98 research outputs found

    Analysis of reliable deployment of TDOA local positioning architectures

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    .Local Positioning Systems (LPS) are supposing an attractive research topic over the last few years. LPS are ad-hoc deployments of wireless sensor networks for particularly adapt to the environment characteristics in harsh environments. Among LPS, those based on temporal measurements stand out for their trade-off among accuracy, robustness and costs. But, regardless the LPS architecture considered, an optimization of the sensor distribution is required for achieving competitive results. Recent studies have shown that under optimized node distributions, time-based LPS cumulate the bigger error bounds due to synchronization errors. Consequently, asynchronous architectures such as Asynchronous Time Difference of Arrival (A-TDOA) have been recently proposed. However, the A-TDOA architecture supposes the concentration of the time measurement in a single clock of a coordinator sensor making this architecture less versatile. In this paper, we present an optimization methodology for overcoming the drawbacks of the A-TDOA architecture in nominal and failure conditions with regards to the synchronous TDOA. Results show that this optimization strategy allows the reduction of the uncertainties in the target location by 79% and 89.5% and the enhancement of the convergence properties by 86% and 33% of the A-TDOA architecture with regards to the TDOA synchronous architecture in two different application scenarios. In addition, maximum convergence points are more easily found in the A-TDOA in both configurations concluding the benefits of this architecture in LPS high-demanded applicationS

    Effect of Gamma radiation on mycotoxins solutions

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    Due to the high toxicity of mycotoxins, many methods have been used to reduce or eliminate them from food and feed. Gamma radiation is one technique that has been investigated with some promising results in degradation of some mycotoxins from food. The aim of this study was to clarify the effect of gamma irradiation on aflatoxin B1 (AFB1) aflatoxin B2 (AFB2), aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2), ochatoxin A (OTA) and zearelone (ZEA). The effect of the presence of moisture during the irradiation process was evaluated. Solutions with the same initial mycotoxin concentration were submitted to gamma radiation doses ranging from 0 to 10.0 kGy, at distinct moisture level ‚Äď dehydrated, in water, and in methanol:water solution. Mycotoxins levels were determined by high-performance liquid chromatography with fluorescence detection (HPLC-FL), and photochemical post-column derivatization (for aflatoxins). The results showed degradation of mycotoxins with doses above 3.0 kGy, but only when irradiated in aqueous environment. With dehydrated samples, no significant reduction was observed. The results showed that gamma radiation was effective in reducing the mycotoxins concentration, but the presence of water (mainly due to the formation of hydroxyl radicals) had a very significant effect.Funda√ß√£o para a Ci√™ncia e a Tecnologia (FCT) - SFRH/BD/79364/201, SFRH/BPD/43922/2008Programa Operacional do Norte (Adl. Portugal) - ChestNutsRad (contract number 13198

    Social media and eating disorder psychopathology: a systematic review

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    The relationship between socialization through social media (SM) and eating disorders (EDs) is a serious problem for public health, largely affecting the mental health of younger people. This work aimed to identify scientific works addressing ED psychopathologies, studying their relationship with SM usage. In this systematic review, we analyze the available scientific evidence, thereby providing tools for intervention, prevention, and treatment. A systematic review and PRISMA analysis of narrative syntheses was carried out. Works were selected from the databases of Web of Science, Scopus, PubMed, and PsycINFO. Out of a total of 257 references, 19 articles were identified and selected; among them, correlational studies predominated. A growing interest in the subject matter was identified, as it is undergoing constant changes. The investigations found that EDs and SM usage are influenced by the time spent on SM, the type of interactions, and shared photographs, as well as gender and sociocultural context

    Oral lipomas in a Brazilian population : a 10-year study and analysis of 450 cases reported in the literature

