Federal University of Rio Grande do Norte

www.ufrn.br/english/
Natal, Brazil

The Federal University of Rio Grande do Norte is a public Brazilian university funded by the Brazilian federal government, located in the city of Natal, Rio Grande do Norte, Brazil.Formally established on December 18, 1960, it includes 60 departments providing over 70 different undergraduate courses, as well as a number of graduate programs.UFRN is the top ranked university in the state of Rio Grande do Norte, and one of the best among universities from all over the country according to 2012 league tables. Wikipedia.


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Cavalcanti E.J.C.,Federal University of Rio Grande do Norte
Renewable and Sustainable Energy Reviews | Year: 2017

The exergoeconomic and exergoenvironmental analysis of cogenerative system that combine a gas/steam turbine system and a solar field have been performed. The model is developed in order to produce around 400 MW of electrical power to investigate the effect of solar collector field in performance of each component. In addition, the exergy destruction, exergetic efficiency, cost rate and environmental impact per exergy unit, cost rate and environmental impact per exergy unit of product and fuel, cost rate and environmental impact rate associated with the exergy destruction, exergoeconomic and exergoenvironmental factor for each component are evaluated. The results reveal that the condenser needs to increase investment costs to increase the total thermodynamic efficiency and it needs to increase its exergetic efficiency to reduce the total environmental impact from an exergoeconomic and exergoenvironmental point of view. The exergoeconomic and exergoenvironmental analysis show that the effects of solar field leads to 4.2% increasing in the net produced electricity; 2.6% increasing in the average cost rate per exergy unit of electricity and −3.8% decreasing average environmental impact per exergy unit of electricity. © 2016 Elsevier Ltd


News Article | April 17, 2017
Site: www.newscientist.com

It tastes foul and makes people vomit. But ayahuasca, a hallucinogenic concoction that has been drunk in South America for centuries in religious rituals, may help people with depression that is resistant to antidepressants. Tourists are increasingly trying ayahuasca during holidays to countries such as Brazil and Peru, where the psychedelic drug is legal. Now the world’s first randomised clinical trial of ayahuasca for treating depression has found that it can rapidly improve mood. The trial, which took place in Brazil, involved administering a single dose to 14 people with treatment-resistant depression, while 15 people with the same condition received a placebo drink. A week later, those given ayahuasca showed dramatic improvements, with their mood shifting from severe to mild on a standard scale of depression. “The main evidence is that the antidepressant effect of ayahuasca is superior to the placebo effect,” says Dráulio de Araújo of the Brain Institute at the Federal University of Rio Grande do Norte in Natal, who led the trial. Shamans traditionally prepare the bitter, deep-brown brew of ayahuasca using two plants native to South America. The first, Psychotria viridis, is packed with the mind-altering compound dimetheyltryptamine (DMT). The second, the ayahuasca vine (Banisteriopsis caapi), contains substances that stop DMT from being broken down before it crosses the gut and reaches the brain. To fool placebo recipients into thinking they were getting the real thing, de Araújo and his team concocted an equally foul tasting brown-coloured drink. They also carefully selected participants who had never tried ayahuasca or other psychedelic drugs before. A day before their dose, the participants filled in standard questionnaires to rate their depression. The next day, they spent 8 hours in a quiet, supervised environment, where they received either the placebo or the potion, which produces hallucinogenic effects for around 4 hours. They then repeated filling in the questionnaires one, two and seven days later. Both groups reported substantial improvements one and two days after the treatment, with placebo scores often as high as those of people who had taken the drug. In trials of new antidepressant drugs, it is common for as many as 40 per cent of participants to respond positively to placebos, says de Araújo. But a week into this trial, 64 per cent of people who had taken ayahuasca felt the severity of their depression reduce by 50 per cent or more. This was true for only 27 per cent of those who drank the placebo. “The findings suggest a rapid antidepressant benefit for ayahuasca, at least for the short term,” says David Mischoulon of Massachusetts General Hospital in Boston. “But we need studies that follow patients for longer periods to see whether these effects are sustained.” “There is clearly potential to explore further how this most ancient of plant medicines may have a salutary effect in modern treatment settings, particularly in patients who haven’t responded well to conventional treatments,” says Charles Grob at the University of California, Los Angeles. If the finding holds up in longer studies, it could provide a valuable new tool for helping people with treatment-resistant depression. An estimated 350 million people worldwide experience depression, and between a third to a half of them don’t improve when given standard antidepressants. Ayahuasca isn’t the only psychedelic drug being investigated as a potential treatment for depression. Researchers have also seen some benefits with ketamine and psilocybin, extracted from magic mushrooms, although psilocybin is yet to be tested against a placebo.


