On the distribution of an effective channel estimator for multi-cell massive MIMO

Accurate channel estimation is of utmost importance for massive MIMO systems to provide significant improvements in spectral and energy efficiency. In this work, we present a study on the distribution of a simple but yet effective and practical channel estimator for multi-cell massive MIMO systems suffering from pilot-contamination. The proposed channel estimator performs well under moderate to aggressive pilot contamination scenarios without previous knowledge of the inter-cell large-scale channel coefficients and noise power, asymptotically approximating the performance of the linear MMSE estimator as the number of antennas increases. We prove that the distribution of the proposed channel estimator can be accurately approximated by the circularly-symmetric complex normal distribution, when the number of antennas, M, deployed at the base station is greater than 10

On Investigating the Potential Effects of Private Autonomous Vehicle Use on Home/Work Relocations and Commute Times

You're viewing a past article from the Good Systems Grand Challenge team at The University of Texas at Austin published in 2020.Office of the VP for Researc

A insustentabilidade da visão tradicional sobre Direitos Humanos nas questões de gênero: a Corte Interamericana de Direitos Humanos no caso Rosendo Cantú y Otra versus México

O presente estudo objetiva investigar a insustentabilidade da visão tradicional sobre os direitos humanos nas questões de gênero a partir da atuação da Corte Interamericana de Direito Humanos, analisando uma decisão que trata sobre violência de gênero contra mulher, pautando-se pela teoria crítica dos direitos humanos e se respectiva Corte atua neste sentido. Para tanto, utiliza-se o método de abordagem fenomenológico-hermenêutico aliado ao método de procedimento monográfico; contando ainda com a técnica de pesquisa da documentação indireta e pesquisa jurisprudencial. Inicialmente desenvolve-se o tema da cultura de violência de gênero enquanto violação de direitos humanos para, no segundo momento, aliá-lo à teoria crítica dos direitos humanos. Ao final, analisa-se a decisão da Corte Interamericana, verificando uma atuação jurisdicional crítica sobre direitos humanos e violência de gênero, de forma a seguir uma visão sustentável em relação às questões de gênero, para além dos formalismos jurídicos e de uma visão tradicional sobre o tema

Quality Assessment of Photoplethysmography Signals For Cardiovascular Biomarkers Monitoring Using Wearable Devices

Photoplethysmography (PPG) is a non-invasive technology that measures changes in blood volume in the microvascular bed of tissue. It is commonly used in medical devices such as pulse oximeters and wrist worn heart rate monitors to monitor cardiovascular hemodynamics. PPG allows for the assessment of parameters (e.g., heart rate, pulse waveform, and peripheral perfusion) that can indicate conditions such as vasoconstriction or vasodilation, and provides information about microvascular blood flow, making it a valuable tool for monitoring cardiovascular health. However, PPG is subject to a number of sources of variations that can impact its accuracy and reliability, especially when using a wearable device for continuous monitoring, such as motion artifacts, skin pigmentation, and vasomotion. In this study, we extracted 27 statistical features from the PPG signal for training machine-learning models based on gradient boosting (XGBoost and CatBoost) and Random Forest (RF) algorithms to assess quality of PPG signals that were labeled as good or poor quality. We used the PPG time series from a publicly available dataset and evaluated the algorithm s performance using Sensitivity (Se), Positive Predicted Value (PPV), and F1-score (F1) metrics. Our model achieved Se, PPV, and F1-score of 94.4, 95.6, and 95.0 for XGBoost, 94.7, 95.9, and 95.3 for CatBoost, and 93.7, 91.3 and 92.5 for RF, respectively. Our findings are comparable to state-of-the-art reported in the literature but using a much simpler model, indicating that ML models are promising for developing remote, non-invasive, and continuous measurement devices.Comment: 9 page

New Algorithm to Discriminate Phase Distribution of Gas-Oil-Water Pipe Flow With Dual-Modality Wire-Mesh Sensor

Three-phase gas-oil-water flow is an important type of flow present in petroleum extraction and processing. This paper reports a novel threshold-based method to visualize and estimate the cross-sectional phase fraction of gas-oil-water mixtures. A 16×16 dual-modality wire-mesh sensor (WMS) was employed to simultaneously determine the conductive and capacitive components of the impedance of fluid. Then, both electrical parameters are used to classify readings of WMS into either pure substance (gas, oil or water) or two-phase oil-water mixtures (foam is neglected in this work). Since the wire-mesh sensor interrogates small regions of the flow domain, we assume that the three-phase mixture can be segmented according to the spatial sensor resolution (typically 2–3 mm). Hence, the proposed method simplifies a complex three-phase system in several segments of single or two-phase mixtures. In addition to flow visualization, the novel approach can also be applied to estimate quantitative volume fractions of flowing gas-oil-water mixtures. The proposed method was tested in a horizontal air-oil-water flow loop in different flow conditions. Experimental results suggest that the threshold-based method is able to capture transient three-phase flows with high temporal and spatial resolution even in the presence of water-oil dispersion regardless of the continuous phase

