Estimulação optogenética do septo medial no rato anestesiado e em livre comportamento

Theta rhythm consists of an electrophysiological hippocampal oscillation present in mammalian species (4-12 Hz with variations across species). This oscillation is present during active waking and is also prevalent in local field potentials (LFP) during rapid eye movement sleep (REM sleep). Several studies have shown that theta rhythm is important in cognitive tasks and that the medial septum is a key region for its occurrence. The septum sends cholinergic, GABAergic and glutamatergic projections to the hippocampus, which in turn projects axons to the septum. Besides the septum, other regions are involved in regulating theta rhythm, forming a complex network of interactions among brain areas that result in theta rhythm. Optogenetics is a recently developed method that has been widely used in various research areas. It allows us to manipulate the electrical activity of neurons through light stimulation. One of the existing techniques consists in using a viral vector to induce the neuronal expression of ion channels associated with the light-sensitive molecule rhodopsin (e.g. ChR2). Once infected, the neurons become sensitive to light of a particular wavelength. The present M. Sc. research aimed to perform luminous stimulation of the brain in anesthetized and freely behaving animals using chronically implanted electrodes and optical fibers in animals infected with a viral vector for ChR2 expression. Surgical viral injections were performed in the medial septum; histological results confirmed the expression of ChR2 by way of the presence of the eYFP reporter protein in the septum and also in hippocampal processes. Moreover, we performed acute experiments with luminous stimulation of the medial septum and LFP recordings of the septum and hippocampus of anesthetized animals. Action potentials were recorded in the septum. In these experiments we observed a significant increase in the firing rates of septal neurons during luminous stimulation (n = 300 trials). Furthermore, we found an early light-evoked response in the hippocampal LFP. Chronic experiments with luminous stimulation of the medial septum and hippocampus in freely behaving animals were also performed in combination with LFP recordings. We found that the luminous stimulation of the septum is able to induce theta rhythm in the hippocampus. Together, the results demonstrate that the luminous stimulation of the medial septum in optogenetically-modified animals causes relevant electrophysiological changes in the septum and the hippocampus.

Análise por meio de espectroscopia de emissão óptica das espécies ativas em nitretação iônica e gaiola catódica

Plasma process like ionic nitriding and cathodic cage plasma nitriding are utilized in order to become hard surface of steels. The ionic nitriding is already accepted in the industry while cathodic cage plasma nitriding process is in industrial implementation stage. Those process depend of plasma parameters like electronic and ionic temperature (Te, Ti), species density (ne, ni) and of distribution function of these species. In the present work, the plasma used to those two processes has been observed through Optical Emission Spectroscopy OES technique in order to identify presents species in the treatment ambient and relatively quantify them. So plasma of typical mixtures like N2 H2 has been monitored through in order to study evolution of those species during the process. Moreover, it has been realized a systematic study about leaks, also thought OES, that accomplish the evolution of contaminant species arising because there is flux of atmosphere to inside nitriding chamber and in what conditions the species are sufficiently reduced. Finally, to describe the physic mechanism that acts on both coating techniques ionic nitriding and cathodic cage plasma nitriding

Tributação, finanças públicas e política fiscal: uma análise sob a óptica do direito e economia

In the Brazilian legal scenario, the study of taxation has traditionally been restricted to positivist analysis, concerned with investigating the formal aspects of the tax legal rule. Despite its relevance to the formation of the national doctrine of tax, such formalist tradition limits the discipline, separating it from reality and the socioeconomic context in which the Tax Law is inserted. Thus, the proposal of the dissertation is to examine the fundamentals and nature of taxation and tax legal rules from the perspective of Law and Economics (Economic Analysis of Law). For this purpose, the work initially reconnects the Tax Law and Science of Finance (or Public Finance) and Fiscal Policy, undertaking not only a legal analysis, but also economic and financial analysis of the theme. The Economics of Public Sector (or Modern Public Finance) will contribute to the research through topics such as market failures and economic theory of taxation, which are essential to an economic approach to Tax Law. The core of the work lies in the application of Law and Economics instruments in the study of taxation, analyzing the effects of tax rules on the economic system. Accordingly, the dissertation examines the fundamental assumptions that make up the Economic Analysis of Law (as the concept of economic efficiency and its relation to equity), relating them to the tax phenomenon. Due to the nature of the Brazilian legal system, any worth investigation or approach, including Law and Economics, could not pass off the Constitution. Thus, the constitutional rules will serve as a limit and a prerequisite for the application of Law and Economics on taxation, particularly the rules related to property rights, freedom, equality and legal certainty. The relationship between taxation and market failures receives prominent role, particularly due to its importance to the Law and Economics, as well as to the role that taxation plays in the correction of these failures. In addition to performing a review of taxation under the approach of Economic Analysis of Law, the research also investigates the reality of Brazilian tax system, applying the concepts developed in relevant cases and issues to the national scene, such as the relationship between taxation and development, the compliance costs of taxation, the tax evasion and the tax enforcement procedure. Given the above, it is intended to lay the groundwork for a general theory of Economic Analysis of Tax Law, contextualizing it with the Brazilian tax system

