Estrategia de movimiento basada en deep learning y visión por ordenador para robot cuadrúpedo

La locomoción es uno de los principales desafíos presentes en el campo de la robótica. Esta habilidad expande el alcance de los robots, y les permite resolver un gran abanico de tareas, desde aplicaciones cotidianas del día a día, hasta exploraciones en terrenos desconocidos. En este documento se detalla el desarrollo de una estrategia de movimiento, basada en inteligencia artificial, para un robot cuadrúpedo. El algoritmo desarrollado tiene como objetivo hacer que el robot alcance (de forma autónoma) un determinado objeto. El sistema propuesto está compuesto por varias entidades: un sensor cámara instalado en la parte frontal del robot para capturar imágenes del entorno, una red neuronal convolucional para clasificar la posición relativa del objetivo, y una estructura de robot cuadrúpedo encargada de realizar las acciones de movimiento determinadas por el algoritmo de control. El desarrollo de este proyecto se ha llevado a cabo siguiendo una metodología ascendente. Resolviendo en primer lugar una simplificación del problema planteado, se ha aumentado la complejidad de cada estrategia de movimiento hasta alcanzar resultados satisfactorios. Cada etapa del desarrollo sigue la misma estructura: diseño del algoritmo de control, implementación y análisis de resultados. Gracias a ello, ha sido posible observar cuáles son las virtudes y carencias de cada estrategia de movimiento, permitiendo mejorar el desempeño del sistema en etapas posteriores. El resultado final es una estrategia de movimiento funcional, capaz de conducir el robot hasta el objetivo deseado gracias a los excelentes resultados obtenidos en el modelo de clasificación.Locomotion is one of the main challenges to overcome in robotic technologies, this skill enable robotics to be applied over a wide range of tasks spanning day-to-day applications up to exploration tasks in unknown and far territories. This document details the development of a movment strategy definition on a four-legged robot based on artificial intelligence. The algorithm developed is made to enable the robot reach the objective autonomously, this system is composed of various subsystems: A camera installed in the front, to capture images of the surrounding. A convolutional neural network allows classification of the object's relative position and finally the robot's structural awareness that will execute the movements to be performed as per tasks generated by the control unit. This project has been executed following an ascending methodology. Solving by first a simplification of the proposed problem, the complexity of each movement strategy has been increased until achieve satisfactory results. Each development stage follows the next structure: control algorithm design, implementation and analysis of the performed task. As a result, it has been possible to evaluate the strengths and weaknesses of each movement strategy, and then improve the system performance on subsequent stages. Thanks to the excellent accuracy acquired on the classification models, the final result is a functional movement strategy able to drive the robot to the desired object

Phytochemical profile and antimicrobial properties of volatile compounds of Satureja calamintha (L) Scheel from northern Algeria

Purpose: To undertake the phytochemical screening of Satureja calamintha (L.)  Scheel., and evaluate the antimicrobial activities of its volatile compounds.Methods: Qualitative phytochemical analysis of the plant was performed using  standard methods. The extraction of essential oils (EOs) was conducted using  steam distillation, while the chemical composition was determined using gas chromatography-mass spectrometry (GC-MS). The antimicrobial activities of the oils were evaluated against ten bacterial and six fungal strains using disc-diffusion assay and poisoned food technique, respectively.Results: After steam distillation, the extraction yield was 0.54 ± 0.11 %. GC-MS analysis identified approximately 99.99 % of the EOs. The three most abundant compounds identified were l-menthone (32.10 %), neo-menthol (32.07 %) and pulegone (22.35 %). The oils had significant (p < 0.05) antimicrobial activities against the tested bacterial and fungal strains, except Bacillus cereus and Candida albicans. The lowest minimum inhibitory concentration (MIC) for bacteria was 0.007 % (v/v) against Enterococcus faecalis and Klebsiella pneumoniae, whereas for fungi, it was 0.500 % (v/v) against Candida albicans. Moreover, Enterococcus faecalis and Listeria innocua had the lowest minimum bactericidal concentration (MBC) at 0.125 % (v/v), in contrast to the lowest fungicidal concentration (MFC) for Candida albicans at 0.500 % (v/v).Conclusion: These results demonstrate that EOs from Satureja calamintha (L.)  Scheel. possess significant antimicrobial activities which might be useful for  therapeutic and pharmaceutical applications.Keywords: Satureja calamintha, Phytochemicals, Essential oils, Antimicrobial activity, Steam distillatio

