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The aim of the study is to investigate the relationship between variability in tropospheric ozone in Taiwan and the regional atmospheric circulation, paying particular attention to the influence of long-range transport on ozone pollution levels. The study period is 1994 to 2004. The data used in this study include air pollution data from the Taiwan Air Quality Monitoring Network and NCEP/NCAR reanalysis data. The spatial and temporal variations in weather types have been characterised using an objective circulation classification scheme and relationships with episodes of high ozone levels over Taiwan have been determined. The signature of the large-scale atmospheric circulation associated with high ozone pollution and the connection with long-range transport of ozone precursors and ozone have been identified using spatial composites and back-trajectory analysis. Trajectories were calculated using the Hybrid Single-Particle Integrated Trajectory model. The air pollution data analysis shows that Taiwan experiences a seasonal cycle in ozone levels, with maxima in spring and autumn and a minimum in summer. The spatial composite and back trajectory analyses indicate that long-range transport does play a role in increasing high ozone episodes in Taiwan. A link with the seasonal variation of the monsoon circulations at different times is shown, with a weaker summer monsoon and a stronger winter monsoon circulation associated with enchanced ozone levels over Taiwan. The characteristics of atmospheric circulation for ozone pollution episodes include enhanced north and northeasterly flows, originating from nearby polluted areas and suggest that mainland China, Korea and Japan are source regions of ozone and its precursors for Taiwan. Moreover, the transport pathways at the high level of 2000m show that the southern China is also prominent source region, which is a previously unidentified distant source of ozone pollution in Taiwan. It is suggested that the increase of ozone pollution in summer found in this study is caused by a weaker summer monsoon circulation in recent years. While it is emphasised that variability in long-range transport is the only factor affecting ozone pollution levels over Taiwan, the influence of global warming on the Asian monsoon circulation and, hence, long-range transport of ozone and its precursors warrants serious consideration.

Cigarette smoking is generally known for its detrimental effects on health; however, extensive epidemiological studies have indicated inverse correlation between smoking and Parkinson’s Disease (PD), a progressive neurodegenerative disorder characterized by loss of dopaminergic (DAergic) neurons in the substantia nigra (SN). Subsequent studies have shown that nicotine protects DAergic neurons against nigrostriatal damage in PD primate and rodent models. Nicotine became the focus of these studies due to its well-known ability to modulate function and activity of midbrain DAergic neurons. Because altered circuit activation can induce neurons to acquire a DAergic phenotype in the mature brain, we hypothesized that chronic nicotine treatment contributes to neuroprotection against nigrostriatal damage in an animal model of PD via a mechanism of neurotransmitter plasticity. Nicotine was given to adult mice in drinking water for two weeks. Brains of various transgenic reporter mouse lines were subsequently processed for immunohistochemistry and retrobead tracing for detection of tyrosine hydroxylase and other cell markers in the SN, and neuronal connectivity. Selective overexpression of human A53T alpha synuclein in midbrain DAergic neurons was used as a PD mouse model. Our findings showed that chronic nicotine treatment significantly increased DA expression within a pool of SNr (pars reticulata) GABAergic neurons that express transcription factors associated with DA differentiation, such as Nurr1 and Foxa2, prior to nicotine exposure. More importantly, our retrograde labelling experiments showed that this GABAergic neuronal pool in the SNr projects to the caudate nucleus, the same target of SNc (pars compacta) DAergic neurons. Ongoing behavioral experiments on a PD mouse model confirmed that nicotine treatment ameliorates some motor deficits in these mice. Our results indicate that neurotransmitter plasticity occurs in the SN in response to chronic nicotine treatment. Understanding its role in neuroprotection against nigrostriatal damages in PD could reveal insights that may lead to the development of new treatments for Parkinson’s Disease.

Following Smith's (1991, 1997) two-component theory, this dissertation investigates the structural characteristics and the semantic properties of the temporal system, including tense, mood, viewpoint aspect, situation aspect and discourse modes, of Iquito, a highly endangered and moribund language spoken in the northern Peruvian Amazon. Iquito has three tenses: Extended Current Tense, Recent Past Tense, and Distant Past Tense. Extended Current Tense gives a Reference Time (RT) frame from the day which includes Speech Time (SpT) to the infinite future. Therefore, situations occurring earlier on the same day or unrealized situations both appear in sentences with this tense. The temporal interpretation is inferred from the combination of aspect and mood morphology. Recent Past Tense gives a frame of RT from yesterday to one to two years prior to SpT. Distant Past Tense gives a frame of RT from one to two years prior to SpT extending backward to the infinitely remote past. Temporal boundaries among the tenses are not rigidly fixed in terms of a metrical conception of time. Iquito has seven perfective aspects, including a General, a Momentary, a Remote, two Deictic, an Allative, and an Ablative Perfective Aspect and one Imperfective Aspect. Remote Perfective Aspect incorporates an adverbial component while Ablative and Allative Perfectives incorporate directional components and Deictic Perfectives incorporate deictic components. The system of perfective aspects in Iquito manifests the importance of expressing the realization of an event in conjunction with information about the time of the day, location, and routing in terms of location. Regarding situation aspect, I propose that there are six types in Iquito, including States, Activities, Accomplishments, Achievements, Semelfactives and Motions, which all manifest language-specific correlates. With respect to grammatical moods, realis and irrealis moods are manifested in Iquito through a typologically unique strategy: word order change and vowel hiatus resolution. Regarding Discourse Modes, I find four modes in Iquito, including Narrative, Report, Description and Information. In addition, Quoted Speech manifests an interesting mixture of modes. This dissertation adds another dimension to the close connections among tense, aspect and mood, and contributes to linguistic documentation and advances the structural and semantic analysis of Iquito and Amazonian languages. It also contributes to research on the crosslinguistic variation of temporal semantics and to linguistics in general through an interesting case study.

Using data recorded by the CLEO II detector operating at the Upsilon(4S) resonance at the Cornell Electron Storage Ring, several properties of B mesons are measured using a partially reconstructed tag of the decay mode bar{B0} -> D*+ l- bar{nu}. Using 2.38 fb**{-1} of on-resonance data and the averaged B meson semileptonic branching fraction through inclusive lepton momentum spectrum obtained by previous CLEO analysis, we measure the B0 and B- semileptonic branching fraction to be (10.78 +/- 0.60 +/- 0.69)% and (10.25 +/- 0.57 +/- 0.65)% respectively, which yields the lifetime ratio tau_+/tau_0 = 0.950 +0.117-0.080 +0.091-0.068, assuming the equality of semileptonic partial branching width for bar{B0} and B-. With a larger dataset of 3.1 fb**{-1}, we measured the B0-bar{B0} mixing parameter chi_d to be 0.189 +/- 0.019 +/- 0.006.