L-glutamate is the predominant excitatory amino acid neurotransmitter inthe mammalian central nervous system. Prior aging studies have focusedprimarily on dopaminergic circuitry of the striatum, and data obtained studyingglutamate regulation in the striatum have been largely equivocal. Thesediscrepancies are due in large part to the limitations of microdialysis; while it isextremely sensitive to minute concentrations of analyte, it is lacking in terms ofthe temporal resolution necessary to study a neurotransmitter with rapid releaseand clearance kinetics such as glutamate. In order to address this matter, ourlaboratory has designed a ceramic-based multisite microelectrode with thecapability to detect and analyze fluctuations in extracellular glutamateconcentrations on a sub-second basis. These microelectrodes were utilized tostudy the phasic release and uptake dynamics of potassium-evoked glutamate inthe striatum of young (6 month), late-middle aged (18 month) and aged (24month) Fischer 344 rats. Our results showed a reduced glutamate clearancerate and an attenuated response to potassium depolarization in the corticostriatalprojections of aged animals in comparison to other age groups. In addition,average maximal glutamate release amplitudes were decreased in the striatumof aged animals. Pressure ejection of exogenous glutamate solution furtherconfirmed the decreased glutamate clearance ability of the aged striatum. Thesepotassium and exogenous glutamate data also highlighted a markeddorsoventral gradient in the striatum in terms of glutamate release and clearanceability. We further explored this phenomenon of age-related decreased glutamateuptake by coupling our in vivo technology with classical immunoblotting andbiotinylation techniques in order to investigate glutamate transporter regulation.Decreased glutamate clearance in the aged rats cannot be attributed to areduction in steady-state total transporter protein levels. Rather, our resultsindicate that reduced plasma membrane surface trafficking of GLAST in the agedstriatum may be partially responsible for this effect. Finally, we modified ourmicroelectrodes to study basal glutamate levels in the striatum of the aging,freely moving rat. This approach allowed us to study extracellular glutamateregulation free from the potential confounding variable of anesthesia. Our resultsdemonstrate that there is no significant alteration in basal glutamate levels inaging in the brain regions investigated. More importantly, this study validated theefficacy of the utilization of ceramic-based multisite microelectrodes for the studyof alterations in glutamate neurotransmission in the aging, freely moving rat, andit lays the foundation for future work correlating such changes with age associatedimpairments in motor function.

L-glutamate (Glu) is the predominant excitatory neurotransmitter inthe mammalian central nervous system (CNS) and is associated with a widevariety of functions including motor behavior and sensory perception. Whilemicrodialysis methods have been used to record tonic levels of Glu, little isknown about the more rapid changes in Glu signals that may occur in awakeanimals. We have previously reported acute recording methods using anenzyme-based microelectrode array (MEA) with fast temporal resolution (800msec), that is minimally invasive and is capable of detecting low levels of Glu (andlt;0.2 ??M) in anesthetized animals with little interference from other analytes. Wehave made a series of modifications to the MEA design to allow for reliablemeasures in the brain of awake behaving rats. In these studies, wecharacterized the effects of chronic implantation of the MEA into the striatum andprefrontal cortex (PFC) of Fischer 344 and Long Evans rats. We measuredresting levels of Glu and local application of Glu for 7 days without a significantloss of sensitivity and determined that Glu measures due to exogenous Gluvaried between rat strain and brain region. In addition, we determined theviability of the recordings in the brains of awake animals. We performed studiesof tail-pinch induced stress which caused an increase in Glu in the striatum andPFC of Long Evans and Fischer 344 rats. Histological data show that chronicimplantation of our MEAs caused minimal injury to the CNS. Taken together, ourdata support that chronic recordings of tonic and phasic Glu can be carried out inawake rats reliably for 7 days in vivo allowing for longer term studies of Gluregulation in behaving rats.

