669 research outputs found
The great powers and the establishment of security regimes:: the formation of the Concert of Europe, 1792-1815
No full textOver the past two centuries, international relations have been marked by greater institutionalization. This trend has characterized not only trade and economic relations but also such highly sensitive areas as security and political-military cooperation among states. The institutionalization of security issues by means of establishing global and regional security organizations, such as the UN and NATO, or issue-specific security regimes, such as the non-proliferation regime, raises important questions about the changing nature of international relations. Why do states cooperate to establish international security regimes in the first place? Why do they succeed in establishing security regimes in some cases and fail in others?
In my dissertation I addresses these questions by studying several attempts made by the great powers between 1792 and 1815 to form an early case of a security regime, known as the Concert of Europe. As an example of successful great power cooperation in security issues, the study of the Concert has recently acquired a great deal of political as well as academic importance, leading to the emergence of substantial scholarship among historians and political scientists. The literature on the Concert is abundant, however, it suffers from a major weakness: it offers bivariate explanations of regime formation, emphasizing either power, interests or knowledge as the key variable. The same weakness characterizes the regime scholarship in general. I redress these weaknesses in the scholarship by using a multivariate approach to the study of the formation of the Concert. I focus on the interplay of four key factors -- power, interests, knowledge and leadership in the creation of the European Concert.
I do not treat the formation of the Concert of Europe as a single case study. The formation of the Concert constitutes a series of mini-cases and thus may be viewed as a small-N study. Between 1792 and 1815 the great powers went through several rounds of negotiations over the creation of a European concert, which corresponded to the formation of several anti-French coalitions. The Second and the Third Coalitions represent cases of failure to form a European concert, while the Grand Coalition (1814-1815) is a clear-cut case of success.
The findings reached on the basis of all four case-studies are numerous and shed new light on the relative role played by the key major factors -- power, interests, knowledge and leadership in the creation of security regimes. As a theory-generating small-N study, the findings of the dissertation may be tested in other cases of security regime formation such as the creation of the League of Nations (1919) or the United Nations (1945).Ph.D.Includes bibliographical references (p. 226-240)
The "Akopian" vault performed by elite male gymnasts: Which biomechanical variables are related to a judge's score?
No full textBackground: A vaulting performance takes a short time and it is influenced by and affects the quantity of mechanical variables. The significant relationships between the vaulting score and specific aspects of the gymnast's vault should conduct coaches to monitor these variables as a part of training or routine testing. Objective: The aim of the current study was to determine the biomechanical variables that are related to a successful performance of the Akopian vaults performed by top level male gymnasts during the World Cup competition. Methods: Fifteen top-level male gymnasts participated in this study. For the 3D analysis, two digital camcorders with a frame rate of 50 Hz were used. The data were digitized by the Simi motion software. The Hay and Reid method was used to identify the biomechanical variables that determine the linear and angular motions of the handspring and front somersault vaults. A correlation analysis was used to establish the relationship between the biomechanical variables and the judges' scores. The level of statistical significance was determined at the value of p < .05. Results: In the Akopian vaults, in five out of 24 variables arising from the deterministic model showed a significant relationship to the score. A significant correlation was found in the maximum height of the body center of mass in the second flight phase, in the height of the body center of mass at the mat touchdown, in the change of the vertical velocity during the take-off from the vaulting table, and in the duration of the second flight phase. Conclusions: The results of the study suggest that a successful execution of Akopian vaults and the achievement of a higher score required: to maximize the change in vertical velocity in the table contact phase and maximize vertical velocity in the table take-off phase; to maximize the amplitude of the second flight phase, which is determined by the duration of the second flight phase, by the maximum height of the body center of mass in the second flight phase and by the distance of the vaulting table during landing; and to maximize the height of the body center of mass in the mat contact phase
ARMENIAN HISTORIOGRAPHY OF V-VII CENTURIES: SPECIFICITY OF STRUCTURE AND COMPOSITIONAL TECHNIQUES OF NARRATION
No full textFocusing on the historical works of the first Armenian historians and writers of V-VII centuries the issue scrutinizes the peculiarities and formula of the textual organization characteristic to the Armenian "Histories". The author concludes that the structures of the works under consideration draw upon somewhat common historical scenario implying the fate of the Armenian people’s instant dependance on their commitment to the Christianity. The author shows that the events of the Armenian late antique history gave grounds for developing of two different blueprints of the Armenian history: the worst-case and the optimistic ones
ARMENIAN HISTORIOGRAPHY OF V-VII CENTURIES: SPECIFICITY OF STRUCTURE AND COMPOSITIONAL TECHNIQUES OF NARRATION
