The coordination chemistry of saturated molecules

Our understanding of bonding in transition metal complexes, as well as our ability to use that understanding in the synthesis and application of new species, has evolved over the last 100 years; and in some sense this special feature on the coordination chemistry of saturated molecules may be considered to represent its culmination. The nature of complexes between transition metal ions and neutral molecules such as ammonia was first correctly described by Werner around the beginning of the 20th century. Interpretations in terms of electronic bonding theories followed soon after. The key feature, of course, is the availability of a low-energy filled "lone pair" orbital available for donation to a vacant orbital on the electron-accepting metal ion

Non-Measles Hemadsorption in a Cell Line Persistently Infected with Measles Virus (BGM/MV)

Adsorption of Rhesus monkey erythrocytes to the plasma membranes of measles virus infected cells is frequently carried out to detect the presence of plasma membrane-associated measles virus hemagglutinin. The hemagglutinin is a viral genome-coded structural glycoprotein of the measles virion that is associated with the plasma membrane of the host cell during measles virus replication. BGM/MV, anon-virogenic line of African green monkey kidney cells persistently-infected with measles virus, adsorbed Rhesus monkey erythrocytes in an inverse fashion relative to the number of cells present in the culture and the time post-seeding. Serological studies employing the hemadsorption-inhibition and membrane immunofluorescence assay procedures, suggested that this phenomenon was not mediated by the viral hemagglutinin. Assays for Simian virus-5 and mycoplasma, contaminating agents that induce erythrocyte adsorption, were negative. Incubation of BGM/MV cells at 33°C or with graded concentrations of fetal calf serum, to stimulate the metabolism of resting (Go) cells, suggested that adsorption was related to a phase(s) of the cell growth cycle other than Go₁, for adsorption was prolonged and stimulated in a dose-response fashion, respectively. Comparative adsorption studies employing the parent cell line (BGM), not infected with measles virus, were performed using various species of erythrocytes. While both cell lines adsorbed Rhesus monkey erythrocytes in an inverse fashion relative to cell density, differences were noted in the adsorption of some of the other species of erythrocytes. These data suggest that Rhesus monkey erythrocyte adsorption to BGM/MV cells was mediated by a receptor(s) of cellular origin

Survey of anadromous fish spawning areas: completion report, project AFC-8 July 1970 - January 1975 for Potomac River drainage, Upper Chesapeake Bay drainage

This report summarizes Project AFC-8 ("Survey of Anadromous Fish Spawning Areas") stream investigation and improvement activities for the entire study period of July 1970 to January 1975. The four and one-half year study included four inter-related jobs or types of stream investigation: Literature and Data Review, Fishery Investigation, Stream Investigation, Data Summarization and Storage/Preparation of Report. (Document has 229 pages.

Calibration of Willingness-to-Accept

This paper calibrates real and hypothetical willingness-to-accept estimates elicited for consumer goods in a multi-unit, random nth-price auction. Using a within-subject experimental design, we find that people understated their real willingness to accept in the hypothetical regimes, framed both as demand and non-demand revealing. After controlling for personspecific effects, however, hypothetical and real statements are equivalent on the margin.

Estimating Abundance from Counts in Large Data Sets of Irregularly-Spaced Plots using Spatial Basis Functions

Monitoring plant and animal populations is an important goal for both academic research and management of natural resources. Successful management of populations often depends on obtaining estimates of their mean or total over a region. The basic problem considered in this paper is the estimation of a total from a sample of plots containing count data, but the plot placements are spatially irregular and non randomized. Our application had counts from thousands of irregularly-spaced aerial photo images. We used change-of-support methods to model counts in images as a realization of an inhomogeneous Poisson process that used spatial basis functions to model the spatial intensity surface. The method was very fast and took only a few seconds for thousands of images. The fitted intensity surface was integrated to provide an estimate from all unsampled areas, which is added to the observed counts. The proposed method also provides a finite area correction factor to variance estimation. The intensity surface from an inhomogeneous Poisson process tends to be too smooth for locally clustered points, typical of animal distributions, so we introduce several new overdispersion estimators due to poor performance of the classic one. We used simulated data to examine estimation bias and to investigate several variance estimators with overdispersion. A real example is given of harbor seal counts from aerial surveys in an Alaskan glacial fjord.Comment: 37 pages, 7 figures, 4 tables, keywords: sampling, change-of-support, spatial point processes, intensity function, random effects, Poisson process, overdispersio

Intra- and Intermolecular C−H Activation by Bis(phenolate)pyridineiridium(III) Complexes

A bis(phenolate)pyridine pincer ligand (henceforth abbreviated as ONO) has been employed to support a variety of iridium complexes in oxidation states I, III, and IV. Complexes (ONO)IrL_2Me (L = PPh_3, PEt_3) react with I_2 to cleave the Ir–C bond and liberate MeI, apparently via a mechanism beginning with electron transfer to generate an intermediate Ir(IV) complex, which can be isolated and characterized for the case L = PEt_3. The PPh_3 complex is transformed in benzene at 65 °C to the corresponding phenyl complex, with loss of methane, and subsequently to a species resulting from metalation of a PPh_3 ligand. Labeling and kinetics studies indicate that PPh_3 is the initial site of C–H activation, even though the first observed product is that resulting from intermolecular benzene activation. C–H activation of acetonitrile has also been observed

Activation of a C−H Bond in Indene by [(COD)Rh(μ_2-OH)]_2

The air- and water-tolerant hydroxy-bridged rhodium dimer [(COD)Rh(μ_2-OH)]_2 cleanly activates the aliphatic C−H bond in indene to generate [(COD)Rh(η^3-indenyl)]. The mechanism involves direct coordination of indene to the dimer followed by rate-determining C−H bond cleavage, in contrast to the previously reported analogous reactions of [(diimine)M(μ_2-OH)]_2^(2+) (M = Pd, Pt), for which the dimer must be cleaved before rate-determining displacement of solvent by indene. Another difference is observed in the reactions with indene in the presence of acid: the Rh system generates a stable η^6-indene 18-electron cation, [(COD)Rh(η^6-indene)]+, that is not available for Pd and Pt, which instead form the η^3-indenyl C−H activation products. The crystal structure of [(COD)Rh(η^6-indene)] is reported

Economic Contribution of State Parks to the North Dakota Economy

North Dakota's state parks are an important part of tourism which is an important component of the infrastructure supporting the state's economy. The purpose of this study was to estimate the contribution of state parks to the North Dakota economy in the form of increased levels of business activity, employment, personal income, and tax collections.Resource /Energy Economics and Policy,