Direct visualisation of lipid bilayer cubic phases using Atomic Force Microscopy

Inverse bicontinuous cubic (Q(II)) phases are nanostructured materials formed by lipid self-assembly. We have successfully imaged thin films of hydrated Q(II) phases from two different systems using AFM. The images show periodic arrays of water channels with spacing and symmetry consistent with published SAXS data on the bulk materials.

Phytoplankton–zooplankton dynamics in the ‘presence’ or ‘absence’ of toxic phytoplankton

The inhibitory effects of toxin-producing phytoplankton (TPP) on zooplankton modulate the dynamics of marine plankton. In this article, we employ simple mathematical models to compare theoretically the dynamics of phytoplankton–zooplankton interaction in situations where the TPP are present with those where TPP are absent. We consider two sets of three-component interaction models: one that does not include the effect of TPP and the other that does. The negative effects of TPP on zooplankton is described by a non-linear interaction term. Extensive theoretical analyses of the models have been performed to understand the qualitative behaviour of the model systems around every possible equilibria. The results of local-stability analysis and numerical simulations demonstrate that the two model-systems differ qualitatively with regard to oscillations and stability. The model system that does not include TPP is asymptotically stable around the coexisting equilibria, whereas, the system that includes TPP oscillates for a range of parametric values associated with toxin-inhibition rate and competition coefficients. Our analysis suggests that the qualitative dynamics of the plankton–zooplankton interactions are very likely to alter due to the presence of TPP species, and therefore the effects of TPP should be considered carefully while modelling plankton dynamics.

Numerical analyses of Runge–Kutta implicit–explicit schemes for horizontally explicit, vertically implicit solutions of atmospheric models

With the prospect of exascale computing, computational methods requiring only local data become especially attractive. Consequently, the typical domain decomposition of atmospheric models means horizontally-explicit vertically-implicit (HEVI) time-stepping schemes warrant further attention. In this analysis, Runge-Kutta implicit-explicit schemes from the literature are analysed for their stability and accuracy using a von Neumann stability analysis of two linear systems. Attention is paid to the numerical phase to indicate the behaviour of phase and group velocities. Where the analysis is tractable, analytically derived expressions are considered. For more complicated cases, amplification factors have been numerically generated and the associated amplitudes and phase diagnosed. Analysis of a system describing acoustic waves has necessitated attributing the three resultant eigenvalues to the three physical modes of the system. To do so, a series of algorithms has been devised to track the eigenvalues across the frequency space. The result enables analysis of whether the schemes exactly preserve the non-divergent mode; and whether there is evidence of spurious reversal in the direction of group velocities or asymmetry in the damping for the pair of acoustic modes. Frequency ranges that span next-generation high-resolution weather models to coarse-resolution climate models are considered; and a comparison is made of errors accumulated from multiple stability-constrained shorter time-steps from the HEVI scheme with a single integration from a fully implicit scheme over the same time interval. Two schemes, “Trap2(2,3,2)” and “UJ3(1,3,2)”, both already used in atmospheric models, are identified as offering consistently good stability and representation of phase across all the analyses. Furthermore, according to a simple measure of computational cost, “Trap2(2,3,2)” is the least expensive.

Organization of ventral tegmental area projections to the ventral tegmental area-nigral complex in the rat

The ventral tegmental area (VTA) is a nodal link in reward circuitry. Based on its striatal output, it has been subdivided in a caudomedial part which targets the ventromedial striatum, and a lateral part which targets the ventrolateral striatum [Ikemoto S (2007) Dopamine reward circuitry: two projection systems from the ventral midbrain to the nucleus accumbens-olfactory tubercle complex. Brain Res Rev 56:27-78]. Whether these two VTA parts are interconnected and to what extent the VTA innervates the substantia nigra compacta (SNc) and retrorubral nucleus (RR) are critical issues for understanding information processing in the basal ganglia. Here, VTA projections to the VTA-nigral complex were examined in rats, using Phaseolus vulgaris leucoagglutinin (PHA-L) as anterograde tracer. The results show that the dorsolateral VTA projects to itself, as well as to the dorsal tier of the SNc and RR, largely avoiding the caudomedial VTA. The ventrolateral VTA innervates mainly the interfascicular nucleus. The components of the caudomedial VTA (the interfascicular, paranigral and caudal linear nuclei) are connected with each other. In addition, the caudomedial VTA (especially the paranigral and caudal linear nuclei) innervates the lateral VTA, and, to a lesser degree, the SNc and RR. The caudal pole of the VTA sends robust, bilateral projections to virtually all the VTA-nigral complex, which terminate in the dorsal and ventral tiers. Modest inputs from the medial supramammillary nucleus to ventromedial parts of the VTA-nigral complex were also identified. In double-immunostained sections, PHA-L-labeled varicosities were sometimes found apposed to tyrosine hydroxylase-positive neurons in the ventral mesencephalon. Overall, the results underscore that VTA projections to the VTA-nigral complex are substantial and topically organized. In general, these projections, like the spiralated striato-nigro-striatal loops, display a medial-to-lateral organization. This anatomical arrangement conceivably permits the ventromedial striatum to influence the activity of the lateral striatum. The caudal pole of the VTA appears to be a critical site for a global recruitment of the mesotelencephalic system. (C) 2008 IBRO. Published by Elsevier Ltd. All rights reserved.