Studying the Impact on Urban Health over the Greater Delta Region in Egypt Due to Aerosol Variability Using Optical Characteristics from Satellite Observations and Ground-Based AERONET Measurements

This research addresses the aerosol characteristics and variability over Cairo and the Greater Delta region over the last 20 years using an integrative multi-sensor approach of remotely sensed and PM10 ground data. The accuracy of these satellite aerosol products is also evaluated and compared through cross-validation against ground observations from the AErosol RObotic NETwork (AERONET) project measured at local stations. The results show the validity of using Multi-angle Imaging Spectroradiometer (MISR) and Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on the Terra and Aqua platforms for quantitative aerosol optical depth (AOD) assessment as compared to Ozone Monitoring Instrument (OMI), Sea-viewingWide Field-of-view Sensor (SeaWiFS), and POLarization and Directionality of the Earth’s Reflectances (POLDER). In addition, extracted MISR-based aerosol products have been proven to be quite eective in investigating the characteristics of mixed aerosols. Daily AERONET AOD observations were collected and classified using K-means unsupervised machine learning algorithms, showing five typical patterns of aerosols in the region under investigation. Four seasonal aerosol emerging episodes are identified and analyzed using multiple indicators, including aerosol optical depth (AOD), size distribution, single scattering albedo (SSA), and Ångström exponent (AE). The movements and detailed aerosol composition of the aforementioned episodes are demonstrated using NASA’s Goddard Space Flight Center (GSFC) back trajectories model in collaboration with aerosol subtype products from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) mission. These episodes indicate that during the spring, fall, and summer, most of the severe aerosol events are caused by dust or mixed related scenarios, whereas during winter, aerosols of finer size lead to severe heavy conditions. It also demonstrates the impacts of different aerosol sources on urban human health, which are presented by the variations of multiple parameters, including solar radiation, air temperature, humidity, and UV exposure. Scarce ground PM10 data were collected and compared against satellite products, yet owed to their discrete nature of availability, our approach made use of the Random Decision Forest (RDF) model to convert satellite-based AOD and other meteorological parameters to predict PM10. The RDF model with inputs from the Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2) and Global Land Data Assimilation System (GLDAS) datasets improves the performance of using AOD products to estimate PM10 values. The connection between climate variability and aerosol intensity, as well as their impact on health-related PM2.5 over Egypt is also demonstrated

Perception of Biostatistics by Lebanese Medical Students: A Cross-Sectional Study

Background: Inadequate use of statistics in biomedical research might not only affect science but also harm human beings if applied in medical practice. Biostatistics is fundamental to improve understanding and appraising of evidence-based medicine (EBM); yet, it is still not well understood and appreciated by medical students. Therefore, early exposure of medical students and physicians-in-training to research tools including Biostatistics is of utmostimportance.Objective: The aim of this study is to determine the perception of Biostatistics by medical students at a private medical school in Beirut, Lebanon, and to identify its best implementation time in the medical curriculum.Methods: This is a cross-sectional study based on a self-administered questionnaire distributed among medical students in their pre-clerkship years (first three years of a 6-year program) who undertook Biostatistics. The assessment of perception was based on the 5-point Likert scale anchored by Strongly disagree = 1 and Strongly agree = 5 including 36 questions distributed into four domains to assess the course value, difficulty, behavioral, and expectations.Results: 186 of 269 students responded to the questionnaire, yielding a response rate of 69.14%. Around 60% of students declared that the knowledge gained from biostatistics courses is useful to their future career, and almost 70% understood the main concepts of biostatistics. 57.7% of students perceived that lack of practicing exercises might contribute to making the course more difficult. The mean score of domains was higher in females but did not significantly differ within the three academic years. Only 35.1% of the students positively perceived the importance of biostatistics modules, mostly third-year students.Conclusion: Although the majority of medical students perceived biostatistics modules negatively, they were aware of the relevance of biostatistics to their medical career and real-life health issues

Identification of Candidate Genes and Genomic Regions Associated with Adult Plant Resistance to Stripe Rust in Spring Wheat