No full textFocusing on the historical works of the first Armenian historians and writers of V-VII centuries the issue scrutinizes the peculiarities and formula of the textual organization characteristic to the Armenian "Histories". The author concludes that the structures of the works under consideration draw upon somewhat common historical scenario implying the fate of the Armenian people’s instant dependance on their commitment to the Christianity. The author shows that the events of the Armenian late antique history gave grounds for developing of two different blueprints of the Armenian history: the worst-case and the optimistic ones
D2 dopamine receptor-mediated inhibition of a hyperpolarization-activated current in rod photoreceptors
No full text 1. Using the whole cell patch clamp method, we investigated the effect of dopamine on a hyperpolarization-activated current (Ih) in the inner segments of rod photoreceptors of the Xenopus retina. 2. Ih was elicited by hyperpolarizing voltage steps to -120 mV from a holding potential of -40 mV. Dopamine reversibly reduced Ih in a dose-dependent manner. Dopamine-mediated inhibition of Ih was blocked by the D2 dopamine antagonist sulpiride. 3. The D2 dopamine agonist quinpirole (0.1-20 microM) inhibited Ih whereas the D1 agonist SKF-38393 (100 microM) had no effect on Ih. Quinpirole-induced inhibition of Ih was blocked by sulpiride, but not by the D4 antagonist, clozapine. The D3 agonists (+/-)-7-hydroxy-2-dipropylaminotetralin hydrochloride and trans-7-hydroxy-2[N-propyl-N-(3'-iodo-2'-propenyl)amino]-tetralin maleate were, respectively, 5 and 100 times less effective than quinpirole in inhibiting Ih. 4. Quinpirole failed to reduce Ih when the internal solution contained GDP beta S (500 microM). Internal application GTP gamma S (300 microM) progressively and irreversibly reduced Ih and blocked a further reduction by quinpirole, indicating that the inhibition of Ih by quinpirole involves a G protein. 5. The inhibition of Ih by quinpirole was not affected by intracellularly applied adenosine 3',5'-cyclic monophosphate (cAMP) or by the protein kinase inhibitor H-7, indicating that a cAMP-mediated second messenger cascade does not participate in the dopamine-mediated inhibition. 6. Ih was not altered when the patch pipette contained a nominally Ca(2+)-free internal solution, but the inhibition of Ih by quinpirole was abolished, suggesting an involvement of Ca(2+) in the quinpirole-induced effect. 7. We conclude that a D2 dopamine receptor modulates Ih through the activation of a G protein and that intracellular Ca2+, but not cAMP, plays a key role in this process. 8. The reduction of Ih by dopamine may reduce the ability of rods to signal time-modulated light stimuli. </jats:p
Modulation of transient outward potassium current by GTP, calcium, and glutamate in horizontal cells of the Xenopus retina
No full text 1. Membrane currents of luminosity horizontal cells (L-HCs) and chromatic horizontal cells (C-HCs) isolated from the Xenopus retina were characterized using the whole-cell patch-clamp technique. 2. The current-voltage curve for the L-HC had a characteristic negative slope conductance in the voltage range of -30 to -10 mV that was not evident in the C-HC. 3. A transient outward 4-aminopyridine-sensitive potassium current (A-current) was the most prominent current in C-HCs but was also present in L-HCs. A-current characteristics in the two horizontal cell (HC) classes were closely similar. Its threshold of activation was above -45 mV. The half-voltage of inactivation was close to -70 mV. The decay of the A-current was fit by a single exponential with time constants of 30 and 40 ms at depolarizing voltage steps to -10 and +30 mV, respectively. 4. The voltage for 50% A-current inactivation shifted toward negative potentials shortly after we established the whole-cell configuration. This shift was changed to more positive potentials by internal application of guanosine 5'-triphosphate, resulting in a significant overlap of A-current activation and inactivation functions near -40 mV, which is well within the normal operating range of the HC. 5. Internal application of the G-protein activator GTP gamma S shifted the voltage-dependent inactivation of the A-current toward positive potentials by +15 mV. In contrast, GDP beta S shifted the inactivation curve by about -10 mV, similar to what was observed in untreated cells. 6. GTP and GTP gamma S increased the rate of recovery from inactivation and slowed down the rate of inactivation of the A-current enabled by a depolarizing prepulse. 7. Glutamate superfused in the bath solution significantly accelerated the rate of inactivation of A-current induced by depolarizing prepulses. The rate of A-current recovery from inactivation, however, was not affected by glutamate. 8. Removal of calcium from the bath solution reversibly decreased the amplitude of the A-current without a significant shift in its threshold of activation. </jats:p
Direct Band Gap AlGaAs Wurtzite Nanowires
No full textWurtzite AlGaAs is a technologically promising yet unexplored material. Here we study it both experimentally and numerically. We develop a complete numerical model based on an 8-band Formula Presented method, including electromechanical fields, and calculate the optoelectronic properties of wurtzite AlGaAs nanowires with different Al content. We then compare them with our experimental data. Our results strongly suggest that wurtzite AlGaAs is a direct band gap material. Moreover, we have also numerically obtained the band gap of wurtzite AlAs and the valence band offset between AlAs and GaAs in the wurtzite symmetry.</p
A SUPL based A-GPS simulator support for indoor positioning
No full textThe author has granted permission for their work to be available to the general public.During recent years location technologies have emerged as a research area with many possible applications and potential impacts in wireless communications, surveillance, and military equipment, etc. This is essentially driven by the success of US Global Positioning System (GPS) and the development of other Global Navigation Satellite Systems (GNSS). Conventional GPS receivers are designed to operate in open-sky environments and have difficulty dealing with signal blockage from buildings and foliage which deteriorates their performance in urban canyons, indoors, and underground. This is mainly due to additional attenuations and multipath distortions of satellite signals which are already weakened due to long distance propagation losses.
