The molecular mechanism(s) by which DEET (N,N-diethyl-m-toluamide) acts as an insect "repellent" has not been resolved. Using forward genetic screens in Caenorhabditis elegans, we have isolated five DEET-resistant mutants (der-1) after EMS mutagenesis of DEET-sensitive N2. Two are allelic and have been mapped between 2.4 mu and 2.9 mu on linkage group (LG) IV. Specifically, 3F (factor) cross data between two markers unc-5 (1.78 mu) and egl-19 (3.34 mu) on LGIV showed that 11/22 (50%) Egl-19 recombinants were DEET-resistant and 11/22 (50%) were DEET sensitive for allele hf175. In case of allele hf176, the data were 19/32 (59%) and 13/32 (41%), respectively. In addition, all Lin-33 recombinants from the 3F cross between two references unc-5 (1.78 mu) and lin-33 (2.55 mu) showed DEET sensitivity in both hf175 and hf176. Several additional 3F crosses are in various stages of completion. Interestingly, wild-type strains CB4856, AB1, and AB2 have been shown to be DEET resistant relative to the wild-type strains N2 and CB4852, which are both DEET sensitive. These findings suggest that DEET-resistance may be more common than we originally expected. Successful cloning of the der-1 gene is an important step not only to elucidate the mechanism of DEET action but may prove useful in designing the next generation of chemicals that helps reducing insect-borne-diseases.

The Agua Blanca fault system is a dextral strike-slip fault system in northwestern Baja California, Mexico. Despite no historic seismic activity, the geomorphology suggests that the fault is active. Geomorphic maps (~1:10,000) were completed within three field areas along the western segment of the main fault. Diagnostic features such as deflected stream channels provide evidence of recent fault activity. The presence of well-developed triangular facets suggests an additional normal component to this strike-slip system. Ground-penetrating radar surveys were conducted to image the fault in the near surface. Many more fault splays were mapped within the sections than were visible at the surface, indicating the complexity of the fault system. Alluvial surfaces were identified within the sections and characterized based on continuity and shape of reflectors.

This research involved the formation of novel molecules, and the first observation of infrared active modes and infrared active combination bands of already discovered molecules. The molecules were produced by the laser evaporation of germanium, germanium-carbon, and carbons rod previously sintered in a new built vacuum furnace. The infrared spectra were taken using Bomem FTIR spectrometer with an interface infrared optics toward the formation chamber. These molecules were theoretically simulated using commercial quantum chemistry suites of programs and homemade codes. The linear GeC₅Ge germanium-carbon chain has been detected for the first time through the dual laser evaporation of graphite and germanium, the &nu;₄(&sigma;_u) vibrational fundamental was observed at 2158.0 cm<super>-1</super>. Two new vibrational fundamentals of linear GeC₃Ge, &nu;₄(&sigma;₄ = 735.3 cm<super>-1</super> and &nu;₆(&#sigma;_u) = 580.1 cm<super>-1</super>, have been observed. This is apparently the first observation of germanium isotopic shifts in vibrational spectra Linear GeC₃ has been formed by the dual laser ablation of germanium and carbon rods and by single laser ablation of a sintered germanium-carbon rod, and trapped in Ar matrices. Two vibrational fundamentals of linear GeC₃ &nu;₁(&sigma;) = 1903.9 cm<super>-1</super> and &nu;₂(&sigma;) = 1279.6 cm<super>-1</super>, have been observed. In the present work there is no spectroscopic evidence of cyclic structures for GeC₃ with either the transannular Ge-C or C-C bond although at the coupled cluster level of theory they are both predicted to be ~7-9 kcal/mol lower in energy than the linear isomer. This result suggests a need for further theoretical studies of GeC₃ to see if the cyclic isomers are indeed more stable than the linear. New combination bands of carbon chains have been observed, (&nu;₁+&nu;₄) = 3388.8 cm<super>-1</super> of linear C₅ and (&nu;₂+&nu;₇) = 3471.8 cm<super>-1</super> of linear C₉. Since the asymmetric stretching1 modes involved in these absorptions have been measured previously it has been possible to assign the infrared inactive symmetric stretching modes, the &nu;₁(&sigma;_g) mode of linear C₅ at 1942 cm<super>-1</super> and the &nu;₂(&sigma;_g) mode of linear C₉ at 1870 cm<super>-1</super>. The &nu;₁(&sigma;_g) mode of linear C₅ is the last undetected fundamental of this molecule. The &nu;₆(&sigma;_u) weakest asymmetric stretching mode of linear C₇ has been detected for the first time and has been assigned at 1100.1 cm<super>-1</super> in solid Ar. The calculation of the intensities of combination bands presented in this work suggests that the second derivatives computed numerically from the first derivatives are precise enough to predict intensities of combination/difference bands with magnitudes of order ~5 km/mol. Therefore, computing the fundamentals intensities using the mechanical (up to the quartic term) and electrical (up to the second term) anharmonicity corrections might clarify why the intensity predictions using only the first dipole-moment derivatives with pure harmonic states are so inexact. To my knowledge, the inexactness of the calculated fundamental intensities is attributed to the method used for the calculation of the first derivatives of the dipole-moment rather than including anharmonic terms.

