Syntheses, molecular structures, and fiber-optic infrared spectroelectrochemistry of nitrosyl metalloporphyrins containing axially bound alkoxide, thiolate, imidazole, and imidazolate ligands.

This dissertation describes the syntheses, molecular structures, and infrared spectroelectrochemistry of nitrosyl ruthenium and osmium porphyrins containing axially bound alkoxide, thiolate, imidazole, and imidazolate ligands.Chapter 3 describes the syntheses of the neutral and cationic (por)Ru(NO)(RIm) (por = TPP, TTP, T(p-OMe)PP), OEP; RIm = imidazolate (Im), imidazole (HIm), 1-methylimidazole (1-MeIm), 4-methylimidazole (4-MeHIm), 5-methylimidazolate (5-MeIm), and 5-methylimidazole (5-MeHIm)) compounds. The neutral imidazolate (por)Ru(NO)(RIm) (R = nothing, 4-Me) complexes were prepared from the addition of the corresponding RHIm to (por)Ru(NO)(O- i-C5H11). The cationic imidazole [(por)Ru(NO)(RIm)] + complexes were prepared from the solvent-free addition of RHIm (R = nothing, 1-Me, 4-Me) to the precursor [(por)Ru(NO)]+ complex. Both the neutral imidazolate and cationic imidazole complexes were characterized by IR and 1H NMR spectroscopy, and by FAB or ESI mass spectrometry. The IR spectra (in CH2Cl2) of the neutral imidazolate complexes displayed nuNO bands in the 1845--1855 cm-1 range, while the cationic imidazole complexes displayed similar bands in the 1854--1877 cm-1 range. Bands in these ranges are suggestive of linear NO ligands in these types of complexes. The 1H NMR spectra of the product that resulted from addition of 4-methylimidazole to [(OEP)Ru(NO)]+ resulted in two sets of peaks that were assigned to the structurally isomeric [(OEP)Ru(NO)(4-MeHIm)]+ and [(OEP)Ru(NO)(5-MeHIm)] + complexes. Further, we were able to determine that the less sterically stable 4-MeHIm containing isomer undergoes a first order dissociation of the 4-MeHIm ligand from the Ru center with the rate constant (k) of 1.44 x 10-5 s-1 with a half-life (t1/2) of 4.81 x 104 s. This was followed by the rebinding of the ligand to the metal center to form the [(OEP)Ru(NO)(5-MeHIm)]+ isomer. The solid-state crystal structures of the imidazolate and imidazole adducts of the (OEP)Ru(NO) complexes were determined by single-crystal X-ray crystallography.Chapter 2 describes the syntheses of (OEP)Ru(NO)(XR) (XR = OEt, SEt, S-i-C5H11, SPh) complexes and the redox behavior of the osmium and ruthenium compounds (OEP)M(NO)(OEt) and (OEP)M(NO)(SEt) (M = Os, Ru), as determined by cyclic voltammetry and infrared spectroelectrochemistry. The (OEP)Ru(NO)(XR) complexes were prepared in 61--85% yields through the formal trans addition of RSNO to (OEP)Ru(CO) with loss of CO. These nitrosyl alkoxide and thiolate complexes were characterized by IR and 1H NMR spectroscopy, and by ESI mass spectrometry. Infrared spectroelectrochemical studies revealed that the (OEP)Os(NO)(OEt) compound undergoes a single reversible oxidation process in dichloromethane. In contrast, the thiolate compound (OEP)Os(NO)(SEt) undergoes a net irreversible oxidation resulting in formal loss of the SEt ligand. Extended Huckel calculations on crystal structures of these two compounds provide insight into the nature of their HOMOs. In the case of the alkoxide compound, the HOMO is largely metalloporphyrin centered. However, the HOMO of the thiolate compound consists of a pi bonding interaction between the metal dxz orbital and the px orbital on the sulfur, and a pi antibonding interaction between the metal d orbital and a pi* orbital on NO. The redox behavior of the Ru analogues have been determined, and are compared with those of the Os compounds.Chapter 4 describes the electrochemistry and infrared spectroelectrochemistry of (OEP)Ru(NO)(Im) and [(OEP)Ru(NO)(RIm)]+ (R = H, 1-Me). Electrochemical oxidation of the (OEP)Ru(NO)(Im) complex in CH2Cl2 displayed a partially reversible single electron transfer centered on the porphyrin followed by an apparent radical hydrogen extraction from the solvent by the nitrogen atom of the imidazolate ring to form the cationic [(OEP)Ru(NO)(HIm)] + derivative. The [(OEP)Ru(NO)(HIm)]+ and [(OEP)Ru(NO)(1-MeIm)] + complexes, on the other-hand, exhibit porphyrin based reversible single electron transfers upon oxidation. However, the reduction of the [(OEP)Ru(NO)(HIm)] + complex proceeds through a partially reversible single electron transfer followed by an apparent H· extraction from the nitrogen atom of the imidazole by the solvent system to form the neutral (OEP)Ru(NO)(Im) derivative. The reduction of the 1-MeIm complexes proceeds through a partially reversible single electron transfer that was followed by the loss of the bond between 1-MeIm ligand the ruthenium center of the porphyrin. Extended Huckel calculations on crystal structures of the (OEP)Ru(NO)(Im) and [(OEP)Ru(NO)(HIm)]+ complexes provides insight on their redox properties. The calculated HOMOs for the isoelectronic structures show charge centered on the porphyrin, providing supporting evidence for the generation of porphyrin-centered pi-radical cations upon oxidation. The calculated LUMO of the cationic complex, however, suggests that the reduction first occurs on the metal-nitrosyl fragment of the [(OEP)Ru(NO)(HIm)] + complex, increasing the antibonding interaction between the metal dxz and pi*. orbital on NO. Presumably, the resulting unfavorable bent Ru-NO- like geometry is relieved by an electronic rearrangement that leads to the extraction of H· from the nitrogen of the imidazole by the solvent system.Chapter 1 introduces the fundamental issues involved in the chemistry of Group 8 Fe, Ru, and Os nitrosyl porphyrin complexes with trans and O- and S-bound ligands, imidazole, and pyridine and their derivatives. Additionally, this chapter introduces important aspects of the biochemistry of the relevant nitrosyl adducts of heme proteins

