Palmeira E.S.,State University of Santa Cruz |
Bedregal B.C.,Federal University of Rio Grande do Norte
Computers and Mathematics with Applications | Year: 2012
The primary goal of this paper is to present a method of extending t-norms, t-conorms and fuzzy negations from a sublattice M to the bounded lattice L by considering a more general version of the idea of the sublattice. In general terms, we consider M as a sublattice of the bounded lattice L, if M has the same lattice structure of the L equipped with the restriction of operations of L and is a subset of L. However, this latter condition may be relaxed without losing the essence of the usual definition of the sublattice. This is done through the use of retractions. Furthermore, the same idea is employed to extend t-subnorms and present some results related to extension and automorphism. Additionally, a formalization of a relaxed notion of De Morgan triple and its extension is provided. © 2012 Published by Elsevier Ltd.
Calzetta E.,IFIBA |
Kandus A.,State University of Santa Cruz
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014
We study the possibility that primordial magnetic fields generated in the transition between inflation and reheating posses magnetic helicity, HM. The fields are induced by stochastic currents of scalar charged particles created during the mentioned transition. We estimate the rms value of the induced magnetic helicity by computing different four-point scalar quantum electrodynamics Feynman diagrams. For any considered volume, the magnetic flux across its boundaries is in principle not null, which means that the magnetic helicity in those regions is gauge dependent. We use the prescription given by Berger and Field and interpret our result as the difference between two magnetic configurations that coincide in the exterior volume. In this case, the magnetic helicity gives only the number of magnetic links inside the considered volume. We calculate a concrete value of HM for large scales and analyze the distribution of magnetic defects as a function of the scale. Those defects correspond to regular as well as random fields in the considered volume. We find that the fractal dimension of the distribution of topological defects is D=1/2. We also study if the regular fields induced on large scales are helical, finding that they are and that the associated number of magnetic defects is independent of the scale. In this case, the fractal dimension is D=0. We finally estimate the intensity of fields induced at the horizon scale of reheating and evolve them until the decoupling of matter and radiation under the hypothesis of the inverse cascade of magnetic helicity. The resulting intensity is high enough and the coherence length long enough to have an impact on the subsequent process of structure formation. © 2014 American Physical Society.
Mariano R.,State University of Santa Cruz
Zootaxa | Year: 2011
A new species of Paramaka is described based on nymphs and male imagos from State of Mato Grosso, Brazil. The imago of Paramaka pearljam sp. n. can be easily separated from the other species of the genus by the presence of a conspicuous and large median projection with apex curved ventrally on styliger plate; and in nymph by the gills not ended in a thin apical process and tarsal claw without accessory denticles. A new key is proposed and new geographic records for the genus are reported. Copyright © 2011 · Magnolia Press.
Multivariate analysis and geostatistics of the fertility of a humic Rhodic Hapludox under coffee cultivation [Análise Multivariada e Geoestatística da Fertilidade de um Latossolo Vermelho-Amarelo Húmico Cultivado Com Café]
de Assis Silva S.,State University of Santa Cruz |
de Souza Lima J.S.,Federal University of Espirito Santo
Revista Brasileira de Ciencia do Solo | Year: 2012
The spatial variability of soil and plant properties exerts great influence on the yeld of agricultural crops. This study analyzed the spatial variability of the fertility of a Humic Rhodic Hapludox with Arabic coffee, using principal component analysis, cluster analysis and geostatistics in combination. The experiment was carried out in an area under Coffea arabica L., variety Catucai 20/15 - 479. The soil was sampled at a depth 0.20 m, at 50 points of a sampling grid. The following chemical properties were determined: P, K+, Ca2+, Mg2+, Na+, S, Al3+, pH, H + Al, SB, t, T, V, m, OM, Na saturation index (SSI), remaining phosphorus (P-rem), and micronutrients (Zn, Fe, Mn, Cu and B). The data were analyzed with descriptive statistics, followed by principal component and cluster analyses. Geostatistics were used to check and quantify the degree of spatial dependence of properties, represented by principal components. The principal component analysis allowed a dimensional reduction of the problem, providing interpretable components, with little information loss. Despite the characteristic information loss of principal component analysis, the combination of this technique with geostatistical analysis was efficient for the quantification and determination of the structure of spatial dependence of soil fertility. In general, the availability of soil mineral nutrients was low and the levels of acidity and exchangeable Al were high.