Martinez-Huitle C.A.,Federal University of Rio Grande do Norte | Rodrigo M.A.,University of Castilla - La Mancha | Sires I.,University of Barcelona | Scialdone O.,University of Palermo
Chemical Reviews | Year: 2015

Traditional physicochemical and biological techniques, as well as advanced oxidation processes (AOPs), are often inadequate, ineffective, or expensive for industrial water reclamation. Within this context, the electrochemical technologies have found a niche where they can become dominant in the near future, especially for the abatement of biorefractory substances. In this critical review, some of the most promising electrochemical tools for the treatment of wastewater contaminated by organic pollutants are discussed in detail with the following goals: (1) to present the fundamental aspects of the selected processes; (2) to discuss the effect of both the main operating parameters and the reactor design on their performance; (3) to critically evaluate their advantages and disadvantages; and (4) to forecast the prospect of their utilization on an applicable scale by identifying the key points to be further investigated. The review is focused on the direct electrochemical oxidation, the indirect electrochemical oxidation mediated by electrogenerated active chlorine, and the coupling between anodic and cathodic processes. The last part of the review is devoted to the critical assessment of the reactors that can be used to put these technologies into practice. © 2015 American Chemical Society.


Brillas E.,University of Barcelona | Martinez-Huitle C.A.,Federal University of Rio Grande do Norte
Applied Catalysis B: Environmental | Year: 2015

As the environment preservation gradually becomes a matter of major social concern and more strict legislation is being imposed on effluent discharge, more effective processes are required to deal with non-readily biodegradable and toxic pollutants. Synthetic organic dyes in industrial effluents cannot be destroyed in conventional wastewater treatment and consequently, an urgent challenge is the development of new environmentally benign technologies able to mineralize completely these non-biodegradable compounds. This review aims to increase the knowledge on the electrochemical methods used at lab and pilot plant scale to decontaminate synthetic and real effluents containing dyes, considering the period from 2009 to 2013, as an update of our previous review up to 2008. Fundamentals and main applications of electrochemical advanced oxidation processes and the other electrochemical approaches are described. Typical methods such as electrocoagulation, electrochemical reduction, electrochemical oxidation and indirect electro-oxidation with active chlorine species are discussed. Recent advances on electrocatalysis related to the nature of anode material to generate strong heterogeneous OH as mediated oxidant of dyes in electrochemical oxidation are extensively examined. The fast destruction of dyestuffs mediated with electrogenerated active chlorine is analyzed. Electro-Fenton and photo-assisted electrochemical methods like photoelectrocatalysis and photoelectro-Fenton, which destroy dyes by heterogeneous OH and/or homogeneous OH produced in the solution bulk, are described. Current advantages of the exposition of effluents to sunlight in the emerging photo-assisted procedures of solar photoelectrocatalysis and solar photoelectro-Fenton are detailed. The characteristics of novel combined methods involving photocatalysis, adsorption, nanofiltration, microwaves and ultrasounds among others and the use of microbial fuel cells are finally discussed. © 2014 Elsevier B.V.


Fichet S.,Federal University of Rio Grande do Norte
Nuclear Physics B | Year: 2014

We present a technique to determine the scale of New Physics (NP) compatible with any set of data, relying on well-defined credibility intervals. Our approach relies on the statistical view of the effective field theory capturing New Physics at low energy. We introduce formally the notion of testable NP and show that it ensures integrability of the posterior distribution. We apply our method to the Standard Model Higgs sector in light of recent LHC data, considering two generic scenarios. In the scenario of democratic higher-dimensional operators generated at one-loop, we find the testable NP scale to lie within [10, 260] TeV at 95% Bayesian credibility level. In the scenario of loop-suppressed field strength-Higgs operators, the testable NP scale is within [28, 1200] TeV at 95% Bayesian credibility level. More specific UV models are necessary to allow lower values of the NP scale. © 2014 The Author.


Freitas D.A.,Federal University of Rio Grande do Norte
The Cochrane database of systematic reviews | Year: 2013

