Espectro de Polariton de Plasmons e Ondas de Luz em Quasi-Cristais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Interação estrela planeta: sobre o magnetismo de planetas gigantes gasosos

In this thesis we analyze the effects that the presence of a near gas giant planet can cause in its host star. It has been argued that the star planet interaction can cause changes in the coronal and chromospheric stellar activity. With this in mind, we analyze a sample of 53 extrasolar planets orbiting F, G and K main sequence stars, among them three super-Earths. In this analysis, we look for evidence of changes in the chromospheric activity due to the proximity of the giant planet. We show that, so far, there is not enough evidence to support such a hypothesis. Making use of the same sample and also taking in account available data for the Solar System, we revisit the so-called magnetic Bode s law. This law proposes the existence of a direct relationship between magnetism and rotation. By using estimations for the stellar and planetary magnetic momentM and the angular momentumL, we construct a Blackett s diagram (logL 􀀀logM). In this diagram is evident that the magnetic Bode s law is valid for both the Solar System and the new planetary systems

Ondas de spin em quasi-cristais magnônicos

In this paper we investigate the spectra of band structures and transmittance in magnonic quasicrystals that exhibit the so-called deterministic disorders, specifically, magnetic multilayer systems, which are built obeying to the generalized Fibonacci (only golden mean (GM), silver mean (SM), bronze mean (BM), copper mean (CM) and nickel mean (NM) cases) and k-component Fibonacci substitutional sequences. The theoretical model is based on the Heisenberg Hamiltonian in the exchange regime, together with the powerful transfer matrix method, and taking into account the RPA approximation. The magnetic materials considered are simple cubic ferromagnets. Our main interest in this study is to investigate the effects of quasiperiodicity on the physical properties of the systems mentioned by analyzing the behavior of spin wave propagation through the dispersion and transmission spectra of these structures. Among of these results we detach: (i) the fragmentation of the bulk bands, which in the limit of high generations, become a Cantor set, and the presence of the mig-gap frequency in the spin waves transmission, for generalized Fibonacci sequence, and (ii) the strong dependence of the magnonic band gap with respect to the parameters k, which determines the amount of different magnetic materials are present in quasicrystal, and n, which is the generation number of the sequence k-component Fibonacci. In this last case, we have verified that the system presents a magnonic band gap, whose width and frequency region can be controlled by varying k and n. In the exchange regime, the spin waves propagate with frequency of the order of a few tens of terahertz (THz). Therefore, from a experimental and technological point of view, the magnonic quasicrystals can be used as carriers or processors of informations, and the magnon (the quantum spin wave) is responsible for this transport and processing

Um estudo da rotação em estrelas da seqüência principal

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Efeitos da interação dipolar na nucleação de vórtices em nano-cilindros magnéticos

The effect of confinement on the magnetic structure of vortices of dipolar coupled ferromagnetic nanoelements is an issue of current interest, not only for academic reasons, but also for the potential impact in a number of promising applications. Most applications, such as nano-oscillators for wireless data transmission, benefit from the possibility of tailoring the vortex core magnetic pattern. We report a theoretical study of vortex nucleation in pairs of coaxial iron and Permalloy cylinders, with diameters ranging from 21nm to 150nm, and 12nm and 21nm thicknesses, separated by a non-magnetic layer. 12nm thick iron and Permalloy isolated (single) cylinders do not hold a vortex, and 21nm isolated cylinders hold a vortex. Our results indicate that one may tailor the magnetic structure of the vortices, and the relative chirality, by selecting the thickness of the non-magnetic spacer and the values of the cylinders diameters and thicknesses. Also, the dipolar interaction may induce vortex formation in pairs of 12nm thick nanocylinders and inhibit the formation of vortices in pairs of 21nm thick nanocylinders. These new phases are formed according to the value of the distance between the cylinderes. Furthermore, we show that the preparation route may control relative chirality and polarity of the vortex pair. For instance: by saturating a pair of Fe 81nm diameter, 21nm thickness cylinders, along the crystalline anisotropy direction, a pair of 36nm core diameter vortices, with same chirality and polarity is prepared. By saturating along the perpendicular direction, one prepares a 30nm diameter core vortex pair, with opposite chirality and opposite polarity. We also present a theoretical discussion of the impact of vortices on the thermal hysteresis of a pair of interface biased elliptical iron nanoelements, separated by an ultrathin nonmagnetic insulating layer. We have found that iron nanoelements exchange coupled to a noncompensated NiO substrate, display thermal hysteresis at room temperature, well below the iron Curie temperature. The thermal hysteresis consists in different sequences of magnetic states in the heating and cooling branches of a thermal loop, and originates in the thermal reduction of the interface field, and on the rearrangements of the magnetic structure at high temperatures, 5 produce by the strong dipolar coupling. The width of the thermal hysteresis varies from 500 K to 100 K for lateral dimensions of 125 nm x 65 nm and 145 nm x 65 nm. We focus on the thermal effects on two particular states: the antiparallel state, which has, at low temperatures, the interface biased nanoelement with the magnetization aligned with the interface field and the second nanoelement aligned opposite to the interface field; and in the parallel state, which has both nanoelements with the magnetization aligned with the interface field at low temperatures. We show that the dipolar interaction leads to enhanced thermal stability of the antiparallel state, and reduces the thermal stability of the parallel state. These states are the key phases in the application of pairs of ferromagnetic nanoelements, separated by a thin insulating layer, for tunneling magnetic memory cells. We have found that for a pair of 125nm x 65nm nanoelements, separated by 1.1nm, and low temperature interface field strength of 5.88kOe, the low temperature state (T = 100K) consists of a pair of nearly parallel buckle-states. This low temperature phase is kept with minor changes up to T= 249 K when the magnetization is reduced to 50% of the low temperature value due to nucleation of a vortex centered around the middle of the free surface nanoelement. By further increasing the temperature, there is another small change in the magnetization due to vortex motion. Apart from minor changes in the vortex position, the high temperature vortex state remains stable, in the cooling branch, down to low temperatures. We note that wide loop thermal hysteresis may pose limits on the design of tunneling magnetic memory cells