News Article | December 25, 2015
Jorge* is around 60 years old, works a white collar job, has gray hair, married children, and grown grandchildren. People who work with him would never imagine that he participates in religious rituals using a mind altering tea. And yet, thanks to ayahuasca, Jorge became a teetotaler. A big change for someone who, when he was younger, would buy several cases of whiskey at once. “I opened the boxes and started emptying the bottles in the kitchen sink. My wife was shocked,” he told me. He’s not the only alcoholic to renounce booze after an experience with the mystical drink. In 2010, after a decade of failed treatments, Robert Rhatigan took a trip to the Peruvian Amazon, where he participated in four rituals conducted by a shaman. During a speech at a TEDx event, he recounted how he “saw” the “several components from his mind floating in space, as if they were pieces of a puzzle” while under the effects of ayahuasca. The experience lasted two hours and included hymns sung by the shaman and severe purging sessions. By the end of the ceremony, he “saw” the pieces returning to his head. The one that corresponded to his alcohol addiction no longer fit in. There he knew that he was cured. “My transformation is something far from understood in Western medicine,” he says. There are some hospitals, universities, and research institutes in the West and around the world that are experimenting with powerful psychoactive substances, such as psilocybin, ibogaine and even LSD are being analyzed in hospitals and research institutes all around the world. “Regarding ayahuasca studies, Brazil is at the forefront of research,” said Luis Fernando Tófoli, professor of the medical psychology and psychiatry department of Unicamp and coordinator of the Laboratory of Interdisciplinary Studies of psychoactive drugs, in Portuguese. This year, a study conducted by Brazilian researchers was published in Nature. The piece examined the effects of the drink on two men and four women who showed symptoms of depression, ranging from moderate to severe. The participants consumed ayahuasca only once in doses that ranged between 120ml to 200ml prepared by a church of Santo Daime. They then had their mental health monitored through three questionnaires repeated eight times, the first one 40 minutes after intake and the last one three weeks later. The results showed that there were improvements shown by every participant, disregarding the levels of depression they displayed. According to one of the surveys, one day after the experiment, there had been a reduction of 62 percent in symptoms. One week later, the efficacy kept going up, getting up to 72 percent. According to another survey, depression symptoms such as sadness, difficulty concentrating, suicidal and negative thoughts, had been reduced by 82 percent. Side effects were not detected, although half of the subjects had vomited under influence of the tea. The results impressed the researchers. “We observed antidepressant effects the first hours after administering ayahuasca, and they remained significant for two to three weeks,” Flávia de Lima Osório and Rafael Guimarães dos Santos, two of the authors, said in an email in Portuguese. She’s a lecturer in the department of neurosciences and behavioral sciences of the Universidade de São Paulo (USP) Medical School in Ribeirão Preto and he is a postdoctoral researcher in the same department. “Besides, ayahuasca was tolerated quite well by the patients. The majority described the experience as positive, even if there was vomiting and nausea.” The fast results could be good news for those who need quick-acting treatments. “Antidepressants that are currently available take weeks to produce therapeutic effects, in addition to having significant side effects, such as sexual dysfunction and weight gain,” Flávia wrote. “Many patients don't get an effective therapeutic response. New pharmaceuticals, that act faster and more efficiently with less side effects, are necessary.” Tófoli agreed. “Antidepressants that were recently introduced to the market, do the same as the older ones. New substances able to act on other receptors, haven't been introduced yet. Psychopharmacology has not been able to get that type of response,” he said. The combination of being thirsty for good news with the thrill associated to mind altering performed in labs can help one understand the hype that followed the release of the research. After becoming news on Nature, the research was highlighted by some leading news channels around the world, from Huffington Post to Scientific American. The news coverage made the researchers wary. Flávia requested to be interviewed only by email “because there were already issues with previous reports.” She also reiterated that nothing is really demonstrated. “This is a pilot-study, with a few volunteers and without double-blind testing controlled by placebo. On studies with antidepressants in general, the placebo effect can be very significant. Therefore, we can’t affirm yet that ayahuasca has antidepressant capabilities, let alone that it can cure depression,” she wrote. A new wave of ayahuasca enthusiasts may appear in the very near future. In Natal, the researcher Dráulio de Barros Araújo, from the Brain Institute of UFRN, coordinates a study using placebos to compare the effects of the tea in a group setting of 80 people, half of them diagnosed with depression. On top of receiving medical supervision, the subjects will be submitted to high definition electroencephalography (EEG) exams. “A study with this kind of consolidated methodology aiming to evaluate the potential benefits of ayahuasca for depression patients has never been done before” said Tófoli, one of the researchers. “If we find positive results, we have all we need to cause a certain impact.” Another study, published this year in the journal Physiology and Behaviour, analyzed the effects of ayahuasca on lab rats that were addicted to alcohol. The study was authored by Alexandre Justo de Oliveira-Lima, who is a pharmacology professor at State University of Santa Cruz; Eduardo Marinho, of the same university; and Laís Berro, of Federal University of São Paulo; along with researchers from Brás Cubas University and from the Institute of Forensic Science of São