Large time behaviour for functional differential equations with dominant eigenvalues of arbitrary order

The spectral theory for linear autonomous neutral functional differential equations (FDE) yields explicit formulas for the large time behaviour of solutions. Our results are based on resolvent computations and Dunford calculus, applied to establish explicit formulas for the large time behaviour of solutions of FDE. We investigate in detail a class of two-dimensional systems of FDE. (C) 2009 Elsevier Inc. All rights reserved.

Chaotic phase synchronization and desynchronization in an oscillator network for object selection

Object selection refers to the mechanism of extracting objects of interest while ignoring other objects and background in a given visual scene. It is a fundamental issue for many computer vision and image analysis techniques and it is still a challenging task to artificial Visual systems. Chaotic phase synchronization takes place in cases involving almost identical dynamical systems and it means that the phase difference between the systems is kept bounded over the time, while their amplitudes remain chaotic and may be uncorrelated. Instead of complete synchronization, phase synchronization is believed to be a mechanism for neural integration in brain. In this paper, an object selection model is proposed. Oscillators in the network representing the salient object in a given scene are phase synchronized, while no phase synchronization occurs for background objects. In this way, the salient object can be extracted. In this model, a shift mechanism is also introduced to change attention from one object to another. Computer simulations show that the model produces some results similar to those observed in natural vision systems.

Suppressing grazing chaos in impacting system by structural nonlinearity

In this note we investigate the influence of structural nonlinearity of a simple cantilever beam impacting system on its dynamic responses close to grazing incidence by a means of numerical simulation. To obtain a clear picture of this effect we considered two systems exhibiting impacting motion, where the primary stiffness is either linear (piecewise linear system) or nonlinear (piecewise nonlinear system). Two systems were studied by constructing bifurcation diagrams, basins of attractions, Lyapunov exponents and parameter plots. In our analysis we focused on the grazing transitions from no impact to impact motion. We observed that the dynamic responses of these two similar systems are qualitatively different around the grazing transitions. For the piecewise linear system, we identified on the parameter space a considerable region with chaotic behaviour, while for the piecewise nonlinear system we found just periodic attractors. We postulate that the structural nonlinearity of the cantilever impacting beam suppresses chaos near grazing. (C) 2007 Elsevier Ltd. All rights reserved.

Utvärdering av digitala provtryckssystem

Six different Digital Proofing Systems from three different techniques have been evaluated as totechnique, printing quality, economy and usability. Digital proof from two paper qualities, coatedand uncoated, has been compared with references printed in offset, to see how good they match eachother. Only two Proofing Systems manage to print on reference paper. The other Proofing Systemsuse special paper for digital proof.Measurements and visuell judgement show that the Digital Proofing Systems visualise referencepictures with quite good quality. Proof optimised for coated paper visualise the colours with goodresult. Proof optimised for uncoated paper shows higher quality than the references, which depends onthe surface of the proofing paper. Comparison between reference paper and proofing paper has takenplace as to differences in colour and paper quality.The Digital Proofing Systems are fully automatic, which demand a quite comprised education forcorrect handling. The purchase price and printing costs vary considerably between the ProofingSystems.

Tillämpning och utvärdering av kriterier för eTjänstetydlighet och handlingsbarhet : Actability, eTjänstetydlighet, MA/SIMM

A sequence of actions in the world have influenced the information science, one of these actions is the lateral movement in how companies use their IT-systems. IT-systems today, in comparison to before, are used by companies to improve their relationship with their customers. Every year a big amount of money is spent on developing and improving IT-systems. That is why it is important to develop and create IT-systems that are clear, and which encourage, enable and simplify a user’s action. There are criteria to use in actability and “eTjänstetydlighet”. I have in this thesis used acknowledged criteria for actability and “eTjänstetydlighet” to analyze two IT-systems that are equal to each other. This is to show how companies can develop and adjust their IT-system so that they will match today’s point of view. I have also in this thesis chosen to evaluate the usage of criteria for “eTjänstetydlighet” and that is because no one has done that before. The result of this thesis gave Monster and Proffice measures for how to develop their IT-systems. The result of this thesis also gave indications of fuzziness when using criteria for “eTjänstetydlighet”, however, I was able to use the criteria the way they were supposed to be used to fulfill their purpose.