Europos Sąjungos pilietybės koncepcija, pirmiausia pristatyta Mastrichto sutartimi (1992 m.), vėliau patikslinta Amsterdamo sutartimi (1997 m.), ilgai buvo laikoma tuščiu pažadu. Nors pradžioje ši simbolinės reikšmės koncepcija nesukūrė naujų teisių, tačiau dabar tapo esmine kylančioje Europos santvarkoje. Dėl Teisingumo Teismo dinamiškos praktikos ir jos kodifikavimo naujojoje Direktyvoje 2004/38/EB dėl Sąjungos piliečių ir jų šeimos narių teisės laisvai judėti ir gyventi valstybių narių teritorijoje koncepcijos vaidmuo pradėjo keistis. Europos Sąjungos pilietybė pamažu tampa tiesioginiu teisių šaltiniu išeinant už ekonominio konteksto ribų. Darbe analizuojama ekonomiškai neaktyvių Europos Sąjungos piliečių teisė laisvai judėti ir įsikurti Sąjungos teritorijoje. Pagrindinis darbo tikslas – aptarti esamą ir potencialiai galimą laisvo judėjimo principo išplėtimą ekonomiškai neaktyvių Sąjungos piliečių atžvilgiu. Pirmoje darbo dalyje akcentuojamas Europos Sąjungos pilietybės principas kaip nepriklausomas ekonomiškai neaktyvių Europos Sąjungos piliečių teisių šaltinis. Analizuojamas teisės laisvai judėti turinys, ypač daug dėmesio skiriama Sutarties 17 ir 18 straipsnių analizei, siekiant nustatyti, kokias naujoves skatina ir problemas kelia šių straipsnių taikymas naujausioje Teisingumo Teismo praktikoje, t.y., ar Sutarties 17-18 straipsnių nuostatos sukuria autonomišką ir tiesioginę teisę laisvai judėti ir įsikurti Europos Sąjungoje; ar pakeičia “išimtinai vidaus situacijos”... [toliau žr. visą tekstą] / First introduced by the Maastricht Treaty, and subsequently revised by the Amsterdam Treaty, European Union (EU) citizenship long remained an empty promise. Even if it did not offer much in terms of new rights at first, EU citizenship has now become a key element of the rising European polity. Recently, indeed, and thanks primarily to the European Court of Justice’s (ECJ) case-law and its codification in Directive 2004/38/EC on the rights of movement and residence of EU citizens and their family, things have started to change. European citizenship is slowly becoming a direct source of rights outside the economic context. This academic master work explores the right of economically inactive EU citizens to move and reside freely within the territory of European Union. The main purpose of this work is to review the existing and potential extension as well as challenges to the principle of free movement of economically inactive EU citizens. Part I of this work highlights the principle of EU citizenship as an independent source of rights of economically inactive people. This part explores the material scope of free movement rights concentrating on the added value of Articles 17-18 EC: whether the new provisions introduce an autonomous and directly effective right to move and reside in a Member State; whether Article 17 and 18 change the law as it relates to ‘wholly internal situations’; whether Articles 17 and 18 contribute to the creation of new substantive rights for EU... [to full text]

<p>In recent years, large-scale brain recordings in nonhuman primates have been a driving force for both fundamental neuroscience and the field of brain-machine interfaces (BMIs). This required monkey implants connected to external amplifiers and computers with ever increasing number of cables. As shown with our recent demonstration of 2,000 neurons recorded in one monkey, a tethered recording system begins to get bulky and complex, particularly for our BMI and neurophysiological research. To address this problem, we developed a multichannel wireless recording framework. The system was been tested in freely moving rhesus monkey by integrating wireless neural recordings with external computers performing BMI decoding, behavioral manipulanda and optical tracking. This technology can be applied to primate behavior research and, in the near future, wireless, fully implantable human neuroprosthetics, which is of great significance to those suffering from locomotor deficiencies, such as those brought on by spinal cord injury and stroke. Aided with these advances, I was able to study monkeys in unrestrained locomotion while their cortical activity was continuously monitored. I also explored unrestrained behaviors and how they showed distinct transitions in neural dynamics as monkeys engaged in different behavioral activities or learned new motor skills, such as bipedal walking. I was able to decode them many of these behavioral states from cortical activity with neural classifiers. Lastly, monkeys were able to perform BMI tasks continuously for many hours, allowing us to prove the relevance of unrestrained noise in BMI performance. Lastly, I present my role in developing two brain actuated movement platforms, a robotic exoskeleton under the guise of the WalkAgain project, and a microelectrode BMI enabled wheelchair. This body of work should assist those on the path to the next generation of clinical neuroprostheses and neural communication systems.</p> / Dissertation

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Background subtraction is the algorithmic process that segments out the region of interest often known as foreground from the background. Extensive literature and numerous algorithms exist in this domain, but most research have focused on videos captured by static cameras. The proliferation of portable platforms equipped with cameras has resulted in a large amount of video data being generated from moving cameras. This motivates the need for foundational algorithms for foreground/background segmentation in videos from moving cameras. In this dissertation, I propose three new types of background subtraction algorithms for moving cameras based on appearance, motion, and a combination of them. Comprehensive evaluation of the proposed approaches on publicly available test sequences show superiority of our system over state-of-the-art algorithms. The first method is an appearance-based global modeling of foreground and background. Features are extracted by sliding a fixed size window over the entire image without any spatial constraint to accommodate arbitrary camera movements. Supervised learning method is then used to build foreground and background models. This method is suitable for limited scene scenarios such as Pan-Tilt-Zoom surveillance cameras. The second method relies on motion. It comprises of an innovative background motion approximation mechanism followed by spatial regulation through a Mega-Pixel denoising process. This work does not need to maintain any costly appearance models and is therefore appropriate for resource constraint ego-vision systems. The proposed segmentation combined with skin cues is validated by a novel application on authenticating hand-gestured signature captured by wearable cameras. The third method combines both motion and appearance. Foreground probabilities are jointly estimated by motion and appearance. After the mega-pixel denoising process, the probability estimates and gradient image are combined by Graph-Cut to produce the segmentation mask. This method is universal as it can handle all types of moving cameras.