Paulo. Research with animals is one step in the development of new drugs and, also, a resource for better understanding of organic alterations caused by the process of addition. The problematic of use of drugs, by both animals and by humans, is linked to the feedback loop between the ventral tegmental area (VTA) and nucleus accumbens, which theoretically make up our reward and pleasure system. Oliveira-Lima already had experience with analyzing how drugs like anti-psychotics fight alcohol addiction. Stories about the possible benefits of ayahuasca caught his attention. “We decided to do this research because there’s this ambivalence regarding what causes benefits, if it’s the religious experience or the tea acting directly,” Lima said in Portuguese. During the study, rats were injected with ethyl alcohol to induce changes in cerebral activity and behavior. Their motor skills were then evaluated. Because low doses of alcohol have a stimulant power, the subjects tend to move through greater distances when they are under the influence. There were two experimental phases. During the first phase, the animals were separated into groups. One group received doses of saline, which served as a control. Others received doses of ayahuasca with different concentration levels and, later, alcohol injections. “We are simulating a situation where a person goes to a ritual, takes the tea and then drinks alcohol,” Lima said. One group received just alcohol injections, always with the same dose. Ten days later, the researchers compared the frequency with which the animals moved. The results showed that those who received ayahuasca moved about 50 percent less than those who only had alcohol, suggesting that the tea desensitized the rats to alcohol. The tea appeared to prevent the changes in cerebral activity induced by alcohol, resulting in milder behavioral responses. In the second experiment, the animals were again split in several groups. One received saline injections only to serve as a control. The remainder of them were sensitized by alcohol, that is, they became dependent. Afterwards, ayahuasca injections were administered for eight consecutive days, in attempt to revert the sensitization. After seven days, new alcohol injections were given and movement frequencies between groups were compared. The graph showed that animals that were experiencing the effects of alcohol for the first time, as well as the ones submitted to the desensitization process with the tea earlier, displayed exactly the same behavior. In other words: the “dependency” was reverted. It’s as if an individual who was addicted to alcohol went to rehabilitation and got treated by being given ayahuasca for just a few months, Olivera-Lima said. “With sensitization reversal, that person would be less prone to feel like drinking again,” he said. “And even if they relapsed, at first the experience would be milder.” In theory, as we learn more about the neurochemistry of ayahuasca, we could engineer medications that wouldn’t require patients to spend hours vomiting while hallucinating in a sweat lodge (by the way, it’s worth to point out that the rats didn't vomit during the study). “Nowadays there are few medical options that are effective enough for the treatment of alcoholism. From studies like these, pharmaceutical companies can become dedicated in developing new products. I believe that ayahuasca will be a big source for the treatment of addiction in the next decades,” Lima said. The next step for the researchers will be to repeat the process of sensitization and desensitization and then remove the brains from the rats to analyze the changes. Unfortunately, a recent budget cut for Brazil’s National Program of Post-Graduation will likely impair these experiments. “Although scholarships have been preserved, those cuts affect up 75 percent of the budget that cover the necessary means for the research,” Lima said. “One equipment line that was going to be purchased, for example, was cancelled for the year. That will reflect negatively on Brazilian science for the next five years.” One of the reasons Brazil has some of the most active research in ayahuasca is because back in the 80s, legislation was passed to permit religious use of the tea. “We are grateful for the religious groups because they gained rights and conditions that allow us now to do research,” said Tófoli. He emphasizes that studies have shown ayahuasca is not for everyone. “There are people who can have psychotic breakdowns,” he said. The ayahuasca debate still is far from resolution. There are many external factors that may play into the effectiveness of a medication. Getting a prescription involves so much more than just consuming a drug. That experience includes many seemingly irrelevant, but potentially important, sub-experiences. The patient is thinking, either subconsciously or consciously, about whatever negative stigma or positive association they have with the drug. They’re having an experience with the psychiatrist, and another at the pharmacy. There may be effects of stress or emotion at any of these stages. The same is true of ayahuasca, but such emotional impacts may be magnified because the drug is so mind-altering. This can introduce new ethical questions as well as uncertainties about what’s actually causing the effects. Recall the experience Robert Rhatigan had, where he cured his addiction after “seeing it” outside of his own mind. With ayahuasca, there seem to be more things involved than just neurochemistry. “Many people decide to change things about their lives during the experience. There are those who decide to become vegetarians, for example,” said Tófoli. “How would we talk about whether the benefits are caused by the chemistry or what a person experiences during the mind altering process? We can't be sure.” But wait. Didn't the experiment with the rats demonstrate that it is essentially a physiological matter, independent of what happens in the conscious mind of who is experimenting ayahuasca? “And who says that the rats don't have a conscious mind?” Tófoli said. A very psychedelic response. But it’s a good reminder that we’re still far from understanding the fundamentals of ayahuasca therapy. *Jorge requested his real name to be withheld. This article was translated from Motherboard Brazil.