High Dimensional Classification with combined Adaptive Sparse PLS and Logistic Regression

Motivation: The high dimensionality of genomic data calls for the development of specific classification methodologies, especially to prevent over-optimistic predictions. This challenge can be tackled by compression and variable selection, which combined constitute a powerful framework for classification, as well as data visualization and interpretation. However, current proposed combinations lead to instable and non convergent methods due to inappropriate computational frameworks. We hereby propose a stable and convergent approach for classification in high dimensional based on sparse Partial Least Squares (sparse PLS). Results: We start by proposing a new solution for the sparse PLS problem that is based on proximal operators for the case of univariate responses. Then we develop an adaptive version of the sparse PLS for classification, which combines iterative optimization of logistic regression and sparse PLS to ensure convergence and stability. Our results are confirmed on synthetic and experimental data. In particular we show how crucial convergence and stability can be when cross-validation is involved for calibration purposes. Using gene expression data we explore the prediction of breast cancer relapse. We also propose a multicategorial version of our method on the prediction of cell-types based on single-cell expression data. Availability: Our approach is implemented in the plsgenomics R-package.Comment: 9 pages, 3 figures, 4 tables + Supplementary Materials 8 pages, 3 figures, 10 table

ESCOAMENTO de Materiais Viscoplásticos: Dam Break Flow

Ao longo do último século, o Dam Break Flow vem sendo estudado por muitos autores. A compreensão deste tipo de fenômeno é de grande relevância, uma vez que envolve aplicações em barragens que oferecem múltiplos benefícios para a humanidade. Porém, o rompimento de uma dessas barragens pode trazer consequências indesejáveis e imensuráveis para a sociedade e para o setor de mineração, por exemplo. Neste trabalho estamos interessados em entender como o número de Froude e as propriedades não-newtonianas, particularmente a viscoplasticidade, afetam o perfil de interface do escoamento e a distância alcançada pelo material após o Dam Break Flow. Tais resultados são comparados com o deslocamento de um fluido newtoniano. Através de uma simples abordagem experimental, uma solução de material viscoplástico ou newtoniana incialmente armazenada em um reservatório é instantaneamente liberada. As imagens do escoamento são capturadas durante o teste de duas maneiras diferentes. Uma é feita utilizando uma câmera CCD e a outra é através da Velocimetria por Imagem de Partícula. A partir das imagens obtidas pela câmera CCD, obtém-se um mapa do escoamento, com as suas respectivas velocidades, nível de líquido, formato das interfaces ar-líquido e distância percorrida pelo material são observadas. Já os resultados obtidos com o PIV, são para determinar o campo de velocidade dos momentos iniciais do Dam Break Flow para os diferentes tipos de materiais estudados. Neste trabalho, é mostrado que a plasticidade do material tem total influência sobre a distância alcançada pelo escoamento e também resultam em instabilidades ao longo do mesmo. Foi ainda identificado que o fluido viscoplástico alcança velocidades iniciais maiores que o caso newtoniano. Porém, no decorrer do escoamento, decrescem rapidamente. Quando analisado o caso viscoplástico para um leito com rugosidade, nota-se que para uma superfície lisa, há deslizamento do material de forma significativa para altos valores de plasticidade. Através da análise com PIV, foi constatado que a velocidade de frente de onda é um pouco menor do que a velocidade máxima obtida pelo escoamento. Palavras chave: Dam Break Flow, material viscoplástico, PIV, plasticidade, deslizamento

Electron densities in the upper ionosphere of Mars from the excitation of electron plasma oscillations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94727/1/jgra19333.pd

Avaliação da Influência de Implementos de Plantio Direto do Milho com Tomografia de Raios Gama.

bitstream/CNPDIA/10463/1/BPD10_2005.pd

Determinants of surgeon choice in cases of suspected implant rupture following mastectomy or aesthetic breast surgery: Clinical implications

Implant ruptures may be diagnosed by physical examination, ultrasound (US), and magnetic resonance imaging (MRI). The absence of standard guidelines to approach to implant ruptures may cause unnecessary surgical revisions in the absence of radiological confirmation of prosthetic damages.The purpose of this study was to analyze the diagnostic procedures applied to patients with suspected prosthetic rupture and surgeon choices to perform a revision or to plan a clinical and radiological follow-up.We conducted a retrospective study on 62 women submitted to revision surgery due to radiological diagnosis of suspected implant rupture, following mastectomy or aesthetic reconstruction, and admitted to a Plastic Surgery Department between 2008 and 2018.Seventy-three implants, believed to be ruptured, were explanted. One-third of these were intact and unnecessarily explanted. US associated with MRI evaluation resulted in the most helpful diagnostical method.A standardized clinical and radiological approach is essential to manage breast implant ruptures successfully. An innovative protocol is proposed in order to: ensure the appropriate management of implant ruptures and prevent unnecessary surgical revisions; reduce the risk of claims for medical malpractice in cases of unsatisfactory final aesthetic results or worse than before

Effect of grazing intensities and seed furrow openers on corn development and yield in a crop-livestock system