<p>The role of intrinsic hydrodynamic instability of the premixed flame (known as Landau-Darrieus instability) in various flame phenomena is studied by means of direct numerical simulations of the complete system of hydrodynamic equations. Rigorous study of flame dynamics and effect of Landau-Darrieus instability is essential for all premixed combustion problems where multidimensional effects cannot be disregarded.</p><p>The present thesis consists of three parts. The first part deals with the fundamental problem of curved stationary flames propagation in tubes of different widths. It is shown that only simple "single-hump" slanted stationary flames are possible in wide tubes, and "multi-hump" flames in a laminar flow are possible in wide tubes only as a non-stationary mode of flame propagation. The stability limits of curved stationary flames in wider tubes are obtained, together with the dependence of the velocity of the stationary flame on the tube width. The flame dynamics in wider tubes is shown to be governed by a large-scale stability mechanism resulting in a highly slanted flame front.</p><p>The second part of the thesis is dedicated to studies of acceleration and fractal structure of outward freely propagating flames. It is shown that in direct numerical simulation the development of Landau-Darrieus instability results in the formation of fractal-like flame front structure. The fractal excess for radially expanding flames in cylindrical geometry is evaluated. Two-dimensional simulation of radially expanding flames in cylindrical geometry displays a radial growth with 1.25 power law temporal behavior after some transient time. It is shown that the fractal excess for 2D geometry obtained in the numerical simulation is in good agreement with theoretical predictions. The difference in fractal dimension between 2D cylidrical and three-dimensional spherical radially expanding flames is outlined. Extrapolation of the obtained results for the case of spherical expanding flames gives a radial growth power law that is consistent with temporal behavior obtained in the survey of experimental data.</p><p>The last part of the thesis concerns the role of Landau-Darrieus instability in the transition from deflagration to detonation. It is found that in sufficiently wide channels Landau-Darrieus instability may invoke nucleation of hot spots within the folds of the developing wrinkled flame, triggering an abrupt transition from deflagrative to detonative combustion. It is found that the mechanism of the transition is the temperature increase due to the influx of heat from the folded reaction zone, followed by autoignition. The transition occurs when the pressure elevation at the accelerating reaction front becomes high enough to produce a shock capable of supporting detonation.</p>

Animals must sense their surroundings to update their internal representations of the external environment, and exploratory behaviours such as sensory sampling are influenced by past experiences. This thesis investigates how voluntary sensory sampling activities undergo learning-dependent changes. Studies of freely behaving animals impose two major challenges: 1) the accuracy of biological measurements is compromised by movement-induced artifacts, and 2) large degrees of freedom in unrestrained behaviours confound well-controlled studies. Pulse-type weakly electric fish (WEF) are an ideal choice to study adaptive sensory sampling from unrestrained animals, since they generate readily observable and quantifiable sensory capture events expressed by discrete pulses of electric organ discharges (EODs). To study the voluntarily movements and sensory sampling while animals navigated in darkness, we developed three novel experimental techniques to track movements and detect sensory sampling from a freely behaving WEF: 1) an EOD detector to remotely and accurately measure the sensory sampling rate, 2) an electrical tracking method to track multiple WEF using their own EODs, and 3) visual tracking algorithm for robust body tracking through water under infrared illumination. These techniques were successfully applied to reveal novel sensory sampling behaviours in freely exploring Gymnotus sp. Cortical activity precedes self-initiated movements by several seconds in mammals; this observation has led into inquiries on the nature of volition. Here we demonstrate the sensory sampling enhancement also precedes self-initiated movement by a few seconds in Gymnotus sp. Next, we tested whether these animals can be trained to learn a location of food using electrically detectable landmarks and, if so, whether they can use their past experiences to optimize their sensory sampling. We found that animals revisited the missing food location with high spatial accuracy, and they intensified their sensory sampling near the expected food location by increasing the number of EOD pulses per unit distance travelled.