Equalização neural aplicada a sistemas com modulação bidimensional em fibra óptica

Nowadays, optic fiber is one of the most used communication methods, mainly due to the fact that the data transmission rates of those systems exceed all of the other means of digital communication. Despite the great advantage, there are problems that prevent full utilization of the optical channel: by increasing the transmission speed and the distances involved, the data is subjected to non-linear inter symbolic interference caused by the dispersion phenomena in the fiber. Adaptive equalizers can be used to solve this problem, they compensate non-ideal responses of the channel in order to restore the signal that was transmitted. This work proposes an equalizer based on artificial neural networks and evaluates its performance in optical communication systems. The proposal is validated through a simulated optic channel and the comparison with other adaptive equalization techniques

Diagnóstico de descarga de cátodo oco de ar e pós-descarga Ar N2 por espectroscopia de emissão óptica e espectrometria de massa

Many applications require that the plasma discharge is produced apart from the surface to be processed, thus preventing damage caused by bombardment and/or plasma radiation. In the post-discharge regime in various applications thermally sensitive materials can be used. In this work, active species produced by discharge and post-discharge hollow cathode were diagnosed by optical emission spectroscopy and mass spectrometry. The discharge was produced with the gases Ar and Ar - N2 gas flow ranging from 1 to 6 cm3/min and electric current between 150 to 600 mA. It was estimated that the ion density inside the hollow cathode, with 2 mm diameter ranged between 7.71 and 14.1 x 1015 cm-3. It was observed that the gas flow and the electric current changes the emission intensity of Ar and N2 species. The major ionic species detected by quadrupole mass spectrometry were Ar+ and N2+. The ratio of optical emission intensities of N2(1 +)/Ar(811 nm) was related to the partial pressure of N2 after the hollow cathode discharge at low pressure

História da ciência como estratégia didática no ensino médio: um breve olhar de conteúdos da óptica

From a critique of aspects of the current teaching of physics, we propose in this paper an investigation into the conceptions of Nature of Science (NOS) submitted by students from the high school level, as well as the inclusion of discussions about some elements of NOS, through the History and Philosophy of Science, understanding them as facilitating strategy for more effective learning of Physics and, more specifically, the contents of optics. Based on the historical period corresponding to Greek antiquity to the mid-nineteenth century, built and applied a teaching unit to a high school class at the Federal Institute of Education, Science and Technology of Rio Grande do Norte (IFRN) Ipanguaçu campus. Our teaching unit involved the reading and interpretation of texts with historical content, observation and assembling five experimental activities, among other activities. Data analysis occurred through questionnaires investigative applied before and after the completion of the teaching unit, as well as questionnaires for content present in the texts. Although not significant, the results indicated that the application of the teaching unit allowed the (re) construction of some conceptions about NOS targets students present in our work, and contribute to a better learning content and greater optical science approach and its nature

O ensino de óptica no nível fundamental: uma proposta de ensino aprendizagem contextualizada para a oitava série