An Eye-Opening Approach to Developing and Communicating Integrated Environmental Assessments

Communication among managers, the public, and scientists is the key to successful ecosystem management; however, the varied perspectives and interests of these groups can make such communication difficult. One way to achieve effective communication is to develop a common knowledge base by combining syntheses of key scientific results with information-rich visual elements. Within a management landscape, integrated environmental assessments provide a useful framework for evaluating resources and directing management efforts. The integrated assessment process involves (1) initial investigation, (2) development of a conceptual framework, (3) data navigation, (4) environmental report cards, and (5) science communication. Each step requires the synthesis and visualization of information on the status and trends connected with multiple natural resources. We provide a case study, using examples from selected National Park Service sites in the mid-Atlantic region of the United States. Visual elements (conceptual diagrams, maps, graphs, tables, and photographs) were used to facilitate comparative assessments and to provide a more visual, or eye-opening , approach to effective environmental decision making

Sustained Economic Value of a Wellness and Disease Prevention Program: An 8-Year Longitudinal Evaluation

The objective of this study was to determine the sustained economic impact of a health promotion/disease prevention program delivered through a large regional health plan. This was a retrospective analysis of health risk, health claims, and cost using a mixed model factorial design for the years 2002?2009 that compared program participants to nonparticipants. All analyses were adjusted for age, sex, morbidity, and baseline health care costs as appropriate. The findings presented herein indicate a positive return on investment (ROI) for each program year with ratios ranging from a low of 1.16:1 to a high of 2.83:1. The average ROI collapsed across all 8 years was 2.02:1. The 2009 ROI approximated over $6 million in total savings. This study demonstrates the sustained economic value of a comprehensive health promotion program. (Population Health Management 2014;17:90?99)Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140181/1/pop.2013.0042.pd