Evolução da atividade cromosférica, abundância de lítio e rotação das estrelas análogas e gêmeas solares

The study of solar-type stars also includes the familiar solar analogs and twins. These objects have been one of the major research subjects in astrophysics nowadays. A direct comparison of solar activity with chromospheric activity indices for a set of stars very similar to the Sun (twins and analogs) provides an excellent opportunity to study the evolution of stellar activity on timescales of the order of the lifetime on the main sequence. This work deals with the relationship between the abundance of lithium, chromospheric activity, X-ray emission and rotation period in terms of stellar ages. We explore the influence of stellar evolution in the global properties of the stars and the aspects linked to its coronal, chromospheric and magnetic activity. Our main objective is to probe the law of decay of each of these parameters based on a sample of stars classified as well-connected as analogs stars and solar twins.

O enigmático problema das gigantes ricas em Lítio e as perspectivas com o satélite Kepler

Lithium (Li) is a chemical element with atomic number 3 and it is among the lightest known elements in the universe. In general, the Lithium is found in the nature under the form of two stable isotopes, the 6Li and 7Li. This last one is the most dominant and responds for about 93% of the Li found in the Universe. Due to its fragileness this element is largely used in the astrophysics, especially in what refers to the understanding of the physical process that has occurred since the Big Bang going through the evolution of the galaxies and stars. In the primordial nucleosynthesis in the Big Bang moment (BBN), the theoretical calculation forecasts a Li production along with all the light elements such as Deuterium and Beryllium. To the Li the BNB theory reviews a primordial abundance of Log log ǫ(Li) =2.72 dex in a logarithmic scale related to the H. The abundance of Li found on the poor metal stars, or pop II stars type, is called as being the abundance of Li primordial and is the measure as being log ǫ(Li) =2.27 dex. In the ISM (Interstellar medium), that reflects the current value, the abundance of Lithium is log ǫ(Li) = 3.2 dex. This value has great importance for our comprehension on the chemical evolution of the galaxy. The process responsible for the increasing of the primordial value present in the Li is not clearly understood until nowadays. In fact there is a real contribution of Li from the giant stars of little mass and this contribution needs to be well streamed if we want to understand our galaxy. The main objection in this logical sequence is the appearing of some giant stars with little mass of G and K spectral types which atmosphere is highly enriched with Li. Such elevated values are exactly the opposite of what could happen with the typical abundance of giant low mass stars, where convective envelops pass through a mass deepening in which all the Li should be diluted and present abundances around log ǫ(Li) ∼1.4 dex following the model of stellar evolution. In the Literature three suggestions are found that try to reconcile the values of the abundance of Li theoretical and observed in these rich in Li giants, but any of them bring conclusive answers. In the present work, we propose a qualitative study of the evolutionary state of the rich in Li stars in the literature along with the recent discovery of the first star rich in Li observed by the Kepler Satellite. The main objective of this work is to promote a solid discussion about the evolutionary state based on the characteristic obtained from the seismic analysis of the object observed by Kepler. We used evolutionary traces and simulation done with the population synthesis code TRILEGAL intending to evaluate as precisely as possible the evolutionary state of the internal structure of these groups of stars. The results indicate a very short characteristic time when compared to the evolutionary scale related to the enrichment of these stars