This dissertation presents the investigation and possible interference in the current teaching of physics, specially of optics, in the eighth grade/ ninth year / fourth cycle of junior high school. The context of the current science teaching is also presented. Besides, the following aspects are discussed: the preparation of the eighth grade teachers, their professional needs, the pedagogical practices and the theoreticmethodological difficulties faced by them. Another important issue in Science Teaching, which is also discussed in this dissertation, is the need for an efficient scientific literacy so that the citizen may express value judgment about Science and Technology issues. The data about the context were gathered from questionaires answered by the teachers. In value of this information, lesson plans were elaborated and implemented. The goal was to point out alternatives for the development of a teaching-learning evaluation which would be both pleasant for the teachers in relation to the implemented methodology, end meaningful for the students by adding elements such as: interdisciplinary approach, contextualization and preparation by competences. Furthermore it was carried out a deeper analysis of the Brazilian curriculum references (LDB, DCN, PCN, RCB) and content aspects (concepts, procedures e attitudes) to be executed by that branch of human knowledge, aiming at a really Contextualized Science Teaching, qualified and pleasant for the eighth grade level. It is also presented in this paper the profile or the Professional which teach this level at state public schools in Russas, state of Ceará, Vale do Jaguaribe Region. The efficacy of the lesson plans were also analysed by using evaluation procedures with the eighth grade students of the following schools: CAIC Senador Carlos Jereissati and EEF Manuel Matoso Filho, from which the concepts acquired during the implementation of the classes became evident in the students

Avaliação imuno-histoquímica das galectinas -1, -3 e -7 em displasia epitelial ora

Introdução: A displasia epitelial oral (DEO) é uma lesão potencialmente maligna, cujo diagnóstico e gradação se baseia na histologia das alterações arquiteturais e citológicas, preconizados pela OMS, que divide a lesão em leve, moderada e severa, o qual é subjetivo. Maior concordância é observada no uso do sistema binário (baixo/alto risco), o qual está relacionado ao risco de transformação maligna. As galectinas constituem uma família de lectinas e estão envolvidas na tumorigênese, sendo a -1, -3 e -7 as mais investigadas, devido a expressão alterada em cânceres orais. Materiais e métodos: Foi analisada a expressão imuno-histoquímica dessas proteínas em 50 espécimes de DEO (21 baixo/ 29 alto risco) e 5 de mucosa oral normal e relacionamos com a presença/ausência de marcação, padrão de distribuição, intensidade, localização epitelial (estratificação) (1/3 inferior, médio e superior), e localização celular (compartimento) (núcleo, citoplasma e membrana) . Resultados: Dos 29 casos de alto e dos 21 de baixo risco, 21 (72,4%) e 12 (57,1%) foram positivos para a galectina -1, respectivamente. Dessa forma, de 50 casos, 33 foram positivos. O núcleo e citoplasma foram positivos em 91,7% nas de baixo risco e em 90,5% nas de alto. Todos os casos de mucosa normal foram negativos. Com relação a galectina -3, dos 21 casos das DEOs de baixo risco, 12 (57,1%) apresentaram expressão e dos 29 casos das DEOs de alto risco, 15 (51,7%) foram positivos, havendo imunoexpressão em um total de 27 casos. O padrão difuso, assim como a fraca intensidade foram os mais freqüentes para os 2 graus. O núcleo e o citoplasma foram a localização mais comum tanto nas lesões de baixo (58,3%), quanto nas de alto risco (66,7%). Quatro casos de mucosa normal foram positivos, com marcação membranar e intensidade fraca. Dos 21 casos das DEOs de baixo risco, 17 (81%) apresentaram expressão imuno-histoquímica para a galectina -7 e das 29 DEOs de alto risco, 27 (93,1%) foram positivos. Então, a expressão imuno-histoquímica da galectina -7 foi observada em 44 casos, a maioria com intensidade de moderada a forte. O núcleo e o citoplasma foram a localização mais freqüente, nas de baixo (70,6%) e alto risco (66,7%). Quatro espécimes de mucosa normal marcaram membrana em terço médio e superior, com intensidade moderada a forte. Conclusões: Alterações na expressão das galectinas -3 e -7 e principalmente da -1 sugerem seu envolvimento na fisiopatologia das displasias, participando do processo de transformação de fenótipo normal para o displásico.

