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Public transit agencies have begun to adopt alternative propulsion technologies to reduce urban transit bus emissions associated with conventional diesel (CD) engines. Among the most popular alternatives are emission controlled diesel buses (ECD), defined here to be buses with continuously regenerating diesel particle filters burning low-sulfur diesel fuel, and buses burning compressed natural gas (CNG). This study uses a series of simplifying assumptions to arrive at first-order estimates for the incremental costeffectiveness (CE) of ECD and CNG relative to CD. The CE ratio numerator reflects acquisition and operating costs. The denominator reflects health losses (mortality and morbidity) due to primary particulate matter (PM), secondary PM, and ozone exposure, measured as quality adjusted life years (QALYs). We find that CNG provides larger health benefits than does ECD (nine vs six QALYs annually per 1000 buses) but that ECD is more cost-effective than CNG ($270 000 per QALY for ECD vs $1.7 million to $2.4 million for CNG). These estimates are subject to much uncertainty. We identify assumptions that contribute most to this uncertainty and propose potential research directions to refine our estimates. [ABSTRACT FROM AUTHOR]

Investigates the calcium-induced conformational switching of Paramecium calmodulin (CaM) to provide evidence for domain coupling by CaM. Nuclear magnetic resonance of Paramecium CaM; Titration of sites I and II; Changes at the domain boundaries.

Reports on the measurement of carbon nuclear magnetic resonance (NMR) chemical shift tensors for two forms of solid 10-deacetyl baccatin III to investigate the origins of solid-state NMR. Finding that lattice interactions cannot fully account for the shift differences in the two forms; Possible appearance of the observed tensor differences from conformational variations in ring substituents.

Reports on the development of a method for the introduction of 5-fluoro group for easy access to a wide variety of 5-fluoro glycosides and glycosyl phosphates. Fluoridolysis of C-5, 6 epoxides; Synthesis of two fluorinated carbohydrates.

Focuses on the dissection of the pathway of molecular recognition by calmodulin. Use of amide hydrogen exchange; Decline of individual protection factors; Disruption of ion pairs between calmodulin and the bound model.

Examines the synthesis and spectroscopic properties of elongated ruthenium dihydrogen complexes. Temperature and isotope dependence of dihydrogen ligand distances; Dihydrogen/dihydride equilibria; Isotope exchange and H-D coupling.

Investigates the electrophilic fluorination of enantiomerically pure 2-pyrrolidinones derived from glutamic acid as method for the synthesis of single stereoisomers of 4-fluorinated glutamic acids. Synthesis of fluorination substrates; Monofluorination of lactam, substrates; Difluorination of lactam substrates.

Examines the characterization of stereochemistry and molecular conformation using solid-state nuclear magnetic resonance tensors. Comparison of [sup 13]C tensor principal values with ab initio computed values for possible computer-generated stereoisomers; Advantages of chemical shift tensor over isotropic shift; Sensitivity of [sup 13]C tensor principal values to stereochemical differences in the terrain.

Investigates the effect of ozone on the trihalomethane and haloacetic acid (HAA) formation of algae species, Scenedesmus quadricuada and Cyclotella. Composition of disinfection byproducts from algae; Distribution of chlorinated HAA species for Cyclotella; Difference in HAA production between the control and the ozonated sample.

Examines the role of singlet diradicals in 2-carbenabicyclo[3.2.1]octa-3,6-diene reactions. Mechanism for the formation of hydrocarbons Fraction; Generation of the compound; Abstraction of hydrogen by triplet carbene IT.

Examines the capacity of pyrylium and thiopyrylium ions to act as combined quenchers of photoexcited redox dyes and transmembrane charge carriers to generate long-lived charged separation across bilayer membranes. Rate of diffusion measurement of dihexadecyl phosphate-associated ions; Proton permeabilities of planar lipid bilayers and liposomes.

Investigates the rotation barrier of carbon-nitrogen bond in a simple enolate anion, lithium acetamide. Comparison among amidate anion 2, vinylamine 3 and simulated dimer 4; Results of the conjugation effects; Importance of double bond polarization as a feature of the electronic structure.

Investigates the bioreduction of nickel-substituted hydrous ferric oxide (NiHFO) by Shewanella putrefaciens during anaerobic respiration and the partitioning of the associated nickel and iron into aqueous and solid phases as a function of buffer type and solution composition. NiHFO reduction by Shewanella; Bioreduction-induced solubilization of metals.

Examines the hydrolysis of an organophosphate ester by manganese dioxide. Characterization of the oxide; Products of reaction; Rates of hydrolysis.

Examines the tandem nitroaldol-dehydration reactions of phenylsulfonylnitromethane. Utilization of lithium diisopropylamide; Implication of unsaturated nitrosulfones for the formation of bis(alpha-nitrosulfones); Reaction of propanal with the dilithium salt of phenylsulfonylnitromethane.