Efeitos da eletroestimulação percutânea na incontinência urinária e qualidade de vida pós-prostatectomia: registro de seis casos

Introduction: Radical prostatectomy surgery is the best treatment currently adopted by detecting prostate cancer. The urinary incontinence is one more common and difficult to treat postoperative complications, which causes a negative impact on quality of life of the individual prostatectomy . The surface electrical nerve stimulation involves the transmission of electrical impulses from an external stimulator for peripheral nerve through surface electrodes attached to skin. It is an easy and efficient technique, widely used for pain relief, rehabilitation and muscle strengthening. Objective: To analyze the effect of T10-L2 percutaneous electrical stimulation, in individuals with urinary incontinence who underwent radical prostatectomy by the laparoscopic technique. Methods: Six patients had previously undergone radical prostatectomy were submitted to 20 sections of surface electrical stimulation with frequency of 4 Hz, pulse width of 1ms during 20 minutes. All subjects fillid a quality of life - International Consultation on Incontinence Questionnaire- Short FormI - ICIQ-SF questionnaire evaluating. Results: Results showed reduction in the use of the number of pads, number of leaks before and after treatment, and reduced voiding frequency and consequent improvement in quality of life. No side effects were reported. Conclusion: Percutanous electrical stimulation in T10-L2 may be an effective technique to treat urinary incontinence (UI) after radical prostatectomy video laparoscopy

Comparação das respostas fisiológicas entre diferentes testes funcionais em obesos

obesity affects rightly functional capacity diminishing the cardiovascular system efficiency and oxygen uptake (VO2). Field tests, such as, Incremental Shuttle Walking Test (ISWT) and Six Minute Walk Test (6MWT) has been employed as alternative of Cardiopulmonary Exercise Test (CPX), to functional assessing for conditions which transport of oxygen to peripheral is diminished. Nevertheless, the knowing about metabolic variables response in real time and it comparing among different maximal and submaximal tests in obese is absent. Aim: to compare cardiopulmonary, metabolic response during CPX, ISWT and 6MWT and to analyse it influence of adiposity markers in obese. Material e Method: crosssectional, prospective study. Obese included if: (BMI>30Kg/m2; FVC>80%), were assessed as clinical, anthropometric (BMI, body adiposity index-BAI, waist-WC, hip- HC and neck-NC circumferences) and spirometry (forced vital capacity-FVC, Forced expiratory volume-1°second-FEV1, maximal voluntary ventilation-MVV) variables. Obese performed the sequence of tests: CPX, ISWT and 6MWT. Throughout tests was assessed breath-by-breath by telemetry system (Cortex-Biophysik-Metamax3B) variables; oxygen uptake on peak of activity (VO2peak); carbon dioxide production (VCO2); Volume Expiratory (VE); ventilatory equivalents for VO2 (VE/VO2) and CO2 (VE/VCO2); respiratory exchange rate (RER) and perceived effort-Borg6-20). Results: 15 obese (10women) 39.4+10.1years, normal spirometry (%CVF=93.7+9.7) finished all test. They have BMI (43.5+6.6kg/m2) and different as %adiposity (BAI=50.0+10.5% and 48.8+16.9% respectively women and men). Difference of VO2ml/kg/min and %VO2 were finding between CPX (18.6+4.0) and 6MWT (13.2+2.5) but not between ISWT (15.4+2.9). Agreement was found for ISWT and CPX on VO2Peak (3.2ml/kg/min; 95%; IC-3.0 9.4) and %VO2 (16.4%). VCO2(l/min) confirms similarity in production for CPX (2.3+1.0) and ISWT (1.7+0.7) and difference for 6MWT (1.4+0.6). WC explains more the response of CPX and ISWT than other adiposity markers. Adiposity diminishes 3.2% duration of CPX. Conclusion: ISWT promotes similar metabolic and cardiovascular response than CPX in obese. It suggesting that ISWT could be useful and reliable to assess oxygen uptake and functional capacity in obese

Realidade virtual na atividade cerebral: um estudo comparativo entre estados emocionais de adultos jovens e idosos

