Leonardo Oliveira - Academia.edu (original) (raw)

Papers by Leonardo Oliveira

Research paper thumbnail of Aceleração de Assinaturas Baseadas em Atributos para Internet das Coisas

The integration of resource-constrained devices into IoT domains depends on a cryptographic found... more The integration of resource-constrained devices into IoT domains depends on a cryptographic foundation that enables the establishment of the essential security mechanisms. Attribute-based Signatures (ABS) are an elegant option to implement an authentication and authorization scheme. This work discusses different approaches to speed up ABS considering as the target platform the resource-constrained devices on IoT domains. Resumo. Antes de integrar dispositivos com restrições de recursos computacionais em domínios de IoT, deve-se garantir que possuam ferramental criptográfico suficiente para estabelecer mecanismos de segurança essenciais. Neste contexto, as Assinaturas baseadas em Atributos (ABS) mostramse uma opção elegante na implementação de um esquema de autenticação e autorização. Neste trabalho discutimos diferentes abordagens para a aceleração de (ABS) considerando-se como plataforma alvo os dispositivos com restrições de recursos computacionais em domínios de IoT.

Research paper thumbnail of The role of anticoagulation for superior sagittal sinus thrombosis following craniotomy for resection of parasagittal/parafalcine meningiomas

Journal of Neuro-Oncology, 2021

The safety and efficacy of anticoagulation in managing superior sagittal sinus (SSS) thrombosis r... more The safety and efficacy of anticoagulation in managing superior sagittal sinus (SSS) thrombosis remains unclear. The present study investigated the relationship between anticoagulation and cerebrovascular complications in parasagittal/parafalcine meningioma patients presenting with post-surgical SSS thrombosis. We analyzed 266 patients treated at a single institution between 2005 and 2020. Bivariate analysis was conducted using the Mann–Whitney U test and Fisher’s exact test. Multivariate analysis was conducted using a logistic regression model. Blood thinning medications investigated included aspirin, warfarin, heparin, apixaban, rivaroxaban, and other novel oral anticoagulants (NOACs). A symptomatic SSS thrombosis was defined as a radiographically apparent thrombosis with new headaches, seizures, altered sensorium, or neurological deficits. Our patient cohort was majority female (67.3%) with a mean age (±\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\pm$$\end{document} SD) of 58.82 ±\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\pm$$\end{document} 13.04 years. A total of 15 (5.6%) patients developed postoperative SSS thrombosis and 5 (1.9%) were symptomatic; 2 (0.8%) symptomatic patients received anticoagulation. None of these 15 patients developed cerebrovascular complications following observation or anticoagulative treatment of asymptomatic SSS thrombosis. While incidence of any other postoperative complications was significantly associated with SSS thrombosis in bivariate analysis (p = 0.015), this association was no longer observed in multivariate analysis (OR = 2.15, p = 0.16) when controlling for patient age, sex, and anatomical location of the tumor along the SSS. Our single-institution study examining the incidence of SSS thrombosis and associated risk factors highlights the need for further research efforts better prognosticate this adverse outcome. Conservative management may represent a viable treatment strategy for patients with SSS thrombosis.

Research paper thumbnail of Inheritance of Resistance of Soybean for Meloidogyne incognita and Identification of Molecular Marker for Marker Assisted Selection

Journal of Scientific Research and Reports, 2015

Aims: To study the inheritance of resistance to Meloidogyne incognita in soybean cultivar CD 201,... more Aims: To study the inheritance of resistance to Meloidogyne incognita in soybean cultivar CD 201, and identify molecular markers linked to resistance genes/QTLs in soybean. Study Design: The phenotypic assay was a complete randomized design, and mendelian hypothesis was applied. Place and Duration of Study: Biotechnology lab, Coodetec, BR 467, km98. Cascavel, PR, Brazil, between July 2012 to July 2013. Methodology: The population was created by the crossing the cultivars CD 201 (resistant) and BRS 133 (susceptible). F2:3 families were phenotyped for resistance to M. incognita and Original Research Article Oliveira et al.; JSRR, 8(3): 1-8, 2015; Article no.JSRR.18648 2 microsatellite molecular markers were used to identify genes/QTLs associated with resistance. Inheritance hypothesis was tested by Chi square test. Results: The resistance to M. incognita in soybean cultivar CD 201 is given by three epistatic additive genes, two dominant and one recessive. Among the markers, Satt358 is linked to a dominant gene/QTL of resistance explaining 9.9% of the variability in resistance in the evaluated population. The use of this marker allows increasing the frequency resistant or moderately resistant lines in soybean breeding programs. Sixty nine percent of F2:3 families that have at least one allele for resistance in marker Satt358 have resistant or moderately resistant phenotype, and no F2:3 families that is homozygous with the susceptible allele in this locus have resistant phenotype. Conclusion: This finding can help soybean breeders to develop highly resistant cultivar to M. incognita, both, by phenotypic selection and marker assisted selection.