Detection Of KOI-13.01 Using The Photometric Orbit

We use the KOI-13 transiting star-planet system as a test case for the recently developed BEER algorithm (Faigler & Mazeh 2011), aimed at identifying non-transiting low-mass companions by detecting the photometric variability induced by the companion along its orbit. Such photometric variability is generated by three mechanisms, including the beaming effect, tidal ellipsoidal distortion, and reflection/heating. We use data from three Kepler quarters, from the first year of the mission, while ignoring measurements within the transit and occultation, and show that the planet's ephemeris is clearly detected. We fit for the amplitude of each of the three effects and use the beaming effect amplitude to estimate the planet's minimum mass, which results in M_p sin i = 9.2 +/- 1.1 M_J (assuming the host star parameters derived by Szabo et al. 2011). Our results show that non-transiting star-planet systems similar to KOI-13.01 can be detected in Kepler data, including a measurement of the orbital ephemeris and the planet's minimum mass. Moreover, we derive a realistic estimate of the amplitudes uncertainties, and use it to show that data obtained during the entire lifetime of the Kepler mission, of 3.5 years, will allow detecting non-transiting close-in low-mass companions orbiting bright stars, down to the few Jupiter mass level. Data from the Kepler Extended Mission, if funded by NASA, will further improve the detection capabilities.Comment: Accepted to AJ on October 4, 2011. Kepler Q5 Long Cadence data will become publicly available on MAST by October 23. Comments welcome (V2: minor changes, to reflect proof corrections

(Nitrato-κO)oxido(5,10,15,20-tetra­phenyl­porphyrinato-κ4 N)molybdenum(V) benzene solvate

In the title compound, [Mo(C44H28N4)(NO3)O]·C6H6, the porphyrin ring is centrosymmetric. The Mo atom, oxide ion and nitrate ion are equally disordered over two sites, such that the Mo atom is displaced by 0.366 (1) Å towards the oxide ion from the 24-atom mean plane of the porphyrin, and also makes a long Mo—O bond to a nitrate O atom. A centrosymmetric benzene solvent mol­ecule is situated between adjacent porphyrin mol­ecules

Transit Timing Observations from Kepler: VII. Confirmation of 27 planets in 13 multiplanet systems via Transit Timing Variations and orbital stability

We confirm 27 planets in 13 planetary systems by showing the existence of statistically significant anti-correlated transit timing variations (TTVs), which demonstrates that the planet candidates are in the same system, and long-term dynamical stability, which places limits on the masses of the candidates---showing that they are planetary. %This overall method of planet confirmation was first applied to \kepler systems 23 through 32. All of these newly confirmed planetary systems have orbital periods that place them near first-order mean motion resonances (MMRs), including 6 systems near the 2:1 MMR, 5 near 3:2, and one each near 4:3, 5:4, and 6:5. In addition, several unconfirmed planet candidates exist in some systems (that cannot be confirmed with this method at this time). A few of these candidates would also be near first order MMRs with either the confirmed planets or with other candidates. One system of particular interest, Kepler-56 (KOI-1241), is a pair of planets orbiting a 12th magnitude, giant star with radius over three times that of the Sun and effective temperature of 4900 K---among the largest stars known to host a transiting exoplanetary system.Comment: 12 pages, 13 figures, 5 tables. Submitted to MNRA

Unfamiliar Territory: Emerging Themes for Ecological Drought Research and Management

Novel forms of drought are emerging globally, due to climate change, shifting teleconnection patterns, expanding human water use, and a history of human influence on the environment that increases the probability of transformational ecological impacts. These costly ecological impacts cascade to human communities, and understanding this changing drought landscape is one of today\u27s grand challenges. By using a modified horizon-scanning approach that integrated scientists, managers, and decision-makers, we identified the emerging issues in ecological drought that represent key challenges to timely and effective responses. Here we review the themes that most urgently need attention, including novel drought conditions, the potential for transformational drought impacts, and the need for anticipatory drought management. This horizon scan and review provides a roadmap to facilitate the research and management innovations that will support forward-looking, co-developed approaches to reduce the risk of drought to our socio-ecological systems during the 21st century. We used a modified horizon-scanning approach that brought together scientists, managers, and decision-makers to identify the emerging issues around the ecological impacts from drought that represent key challenges to effective response. We found three broad themes within ecological drought that need attention, including novel drought conditions, transformational drought impacts, and anticipatory drought management. This horizon scan and integrated review provides a roadmap to inspire the needed research and management innovations to reduce the risk of 21st century droughts

Comparative genomics of isolates of a pseudomonas aeruginosa epidemic strain associated with chronic lung infections of cystic fibrosis patients