Wheat stripe rust (caused by Puccinia striiformis f. sp. tritici) is a major disease that damages wheat plants and affects wheat yield all over the world. In recent years, stripe rust became a major problem that affects wheat yield in Egypt. New races appeared and caused breakdowns in the resistant genotypes. To improve resistance in the Egyptian genotypes, new sources of resistance are urgently needed. In the recent research, a set of 95 wheat genotypes collected from 19 countries, including Egypt, were evaluated for their resistance against the Egyptian race(s) of stripe rust under field conditions in the two growing seasons 2018/2019 and 2019/2020. A high genetic variation was found among the tested genotypes. Single marker analysis was conducted using a subset of 71 genotypes and 424 diversity array technology (DArT) markers, well distributed across the genome. Out of the tested markers, 13 stable markers were identified that were significantly associated with resistance in both years (p-value ≤ 0.05). By using the sequence of the DArT markers, the chromosomal position of the significant DArT markers was detected, and nearby gene models were identified. Two markers on chromosomes 5A and 5B were found to be located within gene models functionally annotated with disease resistance in plants. These two markers could be used in markerassisted selection for stripe rust resistance under Egyptian conditions. Two German genotypes were carrying the targeted allele of all the significant DArT markers associated with stripe rust resistance and could be used to improve resistance under Egyptian conditions

Expectation and knowledge among patients with keratoplasty indication

OBJETIVO: Conhecer características e dificuldades de acesso aos pacientes selecionados para cirurgia de transplante de córnea em projetos comunitários realizados em um hospital universitário de São Paulo. MÉTODOS: Foi aplicado um questionário a pacientes em duas campanhas realizadas pelo hospital.Analisaram-se as seguintes variáveis: sexo, idade, renda mensal, escolaridade, número de oftalmologistas previamente consultados, acuidade visual corrigida no melhor olho, diagnóstico, indicação prévia, conhecimento sobre o procedimento, doença ocular, sobre a existência de limitações no estilo de vida, possíveis complicações após a cirurgia e expectativa de reabilitação, dentre outras. RESULTADOS: Dos 99 pacientes entrevistados, 57,8% havia abandonado o trabalho devido à dificuldade visual e dependiam da ajuda de terceiros para atividades cotidianas. Dos 90 pacientes que já apresentavam indicação prévia de transplante de córnea (91,0%), metade sequer havia conseguido ingressar na lista de bancos de olhos. Dos pacientes com indicação prévia de transplante, 18,9% desconheciam qual era o seu problema ocular, 27,8% não sabiam o que era o procedimento, 18,7% não estavam cientes de prováveis complicações per e pós-operatórias e 32,2% ignoravam a existência de limitações no estilo de vida após a cirurgia. CONCLUSÃO: Foi observado desconhecimento dos pacientes sobre a sua condição e tratamento. É importante salientar que para um resultado cirúrgico satisfatório há necessidade de uma seleção adequada de pacientes e orientação sobre seu problema ocular, a cirurgia proposta, cuidados e riscos per e pós-operatórios, e perspectivas de reabilitação visual.PURPOSE: To know characteristics and difficulties to access patients' treatment selected to keratoplasty in community projects carried out in a university hospital in São Paulo. METHODS: A questionnaire was applied on patients in two keratoplasty campaigns performed by the hospital. Was analyzed the following variables: gender, age, income, education, number of previous ophthalmologists 'appointment, visual acuity in the better eye, diagnosis, indication for keratoplasty, knowledge about it, the eye disease and the existence of limitations on lifestyle and possible complications after surgery, expectation of rehabilitation, among others. RESULTS: Most of the 99 patients interviewed (57.8%) had left the job because of visual difficulty and dependent on outside help for everyday activities. From the 90 patients who already had early indication of a keratoplasty (91.0%), half of them had not even managed to join the list of eye banks. From the patients with previous indication for keratoplasty, 18.9% didn't know what was their eye problem, 27.8% didn't know what was keratoplasty, 18.7% were not aware of possible complications during and after the surgery and 32, 2% ignored the existence of limitations in lifestyle after surgery. CONCLUSION: The patients' unknowledge about their condition and treatment is clear. It is extremely important to emphasize that to obtain a satisfactory surgical result, there is a need of an appropriate patient selection and guidance about their eye problem, the proposed surgery, care and risk per and post operative as well as the visual rehabilitation perspective

Avaliação das aprendizagens e Feedback: uma experiência investigativa em sala de aula remota

