Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
3,902
result(s) for
"Alves, Pedro A."
Sort by:
Proposal of a Real-Time Test Platform for Tactile Internet Systems
by
Plentz, Patricia D. M.
,
Fernandes, Marcelo A. C.
,
Alves, Pedro V. A.
in
Algorithms
,
Artificial intelligence
,
Communication
2022
This work aimed to develop a real-time test platform for systems associated with the tactile internet area. The proposal comprises a master device, a communication channel and a slave device. The master device is a tactile glove (wearable technology) that works as a tactile interface based on vibratory feedback. The master device can interact with virtual elements (local or remote). The Matlab/Simulink environment and a robotics toolbox form the communication channel and the slave device. The communication channel introduces a bidirectional connection of variable latency, and the slave device is defined as a robotic phantom omni manipulator emulated in Matlab/Simulink. The virtual robotic manipulator, the slave device, can generate different types of tactile sensations in the tactile glove, that is, in the master device. The platform can model tactile sensations such as coarse roughness, fine roughness, smoothness, dripping and softness. The proposed platform presented adequate results and can be used to test various algorithms and methods correlated to the tactile internet.
Journal Article
The use of denaturing solution as collection and transport media to improve SARS-CoV-2 RNA detection and reduce infection of laboratory personnel
by
Silva, Thaís B. S.
,
Sato, Hugo I.
,
Fernandes, Ana P. S. M.
in
Bacterial
,
Bacterial, Fungal and Virus Molecular Biology - Research Paper
,
Biomedical and Life Sciences
2021
Accurate testing to detect SARS-CoV-2 RNA is key to counteract the virus spread. Nonetheless, the number of diagnostic laboratories able to perform qPCR tests is limited, particularly in developing countries. We describe the use of a virus-inactivating, denaturing solution (DS) to decrease virus infectivity in clinical specimens without affecting RNA integrity. Swab samples were collected from infected patients and from laboratory personnel using a commercially available viral transport solution and the in-house DS. Samples were tested by RT-qPCR, and exposure to infective viruses was also accessed by ELISA. The DS used did not interfere with viral genome detection and was able to maintain RNA integrity for up to 16 days at room temperature. Furthermore, virus loaded onto DS were inactivated, as attested by attempts to grow SARS-CoV-2 in cell monolayers after DS desalt filtration to remove toxic residues. The DS described here provides a strategy to maintain diagnostic accuracy and protects diagnostic laboratory personnel from accidental infection, as it has helped to protect our lab crew.
Journal Article
Nested-multiplex PCR detection of Orthopoxvirus and Parapoxvirus directly from exanthematic clinical samples
by
Trindade, Giliane S
,
Lima, Larissa S
,
Abrahão, Jônatas S
in
Animals
,
Biomedical and Life Sciences
,
Biomedicine
2009
Background
Orthopoxvirus
(OPV) and
Parapoxvirus
(PPV) have been associated with worldwide exanthematic outbreaks. Some species of these genera are able to infect humans and domestic animals, causing serious economic losses and public health impact. Rapid, useful and highly specific methods are required to detect and epidemiologically monitor such poxviruses. In the present paper, we describe the development of a nested-multiplex PCR method for the simultaneous detection of OPV and PPV species directly from exanthematic lesions, with no previous viral isolation or DNA extraction.
Methods and Results
The OPV/PPV nested-multiplex PCR was developed based on the evaluation and combination of published primer sets, and was applied to the detection of the target pathogens. The method showed high sensitivity, and the specificity was confirmed by amplicon sequencing. Exanthematic lesion samples collected during bovine vaccinia or contagious ecthyma outbreaks were submitted to OPV/PPV nested-multiplex PCR and confirmed its applicability.
Conclusion
These results suggest that the presented multiplex PCR provides a highly robust and sensitive method to detect OPV and PPV directly from clinical samples. The method can be used for viral identification and monitoring, especially in areas where OPV and PPV co-circulate.
Journal Article
First Case of Glyphosate Resistance in Bromus catharticus Vahl.: Examination of Endowing Resistance Mechanisms
by
Alves, Pedro L. da C. A.
,
Gómez-Lobato, María E.