Análise comparativa da imunoexpressão das proteínas hmlh1 e hmsh2 em carcinomas epidermóides de lábio inferior e queilites actínicas com graus variados de displasia

Lip squamous cell carcinoma (SCC) may develop from a premalignant condition, actinic cheilitis (AC) in 95% of the cases. Both premalignant and neoplastic lip diseases are caused mainly by chronic exposure to the ultraviolet component of solar radiation, especially UVB. This exposure causes disruption of the cell cycle and damage to DNA repair systems, like mismatch repair, altering proteins repair as hMLH1 and hMSH2. This research aimed to investigate the immunohistochemical expression of hMLH1 and hMSH2 proteins in lower lip SCCs and ACs, providing additional information about carcinogenesis of the lower lip. The sample consisted 40 cases of ACs and 40 cases of lower lip SCCs. Histological sections of 3 μm were submitted to immunoperoxidase method, for immunohistochemical analysis of lesions were counted in 1000 cells (positive and negative), data were evaluated both in absolute numbers and percentage of immunostained cells, the latter by assigning scores. Associations of the variables and comparative analysis of biomarker expression were performed by Fisher s exact and Pearson s chi-square, "t" student, one-way ANOVA, Mann- Whitney e Kruskal-Wallis tests. The level of significance was 5%. It was found that, in lower lip SCC, the mean of the proteins was higher in female patients (hMLH1= 369,80 + 223,98; hMHS2 = 534,80 + 343,62), less than 50 years old (hMLH1 = 285,50 + 190,65; hMHS2 = 540,00 + 274,79) and classified as low-grade malignancy (hMLH1 = 264,59 + 179,21; hMHS2 = 519,32 + 302,58), in these data only to sex, for hMLH1 protein, was statistically significant (p=0.034). Comparing the different lesions, we observed that for both hMLH1 and hMSH2 protein, the average of positive epithelial cells decreased as the lesion was graded at later stages. The ACs classified without dysplasia or mild dysplasia had the highest average of immunostained cells (hMLH1 = 721.23 + 88.116; hMHS2 = 781.50 + 156.93). The ACs classified as moderate or severe dysplasia had intermediate values (hMLH1 = 532,86 + 197,72; hMHS2 = 611,14 + 172,48) and SSCs of the lower lip had the lowest averages (hMLH1 = 255,03 + 199,47; hMHS2 = 518,38 + 265,68). There was a statistically significant difference between groups (p<0.001). In conclusion, our data support the hypothesis that changes in immunoexpression of these proteins is related to the process of carcinogenesis of the lower lip

Expressão imuno-histoquímica das integrinas α2ß1, α3ß1, e α5ß1, em mucosa oral normal, hiperplasia fibroepitelial inflamatória oral e displasia epitelial oral

The objective of this study was perform by the streptoavidin-biotin technique an immunohistochemical analysis of α2β1, α3β1e α5β1 integrins in 11 normal oral mucosa (NOM), 16 oral inflammatory fibroepithelial hyperplasia (OIFH) and 25 oral epithelial dysplasia (OED) (16 mild, 2 moderates and 7 severe), to determine if exists qualitative alteration in the expression of these integrins and if this guard relation with the oral epithelial modifications. It was observed that for the α2β1 integrin the majority of the sample showed a predominantly intense labeling diffusely distributed in the intercellular contacts and the cytoplasm of cells of the basal and suprabasal layers, without difference of this profile between the different types of specimens, however with a trend to weak or loss of expression in 21.1% of the OEDs, being all the specimens that had not expressed this heterodimer, severe OEDs. For the α3β1 integrin the majority of the sample showed a weak or absent labeling in basal layer. The α5β1 integrin showed a predominant strong diffuse labeling in the intercellular contacts and cytoplasm in the suprabasal layer, with difference only in the labeling intensity between the types of specimens, inhabiting this difference in the OEDs, where 12 (48%) specimens had shown a weak labeling. It was concluded that the evaluated integrins can be involved in the cell-cell, cell-ECM interactions modulating the cellular differentiation and maintenance of the epithelial structural arrangement. The variable expression of the α5β1 integrin in the OEDs, could suggest, respectively, a role of this molecule in the cellular survival, with intention to perpetuate the modified phenotype in these lesions, or a suppressor role on the modified phenotype due to lack of interaction of this molecule with the fibronectina of the MEC

Caracterização citoarquitetônica, neuroquímica e de aferência óptica do complexo parabraquial do sagui (Callithrix jacchus)