Reports on the analyses of isodesmic reactions for singlet 7-carbenanorbornene (4S), 8-carbene-endo-tricyclo[3.2.1.0[sup 2,4]]octane (5S), 3-carbenabicyclo[3.1.0]hexane (3S), 2-carbenanorbornene 6S, and 2-carbenabicyclooctadiene 7S. Homoaromaticity of carbenes 4S and 5S.

Examines the structural characterization of higher oxidation states of the water oxidation catalyst. Use of Resonance Raman (RR) and optical spectroelectrochemical titrations; Estimation of rate constants; Structure of frozen ion solutions; Consistency of the RR spectrum with the coordination of terminal oxo ligands by cerium4+.

Examines excited-state dynamics in an iron(II) polypyridyl complex using static, nanosecond and femtosecond spectroscopies. Formation of metal-to-ligand charge transfer excited; Identification of spectroscopic signatures for the initial and long-lived excited states; Analysis of single-wavelength kinetics data; Interpretation of ultrafast intersystem crossing.

Examines the solid-state 13C chemical shift tensors in terpenes using nuclear magnetic resonance (NMR) analyses. Evidence of mixed polymorphic forms in solid verbenol; Structural predictions from computed and experimental NMR shift tensors; Characterization of the minor polymorphic form of verbenol.

Discusses the measurement of the monetary value of reduced mortality risk using the `value of a statistical life' (VSL). Definition of an individual's preferences for small changes in risk and income; Theoretical foundation and methods for the estimation of VSL; Dependence of VSL on age, income, baseline mortality risk and latency of the risk.

Investigates the pyrolytic decomposition of the lithium salt of the tosylhydrazone of 4,4-dipehnyl-2,5-cyclohexadienone. Formation of a mixture of products which includes biphenyl, para-terphenyl, the azine of 4,4-diphenyl-2,5-cyclohexadienone and oro-terphenyl; Mechanistic pathway for the formation of oro-terphenyl; Formation of an isobenzene species.

Examines the evidence for coupling of solvation to chromophore structural dynamics in the evolution of charge-transfer excited states. Variable-temperature emission from bypyridyl complexes; Shift of emission spectrum and thermal breadth of solvent response; Change in the nature of emitting species with increasing temperature.

Describes the hydrolysis of adenosine 2',3'-cyclic monophosphate by CuII terpyridine (cutrpy). Relevance of hydrolysis for scission of nucleic acids; Efficacy of aqueous Cu(II) terpyridine for transesterification and hydrolysis of RNA; Evaluation of fractionation factors by ab initio quantum chemical calculation; CutrpyOH+ action as a nucleophilic catalyst.

Examines the use of a damage function model to estimate environmental impacts of power plants. Environmental effect of oil and gas-fueled cogeneration power plants; Evaluation on the potential policy applications; Relationship of the effects on ozone and particulate matter; Importance of plant siting and emission control policies.

Discusses strategies for teaching chemical reaction kinetics and solvent effects in principle from a single generalized version of the law of mass action. Kinetic law for ideal gas reactions and for reactions in dilute ideal solution; Relation between rate constants and equilibrium constants; Solvent effects on reaction times; Reaction kinetics and non-equilibrium thermodynamics.

Presents a study which described the application of PHORMAT and FIREMAT solid-state nuclear magnetic resonance (NMR) techniques in analyzing shift values in terpene parthenolide. Explanation of the NMR analysis techniques; Methodology used; Results and discussion; Conclusion.

Explores the hydroxyl radical formation during peroxynitrous acid decomposition. Formation of oxygen during decomposition of peroxynitrous acid (ONOOH); Formation of OH and NO2 radicals as oxidizing intermediates; Determination of the rate constants of the reactions; Inhibition of oxygen formation by radical scavengers.

Presents an ab-initio molecular orbital study on the chemistry of 2-carbenabicyclo[3.2.1]octadiene. Synthesis of endo-6-ethynylbicyclooctane from the conversions of 2-carbenabicycloocta-3,6-diene, 3-carbenatetracyclooctane and bicycloocta-2,3,6-triene; Equilibrating C8H8; Carbene-to-carbene rearrangement process.

Presents a study which examines the functions of the carboxamide moiety which links the carbohydrate and protein moieties in N-linked glycoproteins. Assessment of methodology used; Findings of the study.

Reports on the preparation of L-lactate dehydrogenase. Catalytic behavior toward the representative gamma-keto acid substrates; Comparison of the level of protein expression; Resistance to thermal denaturation; Support of the validity of ion-pairing approach.

Investigates the role of the exposed loop in transforming growth factor-beta (TGF-beta) centered at residue 71. Synthesis and purification of mutant TGF-beta molecules; Biological properties of the molecules; Growth inhibition assays; Receptor cross-linking; Northern blot assay.