,
De Prado, Rafael
in
Barley
,
Brome
,
Bromus catharticus
2021
Bromus catharticus Vahl. has been used as a valuable forage crop, but it has also been noted as a weed of winter crops and an invader in several countries. In Argentina, a putative glyphosate-resistant population of B. catharticus was identified as a consequence of the lack of effective control with glyphosate in the pre-sowing of wheat. Plant survival and shikimate accumulation analysis demonstrated a lower glyphosate-sensitivity of this population in comparison to a susceptible B. catharticus population. The resistant population was 4-fold more resistant to glyphosate than its susceptible counterpart. There was no evidence of target-site mechanisms of glyphosate resistance or an enhanced capacity to metabolize glyphosate in the resistant population. However, the resistant plants showed a lower foliar retention of glyphosate (138.34 μl solution g −1 dry weight vs. 390.79 μl solution g −1 dry weight), a reduced absorption of 14 C-glyphosate (54.18 vs. 73.56%) and lower translocation of 14 C-glyphosate from the labeled leaf (27.70 vs. 62.36%). As a result, susceptible plants accumulated a 4.1-fold higher concentration of 14 C-glyphosate in the roots compared to resistant plants. The current work describes the first worldwide case of glyphosate resistance in B. catharticus . A reduced foliar retention of herbicide, a differential rate of glyphosate entry into leaves and an altered glyphosate translocation pattern would be the most likely mechanisms of glyphosate exclusion.
Journal Article
Assessing the variability of Brazilian Vaccinia virus isolates from a horse exanthematic lesion: coinfection with distinct viruses
by
Weiblen, Rudi
,
Nogueira, Carlos E. W.
,
Assis, Felipe L.
in
Amino Acid Sequence
,
animal models
,
Animals
2011
During the last bovine vaccinia (BV) outbreaks, several
Vaccinia virus
(VACV) strains were isolated and characterised, revealing significant polymorphisms between strains, even within conserved genes. Although the epidemiology of VACV has been studied in BV outbreaks, there is little data about the circulation of the Brazilian VACV isolates. This study describes the genetic and biological characterisation of two VACV isolates, Pelotas 1 virus (P1V) and Pelotas 2 virus (P2V), which were obtained concomitantly from a horse affected by severe cutaneous disease. Despite being isolated from the same exanthematic clinical sample, P1V and P2V showed differences in their plaque phenotype and in one-step growth curves. Moreover, P1V and P2V presented distinct virulence profiles in a BALB/c mouse model, as observed with other Brazilian VACV isolates. Sequencing and phylogenetic analysis of four different genes demonstrated that the isolates are segregated in different VACV clusters. Our results raise interesting questions about the diversity of VACV isolates in Brazil.
Journal Article
The Phenomenon of Photoinhibition of Photosynthesis and Its Importance in Reforestation
by
da C. A. Alves, Pedro Luís
,
Barja, Paulo Roxo
,
Magalhães, Antônio C. N.
in
Carbon dioxide
,
Cellulose
,
Company business planning
2002
Photoinhibition, defined as the inhibition of photosynthesis caused by excessive radiance, affects field production to a great extent. This phenomenon is particularly relevant in reforestation practices, when one deals with forests of rapid growth such as Eucalyptus. The imposition of additional stress factors during exposure to high radiance increases the potential for photoinhibitory effects, so the inhibition of photosynthesis indicates that the plant is submitted to stressful conditions. Photoinhibition can be reversible, playing a protective role for the photosynthetic systems, but it can also reflect damage that has already occurred in the photo-synthetic apparatus, being irreversible in this case. In this review, we present the physiological and molecular mechanisms of photoinhibition and discuss the interaction between light and other stress factors and its effects on plants destined for reforestation. In addition, the present work analyzes some of the features and strategies that help plants avoid or restrict the occurrence of photoinhibition. For instance, pigments and enzymes which naturally occur in plants can prevent photoinhibition, while preadaptation to nonideal conditions can enhance tolerance to a certain stress factor. Most of these morphological, metabolic, and biochemical mechanisms of defense are related to the dissipation of excessive energy such as heat. Understanding these mechanisms can help improve cultivation procedures, avoid the plants' death, and increase productivity in the field.
Journal Article
The Irinotecan/5-Fluorouracil Combination Induces Apoptosis and Enhances Manganese Superoxide Dismutase Activity in HT-29 Human Colon Carcinoma Cells
by
Schwartsmann, Gilberto
,
Alves, Pedro A.G.
,
Grivicich, Ivana
in
Antineoplastic agents
,
Antineoplastic Agents - pharmacology
,
Apoptosis
2005
Background: We examined whether induction of apoptosis and Mn-superoxide dismutase (Mn-SOD) and Cu,Zn-superoxide dismutase (Cu,Zn-SOD) activities were involved in the greater cytotoxicity of the irinotecan (CPT-11)/5-fluorouracil (5-FU) combination for human colon cancer cells when compared to both drugs alone. Methods: HT-29 and SNU-C4 human colon carcinoma cell lines were treated with 5-FU and CPT-11, then apoptosis was evaluated by flow cytometry and SOD activities were determined by polyacrylamide gel electrophoresis. Results: Enhanced apoptosis of HT-29 cells was observed with all treatments containing 5-FU in SNU-C4 cells; however, in HT-29 cells, apoptosis was enhanced only with the CPT-11/5-FU combination. In the SNU-C4 cell line, none of the treatments exerted a significant effect on Cu,Zn-SOD or Mn-SOD activity. However, in HT-29 cells, the CPT-11/5-FU combination enhanced Mn-SOD activity when compared to cells treated with CPT-11 alone. Nevertheless, the combined treatment did not interfere with Cu,Zn-SOD activity. Conclusion: Treatment with the CPT-11/5-FU combination may promote in HT-29 cell apoptosis by enhancing Mn-SOD activity.
