Federal University of Paraba

João Pessoa, Brazil

Federal University of Paraba

João Pessoa, Brazil

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Kanovich M.,Queen Mary, University of London | Kanovich M.,National Research University Higher School of Economics | Kirigin T.B.,University of Rijeka | Nigam V.,Federal University of Paraba | And 3 more authors.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

Many security protocols rely on the assumptions on the physical properties in which its protocol sessions will be carried out. For instance, Distance Bounding Protocols take into account the round trip time of messages and the transmission velocity to infer an upper bound of the distance between two agents. We classify such security protocols as Cyber-Physical. Time plays a key role in design and analysis of many of these protocols. This paper investigates the foundational differences and the impacts on the analysis when using models with discrete time and models with dense time. We show that there are attacks that can be found by models using dense time, but not when using discrete time. We illustrate this with a novel attack that can be carried out on most distance bounding protocols. In this attack, one exploits the execution delay of instructions during one clock cycle to convince a verifier that he is in a location different from his actual position. We propose a Multiset Rewriting model with dense time suitable for specifying cyber-physical security protocols. We introduce Circle-Configurations and show that they can be used to symbolically solve the reachability problem for our model. Finally, we show that for the important class of balanced theories the reachability problem is PSPACE-complete. © Springer-Verlag Berlin Heidelberg 2015.


Restivo M.T.,University of Porto | Lopes A.M.,University of Porto | MacHado L.D.S.,Federal University of Paraba | De Moraes R.M.,Federal University of Paraba
2011 IEEE Global Engineering Education Conference, EDUCON 2011 | Year: 2011

This work presents different approaches for illustrating one process of determining in the lab the Young Modulus, a material property that describes its stiffness and so is one of the most important properties in engineering design. It describes briefly a classical experimental procedure in a traditional lab, a remote accessed system, a remote & virtual accessed system haptically interacted and finally, a new approach under development, a virtual system with haptic interaction. Along the text some constrains will be discussed and the evolution for this new development will include a short discussion devoted to the increase in capabilities of the virtual experiment when integrating force feedback information and the authors attempt to consider the richness of such a solution compared with others described. © 2011 IEEE.


Brito A.F.,Federal University of Paraiba | Brito A.F.,University of Pernambuco | Alves N.F.B.,Federal University of Paraiba | Araujo A.S.,Federal University of Paraba | And 5 more authors.
Journal of Strength and Conditioning Research | Year: 2011

Active and passive intervals (AI, PI) between exercise series promote different hemodynamic responses; however, the impact of these intervals on the blood pressure response has not yet been investigated. The objective of this study was to compare the impact of AIs and PIs during resistance exercises with the magnitude of postexercise hypotension (PEH). Elderly hypertensive women (n = 21, 61.2 6 2 years of age) completed 4 sessions for upper or lower limbs with AI or PI (3 sets, 15 repetitions, 60% load of 15 repetition maximum (RM), and an interval of 90 seconds between sets). Blood pressure was measured 10 minutes before and at 10, 20, 30, 40, and 50 minutes after the exercise sessions. The heart rate at the end of each AI was always significantly higher than that after the PI, but the perceived exertion as measured by the Perceived Exertion Scale (OMNI-RPE) was similar to that of PI exercise protocols. In the lower limb exercises, AI resulted in significantly and consistently higher PEH than in exercises with PI for both systolic (from 20 minutes postexercise) and diastolic (from 10 minutes postexercise) pressures. The upper limb exercises promoted much more discrete PEH in relation to the lower limb exercises, given that the AI promoted significantly higher PEH relative to the PI protocols, but only for systolic PEH and only from 30 minutes postexercise. This is the first time that AIs between sets in a session of resistance exercises have been shown to be a highly effective methodological strategy to increase PEH in elderly hypertensive women. © 2011 National Strength and Conditioning Association.