In this manuscript, we report an exploratory study built in the context of an institutional program for initial teacher training at Universidade Federal Fluminense. Considering the context of the Covid-19 pandemic, in which schooling was made possible by the contingency of remote learning, we performed a didactic sequence performed in 4 moments (3 synchronous and 1 asynchronous), which explored the concepts of area and perimeter with 25 students from the 6th year of elementary school. The study methodology was based on the qualitative perspective of exploratory studies in which we aimed to investigate the effects of feedback on student learning. We base the theoretical perspective of the investigation according to the conceptions of formative assessment discussed in the current and established literature in the field. In the analysis of the answers found, we realized that the formative feedback inserted in the presented evaluations worked to establish a positive dialogue between teachers and students, it collaborated to deconstruct the outdated idea of "error" as a subjective factor inherent to students in the learning process and it elevated the self-esteem of students who thought they were incapable of mathematical subjects.En este manuscrito, reportamos un estudio exploratorio construido en el contexto de un programa institucional de formación inicial docente en la Universidade Federal Fluminense. Teniendo en cuenta el contexto de la pandemia Covid-19, en el que la escolarización fue posible por la contingencia del aprendizaje remoto, realizamos una secuencia didáctica realizada en 4 momentos (3 sincrónicos y 1 asincrónico), que exploró los conceptos de área y perímetro con 25 alumnos de 6º año de primaria. La metodología de estudio se basó en la perspectiva cualitativa de estudios exploratorios en los que se pretendía investigar los efectos de la retroalimentación en el aprendizaje de los estudiantes. Basamos la perspectiva teórica de la investigación de acuerdo con las concepciones de evaluación formativa discutidas en la literatura actual y establecida en el campo. En el análisis de las respuestas encontradas, nos dimos cuenta de que la retroalimentación formativa insertada en las evaluaciones presentadas funcionó para establecer un diálogo positivo entre docentes y alumnos, colaboró para deconstruir la anticuada idea de "error" como factor subjetivo inherente a los estudiantes. en el proceso de aprendizaje y elevó la autoestima de los estudiantes que se creían incapaces de materias matemáticas.Neste manuscrito, relatamos um estudo exploratório construído no contexto de um programa institucional de formação inicial docente da Universidade Federal Fluminense. Considerando o contexto da pandemia de Covid-19, em que a escolarização foi possibilitada pela contingência do ensino remoto, elaboramos uma sequência didática realizada em 4 momentos (3 síncronos e 1 assíncrono), que explorou os conceitos de área e perímetro com 25 estudantes do 6º ano do ensino fundamental. A metodologia do estudo baseou-se na perspectiva qualitativa dos estudos exploratórios em que objetivamos investigar os efeitos do feedback nas aprendizagens dos estudantes. A   perspectiva teórica foi fundamentada na investigação segundo as concepções de avaliação formativa que a literatura atual e consagrada no campo vem discutido. Nas análises das respostas encontradas, percebemos que o feedback inserido nas avaliações apresentadas funcionou para estabelecer um diálogo positivo entre os professores e os alunos, colaborou para desconstruir a ideia ultrapassada de “erro” como fator subjetivo inerente aos alunos no processo de aprendizagem e elevou a autoestima de alunos que se julgavam incapazes diante de assuntos matemáticos

Choice of induction regimens on the risk of cytomegalovirus infection in donor-positive and recipient-negative kidney transplant recipients

F.L. Luan, M. Samaniego, M. Kommareddi, J.M. Park, A.O. Ojo. Choice of induction regimens on the risk of cytomegalovirus infection in donor-positive and recipient-negative kidney transplant recipients. Transpl Infect Dis 2010: 12: 473–479. All rights reservedLate occurrence of cytomegalovirus (CMV) infection remains a concern in CMV-seronegative kidney and/or pancreas transplant recipients of CMV-seropositive organs (donor positive/recipient negative, D+/R−) despite the use of prophylaxis. We investigated the impact of various antibody induction regimens on CMV infection in this group of patients.A total of 254 consecutive D+/R− kidney and/or pancreas transplant patients were studied. The induction agents rabbit anti-thymocyte globulin (rATG) or basiliximab were used according to the center practice. All patients received prophylaxis with valganciclovir (VGCV) for either 3 or 6 months. The occurrence of CMV infection was confirmed by positive DNA viremia. Multivariate Cox regression analyses were performed to determine risk factors for CMV infection.The cumulative incidence of CMV infection was 58, 112, and 59 cases per 1000 patient-years for patients who received no antibody induction, induction with rATG, or basiliximab induction, respectively ( P =0.02). The use of rATG but not basiliximab was associated with an increased risk for CMV infection (adjusted hazard ratio [AHR] 2.13, 95% confidence interval [CI] 1.24–3.54, P =0.006). Acute rejection and its treatment with rATG were not associated with an increased risk for CMV infection when an additional course of VGCV was given following the treatment. Longer duration of prophylaxis was associated with a reduced risk for CMV infection (AHR 0.54, 95% CI 0.33–0.87, P =0.011).Induction with rATG is associated with increased risk of CMV infection. Longer duration of prophylaxis is beneficial.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79309/1/j.1399-3062.2010.00532.x.pd