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    Objectives: Lipomas are common benign mesenchymal neoplasms that rarely occur in the oral cavity and correspond to less than 4.4% of all benign oral soft tissue tumors. This study describes the clinical, radiological and histological features of cases of oral lipomas seen over a period of 10 years and compared the findings with those reported in the literature. Study Design: All cases of oral lipomas seen between 1999 and 2009 were retrieved from the archives of the Stomatology Division of the Federal University of Cear√°, Brazil. Age, gender, tumor location, clinical findings, duration, histological subtypes, and treatment outcome were recorded. In addition, the English-language literature was searched for studies published between 1966 and 2009. Results: Ten patients (6 women and 4 men) were enrolled in this study. The mean age was 53.4 years (range: 21-73 years). The specific sites involved were the oral mucosa (n=5), vestibule (n=3), gingiva (n=1), and retromolar region (n=1). The mean size of the tumors was 1.94 cm (range 1.0 to 3.0 cm). Radiographically, only one case appeared as a radiolucent area on occlusal film. Microscopically, 4 cases were classified as simple lipoma, 4 as fibrolipoma, 1 as myxoid lipoma, and 1 as angiolipoma. The duration of the tumors ranged from 2 to 84 months, with a mean duration of 30.4 months. All cases were treated by simple surgical excision and there was no recurrence after a mean post-treatment period of 34.5 months. The findings were compared with 450 cases of oral lipomas reported in the literature. Conclusions: Lipomas continue to be an uncommon neoplasm of the oral cavity. Radiography is a valuable tool due to the possible occurrence of bone involvement. Surgical excision is the treatment of choice and recurrence is not expected

    Docência no ensino superior: entre a experiência e o experimento

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    This article is the result of a completed thesis research whose general objective was to understand the limits and possibilities of the dialogue between the experiential knowledge, the formation and the work of the professors of the History course of the Federal University of Maranh√£o in the face of the tensions and contradictions presented by the reality of higher education. The research methodology is based on a critical qualitative approach, based on dialectical historical materialism. Thematic Oral History was used. The theoretical framework is based on the categories of experiential knowledge, work and teacher training. The research revealed through the category experiential dimension that teachers use their references and experiences, in an attempt to establish dialogues with teaching situations carried out individually or collectively, since there are no established spaces for the reflection of practical knowledge in light of theoretical knowledgeEste artigo √© resultado de pesquisa de tese conclu√≠da que teve por objetivo geral compreender os limites e as possibilidades do di√°logo entre os saberes experienciais, a forma√ß√£o e o trabalho dos/as professores/as do curso de Hist√≥ria da Universidade Federal do Maranh√£o diante das tens√Ķes e contradi√ß√Ķes apresentadas pela realidade do ensino superior. A metodologia da pesquisa funda-se na abordagem qualitativa cr√≠tica, a partir do materialismo hist√≥rico dial√©tico. Para tanto utilizou-se a Hist√≥ria Oral tem√°tica. O referencial te√≥rico est√° assentado nas categorias saberes experienciais, trabalho e forma√ß√£o docente. A pesquisa desvelou por meio da categoria dimens√£o experiencial que, os docentes acionam suas refer√™ncias e experi√™ncias, na tentativa de estabelecer di√°logos com as situa√ß√Ķes de ensino realizadas individual ou coletivamente, uma vez que n√£o existe espa√ßos institu√≠dos para a reflex√£o dos saberes da pr√°tica √† luz dos conhecimentos te√≥ricos

