Surface plasmon-polaritons are optical surface waves formed through the interaction of photons with free electrons at the surface of metals. They offer interesting applications in a broad range of scientific fields such as physics, chemistry, biology, and material science. However, many of such applications face limitations imposed by the high propagation losses of these waves at visible and near-infrared wavelengths, which result mainly from power dissipation in the metal. In principle, the propagation losses of surface plasmon-polaritons can be compensated through optical amplification. The objective of this thesis is to provide deeper insights on the physics of surface plasmon-polariton amplification and spontaneous emission in surface plasmon-polariton amplifiers through theoretical and experimental vehicles applied (but not necessarily restricted) to a particular plasmonic mode termed long-range surface plasmon-polariton. On the theoretical side, the objective is approached by developing a realistic theoretical model to describe the small-signal amplification of surface plasmon-polaritons in planar structures incorporating dipolar gain media such as organic dye molecules, rare-earth ions, and quantum dots. This model takes into account the inhomogeneous gain distribution formed near the metal surface due to a non-uniform excitation of dipoles and due to a position-dependent excited-state dipole lifetime that results from near-field interactions between the excited dipoles and the metal. Also, a theoretical model to describe the amplified spontaneous emission of surface plasmon-polaritons supported by planar metallic structures is developed. This model takes into account the different energy decay channels into which an exited dipole located in the vicinity of the metal can relax. The validity of this model is confirmed through experimentation. On the experimental side, the objective is approached by providing a direct experimental demonstration of complete loss compensation in a plasmonic waveguide. The experiments are conducted using the long-range surface plasmon-polariton supported by a symmetric thin gold waveguide incorporating optically pumped organic dye molecules in solution as the gain medium. Also, an experimental study of spontaneous emission in a long-range surface plasmon-polariton amplifier is presented. It is shown that this amplifier benefits from a low spontaneous emission into the amplified mode, which leads to an optical amplifier with low noise characteristics. The experimental setup and techniques are explained in detail.

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Lawrence Bonjour supported coherentism in the early period, but turns to foundationalism in the later period. In this paper I shall focus on two sides in relation to his epistemology. To understand his early and later positions, first, I shall explain his coherentism and foundationalism. Second, I shall consider what objections have been raised to each position. Thus we can evaluate why Bonjour abandoned his coherentism and why his foundationalism succeeds as a plausible theory for empirical justification.

Extensive evidence suggests that glucose has both positive and negative effects on memory and these effects likely involve an influence on the brain. For instance, direct infusions of glucose into the septum (MS) or hippocampus can enhance or impair memory. The present set of experiments attempted to determine the different conditions that dissociate the memory-enhancing and -impairing effects of glucose in rats. Specifically, these experiments examined the effects of glucose in spontaneous alternation, a measure of spatial working memory and shock avoidance, an index of emontional long-term memory. The results showed that the memory-impairing effects of MS infusions of glucose are not concentration-dependent. These data also indicated that the memory-impairing effects of MS glucose elevations are specific to gamma-aminobutyric acid GABA receptor activation but do not depend on increases in MS GABA synthesis or release. Importantly, we showed that the memory-impairing interaction between MS glucose and GABA agonists does not generalize to the hippocampus, suggesting the memory-modulating effects of glucose are brain region-dependent. We showed further that these brain region-dependent effects of glucose are not due to difference in basal extracellular glucose levels. Moreover, these findings showed that the memory-enhancing effects of hippocampus glucose override the memory-impairing interaction between MS glucose and GABA. These findings are important because they are the first to show that the memory-modulating effects of glucose are both neurotransmitter- and brain region-dependent. Furthermore, these findings provide preliminary evidence suggesting that the memory-impairing effects of MS glucose may involve compromised hippocampal function. These data also suggest the memory-impairing effects of MS co-infusions of glucose with GABA agonists likely involve an influence on the GABAergic SH projection. Finally, these findings demonstrate the mnemonic and neurochemical consequences of glucose in the MS and hippocampus, two brain regions affected by normal aging, Alzheimer’s disease, and diabetes.