The association of Virtual Reality (VR) to clinical practice has become common in the recent years, showing to be an additional tool on health care, especially for elderly. Its use has been related to higher therapeutic adhesion levels and well being sensation. Such emotional based aspects are often observed by subjective tools of relative validity. This study analyzed the immediate effects of varied VR contexts balance training over emotional behavior, which was observed under peaks of maximum expression of EEG waves. Methodology: 40 individuals, divided in two groups, both gender, 20 young and 20 elderly, were submitted to a 60 minutes intervention, including balance training under VR. The first 25 minutes referred to initial evaluation, general orientation and cognitive assessment by the use of Mini Mental. The next ten minutes were designated to the avatar creation and tutorial video presentation. Through the following 20 minutes, the individuals from both groups were exposed to the exact same sequence of games under virtual contexts, while submitted to electroencephalography by Emotiv EPOC® focusing Adhesion, Frustration and Meditation states. The virtual interface was provided by the Nintendo® game, Wii Fit Plus, with the scenarios Balance Bubble (1), Penguin (2), Soccer (3), Tight Rope (4) and Table Tilt (5). Finally, a questionnaire of personal impressions was applied on the 5 minutes left. Results: data collected showed 64,7% of individuals from both groups presented higher concentration of adhesion peaks on Balance Bubble game. Both groups also presented similar behavior regarding meditation state, with marks close to 40%, each, on the same game, Table Tilt. There was divergence related to the frustration state, being the maximum concentration for the young group on the Soccer game (29,3%), whilst the elderly group referred highest marks to Tight Rope game (35,2%). Conclusion: Findings suggest virtual contexts can be favorable to adhesion and meditation emotional patterns induction, regardless age and for both sexes, whilst frustration seems to be more related to cognitive motor affordance, likely to be influenced by age. This information is relevant and contributes to the orientation for the best choice of games applied in clinical practice, as for other studies regarding this topic

Estudos ecogenômicos e bioprospectivos de Shewanella ssp

Bacteria trom Shewanella and Geobacter ganera are the most studied iron-reducing microorganisms particularly due to their electron transport systems and contribution to some industrial and environmental problems, including steel corrosion, bioenergy and bioremediation of petroleum-impacted sites. The present study was focused in two ways: the first is an in silico comparative ecogenomic study of Shewanella spp. with sequenced genomes, and the second is an experimental metagenomic work to detect iron-reducing Shewanella through PCR-DGGE of a metabolic gene. The in silico study resulted in positive correIation between copy number of 16S rDNA and genome size in Shewanella spp., with clusters of rrn near lhe origin of replication. This way, the genus is inferred as opportunist. There are no compact genomes and their sequences length varied, ranging from 4306142 nt in S. amazonensis SB2B to 5935403 nt in S. woodyi ATCC 51908, without correIation to temperature range characteristic of each specie. Intragenomic 16S rDNA sequences possess little divergence, but reasonable to resuIt in different phyIogenetic trees, depending on the sequence that is chosen to compare. For moIecuIar detection of iron-reducing Shewanella, it is proposed the mtrB gene as new biomarker. because it codes to a fundamental protein at Fe (III)-reduction. The specific primers were designed and evaluated in silico and resulted in a fragment of 360 pb. In the second study, these primers were tested in a genomic sample from S. oneidensis MR-1, amplifying the expected region. After this successfuI resuIt, the primer set was used as a tool to assess the iron-reducing communities of ShewaneIla genus under an environmental stress, i.e. crude oil contamination in mangrove sediment in Rio Grande do Norte State (Brazil). The primers presented high specificity and the reactions performed resulted in one single band of ampIification in the metagenomic samples. The fingerprinting obtained at DGGE reveaIed temporal variation of Shewanella spp. in analyzed samples. The resuIts presented show the detection of a biotechnological important group of microorganisms, the iron-reducing Shewanella spp. using a metabolic gane as target. It is concluded there are eight or more 16S rDNA sequences in Shewanella genus, with little divergence among them that affects the phylogeny; the pair of primers designed to ampIify mtrB sequences is a viable alternative to detect iron-reducing ShewanelIa in metagenomic approaches; such bacteria are present in the mangrove sediment anaIyzed, with temporal variations in the samples. This is the first experimental study that screened the iron-reducing Shewanella genus in a metagenomic experiment of mangrove sediments subjected to oil contamination through a key metabolic gene