Journal Article
Spectral method for fatigue damage estimation with non-zero mean stress
This thesis consists of a fatigue study carried out on an aluminum alloy 2024-T3 in both time domain and frequency domain. Non-zero mean random signals of strain and stress are analyzed in time domain using usual Rainflow method and the damage is accumulated with the Palmgren-Miner rule, according to mean stress equations. The signals are analyzed in frequency domain using the power spectral density and the probability density function. The spectral domain analysis does not consider the negative effect of the mean stress in metal life under fatigue, so the correction factors for mean stresses developed by Goodman, Morrow, and Smith-Watson-Topper are used to change the power spectral density and, thus, the damage calculated by the probability density functions postulated by Dirlik and Tovo and Benasciutti. It is found that both Dirlik and Tovo and Benasciutti are non-conservative for a non-zero mean stress signal when comparing the damage to the one obtained in time domain analysis. When the spectral method is corrected, the results vary from Rainflow 4.9% for wide band and 6.8% for narrow band signals, always in the conservative zone, therefore predicting more damage. Tovo and Benasciutti 2 method is found to be the spectral function with the closest results when compared to the usual Rainflow method in time domain.
Adaptive horizontal scaling in kubernetes clusters with ANN-based load forecasting
by
Silva, Sérgio N.
,
Fernandes, Marcelo A. C.
,
Alves, Pedro V. A.
in
Artificial intelligence
,
Artificial neural networks
,
Clusters
2025
In modern cloud environments, efficient management of computational resources is a critical challenge due to the growing demand for scalable and high-performance applications. Horizontal scaling in Kubernetes (K8s) clusters is essential for dynamically adjusting resources to match workload demands. However, their reactive nature often limits traditional autoscaling methods like K8s Horizontal Pod Autoscaler (HPA), leading to inefficiencies under variable loads. To overcome these limitations, more advanced and adaptive scaling approaches are needed. Thus, this study introduces an adaptive approach to horizontal scaling in K8s clusters using Artificial Neural Networks (ANNs) for load forecasting, referred to as ANN-HS. The proposed method aims to enhance the efficiency of resource consumption and optimize replica allocation compared to the standard HPA. By leveraging pre-trained regression models, ANN-HS dynamically adjusts resources to meet varying demands, ensuring adherence to latency requirements and improving overall system performance. Experimental results demonstrate that ANN-HS outperforms traditional HPA methods, offering a scalable and flexible solution for managing microservices in cloud environments. This approach provides a robust framework for optimizing horizontal scaling in Kubernetes, contributing to the advancement of intelligent resource management in cluster computing. Experimental results show that ANN-HS significantly improves resource utilization compared to Kubernetes’ HPA. Specifically, ANN-HS reduces CPU consumption by approximately 50% while maintaining Service Level Agreement (SLA) compliance with an average violation rate of less than 10%. Additionally, ANN-HS reduces the number of replicas needed by 66.67%, optimizing resource allocation under varying load conditions.
Journal Article
Can occur hormesis in guinea grass using glyphosate?
by
Alves, Pedro L. da C. A.
,
Gallardo, Gianmarco J. T.
,
Bacha, Allan L.
in
Agricultural production
,
AGRONOMY
,
Flowers & plants
2021
BackgroundRecent studies have demonstrated an increase in plant growth due to the application of low doses of glyphosate, which is part of the phenomenon known as hormesis .ObjectiveThe present study aimed to evaluate the effects of glyphosate doses on the physiological and morphological parameters of Panicum maximum cv. Mombaça.MethodsThe experiment was carried out in a greenhouse for 49 days after the application of glyphosate, in pots arranged in a completely randomized design, with four replications. The treatments consisted of ten doses of glyphosate (0; 3.78; 8.10; 16.64; 33.48; 67.7; 135; 270; 540 and 1,080 g a.e. ha-1). Evaluations of growth, gas exchange, leaf temperature and plants’ intoxication were carried out. The data were subjected to ANOVA and when significant, regression analysis was performed using the models for dose-response curves.ResultsThe physiological parameters, as well as the growth, were positively affected by the subdoses of glyphosate, with higher values than the control. The leaf temperature increased progressively according to the increase in doses.ConclusionSubdoses of 3.78 to 270 g a.e. ha-1 of glyphosate promoted an increase in plant’s growth and physiological parameters.
Journal Article