Investigates two possible mechanisms for enzyme-catalyzed N-glycosylation using chemically synthesized peptide and lipid disaccharide substrates. Fate of deuterium in three stereospecifically deuterated peptides.

Investigates three possible methods for the facile synthesis of polyfunctionalized phosphinates. Examination of the phosphinopeptide analogues of glutathionylspermidine; Discussion on the condensation reaction of the three-components; Examination of retrosynthetic pathways for phosphinates.

Describes the synthesis of sequence-specific phenylacetylene oligomers consisting of functionalized monomers in gram quantities using solid-phase methods. Attachment of growing oligomers to a divinylbenzene cross-linked polystyrene support; Protection of terminal acetylene; Cleavage of the resulting oligomers.

Reports on the reaction of several nucleophiles with N-Cbz-protected di-tert-butyl-DL-4,-4-difluoroglutamate, in the assessment of the synthesis of various fluorinated amino acids and peptides. What further transformation of the products resulted in; Importance of fluorinated amino acids and peptides; Description of experimental methods.

Presents information on the synthesis and characterization of four modified nucleoside phosphoramidite reagents (7, 10, 14 and 18) that contain pendant 2,2'-bipyridine or terpy ligands. What modified nucleosides are designed to deliver; Description of methodology that was utilized.

Examines the synthesis of the phosphonamidate and phosphonate analogues of a gamma-glutamyl peptide. Selective aminolysis of the phosphorus diester; Conversion of monomethyl phosphonic acid into phosphonochloridate.

Describes the solutions to problems encountered during the synthesis of several phosphonates and phosphonamidates from appropriate phosphonochloridates and/or monomethylphosphonates. Physical properties of phosphonochloridates; Coupling of polyfunctional alcohols and amines with simple phosphonochloridates.

Describes a method of the asymmetric synthesis of chiral sulfinate esters and sulfoxides. Demonstration of the utility of the method through the synthesis of the enantiomers of sulforaphane; Reaction of trans-2-2-phenylcyclohexanol with thioylchloride to form diastereomeric chlorosulfate esters.

Gives information on the structural, synthesis and spectroscopic characterization of monosemiquinone and monocatechol complexes of chrominum(III), with focus on inorganic chemistry. Details on the study of electron exchange interactions in transition metal complexes; Role of exchange coupling on the photoinduced dynamics of these compounds; Description of the magnetic and optical characteristics of these molecules.

Provides information on a study examining in greater detail the reactions of ONO2- with one-electron donors in CO2-containing media. Methodology used to conduct the study; Results of the study; Discussion on the results.

Presents the results for variable-temperature studies of laser photoysis of the 5T2...1A1 intersystem crossing in spin-crossover complexes and other related complexes. How the hexadentate ligands are formed; Details of empirical correlation examinations; Preexponential terms for intersystem crossing; Compounds preparation and basic characterization.

Focuses on structural investigations of the catalytic mechanisms of water oxidation. Formation of resonance-enhanced symmetric band; Analogy with one-electron oxidation product; EPR spectrum of oxidized samples.

Studies the ability of mineral phases to facilitate phosphate ester hydrolysis. Scarcity of research on the role of inorganic substrates in facilitating phosphate ester hydrolysis in the natural environment; Effect of variation in pH, mineral loading and organic phosphorus concentration on the hydrolysis of phosphate.

Discusses use of bioreclamation of organochlorine-contaminated soil and groundwater. Description of organohalogens; Limitations of bioremediation of petroleum hydrocarbons; Limited oxygen concentration in presence of extra biodegradable organic carbon; Potential for anaerobic treatment of organic contaminants; Improvements in technology brought about by increasing field experience.

Cites the relative orientations of molecular properties within crystals. High statistical preference for organics in general; Approximate crystallographic symmetry; Electron-donor/acceptor properties; Net directionality of polarizability vectors; Full-matrix least-squares methods.

Presents a laser photolysis study of the 5T2 *** 1A1 intersystem crossing in the ligand [Fe(t-tpchxn)](ClO4)2. Crystal structure of the complex; Relaxation kinetics; Molecular mechanism of 5T2 *** 1A1 relaxation processes.

Examines two different intersystem crossing processes of low-spin polypyridyl ferrous complexes. 5T2 state resulting from photoexcitation as a general feature; Rate of formation; Reasons for fast intersystem crossing; Mechanistic implications.

Examines the transesterification of RNA using chimeric DNA/RNA molecules containing RNA nucleotides embedded in DNA sequences. Description of synthesis, purification and activity.

Reports on the synthesis of a class of sterically hindered dendrimer-metalloporphyrins for use as shape-selective oxidation catalysts. Instrumentation; Synthesis process; Dendrimer-porphyrin manganese(III) complexes; Epoxidation reactions.