Grazing intensity determines both agricultural and livestock production and may shift the crop-livestock system either in a positive or negative direction. High grazing intensity may affect soil physical-chemical and biological traits, affecting a no-tillage system and as a result, reduce crop yields. These effects can be mitigated by the use of a no-till seed planter equipped with different furrow openers that can interact to optimize crop yield. This study aimed to evaluate grazing intensities and seed furrow openers on corn crop development and yield in an integrated crop-livestock system. The experiment was laid out as random block design in a split-plot arrangement with four replications. Black oat + ryegrass grazing intensities were characterized by different pasture sward management, with the entrance of grazing animal at pasture heights of 25, 30, and 35 cm and exit at heights of 5, 10, and 15 cm, respectively. Grazing was a rotational basis with a treatment without grazing as a control. After the grazing period, corn was established using two seed furrow openers (double disc and shank) in the sub-plot level. Soil bulk density was evaluated before and after the grazing period as well as the depth of seed deposition, corn plant development, corn yield components and yield. Soil bulk density increased as grazing intensity increased. Corn yield dynamics were affected by grazing intensity and the type of seed furrow opener

Delineation of management zones using mobile measurements of soil apparent electrical conductivity and multivariate geostatistical techniques

Site-specific management promotes the identification and management of areas within the field, which represent subfield regions with homogeneous characteristics (management zones). However, determination of subfield areas is difficult because of the complex combination of factors which could affect crop yield. One possibility to capture yield variability is the use of soil physical properties to define the management zones as they are related to plant available water. With the aim of characterizing the spatial variability of the main soil physical variables and using this information to determine potential management zones, soil samples were taken from 70 locations in a 33-ha field in Badajoz, southwestern Spain. Firstly, accurate spatial distribution maps of the soil attributes were generated by using regression kriging as the most suitable algorithm in which exhaustive secondary information on soil apparent electrical conductivity (ECa) was incorporated. ECa measurements were carried out with a Veris 3100 operating in both shallow (0–30 cm), ECs, and deep (0–90 cm), ECd,mode. Clay, coarse sand and fine sand were the soil physical properties which exhibited higher correlation with ECa (positively correlated with the finer texture component, clay, and negatively correlated with the coarser ones, coarse and fine sands), particularly with ECs. Thus, this was the secondary variable used to obtain the kriged maps. Later, principal component analysis and fuzzy cluster classification were performed to delineate management zones, resulting in two subfields to be managed separately. This number of subfields was determined using the fuzzy performance index and normalized classification entropy as the way to optimize the classification algorithm

Failure Physics and Reliability of GaN-Based HEMTs for Microwave and Millimeter-Wave Applications: A Review of Consolidated Data and Recent Results

Herein, the results are reviewed concerning reliability of high-electron mobility transistors (HEMTs) based on GaN, which currently represent the technology of choice for high-efficiency microwave and millimeter-wave power amplifiers. Several failure mechanisms of these devices are extensively studied, including converse piezoelectric effects, formation of conductive percolation paths at the edge of gate toward the drain, surface oxidation of GaN, time-dependent breakdown of GaN buffer, and of field-plate dielectric. For GaN HEMTs with scaled gate length, the simultaneous control of short-channel effects, deep-level dispersion, and hot-electron-induced degradation requires a careful optimization of epitaxial material quality and device design

Temporal variability of waves at the proton cyclotron frequency upstream from Mars: Implications for Mars distant hydrogen exosphere

We report on the temporal variability of the occurrence of waves at the local proton cyclotron frequency upstream from the Martian bow shock from Mars Global Surveyor observations during the first aerobraking and science phasing orbit periods. Observations at high southern latitudes during minimum-to-mean solar activity show that the wave occurrence rate is significantly higher around perihelion/ southern summer solstice than around the spring and autumn equinoxes. A similar trend is observed in the hydrogen (H) exospheric density profiles over the Martian dayside and South Pole obtained from a model including UV thermospheric heating effects. In spite of the complexity in the ion pickup and plasma wave generation and evolution processes, these results support the idea that variations in the occurrence of waves could be used to study the temporal evolution of the distant Martian H corona and its coupling with the thermosphere at altitudes currently inaccessible to direct measurements.Fil: Bertucci, Cesar. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Romanelli, Norberto Julio. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Chaufray, J. Y.. LATMOS; FranciaFil: Gomez, Daniel Osvaldo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Mazelle, C.. IRAP; FranciaFil: Delva, M.. IWF-ÖAW; AustriaFil: Modolo, R.. LATMOS; FranciaFil: González Galindo, F.. Instituto de Astrofísica de Andalucía; EspañaFil: Brain, D. A.. University of Colorado Boulder; Estados Unido

Study of the hydrogen escape rate at Mars during Martian years 28 and 29 from comparisons between SPICAM/Mars Express observations and GCM-LMD simulations

EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland, id. EPSC-DPS2019-499-2.- © Author(s) 2019. CC Attribution 4.0 license. https://creativecommons.org/licenses/by/4.0/deed.esWe simulate the 3D Martian hydrogen corona during the Martian years 28 and 29 at different solar longitudes using a set of models of atomic hydrogen density from the surface to the exosphere. These simulations are compared to Mars Express / SPICAM observations and show a strong underestimate of the brightness by our models near southern summer that could be due to an underestimate of the amount of water vapor delivered to the upper atmosphere at this season