Draft of Cheyenne & Arapahoe Report

https://digitalcommons.assumption.edu/mallet-manuscripts/1030/thumbnail.jp

Toxoplasma gondii infection, congenital toxoplasmosis, toxoplasmic retinochoroiditis and neurotoxoplasmosis: an overview

Introduction: The toxoplasmosis disease resulting from Toxoplasma gondii infection can manifest itself in many ways, however, congenital, ocular and cerebral forms require greater care. The infection by this protozoan is directly related to environmental and economic factors of the region. Objective: The present study, through a review in the literature, aimed to reinforce the knowledge about the infection caused by Toxoplasma gondii and its main clinical manifestations. Methods: This is a literature overview from academic books and scientific articles available in the Scientific Electronic Library Online, US National Library of Medicine National Institutes of Health and Google Scholar databases. To search the publications, the following descriptors were used: Toxoplasma gondii, toxoplasmosis, congenital toxoplasmosis, ocular toxoplasmosis and cerebral toxoplasmosis. The most relevant articles corresponding to the period from 2000 to 2017 were selected. Development: Toxoplasmosis may be of congenital or acquired origin after birth. The congenital form occurs during the embryonic/fetal life and through the passage of Toxoplasma gondii through the transplacental route. Ocular disease is common in both congenital and acquired infections and is closely associated with the presence of neurotoxoplasmosis in AIDS patients. Conclusion: Thus, immunocompromised patients and immunosuppressed patients are considered to be risk groups for Toxoplasma gondii infection

Sr ISOTOPES BY LA-MC-ICP-MS PROCEDURES COUPLED WITH THE MACS3 REFERENCE MATERIAL IN A CORAL SAMPLE: A RECORD OF ENVIRONMENTAL CHANGES: Isótopos de Sr analisados por LA-MC-ICP-MS como material de referência MACS3 em uma amostra de coral: um registro de mudanças ambientais

The main aim of this work is to demonstrate that the Laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) is a powerful tool for the analysis of strontium (Sr) isotopes in corals. This work discusses certification strategies for Sr isotopes determination, using reference material (RM) analyses and the results treatment based on detailed data acquired in biological materials, a coral sample. To obtain reliable results, it is essential to properly adjust the mass spectrometer and laser ablation system. Adjusting the equipment to its maximum intensity does not always result in correct 87Sr/86Sr ratios. Therefore, the optimization of the mass spectrometer was performed using the reference material NIST SRM-987 (solution) and adjusting the correct Sr isotope ratio to the reference material (USGS MACS3 and NIST-612, solids) before each analytical session. The protocol applied the solid reference material USGS MACS3 with an isotopic ratio 87Sr/86Sr of 0.72000. The values obtained for this RM varied between 0.7012 and 0.7014, with a correction factor calculated between 0.990 and 0.988. In order to account for potential drifts in the mass spectrometer during an analytical session, the application of bracketing correction and the use of the most convenient reference material are suggested. The analytical uncertainty of Sr data obtained by LA-MC-ICP-MS is comparable to studies carried out on other carbonate materials. The results of ablation techniques are reproducible within the analytical error, which implies that this technique produces robust results when applied to coral carbonates. In addition, several comparative measurements of different reference materials (e.g. USGS MACS3 and NIST 612) and the comparison of the 87Sr/86Sr ratios highlight the robustness of the method. The results along the coral growth axes showed a decrease in the 87Sr/86Sr ratio from the inner to the outer layer of the coral (from 0.70920 to 0.70627), which indicate variations in the availability of particulate matter during the coral growth, probably related to local marine environmental changes.- O objetivo principal deste trabalho é demonstrar que a espectrometria de massa com plasma indutivamente acoplado e ablação a laser (LA-MC-ICP-MS) é uma ferramenta poderosa para a análise de isótopos de Sr em corais. Este trabalho discute estratégias de certificação para determinação de isótopos de Sr, usando análises de material de referência e o detalhamento do tratamento dos resultados adquiridos em materiais biológicos (coral). Para obter resultados confiáveis, é essencial ajustar adequadamente o espectrômetro de massas e o sistema de ablação a laser de forma a obter a intensidade máxima e em seguida promover as correções para obter as razões 87Sr / 86Sr corretas. Nestes termos, a otimização do espectrômetro de massa foi realizada usando o material de referência NIST SRM-987 (em solução) que em sequência foi migrado para a ablação a laser com ajuste da razão isotópica Sr correta para o material de referência (NIST-612, vidro), antes de cada sessão analítica. O protocolo incluiu a utilização material de referência sólido USGS MACS3 com razão isotópica 87Sr / 86Sr de 0,72000. Os valores obtidos para esta RM variaram entre 0,7012 e 0,7014, com fator de correção calculado entre 0,990 e 0,988. A fim de contabilizar possíveis desvios no espectrômetro de massa durante uma sessão analítica, sugere-se a aplicação de correção de bracketing e o uso do material de referência com a mesma matriz. Os resultados das técnicas de ablação são reproduzíveis dentro do erro analítico, o que indica que esta técnica produz resultados robustos quando aplicada a carbonatos de coral. Além disso, várias medições comparativas de diferentes materiais de referência (por exemplo, USGS MACS3 e NIST 612) e a comparação das suas respectivas razões 87Sr / 86Sr destacam a robustez do método. Os resultados ao longo dos eixos de crescimento do coral mostraram uma diminuição na razão 87Sr / 86Sr da camada interna para a externa do coral (de 0,70920 para 0,70627). Estes resultados sugerem variações na disponibilidade de material particulado durante o crescimento do coral, provavelmente relacionado a mudanças ambientais marinhas locais. Palavras-chave: Carbonato biológico. Isótopos de Sr. LA-MC-ICP-MS. Materiais de referência. Metodologia. Ambiente marinho. &nbsp