This thesis describes various methods for producing photon pairs from waveguides. It covers relevant topics such as waveguide coupling and phase matching, along with the relevant measurement techniques used to infer photon pair production. A new proposal to solve the phase matching problem is described along with two conceptual methods for generating entangled photon pairs. Photon pairs are also experimentally demonstrated from a third novel structure called a Bragg Reflection Waveguide (BRW). The new proposal to solve the phase matching problem is called Directional Quasi-Phase Matching (DQPM). It is a technique that exploits the directional dependence of the non-linear susceptiblity ($\chi^{(2)}$) tensor. It is aimed at those materials that do not allow birefringent phase-matching or periodic poling. In particular, it focuses on waveguides in which the interplay between the propagation direction, electric field polarizations and the nonlinearity can change the strength and sign of the nonlinear interaction periodically to achieve quasi-phasematching. One of the new conceptual methods for generating entangled photon pairs involves a new technique that sandwiches two waveguides from two differently oriented but similar crystals together. The idea stems from the design of a Michelson interferometer which interferes the paths over which two unique photon pair processes can occur, thereby creating entanglement in any pair of photons created in the interferometer. By forcing or sandwiching the two waveguides together, the physical space that exists in the standard Micheleson type interferometer is made non-existent, and the interferometer is effectively squashed. The result is that the two unique photon pair processes actually occupy the same physical path. This benefits the stability of the interferometer in addition to miniaturizing it. The technical challenges involved in sandwiching the two waveguides are briefly discussed. The main result of this thesis is the observation of photon pairs from the BRW. By analyzing the time correlation between two single photon detection events, spontaneous parametric down conversion (SPDC) of a picosecond pulsed ti:sapph laser is demonstrated. The process is mediated by a ridge BRW. The results show evidence for type-0, type-I and type-II phase matching of pump light at 783nm, 786nm and 789nm to down converted light that is strongly degenerate at 1566nm, 1572nm, and 1578nm respectively. The inferred efficiency of the BRW was 9.8$\cdot$10$^{-9}$ photon pairs per pump photon. This contrasts with the predicted type-0 efficiency of 2.65$\cdot$10$^{-11}$. This data is presented for the first time in such waveguides, and represents significant advances towards the integration of sources of quantum information into the existing telecommunications infrastructure.

Population-wide synchronized rhythmic bursts of electrical activity are present in a variety of neural circuits. The proposed general mechanisms for rhythmogenesis are often attributed to intrinsic and synaptic properties. For example, the recurrent excitation through excitatory synaptic connections determines burst initiation, and the slower kinetics of ionic currents or synaptic depression results in burst termination. In such theories, a slow recovery process is essential for the slow dynamics associated with bursting. This thesis presents a new hypothesis that depends on the connectivity pattern among neurons rather than a slow kinetic process to achieve the network-wide bursting. The thesis begins with an introduction of bursts of electrical activity in a purely excitatory neural network and existing theories explaining this phenomenon. It then covers the small-world approach, which is applied to modify the network structure in the simulation, and the Morris-Lecar (ML) neuron model, which is used as the component cells in the network. Simulation results of the dependence of bursting activity on network connectivity, as well as the inherent network properties explaining this dependence are described. This work shows that the network-wide bursting activity emerges in the small-world network regime but not in the regular or random networks, and this small-world bursting primarily results from the uniform random distribution of long-range connections in the network, as well as the unique dynamics in the ML model. Both attributes foster progressive synchronization in firing activity throughout the network during a burst, and this synchronization may terminate a burst in the absence of an obvious slow recovery process. The thesis concludes with possible future work.