Souto L.A.,Federal University of Paraba | Nascimento T.P.,Federal University of Paraba
Proceedings - 12th LARS Latin American Robotics Symposium and 3rd SBR Brazilian Robotics Symposium, LARS-SBR 2015 - Part of the Robotics Conferences 2015 | Year: 2015

When using RGB-D SLAM algorithms, a robot often takes into account dynamic and static objects during the 3D mapping step. This paper aims to present a novel approach in the mapping step of Simultaneous Localization and Mapping (SLAM) and map merging algorithms to a multi-robots system. The Object Subtraction Mapping (OS-Map) algorithm subtracts movable objects from the 3D environment and creates a clean 3D map. Therefore, it will be possible to merge the maps in a multi-robot scenario. With the availability of low-cost RGB-D sensors such as the Microsoft Kinect, our approach can be applied to low-cost robots. Both algorithms were applied to a TurtleBot 2 platform which has a RGB-D sensor as its main sensor. The results demonstrated the efficiency on generating and merging clean and accurate maps, using the OS-Map algorithm alongside a RGB-D SLAM approach. © 2015 IEEE.


Guerra F.Q.S.,Federal University of Paraba | Mendes J.M.,Federal University of Paraba | Sousa J.P.D.,Federal University of Paraba | Morais-Braga M.F.B.,Health Science University | And 3 more authors.
Natural Product Research | Year: 2012

The genus Acinetobacter has gained importance in recent years due to involvement in serious infections and antimicrobial resistance. Many plants have been evaluated not only for direct antimicrobial activity, but also as resistance modifying agents. The Essential oil of Citrus limon (EOCL) addition at 156.25μgmL-1 (MIC/8) sub-inhibitory concentration in the growth medium led to MIC decrease for amikacin, imipenem and meropenem. The Essential oil of Cinnamomum zeylanicum (EOCZ) addition at 78.125μgmL-1 (MIC/8) sub-inhibitory concentrations in the growth medium caused drastic MIC reduction of amikacin. Results of combining antibiotics and essential oils had shown us a synergistic effect with both essential oils/amikacin combinations. An additive effect was observed with the combinations of both essential oils and gentamicin. The results of this study suggest that essential oil of C. limon and C. zeylanicum may suppress the growth of Acinetobacter species and could be a source of metabolites with antibacterial modifying activity. © 2012 Taylor & Francis Group, LLC.


Ferreira D.A.P.,University of Sao Paulo | Nakagawa F.,University of Sao Paulo | Altafim R.A.C.,University of Sao Paulo | Da Silva J.F.R.,Elektro Electricity and Services | And 2 more authors.
2013 IEEE Electrical Insulation Conference, EIC 2013 | Year: 2013

Most Brazilian utility companies normally do not consider failures in distribution transformers to be a great economic issue, since detecting these faults can be more costly in terms of time and resources. Thus, proper policies for investigating faults in distribution transformers are usually disregarded by the power utilities and sometimes policies may not even exist. In this context, existing information on faulty distribution transformers may not contain important data. However, new laws affecting power distribution companies are becoming more severe and there are demands for greater efficiency. In this new scenario, a forensic methodology to analyze faults in distribution transformers, created some years ago by many utilities, has recently been resurrected with the analysis of 3,159 distribution transformers. This methodology is known as Forensic Analysis Applied to Distribution Transformers (FAADT). This paper, which analyzes eight damaged distribution transformers, randomly selected from ELEKTRO's distribution lines, validates and refines the FAADT methodology. In order to do this, in addition to FAADT parameters, other parameters, such as polarization and dielectric absorption indices, turns ratio, insulation resistance and physicochemical analyses were also verified. © 2013 IEEE.


Rached T.S.,Federal University of Campina Grande | De S. Santos D.F.,Signove Tecnologia S.A. | Perkusich A.,Federal University of Campina Grande | Almeida H.,Federal University of Campina Grande | De Almeida Holanda M.M.,Federal University of Paraba
2010 International Conference on Information Society, i-Society 2010 | Year: 2010

Assistive technologies have a major impact in the life of people with severe neuromuscular diseases in order to provide or extend functional abilities of people with special needs. Such technologies promote independent life, social inclusion and improve quality of life of disabled people. Brain-Computer Interface (BCI) is a recent technology that allows the direct communication between the brain and the environment. The development of systems that integrates BCI, smart devices and pervasive services enables motor disabled people to control devices anytime and anywhere. This paper presents an architecture for the development of BCI-aware pervasive systems to control multimedia devices. The user needs an electroencephalography (EEG) device and a smart device to interact with any multimedia device. This paper brings the implementation of a BCI-aware pervasive system that enables users to control the XBMC media center to play music or videos. © 2010 i-Society.