Gene expression profiling of Trypanosoma cruzi in the presence of heme points to glycosomal metabolic adaptation of epimastigotes inside the vector

Chagas disease, also known as American trypanosomiasis, is a potentially life-threatening illness caused by the protozoan parasite, Trypanosoma cruzi, and is transmitted by triatomine insects during its blood meal. Proliferative epimastigotes forms thrive inside the insects in the presence of heme (iron protoporphyrin IX), an abundant product of blood digestion, however little is known about the metabolic outcome of this signaling molecule in the parasite. Trypanosomatids exhibit unusual gene transcription employing a polycistronic transcription mechanism through trans-splicing that regulates its life cycle. Using the Deep Seq transcriptome sequencing we characterized the heme induced transcriptome of epimastigotes and determined that most of the upregulated genes were related to glucose metabolism inside the glycosomes. These results were supported by the upregulation of glycosomal isoforms of PEPCK and fumarate reductase of heme-treated parasites, implying that the fermentation process was favored. Moreover, the downregulation of mitochondrial gene enzymes in the presence of heme also supported the hypothesis that heme shifts the parasite glycosomal glucose metabolism towards aerobic fermentation. These results are examples of the environmental metabolic plasticity inside the vector supporting ATP production, promoting epimastigotes proliferation and survival

Prevalence and risk factors of bovine leptospirosis in the State of Maranhão, Brazil

Foram investigados a prevalência e os fatores de risco da leptospirose bovina no Estado do Maranhão. O Estado foi dividido em quatro circuitos amostrais com base em parâmetros de produção distintos que variam conforme os diferentes sistemas de produção, as práticas de manejo, a finalidade de exploração, o tamanho médio dos rebanhos e os sistemas de comercialização. Objetivou-se estudar as características epidemiológicas da leptospirose bovina no Estado do Maranhão, de modo a determinar a prevalência em bovinos e em rebanhos, detectar as sorovariedades de Leptospira spp. presentes, identificar os fatores de risco eventualmente associados à leptospirose em bovinos e diferenciar os circuitos pecuários entre si no que se refere à prevalência de leptospirose. A pesquisa foi realizada em 136 propriedades rurais pertencentes ao circuito I, no qual 841 fêmeas bovinas com idade igual ou superior a 24 meses foram analisadas; 238 do circuito II, com 2.582 fêmeas analisadas; 122 do circuito III, com 869 fêmeas analisadas; e 77 do circuito IV, com 540 fêmeas analisadas; no total, 573 propriedades e 4.832 fêmeas foram estudadas. A presença de anticorpos contra Leptospira spp. foi verificada pela técnica de soroaglutinação microscópica (SAM). Das 4.832 fêmeas bovinas analisadas, 1.904 (35,94%; IC 95% = 33,01% - 38,98%) foram reagentes. Das 573 propriedades analisadas, 380 (64,81%; IC 95% = 61,10% - 68,35%) foram consideradas positivas. As sorovariedades Hardjo e Wolffi foram as mais frequentes em todo o Estado. O circuito III foi o que apresentou menor prevalência de leptospirose em todas as comparações. As variáveis identificadas como fatores de risco de leptospirose foram: presença de equinos (p = 0,000), presença de capivaras (p = 0,034) e rebanhos bovinos com 32 ou mais fêmeas adultas (p = 0,002)