The parabrachial complex (PB) is an area of the brainstem responsible for the processing and transmission of essential physiologic information for the survival of the organisms. This region is subdivided in approximately nine subregions, considering morphology, cytoarchitectural and functional characteristic. Its neurons have an extensive network of connections with other regions of the nervous system. The objective in this work was to map the retinal projection to the PB and make a citoarchitectonic and neurochemical characterization of this region in the common marmoset (Callithrix jacchus), a primate of the New World. The retinal projections were mapped by anterograde transport of the choleric toxin subunit b (CTb). The citoarchitecture was described through the Nissl method, and the neurochemical characterization was made through immunohistochemical technique to the some neurotransmitters and neuroactives substances present in this neural center. In marmoset PB, in the coronal sections labeled by Nissl method, we found a similar pattern to that evidenced in other animal species. The immunoreactivity against CTb was verified in the PBMv in fibers/terminal, characterizing such as retinal innervations in this area. The immunohistochemical technique reveled that the PB contain cells, fibers and/or terminals immunoreactives to the neuronal nuclear protein, Choline acetyl transferase, nitric oxide synthase, serotonin, enkephalin, substance P, Calcium-binding proteins (calbindin, calretinin e parvalbumin), and glial fibrillary acidic protein. The histochemical technique reveled cells and fibers NADPH-diaphorase reactive. Each one of those substances presented a characteristic pattern of demarcation in PB, and some serve as specific markers of subregions

Espectrometria de emissão óptica com plasma indutivamente acoplado aliada à quimiometria na determinação de íons metálicos no molusco Mytella falcata para discriminação de estuários potiguares

This work examined the possibility of using mussel Mytella falcata as bioindicator sample to detect metal ions in several estuaries potiguares, since species substances that accumulate in their tissues due to its characteristics filter feeders have been used for environmental monitoring. The chemometrics by principal components analysis was used to reduce the size of the original data in order to establish a pattern of distribution of metal ion. Samples were collected at three different points in the estuaries Curimataú, Guaraíra-Papeba, Potengi, Galinhos-Guamaré and Piranhas-Assu having been marked with the location using GPS (Global Positioning System). The determination of humidity content and digestion of the samples were performed using methods described in the Compendium of analytical standards of the Institute Adofo Lutz (2005) and the determination of metal ions of the elements Al, Ba, Cd, Cr, Cu, Mn, Ni, Pb, Sn and Zn were performed by optical emission spectrometry with inductively coupled plasma as described by USEPA method 6010C. The results show that it is possible to use this molluscum Mytella falcata in the estuaries of Rio Grande do Norte for the determination of metal ions. The data were subjected to principal components analysis (PCA) which enabled us to verify the distribution pattern of the metal ions studied in several estuaries potiguares and group them according to the metal ions in common with and relate them to the activities in each region

Desenvolvimento e calibração de fotômetro solar para medições da profundidade óptica por aerossóis e coluna de água precipitável

Instrumentation is a tool of fundamental importance for research in several areas of human knowledge. Research projects are often unfeasible when data cannot be obtained due to lack of instruments, especially due to impor ting difficulties and the high costs there associated. Thus, in order to collaborate with the enhancement of a national technology, a multiband hand - held sun p hotometer (FSM - 4) was developed to operate in the 500 nm, 670 nm, 870 nm and 940 nm bands. In the 500 nm, 670 nm and 870 nm bands aerosols are monitored for evaluation of the AOD (Aerosol Optical Depth), and the PWC (Precipitable Water Column) is evaluated in the 940 nm band. For the development of the mech anical and electronic parts for the FSM - 4, th e materials and componen ts should combine low cost and quality of the data collected. The calibration process utilized the Langley method (ML) and Modified Langley Method (MLM). These methods are usually applied at high altitudes in order to provide atmosp heric optical stability. This condition however can be found in low height sites as shown in the research by Liu et al. (2010). Thus, for calibration of the FSM - 4, we investigated the atmospher ic optical stability utilizing the ML and MLM at a site in the cit y of Caicó / RN, located in the s emiarid region in northeastern Brazil. This site lies in a region far aw ay from large urban centers and activities generating anthropogenic atmospheric pollution. Data for calibration of the prototype were collected usin g the FSM - 4 in two separate operations during the dry season, one in December 2012 and another in September 2013. The methodologies showed optical atmospheric instability in the studied region through the dispersion of the values obtained for the calibrati on constant. This dispersion is affected by the variability of AOD and PWC during the appl ication of the above mentioned methods . As an alternative to the descr ibed sun photometer calibration , a short study was performed using the sun photometer worldwide network AERONET/NASA (AERsol RObotic NETwork – US Space Agency), installed in Petrolina / PE in Brazil. Data were collected for three days utilizing the AERONET instruments and the FSM - 4, operating simultaneously on the same site. By way of the ML and MLM techniques, convergent test values were obtained for the calibration constants, despite the low amount of data collected. This calibration transfer methodology proved to be a viable alternative to the FSM - 4 calibration .