Breathing exercises have been widely used worldwide as a complementary therapy to the pharmacological treatment of people with asthma. To evaluate the evidence for the efficacy of breathing exercises in the management of patients with asthma. The search for trials led review authors to review the literature available in The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL and AMED and to perform handsearching of respiratory journals and meeting abstracts. Trial registers and reference lists of included articles were also consulted.The literature search has been updated to January 2013. We included randomised controlled trials of breathing exercises in adults with asthma compared with a control group receiving asthma education or, alternatively, with no active control group. Two review authors independently assessed trial quality and extracted data. RevMan software was used for data analysis based on the fixed-effect model. Continuous outcomes were expressed as mean differences (MDs) with confidence intervals (CIs) of 95%. Heterogeneity was assessed by inspecting the forest plots. The Chi(2) test was applied, with a P value of 0.10 indicating statistical significance. The I(2) statistic was implemented, with a value greater than 50% representing a substantial level of heterogeneity. A total of 13 studies involving 906 participants are included in the review. The trials were different from one another in terms of type of breathing exercise performed, number of participants enrolled, number and duration of sessions completed, outcomes reported and statistical presentation of data. Asthma severity in participants from the included studies ranged from mild to moderate, and the samples consisted solely of outpatients. The following outcomes were measured: quality of life, asthma symptoms, number of acute exacerbations and lung function. Eleven studies compared breathing exercise with inactive control, and two with asthma education control groups. All eight studies that assessed quality of life reported an improvement in this outcome. An improvement in the number of acute exacerbations was observed by the only study that assessed this outcome. Six of seven included studies showed significant differences favouring breathing exercises for asthma symptoms. Effects on lung function were more variable, with no difference reported in five of the eleven studies that assessed this outcome, while the other six showed a significant difference for this outcome, which favoured breathing exercises. As a result of substantial heterogeneity among the studies, meta-analysis was possible only for asthma symptoms and changes in the Asthma Quality of Life Questionnaire (AQLQ). Each meta-analysis included only two studies and showed a significant difference favouring breathing exercises (MD -3.22, 95% CI -6.31 to -0.13 for asthma symptoms; MD 0.79, 95% CI 0.50 to 1.08 for change in AQLQ). Assessment of risk of bias was impaired by incomplete reporting of methodological aspects of most of the included trials. Even though individual trials reported positive effects of breathing exercises, no reliable conclusions could be drawn concerning the use of breathing exercises for asthma in clinical practice. This was a result of methodological differences among the included studies and poor reporting of methodological aspects in most of the included studies. However, trends for improvement are encouraging, and further studies including full descriptions of treatment methods and outcome measurements are required.


Lehum A.C.,Federal University of Rio Grande do Norte
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

Using the superfield formalism and implementing the canonical noncommutativity, the Kählerian effective superpotential is evaluated in the three-dimensional noncommutative supersymmetric Chern-Simons-matter model at the two-loop order. The computation of the Kählerian effective superpotential is enough to determine whether the model can exhibit spontaneous (super)symmetry breaking. It is shown that the model possesses a spontaneous gauge symmetry broken phase, generating masses for the scalar and gauge superfields at the two-loop order. Just as for the commutative version, in the noncommutative case, the supersymmetry cannot be broken by radiative corrections via the Coleman-Weinberg mechanism. © 2012 American Physical Society.


Ribeiro S.,Federal University of Rio Grande do Norte
Pflugers Archiv European Journal of Physiology | Year: 2012

While there is ample agreement that the cognitive role of sleep is explained by sleep-dependent synaptic changes, consensus is yet to be established as to the nature of these changes. Some researchers believe that sleep promotes global synaptic downscaling, leading to a non-Hebbian reset of synaptic weights that is putatively necessary for the acquisition of new memories during ensuing waking. Other investigators propose that sleep also triggers experience-dependent, Hebbian synaptic upscaling able to consolidate recently acquired memories. Here, I review the molecular and physiological evidence supporting these views, with an emphasis on the calcium signaling pathway. I argue that the available data are consistent with sleep promoting experience-dependent synaptic embossing, understood as the simultaneous non-Hebbian downscaling and Hebbian upscaling of separate but complementary sets of synapses, heterogeneously activated at the time of memory encoding and therefore differentially affected by sleep. © 2011 The Author(s).


Bedregal B.C.,Federal University of Rio Grande do Norte
Fuzzy Sets and Systems | Year: 2010

There exist infinitely many ways to extend the classical propositional connectives to the set [0,1], preserving their behaviors in the extremes 0 and 1 exactly as in the classical logic. However, it is a consensus that this issue is not sufficient, and, therefore, these extensions must also preserve some minimal logical properties of the classical connectives. The notions of t-norms, t-conorms, fuzzy negations and fuzzy implications taking these considerations into account. In previous works, the author, joint with other colleagues, generalizes these notions to the set U={[a,b]0≤a≤b≤1, providing canonical constructions to obtain, for example, interval t-norms that are the best interval representations of t-norms. In this paper, we consider the notion of interval fuzzy negation and generalize, in a natural way, several notions related with fuzzy negations, such as the ones of equilibrium point and negation-preserving automorphism. We show that the main properties of these notions are preserved in those generalizations. © 2010 Elsevier B.V. All rights reserved.


Batista R.C.,Federal University of Rio Grande do Norte
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

We show that in clustering dark energy models the growth index of linear matter perturbations, γ, can be much lower than in ΛCDM or smooth quintessence models and presents a strong variation with redshift. We find that the impact of dark energy perturbations on γ is enhanced if the dark energy equation of state has a large and rapid decay at low redshift. We study four different models with these features and show that we may have 0.33<γ(z)<0.48 at 0

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