In recent years, engineers have developed receivers that perform satisfactorily even with severely attenuated signals by providing external assistance such as satellite orbit parameters, reference time and coarse locations. This approach known as Assisted GPS (A-GPS) significantly facilitates the acquisition of satellite signals, relieves the receiver from the data demodulation tasks, and overall increases start-up sensitivity by as much as 25dB when used in combination with massive correlators. A-GPS is one of the standardized technologies for safety applications. US Federal Communication Commission Enhanced 911 (E911) Mandate seeks to improve the effectiveness and reliability of wireless 911 services by providing emergency services personnel with location information that will enable them to dispatch assistance to wireless 911 callers much more quickly.
In A-GPS technology, the assistance data which consists of coarse time, coarse location, ephemeris and almanac data is generated offline and it is transferred to the receivers through communication links. A typical receiver development relies on testing and tuning using GPS simulators. As the A-GPS technology relies on a network involvement for assistance delivery the simulation of A-GPS is very challenging. This thesis provides an approach to overcome the aforementioned limitation and develops A-GPS extension for conventional GPS simulators in accordance to a state-of-the-art standard---Secure User Plane Location (SUPL) protocol. It is a User Plane location protocol which makes use of user data channels such as Internet Protocol (IP) link to enable location based services.
Another research topic in this thesis is a cost-efficient block-correlator algorithm and Labview-based implementation for so-called software GPS receivers. Software GPS receiver (GPS SDR) is a very attractive concept suitable for various hosting platforms. Computational complexity is the main challenge in implementing such receivers as advanced receivers should have hundreds to thousands of correlators. This thesis presents block correlators capable of processing several correlations at a cost of one. The correlators is incorporated in a GPS receiver tracking loop and tested with NI GPS simulator.Electrical and Computer Engineerin
GRK2 Constitutively Governs Peripheral Delta Opioid Receptor Activity
No full textSummaryOpioids remain the standard for analgesic care; however, adverse effects of systemic treatments contraindicate long-term administration. While most clinical opioids target mu opioid receptors (MOR), those that target the delta class (DOR) also demonstrate analgesic efficacy. Furthermore, peripherally restrictive opioids represent an attractive direction for analgesia. However, opioid receptors including DOR are analgesically incompetent in the absence of inflammation. Here, we report that G protein-coupled receptor kinase 2 (GRK2) naively associates with plasma membrane DOR in peripheral sensory neurons to inhibit analgesic agonist efficacy. This interaction prevents optimal Gβ subunit association with the receptor, thereby reducing DOR activity. Importantly, bradykinin stimulates GRK2 movement away from DOR and onto Raf kinase inhibitory protein (RKIP). protein kinase C (PKC)-dependent RKIP phosphorylation induces GRK2 sequestration, restoring DOR functionality in sensory neurons. Together, these results expand the known function of GRK2, identifying a non-internalizing role to maintain peripheral DOR in an analgesically incompetent state
A Compilation of Digital Audio Signal Processing Techniques and Implementations in Real-time along with a Modified and Weighted Convolution Effect
No full textThis item is available only to currently enrolled UTSA students, faculty or staff. To download, navigate to Log In in the top right-hand corner of this screen, then select Log in with my UTSA ID.Digital Audio Signal Processing is most often used as a tool not to enhance or preserve audio signal quality, but to add artistic modifications and unique sounds to the audio signals. A detailed state of the art of current audio effects is covered in Chapters -8, along with practical real-time implementations of each effect through the use of digital recording software. Audio examples of each effect are provided through the use of an extraction algorithm provided at the end of this paper. After providing a thorough history of various categories of audio effects, a new and intriguing audio effect is introduced in Chapter 9 that is created through circular distortions of convolution that create harmonics in the audio signal. The methodology and implications of such a modified and weighted convolution effect are outlined and discussed. Lastly the effect is applied to various audio signals in order to determine the implications of the effect on different instruments and to also provide suggested uses.Electrical and Computer Engineerin
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