Research paper thumbnail of Aceleração de Assinaturas Baseadas em Atributos para Internet das Coisas

The integration of resource-constrained devices into IoT domains depends on a cryptographic found... more The integration of resource-constrained devices into IoT domains depends on a cryptographic foundation that enables the establishment of the essential security mechanisms. Attribute-based Signatures (ABS) are an elegant option to implement an authentication and authorization scheme. This work discusses different approaches to speed up ABS considering as the target platform the resource-constrained devices on IoT domains. Resumo. Antes de integrar dispositivos com restrições de recursos computacionais em domínios de IoT, deve-se garantir que possuam ferramental criptográfico suficiente para estabelecer mecanismos de segurança essenciais. Neste contexto, as Assinaturas baseadas em Atributos (ABS) mostramse uma opção elegante na implementação de um esquema de autenticação e autorização. Neste trabalho discutimos diferentes abordagens para a aceleração de (ABS) considerando-se como plataforma alvo os dispositivos com restrições de recursos computacionais em domínios de IoT.

Research paper thumbnail of The role of anticoagulation for superior sagittal sinus thrombosis following craniotomy for resection of parasagittal/parafalcine meningiomas

Journal of Neuro-Oncology, 2021

The safety and efficacy of anticoagulation in managing superior sagittal sinus (SSS) thrombosis r... more The safety and efficacy of anticoagulation in managing superior sagittal sinus (SSS) thrombosis remains unclear. The present study investigated the relationship between anticoagulation and cerebrovascular complications in parasagittal/parafalcine meningioma patients presenting with post-surgical SSS thrombosis. We analyzed 266 patients treated at a single institution between 2005 and 2020. Bivariate analysis was conducted using the Mann–Whitney U test and Fisher’s exact test. Multivariate analysis was conducted using a logistic regression model. Blood thinning medications investigated included aspirin, warfarin, heparin, apixaban, rivaroxaban, and other novel oral anticoagulants (NOACs). A symptomatic SSS thrombosis was defined as a radiographically apparent thrombosis with new headaches, seizures, altered sensorium, or neurological deficits. Our patient cohort was majority female (67.3%) with a mean age (±\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\pm$$\end{document} SD) of 58.82 ±\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\pm$$\end{document} 13.04 years. A total of 15 (5.6%) patients developed postoperative SSS thrombosis and 5 (1.9%) were symptomatic; 2 (0.8%) symptomatic patients received anticoagulation. None of these 15 patients developed cerebrovascular complications following observation or anticoagulative treatment of asymptomatic SSS thrombosis. While incidence of any other postoperative complications was significantly associated with SSS thrombosis in bivariate analysis (p = 0.015), this association was no longer observed in multivariate analysis (OR = 2.15, p = 0.16) when controlling for patient age, sex, and anatomical location of the tumor along the SSS. Our single-institution study examining the incidence of SSS thrombosis and associated risk factors highlights the need for further research efforts better prognosticate this adverse outcome. Conservative management may represent a viable treatment strategy for patients with SSS thrombosis.

Research paper thumbnail of Inheritance of Resistance of Soybean for Meloidogyne incognita and Identification of Molecular Marker for Marker Assisted Selection

Journal of Scientific Research and Reports, 2015

Aims: To study the inheritance of resistance to Meloidogyne incognita in soybean cultivar CD 201,... more Aims: To study the inheritance of resistance to Meloidogyne incognita in soybean cultivar CD 201, and identify molecular markers linked to resistance genes/QTLs in soybean. Study Design: The phenotypic assay was a complete randomized design, and mendelian hypothesis was applied. Place and Duration of Study: Biotechnology lab, Coodetec, BR 467, km98. Cascavel, PR, Brazil, between July 2012 to July 2013. Methodology: The population was created by the crossing the cultivars CD 201 (resistant) and BRS 133 (susceptible). F2:3 families were phenotyped for resistance to M. incognita and Original Research Article Oliveira et al.; JSRR, 8(3): 1-8, 2015; Article no.JSRR.18648 2 microsatellite molecular markers were used to identify genes/QTLs associated with resistance. Inheritance hypothesis was tested by Chi square test. Results: The resistance to M. incognita in soybean cultivar CD 201 is given by three epistatic additive genes, two dominant and one recessive. Among the markers, Satt358 is linked to a dominant gene/QTL of resistance explaining 9.9% of the variability in resistance in the evaluated population. The use of this marker allows increasing the frequency resistant or moderately resistant lines in soybean breeding programs. Sixty nine percent of F2:3 families that have at least one allele for resistance in marker Satt358 have resistant or moderately resistant phenotype, and no F2:3 families that is homozygous with the susceptible allele in this locus have resistant phenotype. Conclusion: This finding can help soybean breeders to develop highly resistant cultivar to M. incognita, both, by phenotypic selection and marker assisted selection.