Caracterização dos genes scMUTM1 e scMUTM2 de cana-de-açúcar

Plants are organisms sessile and because of this they are susceptible to genotoxic effects due to environmental exposure such as light [including ultraviolet (UV)], heat, drought and chemicals agents. Therefore, there are differents pathways in order to detect a lesion and correct. These pathways are not well known in plants. The MutM/Fpg protein is a DNA glycosylase that is responsible for detect and correct oxidative lesions. In the sugarcane genome, it was found two possible cDNAs that had homology to this protein: scMUTM1 and scMUTM2. The aim of this work was to characterize the role of these cDNAs in plants. In order to do this, the expression level after oxidative stress was evaluated by semiquantitative RT-PCR. Another point analyzed in order to obtain the full-length gene, it was to use a sugarcane genomic library that was hybridized with both cDNAs as a probe. It was found two clones that will bought and sequenced. The promoter region was also cloned. It was obtained sequences only for scMUTM2 promoter region. The sequences obtained were divided into six groups. It was found regulatory motifs such as TATA-box, CAAT-box, oxidative stress element response and regulatory regions that response to light. The other point analyzed was to characterize the N-terminal region by PCR constructs. These constructs have deletions at 5 region. These sequences were introduce into Escherichia coli wild type strain (CC104) and double mutant (CC104mutMmutY). The results showed that proteins with deletions of scMUTM1 N-terminal region were able to complement the Fpg and MutY-glycosylase deficiency in CC104 mutMmutY reducing the spontaneous mutation frequency

Quem nasce em campina grande é campinense : futebol e sociabilidade na rainha da borborema (1954-1965)

This study aims to historicize a problem: How Campinense Club, club social of the city of Campina Grande, became a popular club? This guild was founded in 1915 by a group of graduates, which they called "Campinense" a social club dedicated to the enjoyment of the city's elites. To investigate the mechanisms that have led to this popularity, was chosen that includes a period from 1954 to 1965, when it was created a department where the professional football club won a string of six consecutive championships, considered the main achievement of its history sports. Were used as research sources Borborema the Journal, a newspaper founded in 1957 and that during the period in question, was the spokesman of the main political groups in the city, which on many occasions were the sponsors of the clubs the same. This newspaper had a daily sports column and introduced the red-black team to Paraíba. Were used, although the club's meeting minutes taken as official documents, which allowed it to be mounted on a puzzle of the club's events, since the information about the Campinense present rather fragmented. Finally, respondents were fans, athletes and leaders who, through his lines in a way pointed out other possibilities such as a club, believed to be aristocratic, has become a passion among the fans, giving rise to this conception to be one that Campinense broke with the established elites of the city.

Em nome(s) dos interesses: imaginários toponímicos do Rio Grande do Norte na Primeira República

This paper has the imaginary names as a theme, from which we aim to analyze the imaginaries and invested interests that characterized the implementation and the legitimation of the First Republic in Rio Grande do Norte (1889 1930), making the process of registering names history in that place. For the construction of our object, we studied laws and provincial, state and municipal decrees; annual messages of governors; articles of the following newspapers O Povo, A República, Diário do Natal, O Seridoense, A Notícia and Jornal das Moças; the local cartography and historiography that talk about the study of names. The use of these resources, allied to the empiric method, was driven by a theoretic methodological contribution based on the history of the political imaginary, as discussed by Cornelius Castoriadis, René Rémond, Michel de Certeau and Maria Dick. For the understanding of the imaginaries that (de)limited the spaces of Rio Grande do Norte concerning its names during the First Republic, we bring moment back to the two last imperial decades moment of cleavage between Empire and Republic essential for the fomentation of the imaginary that embodied the organization of our study. From this period, we observe, through the names of some cities, how the northern space would be aligned to the imaginary dynamic of the new political system of the nation, and it had followed to a redirection process of the giving names action, according to the interests of the family organization Albuquerque Maranhão, revealed while determining the names of cities, towns, streets, schools, buildings, etc., in thankfulness to the memory of its members. In the sequence we verified how a new dynamic of giving names helped to understand the process of political transition from the Coast to the Sertão, and at the same time affirmed the power of the political and economical seridoense elite towards the government of the state in the two last decades of the First Republic

Estimadores do tipo núcleo para Variávei s I.I.D. com espaço de estados geral

In this work, the paper of Campos and Dorea [3] was detailed. In that article a Kernel Estimator was applied to a sequence of random variables with general state space, which were independent and identicaly distributed. In chapter 2, the estimator´s properties such as asymptotic unbiasedness, consistency in quadratic mean, strong consistency and asymptotic normality were verified. In chapter 3, using R software, numerical experiments were developed in order to give a visual idea of the estimate process