The food additive aspartame, commonly known by its trademark name NutraSweet, is used world wide in over 5000 food and beverages. Anecdotal and experimental evidence suggest aspartame may have detrimental effects on cognition and memory. In the present study, rats were fed aspartame for a 3 month period and their spatial memory was tested in the radial arm maze. It was hypothesized that rats who received aspartame would commit more memory errors than control rats that were not fed aspartame. Previous evidence also suggests aspartic acid creates lesions in the brain areas surrounding circumventricular organs (CVO). The present study attempted to replicate those findings. Results from the present study found that animals that were given aspartame committed significantly more long-term memory errors and short-term memory errors in the eight arm radial-arm maze. The deficits were mostly related to errors in the first trial. The results also suggested animals given aspartame had significantly fewer neurons in the arcuate nucleus when compared to control animals.

Challenges inherent in implementing changes within the substance abuse treatment field can be offset by transformational leadership actions that promote innovation and attention toward individual needs and abilities. The current study developed and validated the Survey of Transformational Leadership (STL) for application in addiction treatment. Psychometric analyses confirmed nine STL themes, eight representing distinctions between commonly-noted leadership domains: Integrity, Sensible Risk (idealized influence); Demonstrates Innovation, Encourages Innovation (intellectual stimulation); Respects Others, Develops Others (individualized consideration); Task Delegation, Expects Excellence (empowerment); and Inspirational Motivation. The STL scales demonstrate good internal reliability and convergent validity when compared with scales from the Multifactor Leadership Questionnaire and the Attributes of Leadership Behavior Questionnaire. The nine themes can also be combined into a global measure of transformational leadership. Applications of the STL include informing training, selection of change agents, as well as examining relationships with organizational climate and structure.

The chemistry of molybdenum is immensely rich and diverse. Molybdenum is essential for life, and has many applications in industry. The first chapter offers a general perspective of the chemistry of molybdenum in high oxidation states dominated by diverse oxo species, such as the MoO22+ and MoO4+ units that are focus of my research. I describe the importance of MoO22+ complexes as models for the active sites of oxo transfer molybdoenzymes (e.g. DMSO oxidase) and for industrial heterogeneous transformation such as the SOHIO process (one of our ultimate goals). I also outline the importance of MoO4+ complexes as procatalysts for metathesis polymerization and as models of deoxygenated active sites of MoO22+ oxygen catalysts that have triggered our interest. The second chapter introduces the synthesis and full characterization of 4-, 5- and 6-coordinated MoO2(OAr)2L0-1 complexes with bulky aryloxide ligands, starting from the MoO2Cl2 or MoO2Cl2(DMF)2 precursors. Steric and electronic modifications in the aryloxide moieties were performed in order to understand their effect in the final structure and yields of the synthesized complexes. The nature and mechanism of formation of the radical species detected in their synthesis is proposed. The third chapter presents the facile synthesis of varios MoO(OAr)4-nCln complexes starting from the MoO2Cl2 precursor. Their mechanism of formation is proposed and the supporting evidence for this new reaction is provided. Steric and electronic modifications in the aryloxide moieties were used to study their structural and electronic effects in the MoO4+ complexes. The fourth chapter outlines the synthesis of Mo(VI) monooxo bisphenoxides with a characteristic cis-chloro cis-bisphoxide arrangement around the MoO4+ unit. Electronic and steric modifications in the bisphenoxide rings were done to determine their effect in the structure and reactivity of the final complexes. The fifth chapter introduces the application of the synthesized MoO(OAr)4-nCln and MoO(bisphenoxides)2Cl2 complexes as procatalysts for olefin metathesis polymerization of norbornene. The correlation between structure and reactivity of the procatalyst is discussed.