The Analysis of Ilan¡¦s Out-of-Hospital Cardiac Arrest (OHCA) Patients Abstract The study uses Ilan¡¦s out-of-hospital cardiac arrest (OHCA) patients as the research object to understand the variable backgrounds of OHCA patients how they are affected by first aid factors between the period of pre-hospital and post-hospital admission. The study also discusses whether there is a correlation between first aid factors and first aid prognosis among those OHCA patients during pre-hospital and post-hospital admission periods. The study is retrospective and based on the Utstein style format. It collects 284 out-of-hospital cardiac arrest (OHCA) patient cases with trauma and non-trauma (282 effective samples) in an example of a regional teaching hospital in Ilan from 2007 to 2009. It uses descriptive statistics, independent sample t test, and Chi-Square test as the statistical analysis to obtain the following conclusions: 1. There are 282 effective sample patients in the study. There are 57 patients ( 20.2 %) who were return of spontaneous circulation (ROSC) after cardiac arrest approximately 14.77 minutes on average. There are 33 patients (11.7 % ) who survived to be hospitalized for 15.36 days on average, and there are 6 patients ( 2.1 % ) who were discharged from the hospital. 2. Internal medicine disease is the major causative factor of out-of-hospital cardiac arrest. Among those internal medicine disease cases, the history showed hypertension, diabetes mellitus, and heart diseases are the main causes of out-of-hospital cardiac arrest. Patients who are older than 65 years old are the main age groups, accounting for 67.7% of these cases. 3. The pre-hospital admission factors which affect the prognosis after the Emergency Department (ED) are the place of the accident, whether there are witnesses, scene process time , total reaction time , whether automatic external defibrillation was used, and whether people at the scene used CPR. 4. The post-hospital admission factors which affect the prognosis after the ED are initial cardiac rhythm, body temperature, pupil size , dose of epinephrine, whether defibrillation was used, the time of applying emergency first-aid, and medical expense. 5. The percentages of return of spontaneous circulation and survival rates in the study are lower than those of past studies of Taipei City and National Taiwan University Hospital. The possible factors are probably related to differences between rural and urban areas in the quality of emergency medical service systems (EMSS), and healthcare training. 6. From now on, in addition to improving the first-aid continuous monitoring system, we should also enhance EMT related training, and actively educate people to understand and learn CPR, so that comprehensive first-aid systems are available everywhere to effectively increase the success rate of first-aid. Keywords¡GOut-of-hospital cardiac arrest (OHCA), Cardiopulmonary resuscitation

In this study, we study the polarization dependence, gain property, and amplified spontaneous emission in Cr4+: YAG crystal fibers. Cr4+: YAG crystal has an ultra-wide bandwidth of 300 nm. Cr4+: YAG crystal fibers fabricated through laser heated pedestal growth technique are suitable for the applications of fiber amplifiers, fiber lasers, and broadband light sources. The experiment results showed that the polarization-dependent loss has a severe variation as the optical wavelength change. The maximum polarization-dependent loss was up to 18 dB. The main reason of such a large polarization-dependent loss is the combination of multimode interference and the birefringence induced by the non-uniformity of optical waveguide structure and residue strain in Cr4+: YAG crystal fibers. Thus, the results of polarization-dependent loss can be used as a feedback parameter to improve the fabrication process. In the experiment of gain property, bi-directional pump and double-pass transmission scheme was adopted and a 0.2 dB net gain was obtained for the first time at signal wavelength of 1400 nm, pumping wavelength of 1060 nm, and total pumping power of 2.8 W. It shows that Cr4+: YAG crystal fiber has potential to be developed as a broadband fiber amplifier. In the measurement of amplified spontaneous emission spectrum, a wide bandwidth of amplified spontaneous emission of 300 nm with total power of 50 £gWwas obtained at 0.2W pumping power condition. The coupling efficiencies from amplified spontaneous emission to single mode fibers and multimode fibers were 1.5 % and 9.9 %, respectively. This result reveals that it has potential to be developed as a broadband light source. To improve the optical properties of Cr4+: YAG crystal fiber in the future, improving the uniformity of optical fiber waveguide and reducing the residue strain in Cr4+: YAG crystal fiber may suppress the polarization-dependent loss; increasing the fiber length, decreasing the mode number, and employing a cladding pump technique with a well-distributed pump power in the crystal fiber to alleviate the excited state absorption may raise the gain performance and the amplified spontaneous emission power.

