This paper addresses the minimum weight edge cover problem (MEC), which is stated as follows: Given a graph <i>G= (V,E)</i>, find a set of edges <i>S:S⊆E </i>and ∑_e∈S^w(e)</∑<sub>e∈Q^w(e)∀Q: Q is an edge cover. Where an edge cover <i>P</i> is a set of edges such that ∀v∈V <i>v</i> is incident to at least one edge in <i>P</i>. An efficient implementation of a 4/3-approximation for MEC is provided. Empirical results obtained experimentally from practical data sets are reported and compared against various other approximation algorithms for MEC.<br>

The ability of the spatial orientation of the reptiles is not fully researched yet. It is unknown if reptiles use only simple types of navigation, for example cue learning (one key mark), or more difficult types, for example allothetic navigation (combination of marks) or cognitive map (mental representation of the area). The main aim of this thesis was examine the possibility of the spatial orientation in lizard leopard gecko (Eublepharis macularius) in modificated Morris water maze (MWM). Design of the experiments was based on Parallel Map Theory, a theory which describes using spatial information from more navigation frames. The leopard gecko preferences of orientation frames were tested . That means the ability to combinate the spatial information from the bearing maps (one mark and gradient) and the sketch maps (local marks). This ability is prerequisite for creating the integrated map. The research was also focused on the significance of the simple cue learning strategy and cognitive more difficult allothetic navigation for the orientation of leopard gecko. Leopard geckos can use the combination of information from the navigation frames, which indicate the possibility of integrated map creation. Usage of navigation strategies is individual. Keywords: reptiles, leopard gecko, spatial...

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-10-22T10:13:08Z No. of bitstreams: 2 Dissertação - Diego Cruz Abrahão - 2015.pdf: 9765017 bytes, checksum: 6f29592215e8451edda4aa5ad24238f4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-10-22T10:15:40Z (GMT) No. of bitstreams: 2 Dissertação - Diego Cruz Abrahão - 2015.pdf: 9765017 bytes, checksum: 6f29592215e8451edda4aa5ad24238f4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-10-22T10:15:40Z (GMT). No. of bitstreams: 2 Dissertação - Diego Cruz Abrahão - 2015.pdf: 9765017 bytes, checksum: 6f29592215e8451edda4aa5ad24238f4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-03-19 / In this paper we propose two schemes for allocating resource blocks for transmission LTE downlink to maximize the throughput of the system, to guarantee QoS (Quality of Service) parameters for the users and reduce the data loss rate of network. The first proposed scheme uses the Max-min criterion and the second employs a fuzzy inference system to calculate the priorities of users and make scheduling decisions. Both schemes use an estimated effective bandwidth of traffic flows of users. The effective bandwidth of a traffic flow is the rate required to meet a criterion of probability of data loss rate. In this work, the effective bandwidth is estimated adaptively by the parameters of multifractal modeling βMWM (β-Multifractal Wavelet Mode). Are made simulations of the algorithms proposed, considering different propagation models with multipath fading and with different numbers of users in the network. The simulation results are compared with other algorithms presented in the literature, using parameters such as: throughput of the system, data loss rate and fairness index. It is also proposed to use predict of the SNR (Signal-to-Noise Ratio) of users, in the scheduling algorithms, using linear prediction of multi-step filter, in view of the delay in receipt of the channel quality information of the users in the base station and the variation of the signal propagation conditions. The multi-step prediction filter is used with the algorithms of allocation of resource blocks proposed in this work to estimate the signal-to-noise-ratio of users and set well, modulation schemes and code to be used in the LTE network. / Neste trabalho são propostos dois esquemas de alocação de blocos de recurso para a transmissão de downlink LTE, visando maximizar a vazão de dados total do sistema, garantir parâmetros de QoS (Quality of Service) dos usuários e diminuir a taxa de perda de dados da rede. O primeiro esquema proposto utiliza o critério Max-min e o segundo emprega um sistema de inferência fuzzy para calcular as prioridades dos usuários e tomar decisões de escalonamento. Ambos os esquemas utilizam estimações de banda efetiva dos fluxos de tráfego dos usuários. A banda efetiva de um fluxo de tráfego é a taxa necessária para atender a um critério de probabilidade de perda de dados. Neste trabalho, a banda efetiva é estimada de forma adaptativa, através dos parâmetros da modelagem multifractal βMWM (β-Multifractal Wavelet Mode). São realizadas simulações dos algoritmos propostos de alocação de blocos de recurso, considerando diferentes modelos de propagação com desvanecimento de multipercursos e com diferentes quantidades de usuários na rede. Os resultados das simulações são comparados com outros algoritmos apresentados na literatura, através de parâmetros, como: vazão de dados do sistema, taxa de perda de dados e índice de justiça. É proposta ainda, a utilização da predição da relação sinalruído (SNR - Signal-to-Noise Ratio) dos usuários nos algoritmos de escalonamento, utilizando filtro de predição linear de multi-passos, tendo em vista o atraso no recebimento da informação da qualidade do canal dos usuários na estação base e a variação das condições de propagação do sinal. O filtro de predição de multi-passos é utilizado junto com os algoritmos de alocação de blocos de recurso propostos neste trabalho, para estimar a relação sinal-ruído dos usuários e definir, assim, os esquemas de modulação e código a serem utilizados na rede LTE.

