On the zero set of G-equivariant maps

Let $G$ be a finite group acting on vector spaces $V$ and $W$ and consider a smooth $G$-equivariant mapping $f:V\to W$. This paper addresses the question of the zero set near a zero $x$ of $f$ with isotropy subgroup $G$. It is known from results of Bierstone and Field on $G$-transversality theory that the zero set in a neighborhood of $x$ is a stratified set. The purpose of this paper is to partially determine the structure of the stratified set near $x$ using only information from the representations $V$ and $W$. We define an index $s(\Sigma)$ for isotropy subgroups $\Sigma$ of $G$ which is the difference of the dimension of the fixed point subspace of $\Sigma$ in $V$ and $W$. Our main result states that if $V$ contains a subspace $G$-isomorphic to $W$, then for every maximal isotropy subgroup $\Sigma$ satisfying $s(\Sigma)>s(G)$, the zero set of $f$ near $x$ contains a smooth manifold of zeros with isotropy subgroup $\Sigma$ of dimension $s(\Sigma)$. We also present a systematic method to study the zero sets for group representations $V$ and $W$ which do not satisfy the conditions of our main theorem. The paper contains many examples and raises several questions concerning the computation of zero sets of equivariant maps. These results have application to the bifurcation theory of $G$-reversible equivariant vector fields

Estrategia educativa basada en realidad aumentada para el área de Tecnología e Informática en el grado quinto de Primaria

El siguiente proyecto, pretende dar a conocer el diseño y la aplicación de una estrategia educativa en el grado quinto de primaria de la Escuela Normal Superior de Pasto, donde se implementa la tecnología de realidad aumentada (RA) con fines educativos. El diseño estructural de la estrategia empieza desde la selección de un objetivo formativo, que actúa como eje hacia los demás componentes teóricos, pedagógicos y técnicos, necesarios para cualquier proceso educativo que se prevea desarrollar. Este proyecto presenta un análisis sobre las ventajas y desventajas que se encontraron con la aplicación de la estrategia educativa basada en RA, recopilando información valiosa que podría ser tomada en cuenta para el desarrollo de propuestas educativas que busquen incluir este tipo de tecnologías

The Health Impacts of Climate Change: Getting Started on a New Theme

Climate change is widely acknowledged as a key global challenge for the 21st century, and is projected to significantly affect population health and human well-being. All of the climate change-related changes in weather patterns will affect human health, from boosting mental well-being to mortality from largescale disasters. Human health can be affected both directly and indirectly. For various reasons, the health sector has been slow in responding to the projected health impacts of climate change. To effectively prepare for and cope with climate change impacts, public health must move from a focus on surveillance and response to a greater emphasis on prediction and prevention. The targeted agenda program dialogue identified three priorities for climate change related health actions: heat waves, vector-borne diseases; and malnutritio

Comparison of near-interface traps in Al2_2O3_3/4H-SiC and Al2_2O3_3/SiO2_2/4H-SiC structures

Aluminum oxide (Al2O3) has been grown by atomic layer deposition on n-type 4H-SiC with and without a thin silicon dioxide (SiO2) intermediate layer. By means of Capacitance Voltage and Thermal Dielectric Relaxation Current measurements, the interface properties have been investigated. Whereas for the samples with an interfacial SiO2 layer the highest near-interface trap density is found at 0.3 eV below the conduction band edge, Ec, the samples with only the Al2O3 dielectric exhibit a nearly trap free region close to Ec. For the Al2O3/SiC interface, the highest trap density appears between 0.4 to 0.6 eV below Ec. The results indicate the possibility for SiC-based MOSFETs with Al2O3 as the gate dielectric layer in future high performance devices.Comment: 3 figures. Applied Physics Letters, accepted for publicatio

Melt-Extrusion-Based Additive Manufacturing of Transparent Fused Silica Glass

In recent years, additive manufacturing (AM) of glass has attracted great interest in academia and industry, yet it is still mostly limited to liquid nanocomposite-based approaches for stereolithography, two-photon polymerization, or direct ink writing. Melt-extrusion-based processes, such as fused deposition modeling (FDM), which will allow facile manufacturing of large thin-walled components or simple multimaterial printing processes, are so far inaccessible for AM of transparent fused silica glass. Here, melt-extrusion-based AM of transparent fused silica is introduced by FDM and fused feedstock deposition (FFD) using thermoplastic silica nanocomposites that are converted to transparent glass using debinding and sintering. This will enable printing of previously inaccessible glass structures like high-aspect-ratio (>480) vessels with wall thicknesses down to 250 µm, delicate parts including overhanging features using polymer support structures, as well as dual extrusion for multicolored glasses