    Docência no ensino superior: : trabalho e formação no período da pandemia

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    The article deals with the work and training of History teachers at the Federal University of Maranh√£o (UFMA) in the face of the tensions and contradictions presented by the reality of higher education during the pandemic. The research methodology is based on a critical qualitative approach, with dialectical historical materialism as the basis for analysis. The theoretical framework is based on the categories of work and teacher training. The analysis as a whole reveals that work and training is a type of work that is affected by time to the detriment of bureaucracy, which reverberates in individuality and competitiveness that was intensified even more during the pandemic.El art√≠culo aborda el trabajo y la formaci√≥n de los profesores de Historia de la Universidad Federal de Maranh√£o (UFMA) frente a las tensiones y contradicciones presentadas por la realidad de la ense√Īanza superior durante la pandemia. La metodolog√≠a de investigaci√≥n se basa en un abordaje cualitativo cr√≠tico, analizado a partir del materialismo hist√≥rico dial√©ctico. El marco te√≥rico se basa en las categor√≠as de trabajo y formaci√≥n docente. El conjunto de los an√°lisis revela que el trabajo y la formaci√≥n son un tipo de trabajo que se ve afectado por el tiempo en detrimento de la burocracia, lo que repercute en la individualidad y la competitividad que se intensific√≥ a√ļn m√°s durante la pandemia.O artigo trata sobre o trabalho e a forma√ß√£o de professores/as do curso de Hist√≥ria da Universidade Federal do Maranh√£o (UFMA) diante das tens√Ķes e contradi√ß√Ķes apresentadas pela realidade do ensino superior no per√≠odo da pandemia. A metodologia da pesquisa funda-se na abordagem qualitativa cr√≠tica, tendo como base de an√°lise o materialismo hist√≥rico dial√©tico. O referencial te√≥rico est√° assentado nas categorias trabalho e forma√ß√£o docente. O conjunto das an√°lises revela que o trabalho e a forma√ß√£o s√£o um tipo de trabalho que √© afetado pelo tempo em detrimento da burocracia, o que reverbera em individualidade e competitividade que foi intensificada ainda mais no per√≠odo da pandemia

    Analysis of synchronous localization systems for UAVs urban applications

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    [EN] Unmanned-Aerial-Vehicles (UAVs) represent an active research topic over multiple fields for performing inspection, delivery and surveillance applications among other operations. However, achieving the utmost efficiency requires drones to perform these tasks without the need of human intervention, which demands a robust and accurate localization system for achieving a safe and efficient autonomous navigation. Nevertheless, currently used satellite-based localization systems like GPS are insufficient for high-precision applications, especially in harsh scenarios like indoor and deep urban environments. In these contexts, Local Positioning Systems (LPS) have been widely proposed for satisfying the localization requirements of these vehicles. However, the performance of LPS is highly dependent on the actual localization architecture and the spatial disposition of the deployed sensor distribution. Therefore, before the deployment of an extensive localization network, an analysis regarding localization architecture and sensor distribution should be taken into consideration for the task at hand. Nonetheless, no actual study is proposed either for comparing localization architectures or for attaining a solution for the Node Location Problem (NLP), a problem of NP-Hard complexity. Therefore, in this paper, we propose a comparison among synchronous LPS for determining the most suited system for localizing UAVs over urban scenarios. We employ the Cr√†mer‚ÄďRao-Bound (CRB) for evaluating the performance of each localization system, based on the provided error characterization of each synchronous architecture. Furthermore, in order to attain the optimal sensor distribution for each architecture, a Black-Widow-Optimization (BWO) algorithm is devised for the NLP and the application at hand. The results obtained denote the effectiveness of the devised technique and recommend the implementation of Time Difference Of Arrival (TDOA) over Time of Arrival (TOA) systems, attaining up to 47% less localization uncertainty due to the unnecessary synchronization of the target clock with the architecture sensors in the TDOA architecture.S

    Multiple brown tumours of tertiary hyperparathyroidism in a renal transplant recipient: : a case report

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    Tertiary Hyperparathyroidism (HPT) is an uncommon condition that affects patients with secondary HPT after a successful kidney transplant. Bone alterations are the main consequences of this endocrine condition, including the development of an osteolytic lesion called brown tumour. This paper reports an unusual case of multiple brown tumours located in the maxilla and mandible in a 58-year-old renal transplant recipient, with tertiary HPT. Incisional biopsies were performed and, in both samples, the histopathological diagnoses were giant cell lesions. Due to these diagnoses, the medical history of chronic renal failure, and high levels of serum calcium and PTH, lesions were diagnosed as multiple brown tumours of tertiary HPT. The lesions showed regression within the two months following a total parathyroidectomy. Minimal local interventions were established to make an early diagnosis and to treat these lesions. The diagnosis of primary oral lesions was very important in order to demonstrate the relevance of interdisciplinary activity and the inclusion of dentists as part of organ transplant units

