, with an ancestral African cluster predominating in a low-risk, coastal population and a European cluster in a high-risk, mountain population. The human ancestry of the biopsied individuals also varied with geography, with mostly African ancestry in the coastal region (58%), and mostly Amerindian ancestry in the mountain region (67%). The interaction between the host and pathogen ancestries completely accounted for the difference in the severity of gastric lesions in the two regions of Colombia. In particular, African H. pylori ancestry was relatively benign in humans of African ancestry but was deleterious in individuals with substantial Amerindian ancestry. Thus, coevolution likely modulated disease risk, and the disruption of coevolved human and H. pylori genomes can explain the high incidence of gastric disease in the mountain population

Effect of forming gas annealing on the degradation properties of Ge-based MOS stacks

The influence of forming gas annealing on the degradation at a constant stress voltage of multi-layered germanium-based Metal-Oxide-Semiconductor capacitors (p-Ge/GeOx/Al2O3/High-K/Metal Gate) has been analyzed in terms of the C-V hysteresis and flat band voltage as a function of both negative and positive stress fields. Significant differences were found for the case of negative voltage stress between the annealed and non-annealed samples, independently of the stressing time. It was found that the hole trapping effect decreases in the case of the forming gas annealed samples, indicating strong passivation of defects with energies close to the valence band existing in the oxide-semiconductor interface during the forming gas annealing. Finally, a comparison between the degradation dynamics of Germanium and III-V (n-InGaAs) MOS stacks is presented to summarize the main challenges in the integration of reliable Ge–III-V hybrid devices.Fil: Aguirre, Fernando Leonel. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Pazos, Sebastián Matías. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Palumbo, Félix Roberto Mario. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; ArgentinaFil: Fadida, S.. Technion - Israel Institute of Technology; IsraelFil: Winter, R.. Technion - Israel Institute of Technology; IsraelFil: Eizenberg, M.. Technion - Israel Institute of Technology; Israe

A time-domain fourth-order-convergent numerical algorithm to integrate black hole perturbations in the extreme-mass-ratio limit

We obtain a fourth order accurate numerical algorithm to integrate the Zerilli and Regge-Wheeler wave equations, describing perturbations of nonrotating black holes, with source terms due to an orbiting particle. Those source terms contain the Dirac's delta and its first derivative. We also re-derive the source of the Zerilli and Regge-Wheeler equations for more convenient definitions of the waveforms, that allow direct metric reconstruction (in the Regge-Wheeler gauge).Comment: 30 pages, 12 figure

Extraordinarily transparent compact metallic metamaterials

The design of achromatic optical components requires materials with high transparency and low dispersion. We show that although metals are highly opaque, densely packed arrays of metallic nanoparticles can be more transparent to infrared radiation than dielectrics such as germanium, even when the arrays are over 75% metal by volume. Such arrays form effective dielectrics that are virtually dispersion-free over ultra-broadband ranges of wavelengths from microns up to millimeters or more. Furthermore, the local refractive indices may be tuned by altering the size, shape, and spacing of the nanoparticles, allowing the design of gradient-index lenses that guide and focus light on the microscale. The electric field is also strongly concentrated in the gaps between the metallic nanoparticles, and the simultaneous focusing and squeezing of the electric field produces strong ‘doubly-enhanced’ hotspots which could boost measurements made using infrared spectroscopy and other non-linear processes over a broad range of frequencies