Neurogenesis within the hippocampus along with learning/memory are altered by many factors including stress, immune activation, and depression. Chronic dosing with antidepressants has been shown to alleviate many of the symptoms following immune activation. To examine interactions between depression, immune activation, and cognitive dysfunction more closely, the following experiments were conducted. Generally, the current set of experiments examined the effects that repeated bolus injections of LPS have on spatial learning in MWM, memory consolidation in both CFC and MWM, and hippocampal neurogenesis. The effects of chronic (all experiments), or acute imipramine (Experiments 3 and 4) were also examined to see if they influenced the hypothesized LPS-induced decrements. Experiment 1 looked at the effects of chronic imipramine (10mg/kg for 21 days) and 4 bolus injections of LPS (1mg/kg) have on Morris water maze acquisition, and hippocampal neurogenesis after a 3-day break (past the point that central or peripheral cytokines are present). Experiment 2 addressed the effects that chronic imipramine and bolus injections of LPS have on neurogenesis after a 3-day break (i.e., prior to any potential effects of behavioral testing). Experiment 3 examined the effects acute verses chronic imipramine coadministration with a single acute bolus injection of LPS (1mg/kg) on memory consolidation in Morris water maze. Experiment 4 was much like Experiment 3 but instead of MWM, a CFC paradigm was used. Our hypotheses were that LPS-treated animals would show acquisition deficits in MWM, memory consolidation deficits in both MWM and CFC, and show a decline in neurogenesis (at both the initial and survival timepoints). Moreover, we hypothesized that chronic but not acute administration of imipramine would ameliorate all decrements in MWM, CFC, and neurogenesis as the result from repeated or acute bolus LPS administration. The data revealed that LPS did not show the hypothesized effects nor did imipramine in all four studies. We attribute our negative findings may be due to endotoxin tolerance, monocytic priming, TLR-4 down-regulation and/or stress from both behavioral testing and repeated injections.

Early environmental enrichment (EE) can impact many facets of an organism's existence, including significant alterations in neural and immune function. The brain and the immune system interact with one another in a variety of ways and immune challenges may interfere with learning and memory. We examined the possible role of EE in abrogating the negative effects of an innate immune challenge on learning and memory and sickness behavior. We hypothesized that enriched animals will show diminished sickness behavior in a burrowing task after endotoxin exposure (lipopolysaccharide or LPS at a dose of 50ug/kg) versus control animals housed in standard cages. Furthermore, we hypothesized that exposure to EE will lead to fewer learning and memory deficits in a shuttlebox task following exposure to LPS (250 ug/kg). We found that EE appears not to protect against LPS-induced learning deficits and that EE does not ameliorate the effect of LPS on sickness behavior.

Calixarenes are macrocyclic oligomers of phenols bridged with methylenes. They have been extensively studied because of their unique structure, complexing abilities, conformational flexibility, and reactivity. Their chemistry has been applied as an oxo platform for catalyst model studies. The coordination chemistry of the simple calix[4]arenes is now relatively well developed. By contrast, metal compounds containing the larger ring systems, for example calix[5]arene, are still quite rare. Our interest in calix[5]arene chemistry is related to our longer-term research objectives. We are interested in modeling a bifunctional oxo surface, in which two metals can react in a cooperative manner. This requires a conformation that will allow two metals, or a metal and non-metal, to interact on the calixarene "surface" (Chapter1). We synthesized a series of deprotonated calixarenes "calix[n]anions" (including mono- to dianionic species) by the reaction of parent calix[5]arene with alkali metal bases (Chapter 2). In this context, we were able to synthesize and characterize a variety of Ti(IV) (Chapter 3), Mo(VI) (Chapter 4) and Pd(II) (Chapter 5) metallocalix[5]arene complexes using calixanions as starting materials in which the transition metal binds directly to the oxygen surface of the calix[5]arene. Finally, the reactivity of the palladium calix[5]arene complexes was tested and successfully utilized in the synthesis and characterization of the first examples of Pd(II)/Ti(IV) and Pd(II)/Mo(VI) heterobimetallic complexes (Chapter 6).

Polylepis multijuga is a threatened, endemic tree species in the northern Andes of Peru. P. multijuga is wind-pollinated which could allow for gene flow among fragments that would counteract drift and loss of genetic diversity. I collected samples from 371 trees in nine forest fragments and genotyped them at 316 AFLP loci. Genetic diversity (H = 0.131) was low compared to other species and genetic differentiation across all fragments was moderate (PhiPT = 0.14). Short distance (5-50m) genetic spatial autocorrelation within most fragments indicated short distance seed dispersal. Pair-wise genetic distance estimates between fragments (range: 0.036 - 0.487) were not related to geographic distance and instead appeared to be related to habitat. The three most differentiated fragments, which also had the lowest genetic diversity values, were two small, high altitude fragments and a fragment located in a deep ravine suggesting that pollen flow does not effectively connect all fragments in this landscape.