    O SAEB a partir do olhar de uma Professora de Ciências Naturais de uma escola municipal de Codó-MA

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    O presente artigo trata sobre a percep√ß√£o de uma professora de Ci√™ncias Naturais dos anos finais do ensino fundamental de uma escola p√ļblica do munic√≠pio de Cod√≥-MA sobre o Sistema de Avalia√ß√£o da Educa√ß√£o B√°sica-Saeb. A pesquisa foi realizada entre o per√≠odo de agosto e setembro de 2022 e contou com a participa√ß√£o da √ļnica professora de Ci√™ncias Naturais da referida escola. Esse trabalho foi realizado em colabora√ß√£o com o Grupo de Estudos e Pesquisas em Pol√≠ticas Educacionais (GEPESPO) da Universidade Federal do Maranh√£o do Curso Interdisciplinar de Ci√™ncias Naturais/ Biologia. A metodologia do artigo fundamenta-se em uma pesquisa qualitativa com a utiliza√ß√£o de entrevista e question√°rio semiestruturado desenvolvido na referida escola, tendo como foco de an√°lise o materialismo hist√≥rico dial√©tico, compreendendo o contexto escolar e suas contradi√ß√Ķes a partir da exig√™ncia das avalia√ß√Ķes externas. Os resultados apontam que a escola desenvolve atividades preparat√≥rias t√©cnicas com foco apenas em L√≠ngua Portuguesa e Matem√°tica, objetivando uma melhor coloca√ß√£o estat√≠stica e a competi√ß√£o entre institui√ß√Ķes de ensino reverberando na aus√™ncia de uma forma√ß√£o pedag√≥gica avaliativa que dialogue com outros componentes curriculares, e subsidie a melhoria da qualidade educacional do munic√≠pio. Essa pesquisa contribui para a necessidade pontual de uma concep√ß√£o de avalia√ß√£o formativa, lugares de di√°logo entre a escola e a Universidade, quer por meio dos grupos de estudos, quer pela inclus√£o de componentes curriculares como Gest√£o educacional nos projetos pol√≠ticos de cursos de licenciatura como uma pol√≠tica de forma√ß√£o inicial e continuada de professores/as para a educa√ß√£o b√°sica p√ļblica

    Sexismo Institucional en Campa√Īas contra la violencia Machista en Galicia: Deconstruyendo Resistencias Narrativas

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    Introducci√≥n. Se analiza la evoluci√≥n de las campa√Īas institucionales contra la violencia machista en el Estado espa√Īol en consonancia con las transformaciones sociales y las pol√≠ticas p√ļblicas en materia de igualdad que se desarrollaron en este per√≠odo en Espa√Īa. Metodolog√≠a. Se procede, a trav√©s de un an√°lisis cr√≠tico del discurso con perspectiva feminista, a examinar minuciosamente las estructuras discursivas en las que se apoyan las campa√Īas desarrolladas por la Xunta de Galicia desde su inicio en el a√Īo 1999 hasta el a√Īo 2022, analizando el enfoque y el tratamiento que la instituci√≥n utiliza en el abordaje de la violencia machista. Resultados y discusi√≥n. Visto lo anterior, se puede apreciar un incremento de las campa√Īas institucionales a este sujeto desarrolladas en Galicia, y un proceso evolutivo en el tratamiento de la violencia machista que muestra una variabilidad temporal en su direcci√≥n, caracterizada por periodos de retroceso o involuci√≥n. Conclusiones. Al final encontramos que existe una resistencia por parte de la instituci√≥n en el empleo de la perspectiva de g√©nero en sus acciones al no representar la realidad de la violencia machista. La utilizaci√≥n de estereotipos sexistas, la cosificaci√≥n de las mujeres, la justificaci√≥n de los hombres agresores y la exenci√≥n de responsabilidades de la sociedad, fomenta la conservaci√≥n de un imaginario colectivo que culpabiliza a las mujeres de la violencia que sufren lo que se traduce en sexismo institucional y, en consecuencia, en la revictimizaci√≥n de dichas mujeres
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