PubMed | Health Science University and Federal University of Paraba
Type: Journal Article | Journal: Journal of food protection | Year: 2016

In the present study, the efficacy of Cymbopogon citratus D.C. Stapf. essential oil (CCEO) to provoke a 5-log CFU/ml (5-log) inactivation in a mixed composite of Escherichia coli, Listeria monocytogenes, and Salmonella enterica serovar Enteritidis in pineapple (Ananas comosus (L.) Merril) juice (4C) was assessed. Moreover, the effects of CCEO on the physicochemical and sensory quality parameters of pineapple juice were evaluated. The MIC of CCEO was 5 l/ml against the composite mix examined. For L. monocytogenes and E. coli inoculated in juice containing CCEO (5, 2.5, and 1.25 l/ml), a 5-log reduction was detected after 15 min of exposure. This same result was obtained for Salmonella Enteritidis incubated alone in pineapple juice containing CCEO at 5 and 2.5 l/ml. Overall, Salmonella Enteritidis was the most tolerant and L. monocytogenes was the most sensitive to CCEO. The physicochemical properties (pH, titratable acidic [citric acid per 100 g], and soluble solids) of pineapple juice containing CCEO (2.5 and 1.25 l/ml) were maintained. Juice containing CCEO (2.5 and 1.25 l/ml) exhibited similar scores for odor, appearance, and viscosity compared with juice without CCEO. However, unsatisfactory changes in taste and aftertaste were observed in juices containing CCEO. These results suggest that CCEO could be used as an alternative antimicrobial compound to ensure the safety of pineapple juice, although CCEO at the tested concentrations negatively impacted its taste. Therefore, further studies are needed to determine the balance between microbial safety and taste acceptability of pineapple juice containing CCEO.


PubMed | Health Science University, Federal University of Paraba and Rutgers University
Type: Journal Article | Journal: Journal of food protection | Year: 2016

This study assessed the inhibitory effects of the essential oil from Origanum vulgare L. (OVEO) on Staphylococcus aureus, Listeria monocytogenes, and a mesophilic starter coculture composed of lactic acid bacteria (Lactococcus lactis subsp. lactis and L. lactis subsp. cremoris) in Brazilian coalho cheese systems. The MIC of OVEO was 2.5 l/ml against both S. aureus and L. monocytogenes and 0.6 l/ml against the tested starter coculture. In cheese broth containing OVEO at 0.6 l/ml, no decrease in viable cell counts (VCC) of both pathogenic bacteria was observed, whereas the initial VCC of the starter coculture decreased approximately 1.0 log CFU/ml after 24 h of exposure at 10C. OVEO at 1.25 and 2.5 l/ml caused reductions of up to 2.0 and 2.5 log CFU/ml in S. aureus and L. monocytogenes, respectively, after 24 h of exposure in cheese broth. At these same concentrations, OVEO caused a greater decrease of initial VCC of the starter coculture following 4 h of exposure. Higher concentrations of OVEO were required to decrease the VCC of all target bacteria in semisolid coalho cheese slurry compared with cheese broth. The VCC of Lactococcus spp. in coalho cheese slurry containing OVEO were always lower than those of pathogenic bacteria under the same conditions. These results suggest that the concentrations of OVEO used to control pathogenic bacteria in semihard cheese should be carefully evaluated because of its inhibitory effects on the growth of starter lactic acid cultures used during the production of the product.


PubMed | Federal University of Paraba
Type: Journal Article | Journal: Journal of young pharmacists : JYP | Year: 2011

This is the first on the modulation of norfloxacin antibiotic activity by the volatile compounds of an essential oil. We report the chemical composition and antibiotic modifying activity of the essential oil extracted from the leaves of Croton zehntneri Pax et Hoffm (variety estragole), using the minimal inhibitory dose method and gaseous contact. The leaves of Croton zehntneri Pax et Hoffm (Euphorbiaceae) were subjected to hydrodistillation, and the essential oil extracted was examined with respect to the chemical composition, by gas chromatography-mass spectrometry (GC/MS), and to inhibitory activity of efflux pump by gaseous contact. The main component of the essential oil of C. zehntneri was estragole (76,8%). The gaseous components of the oil enhanced the inhibition zone of norfloxacin in 39,5%. This result shows that this oil influences the antibiotic activity of norfloxacin, possibly affecting the bacterial NorA efflux system, and may be used as an adjuvant in the antibiotic therapy of multidrug resistant pathogens.

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