The aim of the present study was to elucidate the possible relationship between the levels of various brain fatty acids and learning indices in aged and young mice classified as &ldquo / good&rdquo / or &ldquo / poor&rdquo / learners basing on their performance in a spatial learning task, the Morris Water Maze. The levels of several fatty acids including palmitic, stearic, oleic, linoleic, arachidonic acid (AA) and docosahexaenoic acid (DHA) were measured using gas chromatography separately in samples from four different brain areas: hippocampus, cortex, striatum and hypothalamus. The level of oleic acid in the cerebral cortex was significantly higher in young-good learners as compared to young-poor learners and higher in young-poor learners than in old-poor learners, with no significant difference in the concentration of this acid between old-good and old-poor learners. The most consistent correlation between animals&rsquo / learning capacity and brain fatty acid&rsquo / level was found for the arachidonic acid in the hippocampal region: AA level was significantly lower in young-good learners as compared to both young-poor learners&rdquo / and old-good learners&rdquo / with young-good learners showing significantly better performance than the two other groups. Interestingly, except hypothalamus, no significant between-group differences were recorded for the remaining fatty acids including DHA, in none of the four brain regions examined.

The aim of the present study was to examine retention of spatial reference memory after 6 (Experiment I) and 15days (Experiment II) of binge-like drinking and during alcohol withdrawal in young adult Wistar rats. Prior to alcohol treatment, rats received Morris Water Maze (MWM) training. Afterwards, rats were intragastrically administered ethanol at the dose increasing from 4.5g-to-12g/kg. Intubation control groups (n=7 and n=10, respectively) received infusions of a sucrose solution without ethanol. Subsequently, all subjects were given a single probe trial in the MWM to test memory retention. In both experiments, there were three alcohol groups: A0 group (n=7) tested 4h after the last alcohol administration for acute effects of ethanol / A24 group (n=7) tested 24h after alcohol cessation, when acute ethanol effects disappear but withdrawal symptoms does not develop yet / A72 group (n=7) tested 72h after the last ethanol infusion for withdrawal effects. Finally, potential molecular changes in hippocampus were examined using Fourier Transform Infra-Red (FT-IR) spectroscopy. The blood alcohol concentration was 605.67&plusmn / 36mg/dl. In Experiment I, due to the low overall level of performance in the memory retention task the behavioral effects of ethanol could not be evaluated and no significant between&ndash / group differences were observed in Experiment II. In Experiment I, no significant changes in the molecular make-up of the hippocampus were noted. Conversely, in Experiment II, significant changes in protein, lipid, and nucleic acid profiles related to ethanol intake and withdrawal were found. They are linked to both development of tolerance to ethanol and adverse withdrawal effects.

The developing flow field in a parallel plate microchannel, induced by wall motion, has been modeled numerically. This type of flow simulates the physical driving mechanism that exists in electro-osmotically generated flow with large channel diameter-to-Debye length ratios (Z). The physics of the flow field were compared between the moving wall model (MWM) and electro-osmotic flow (EOF) at Reynolds numbers of 1 and 1800, and Z > 2500. Also, Z-values between 50 and 500 were studied to investigate the accuracy of the MWM. Results show that for Z-values greater than 100 the MWM shows good agreement with EOF. The dynamics of the developing flow field for the MWM were explored for channel length-to-hydraulic diameter ratios (aspect ratio) of 5, 10, 20 and 40 at ten Reynolds numbers, Re (based on the wall velocity), below Re < 2000. The results show that far from the inlet the maximum fluid velocity occurs at the walls, as is expected, and the minimum velocity occurs at the channel center. Near the channel inlet, however, the centerline velocity is not a minimum but reaches a local maximum due to a resulting pressure imbalance generated by the wall motion. As the aspect ratio increases, the centerline velocity tends to approach the wall velocity far downstream from the inlet. Increases in the Reynolds number have the opposite effect on the centerline velocity. The hydrodynamic developing region, defined by that section of the channel where the wall shear stress is changing, also depends on the channel aspect ratio and Re, and is greater than the developing region for classical pressure-driven flow of a parallel plate channel. Also, the flow field physics was analyzed for a process called electro-mobility focusing (EMF). EMF is a process that separates and detects species of like charge with the use of electro-phoresis and EOF utilizing a varying voltage gradient. The velocity distribution and the effective diffusion were solved for analytically, for both a linear and non-linear voltage gradient, using the MWM and the creeping flow approximations. The resulting equations aid in optimizing the detection system by forcing the lowest effective diffusion (uniform velocity profile) to the detection location.