Pseudomonas aeruginosa is the main cause of fatal chronic lung infections among individuals suffering from cystic fibrosis (CF). During the past 15 years, particularly aggressive strains transmitted among CF patients have been identified, initially in Europe and more recently in Canada. The aim of this study was to generate high-quality genome sequences for 7 isolates of the Liverpool epidemic strain (LES) from the United Kingdom and Canada representing different virulence characteristics in order to: (1) associate comparative genomics results with virulence factor variability and (2) identify genomic and/or phenotypic divergence between the two geographical locations. We performed phenotypic characterization of pyoverdine, pyocyanin, motility, biofilm formation, and proteolytic activity. We also assessed the degree of virulence using the Dictyostelium discoideum amoeba model. Comparative genomics analysis revealed at least one large deletion (40-50 kb) in 6 out of the 7 isolates compared to the reference genome of LESB58. These deletions correspond to prophages, which are known to increase the competitiveness of LESB58 in chronic lung infection. We also identified 308 non-synonymous polymorphisms, of which 28 were associated with virulence determinants and 52 with regulatory proteins. At the phenotypic level, isolates showed extensive variability in production of pyocyanin, pyoverdine, proteases and biofilm as well as in swimming motility, while being predominantly avirulent in the amoeba model. Isolates from the two continents were phylogenetically and phenotypically undistinguishable. Most regulatory mutations were isolate-specific and 29% of them were predicted to have high functional impact. Therefore, polymorphism in regulatory genes is likely to be an important basis for phenotypic diversity among LES isolates, which in turn might contribute to this strain's adaptability to varying conditions in the CF lung

Planetary Candidates Observed by Kepler, III: Analysis of the First 16 Months of Data

New transiting planet candidates are identified in sixteen months (May 2009 - September 2010) of data from the Kepler spacecraft. Nearly five thousand periodic transit-like signals are vetted against astrophysical and instrumental false positives yielding 1,091 viable new planet candidates, bringing the total count up to over 2,300. Improved vetting metrics are employed, contributing to higher catalog reliability. Most notable is the noise-weighted robust averaging of multi-quarter photo-center offsets derived from difference image analysis which identifies likely background eclipsing binaries. Twenty-two months of photometry are used for the purpose of characterizing each of the new candidates. Ephemerides (transit epoch, T_0, and orbital period, P) are tabulated as well as the products of light curve modeling: reduced radius (Rp/R*), reduced semi-major axis (d/R*), and impact parameter (b). The largest fractional increases are seen for the smallest planet candidates (197% for candidates smaller than 2Re compared to 52% for candidates larger than 2Re) and those at longer orbital periods (123% for candidates outside of 50-day orbits versus 85% for candidates inside of 50-day orbits). The gains are larger than expected from increasing the observing window from thirteen months (Quarter 1-- Quarter 5) to sixteen months (Quarter 1 -- Quarter 6). This demonstrates the benefit of continued development of pipeline analysis software. The fraction of all host stars with multiple candidates has grown from 17% to 20%, and the paucity of short-period giant planets in multiple systems is still evident. The progression toward smaller planets at longer orbital periods with each new catalog release suggests that Earth-size planets in the Habitable Zone are forthcoming if, indeed, such planets are abundant.Comment: Submitted to ApJS. Machine-readable tables are available at http://kepler.nasa.gov, http://archive.stsci.edu/kepler/results.html, and the NASA Exoplanet Archiv

Whole Genome Sequence Analysis of Cryptococcus gattii from the Pacific Northwest Reveals Unexpected Diversity

A recent emergence of Cryptococcus gattii in the Pacific Northwest involves strains that fall into three primarily clonal molecular subtypes: VGIIa, VGIIb and VGIIc. Multilocus sequence typing (MLST) and variable number tandem repeat analysis appear to identify little diversity within these molecular subtypes. Given the apparent expansion of these subtypes into new geographic areas and their ability to cause disease in immunocompetent individuals, differentiation of isolates belonging to these subtypes could be very important from a public health perspective. We used whole genome sequence typing (WGST) to perform fine-scale phylogenetic analysis on 20 C. gattii isolates, 18 of which are from the VGII molecular type largely responsible for the Pacific Northwest emergence. Analysis both including and excluding (289,586 SNPs and 56,845 SNPs, respectively) molecular types VGI and VGIII isolates resulted in phylogenetic reconstructions consistent, for the most part, with MLST analysis but with far greater resolution among isolates. The WGST analysis presented here resulted in identification of over 100 SNPs among eight VGIIc isolates as well as unique genotypes for each of the VGIIa, VGIIb and VGIIc isolates. Similar levels of genetic diversity were found within each of the molecular subtype isolates, despite the fact that the VGIIb clade is thought to have emerged much earlier. The analysis presented here is the first multi-genome WGST study to focus on the C. gattii molecular subtypes involved in the Pacific Northwest emergence and describes the tools that will further our understanding of this emerging pathogen