Frånluftsåtervinning i ett äldre flerfamiljehus : Hovgården - Borlänge

I detta examensarbete undersöktes möjligheten att installera värmeåtervinningssystem för ett flerfamiljehus i Hovgården som ligger en bit utanför Borlänge. I rapporten redovisas två olika sätt för energibesparingar som är aktuella för att ersätta borttagning av oljepannan som används i huset i dag. En rad svårigheter dök upp under undersökningen för installation av nytt värmesystem. Lämpliga lösningar kunde hittas efter mycket analys. Syftet med rapporten var att undersöka möjligheten och lönsamheten för installation av något av följande system; FVP eller VBX-modul som kan återvinna värme ur frånluften. Undersökningen visade att varken VBX eller FVP kan ersätta oljepannans värmeavgivning på ett tillfredsställande sätt. Med VBX ökas COP från 2,8 till 3,11 vilket leder till 17 MWh/år elbesparing. Däremot FVP kan försörja huset med 59 MWh/år men kan inte täcka effektbehovet för gården under kallaste dagarna. Resultatet blev att de båda undersökta systemen inte har möjlighet att ersätta oljeeldning.

Jämförelse av två system för att bedöma vinter väglag : Ett nytt system i utvecklingen för att säkra Sveriges vägar

Trafikverket, är den statliga verksamhet som har hand om alla Sveriges vägar och järnvägar har den så kallade nollvisionen som ett huvudmål. Tanken bakom nollvisionen är att de som använder vägarna skall vara säkra och inte komma till skada. En del av uppfyllandet av detta mål är att Trafikverket ger ut korttidsprognoser för väglag och körförhållande. I nuläget så används ett mycket manuellt systemet som heter NTIS, men man håller på att utveckla det nya automatiska systemet RCC som skall kunna ta fram korttidsprognoser baserat på olika former av data, t.ex. data från väderstationer. Syftet med denna studie är att utvärdera hur väl de två olika systemen utför en korttidsprognos och jämföra de mot varandra, samt verkligheten. Denna studie gjordes i form av en förklarande fallstudie. Som datainsamling används dokument i olika former och analysen var kvantitativ då resultatet av utvärdering ger olika procenttal av hur rätt respektive system har. Under undersökningen gång så kom vi fram till att båda systemen hade sina fördelar och nackdelar. T.ex. så det gamla NTIS systemet fortfarande bäst på isigt och moddigt väglag. Medans det nya RCC systemet hade sina egna fördelar, t.ex. snöigt väglag och vått väglag. Samt så hade RCC en klar fördel med sin rapporteringstid, vilket var ett problem man såg med NTIS. Resultat var som sagt ett procenttal av hur rätt de två olika systemen hade, men även förslag till förbättringar. T.ex. hur man skulle kunna ändra RCC regler för bättre resultat.

Endogenous protection in Mercosul: an empirical analysis

This paper analyses the equilibrium structure of protection in Mercosul, developing empirical analyses based on the literature ensuing from the sequence of models set forth by Grossman and Helpman since 1994. Not only Mercosul’s common external tariff (CET) may be explained under a political economy perspective, but the existence of deviations, both at the level of the external tariffs and at that of the internal ones, make it interesting to contrast several structures under this approach. Different general equilibrium frameworks, in which governments are concerned with campaign contributions and with the welfare of the average voter, while organized special-interest groups care only about the welfare of their members, are used as the theoretical basis of the empirical tests. We build a single equation for explaining the CET and two fourequations systems (one equation for each member) for explaining deviations from the CET and from the internal free trade between members. The results (at the two-digit level) shed an interesting light on the sectoral dynamics of protection in each country; notably, Brazil seems to fit in better in the model framework, followed by Uruguay. In the case of the CET, and of deviations from it, the interaction between the domestic lobbies in the four countries plays a major role. There is also suggestion that the lobby structure that bid for deviations, be they internal or external, differs from the one which bid for the CET.