Submitted by Erika Demachki (erikademachki@gmail.com) on 2014-11-06T17:22:37Z No. of bitstreams: 2 Dissertacao - Bruno Henrique Pereira Gonçalves - 2013.pdf: 2765842 bytes, checksum: 73031d592b28fd2dc03d6bbdfa04cc34 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2014-11-06T17:22:46Z (GMT) No. of bitstreams: 2 Dissertacao - Bruno Henrique Pereira Gonçalves - 2013.pdf: 2765842 bytes, checksum: 73031d592b28fd2dc03d6bbdfa04cc34 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-11-06T17:22:46Z (GMT). No. of bitstreams: 2 Dissertacao - Bruno Henrique Pereira Gonçalves - 2013.pdf: 2765842 bytes, checksum: 73031d592b28fd2dc03d6bbdfa04cc34 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-12-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This paper proposes adaptive resource allocation in multiuser wireless networks based on OFDM. Two allocation schemes are proposed: for TDMA networks and LTE networks. The resource allocation schemes that provide QoS are developed from the union of OFDM wireless networks, the proposal of adaptive modeling of traffic flows and the proposal of adaptive estimation of effective bandwidth. The performances of the proposed schemes are verified through simulation. Concepts and studies on traffic modeling, multifractal traffic modeling, theory of effective bandwidth, OFDM, are addressed in order to support the understanding and development of the proposed schemes. An algorithm for adaptive parameter estimation of the multifractal model bMWM is proposed, and studies to estimate the effective bandwidth are presented. Some methods of estimating effective bandwidth are proposed using traffic flow models. / Este trabalho propõe esquemas de alocação adaptativa de recursos em redes sem fio multiusuário OFDM. Dois esquemas de alocação são propostos: para redes TDMA e para redes LTE. Os esquemas de alocação de recursos foram elaborados a partir da união de tecnologia de redes sem fio OFDM, proposta de modelagem adaptativa de fluxos de tráfego e proposta de estimação adaptativa de banda efetiva, de maneira a garantir requisitos de QoS em redesmultiusuário. Simulações são realizadas para validar o desempenho dos esquemas de alocação propostos. Conceitos e estudos sobre modelagem de tráfego, modelagem de tráfego multifractal, teoria de banda efetiva e OFDM são tratados de maneira a subsidiar o entendimento e a elaboração dos esquemas propostos. É proposto um algoritmo para estimação adaptativa de parâmetros do modelo multifractal bMWM, e são apresentados estudos realizados para estimação de banda efetiva. Alguns métodos de estimação de banda efetiva são propostos utilizando modelos de fluxo de tráfego.

Traumatic brain injury (TBI) has a dramatic impact on our society in terms of mortality, morbidity, and inherently high financial costs. Formidable research efforts are being addressed to the identification of neuroprotective agents capable of ameliorating the neurological outcome after TBI. Preclinical studies have recently demonstrated lithium to be a promising neuroprotective agent for both acute ischemic brain injury and chronic neurodegenerative disease. In light of these encouraging data, we designed a lateral fluid-percussion injury (FPI) study aimed at investigating the role of early post-traumatic administration of lithium as a strategy for reducing TBI-induced motor and cognitive deficits. The optimal dose of this agent and the time window for its administration have been determined on the basis of data derived from the assessment of motor and cognitive functioning in experimental animals, as well as from the stereological quantification of neuronal survival (PID 7) within the CA3 and hilar regions of the hippocampus ipsilateral to the FPI. In addition, we attempted to elucidate the mechanisms underlying the neuroprotective properties of this drug via western blot analysis of levels of the pro-apoptotic marker caspase-3 (PID 1, 7) and two neuroplasticity markers, growth associated protein-43 (GAP-43) and brain-derived neurotrophic factor (BDNF) (PID 1, 7, 21). Our findings indicate that low-dose lithium chloride (0.125 or 0.25 mmol/kg), given either 30 min or 8 hr after lateral FPI significantly ameliorates injury-induced cognitive and motor impairment. Specifically, cell survival in the CA3 region of the hippocampus of the injured lithium-treated animals (but not in the hilus) was significantly increased compared to injured vehicle-treated animals. Western blot analyses revealed a significant increase in GAP-43 levels on PID 7 in injured animals when treated with lithium, indicating a possible mechanism for lithium-induced neuroprotection. In contrast, BDNF levels were relatively unchanged until PID 21, and caspase-3 activation was not observed at all, suggesting that these proteins play less significant roles in the observed neuroprotective effects of lithium treatment after lateral FPI. Early administration of lithium, within 8 hours after TBI, holds promise as an effective therapy to ameliorate postinjury neurobehavioral deficits and warrants further investigation in clinical TBI studies.