Quantized spin wave modes in magnetic tunnel junction nanopillars

We present an experimental and theoretical study of the magnetic field dependence of the mode frequency of thermally excited spin waves in rectangular shaped nanopillars of lateral sizes 60x100, 75x150, and 105x190 nm2, patterned from MgO-based magnetic tunnel junctions. The spin wave frequencies were measured using spectrally resolved electrical noise measurements. In all spectra, several independent quantized spin wave modes have been observed and could be identified as eigenexcitations of the free layer and of the synthetic antiferromagnet of the junction. Using a theoretical approach based on the diagonalization of the dynamical matrix of a system of three coupled, spatially confined magnetic layers, we have modeled the spectra for the smallest pillar and have extracted its material parameters. The magnetization and exchange stiffness constant of the CoFeB free layer are thereby found to be substantially reduced compared to the corresponding thin film values. Moreover, we could infer that the pinning of the magnetization at the lateral boundaries must be weak. Finally, the interlayer dipolar coupling between the free layer and the synthetic antiferromagnet causes mode anticrossings with gap openings up to 2 GHz. At low fields and in the larger pillars, there is clear evidence for strong non-uniformities of the layer magnetizations. In particular, at zero field the lowest mode is not the fundamental mode, but a mode most likely localized near the layer edges.Comment: 16 pages, 4 figures, (re)submitted to PR

Concordance of Illness Representations: The Key to Improving Care of Medically Unexplained Symptoms

How can effective patient-provider relationships be developed when the underlying cause of the health condition is not well understood and becomes a point of controversy between patient and provider? This problem underlies the difficulty in treating medically unexplained symptoms and syndromes (MUS; e.g., fibromyalgia, chronic fatigue syndrome), which primary care providers consider to be among the most difficult conditions to treat.1 This difficulty extends to the patient-provider relationship which is characterized by discord over MUS.1 In this article, we argue that the key to improving the patient provider relationship is for the patient and provider to develop congruent illness perceptions about MUS

GEM: An Interactive Simulation Model of the Global Economy

One of the aims of the International Institute for Applied Systems Analysis (IIASA) is to develop methods of systems analysis that lend themselves to applications to policy analysis. Gaming has proved to be an important methodological planning tool in such areas as military and business affairs, but thus far few applications to socioeconomic planning have been attempted. The game described here is a demonstration model, intended to acquaint the reader with the potentialities of this approach as a preanalytical research tool. The model described here, which is named "GEM" (Global Economic Model), is a six person interactive simulation model (or game) intended to generate intuitive insights into the economic interactions among six world regions over the next 50 years

Evaluation of potential miRNA sponge effects of SARS genomes in human

: To date the coronavirus family is composed of seven different viruses which were commonly known as cold viruses until the appearance of the severe acute respiratory coronavirus (SARS-CoV) in 2002, the middle east respiratory syndrome coronavirus (MERS) in 2012 and the severe acute respiratory coronavirus 2 (SARS-CoV-2) which caused the COVID-19 global pandemic in 2019. Using bioinformatic approaches we tested the potential interactions of human miRNAs, expressed in pulmonary epithelial cells, with the available coronavirus genomes. Putative miRNA binding sites were then compared between pathogenic and non pathogenic virus groups. The pathogenic group shares 6 miRNA binding sites that can be potentially involved in the sequestration of miRNAs already known to be associated with deep vein thrombosis. We then analysed ∼100k SARS-CoV-2 variant genomes for their potential interaction with human miRNAs and this study highlighted a group of 97 miRNA binding sites which is present in all the analysed genomes. Among these, we identified 6 miRNA binding sites specific for SARS-CoV-2 and the other two pathogenic viruses whose down-regulation has been seen associated with deep vein thrombosis and cardiovascular diseases. Interestingly, one of these miRNAs, namely miR-20a-5p, whose expression decreases with advancing age, is involved in cytokine signaling, cell differentiation and/or proliferation. We hypothesize that depletion of poorly expressed miRNA could be related with disease severity