Trabalho e família no contexto de teletrabalho: o olhar de teletrabalhadores e seus co-residentes

Esta dissertação tem como objetivo contribuir para o conhecimento sobre o teletrabalho, especialmente, sobre a dinâmica da realização do trabalho na esfera familiar, a partir do home-office telework. Investigou-se de que maneira os teletrabalhadores e sua família dão sentido aos dilemas, oportunidades e exigências da realização do trabalho no ambiente familiar, à luz de suas práticas discursivas. Para tanto, entrevistas semi-estruturadas foram realizadas com 25 teletrabalhadores e seus co-residentes e analisadas sob a ótica da análise de conteúdo. A pesquisa revela que quando a casa dá lugar às atividades profissionais do indivíduo, as relações entre as demandas pessoais, familiares e profissionais se tornam mais próximas, diluídas e entrelaçadas. A aproximação das esferas de trabalho e não-trabalho conduz a uma ruptura nas dinâmicas espaciais, temporais e psicológicas desses domínios, proporcionando aos indivíduos oportunidades de desenvolvimento pessoal. No entanto, as mudanças pelas quais os mesmos terão de passar apresentam potencialidades contraditórias. Ao mesmo tempo em que o teletrabalho proporciona uma oportunidade de integração com a família e flexibilidade para o melhor aproveitamento do tempo de trabalho e não-trabalho, a dificuldade de equilibrar dois mundos construídos sobre discursos diversos, o mundo da casa e da rua, pode despontar uma crise, dependendo do preparo de cada família para essa situação de trabalho. A fim de auxiliar na interpretação dos resultados, os pontos de conteúdo mais expressivos, os quais ilustram o exposto acima, foram expostos em quatro temas relacionados ao telehomework: espaço, flexibilidade de tempo, gênero e equilíbrio trabalho-vida pessoal.

Interactive music visualization: implementation, realization and evaluation

This thesis describes all process of the development of music visualization, starting with the implementation, followed by realization and then evaluation. The main goal is to have to knowledge of how the audience live performance experience can be enhanced through music visualization. With music visualization is possible to give a better understanding about the music feelings constructing an intensive atmosphere in the live music performance, which enhances the connection between the live music and the audience through visuals. These visuals have to be related to the live music, furthermore has to quickly respond to live music changes and introduce novelty into the visuals. The mapping between music and visuals is the focus of this project, in order to improve the relationship between the live performance and the spectators. The implementation of music visualization is based on the translation of music into graphic visualizations, therefore at the beginning the project was based on the existent works. Later on, it was decided to introduce new ways of conveying music into visuals. Several attempts were made in order to discover the most efficient mapping between music and visualization so people can fully connect with the performance. Throughout this project, those attempts resulted in several music visualizations created for four live music performances, afterwards it was produced an online survey to evaluate those live performances with music visualization. In the end, all conclusions are presented based on the results of the online survey, and also is explained which music elements should be depicted in the visuals, plus how those visuals should respond to the selected music elements.

Avaliação da ecotoxicidade de percolados em áreas de disposição de resíduos na região metropolitana de Natal/RN

Leachates are effluent produced by decomposition of solid waste, they have complex composition and can be highly toxic. Therefore such percolated liquid should be collected and treated properly to avoid environmental contamination of soil and of water bodies. The objective of this study was to evaluate the toxicity through ecotoxicological tests with Ceriodaphnia dubia (Cladocera - Crustacea) of percolated liquids generated in two different systems of municipal solid waste (MSW) disposal in the city of Natal/ RN: A Sanitary Landfill in the Metropolitan Region of Natal/ RN, and in a dump off area. Furthermore, it was evaluated the possible contamination of the underground water of the dump off area. Two monthly samples were taken at four points between the months of May/2009 and January/2010. The Point "A" corresponds to the end of the pond leachate treatment in ASRMN; The Point "B" corresponds to a containment pond at the dump. The Point "C" is an area near one of the cells of the dump off area where the leachate outcrops; The Point "D" stands for an underground water well at the area. The last point, called "E" was sampled only once and corresponds to the slurry produced by temporary accumulation of solid waste in the open area of the dump. The ecotoxicological tests, acute and chronic, followed the ABNT 13373/2005 rules, with some modifications. The samples were characterized by measuring the pH number, the dissolved oxygen (DO), the salinity, BOD5, COD, Cd, Cu, Pb, Cr, Fe, Mg, Ni, and Zn. At Point A, the average number of EC50-48h ranged between 1.0% and 2.77% (v/v), showing a high toxicity of the leachate to C.dubia in all months. To this point, positive correlations were found between the EC50- 48 with precipitation. Negative correlations were found between the EC50- 48h with salinity. At point B there was no response of the acute exposure of organisms to the test samples. At point C the EC50-48h ranged from 17.68% to 35.36% in just two months of the five ones analyzed, not correlated meaning. Point D, the EC50-48h level ranged between 12.31% and 71.27%, showed a negative correlation with, only, precipitation. Although it was observed toxicity of underground water in the Landfill Area, there was no evidence of water contamination by leachate, however, due to the toxic character of this water, additional tests should be conducted to confirm the quality of water that is used for human supply. At point E there was no acute toxicity. These results support the dangers of inappropriate disposal of MSW to water bodies due to the high toxicity of the leachate produced highlighting the necessity of places of safe confinement and a treatment system more effective to it