Recently, with the escalating demands for optical communications, the need for bandwidth in optical communication network has increased. The technology breakthrough in dry fiber fabrication opens the possibility for fiber bandwidth from 1.3 to 1.6 £gm. Cr4+:YAG double-clad crystal fiber (DCF) grown by the co-drawing laser-heated pedestal growth method has a strong spontaneous emission spectrum from 1.3 to 1.6 £gm. Such fiber is, therefore, eminently suitable for broadband optical amplifier, amplifier spontaneous emission (ASE) light source, tunable solid-state laser, and optical coherence tomography (OCT) applications. In this thesis, multilayer dielectric thin films were directly deposited by E-gun coating onto the end faces of the heterostructure Cr4+:YAG DCF. In this way we have successfully improved the extracted ASE power by the high reflection (HR) coatings. The backward ASE in the fiber reflected and propagates with gain through the fiber in the forward direction. In dual-pump scheme, as much as 1.7 mW power (DCF length is 9.5 cm) of collimated output ASE was achieved. The dual-pump scheme and HR thin films provided 1.6 time improvements of the ASE output power. For broadband optical amplifier in dual-pump and double-pass scheme, a 3.7-dB gross gain and a 0.7-dB net loss (DCF length is 8.7 cm) at 1.4-£gm signal wavelength have been successfully developed with HR coatings onto one of the Cr4+:YAG DCF end faces. In addition, we have successfully developed the Cr4+:YAG DCF fiber laser by direct HR coatings onto fiber end faces. A record-low threshold of 96 mW (DCF length is 1.6 cm) with a slope efficiency of 6.9% was achieved at room temperature. It is more than four times lower than any previously reported Cr4+:YAG lasers.

Hesitation use is common among all speakers, regardless of whether they are engaged in their dominant or non-dominant language (Fehringer & Fry, 2007; Reed, 2000). The question is whether a bilingual speaker will engage in the same types of hesitations in both languages. If hesitation patterns can be identified consistently across speakers regardless of language, their use as an acoustic cue for speaker identification may be possible. This study examines differences in hesitation use across languages and speaking contexts (reading vs. conversation) in bilingual speakers. Twenty Spanish-English bilinguals (ages 19 -31 years) were tested as part of a larger speaker identification project focusing on bilingual speech patterns. These individuals were recorded in a sound-treated booth while speaking extemporaneously and reading a standardized passage in both Spanish and English. Unfilled pause length and speech segment durations were obtained from one minute speech samples using Praat scripts (Boersma & Weenink, 2014). Pause to speaking ratios were computed in Excel. The number of filled pauses were determined from the same one minute speech samples in English and Spanish. Differences in planning style were demonstrated with step graphs which compared both the frequency and length of alternations between speech and pauses in two participants with different planning styles. Wilcoxon signed ranks tests revealed significant differences in the use of unfilled pauses across speaking contexts in both languages. Both pause to speaking ratios and pause durations were larger in spontaneous speech when compared to read speech. Speech segment durations were shorter in extemporaneous speech and filled pauses were more common in spontaneous speech. Cross-language comparisons were considered within each speaking condition. Results indicated few instances where there were significant differences. There were longer speech segment durations in read speech and more filled pause use in spontaneous speech in English. Further demonstration of these patterns was illustrated through step graphs. The similarities in the hesitation phenomenon between languages suggests that bilingual speakers often use the same planning aspects between languages and carryover aspects of speech production from their first language to their second (Fehringer & Fry, 2007). Therefore, comparisons within and across languages within a specific speaking condition may be useful in speaker identification. However, these findings also indicate the need for caution when comparing speech samples across speaking conditions using unfilled and filled pauses. One should consider hesitation as one of several acoustic cues for use in speaker identification in a cross-language situation.