Efeitos da nicotina no complexo do septo medial na via septo hipocampal em camundongos anestesiados por Ketamina

Nicotine administration in humans and rodents enhances memory and attention, and also has a positive effect in Alzheimer's Disease. The Medial Septum / Diagonal Band of Broca complex (MS/DBB) – a main cholinergic system – massively projects to the hippocampus through the fimbria-fornix, and this pathway is called the septohippocampal pathway. It has been demonstrated that the MS/DBB acts directly on the local field potential (LFP) rhythmic organization of the hippocampus, especially in the rhythmogenesis of Theta (4-8Hz) – an oscillation intrinsically linked to hippocampus mnemonic function. In vitro experiments gave evidence that nicotine applied to the MS/DBB generates a local network Theta rhythm within the MS/DBB. Thus, the present study proposes to elucidate the function of nicotine in the MS/DBB on the septo-hippocampal pathway. In vivo experiments compared the effect of MS/DBB microinfusion of saline (n=5) and nicotine (n=8) on Ketamine/Xylazine anaesthetized mice. We observed power spectrum density in the Gamma range (35 to 55 Hz) increasing in both structures (Wilcoxon Rank-Sum test, p=0.038) but with no change in coherence between these structures in the same range (Wilcoxon Rank-Sum test, p=0.60). There was also a decrease in power of the ketamineinduced Delta oscillation (1 to 3 Hz). We also performed in vitro experiments on the effect of nicotine on membrane voltage and action potential. We patch-clamped 22 neurons in current-clamp mode; 12 neurons were responsive to nicotine, half of them increased firing rate and other 6 decreased, and they significantly differed in action potential threshold (-47.3±0.9 mV vs. -41±1.9 mV, respectively, p=0.007) and halfwidth time (1.6±0.08 ms vs. 2±0.12 ms, respectively, p=0.01). Furthermore, we performed another set of in vitro experiments concerning the connectivity of the three major neuronal populations of MS/DBB that use acetylcholine, GABA or glutamate as neurotransmitter. Paired patch-clamp recordings found that glutamatergic and GABAergic neurons realize intra-septal connections that produce sizable currents in MS/DBB postsynaptic neurons. The probability of connectivity between different neuronal populations gave rise to a MS/DBB topology that was implemented in a realistic model, which corroborates that the network is highly sensitive to the generation of Gamma rhythm. Together, the data available in the full set of experiments suggests that nicotine may act as a cognitive enhancer, by inducing gamma oscillation in the local circuitry of the MS/DBB.

Análise por meio de espectroscopia de emissão óptica das espécies ativas em nitretação iônica e gaiola catódica

Plasma process like ionic nitriding and cathodic cage plasma nitriding are utilized in order to become hard surface of steels. The ionic nitriding is already accepted in the industry while cathodic cage plasma nitriding process is in industrial implementation stage. Those process depend of plasma parameters like electronic and ionic temperature (Te, Ti), species density (ne, ni) and of distribution function of these species. In the present work, the plasma used to those two processes has been observed through Optical Emission Spectroscopy OES technique in order to identify presents species in the treatment ambient and relatively quantify them. So plasma of typical mixtures like N2 H2 has been monitored through in order to study evolution of those species during the process. Moreover, it has been realized a systematic study about leaks, also thought OES, that accomplish the evolution of contaminant species arising because there is flux of atmosphere to inside nitriding chamber and in what conditions the species are sufficiently reduced. Finally, to describe the physic mechanism that acts on both coating techniques ionic nitriding and cathodic cage plasma nitriding