DFT Calculations as a Tool to Analyse Quadrupole Splittings of Spin Crossover Fe(II) complexes

Density functional methods have been applied to calculate the quadrupole splitting of a series of iron(II) spin crossover complexes. Experimental and calculated values are in reasonable agreement. In one case spin-orbit coupling is necessary to explain the very small quadrupole splitting value of 0.77 mm/s at 293 K for a high-spin isomer

Doctor of Philosophy

dissertationThe solution structure of domain IIa of the hepatitis C virus internal ribosome entry site in complex with a racemic benzimidazole inhibitor was determined by NMR spectroscopy with corroborating fluorescence data. A 38 base RNA construct representing the inhibitor-binding region of domain IIa was synthesized by T7 RNA polymerase. Fully and selectively 13C and 15N labeled and isotopically unlabeled RNA samples were produced and studied in complex with the inhibitor. The inhibitor was previously shown to have inhibitory activity in an HCV replicon assay. It was also previously found to bind in the bulge region of domain IIa. In the free RNA, this five base bulge region introduces a bend in the extended domain II that situates the terminus of the domain over the mRNA cleft in the ribosomal E site. This hinge-like bulge region is not a known binding site for any host or viral translational cofactors, but domain II has been shown to be critical for IRES function, and the bulgeinduced bend in domain IIa has been shown to be important for IRES function in mutagenesis assays. Molecular dynamics refinement in explicit solvent and subsequent free energetic analysis indicate that the inhibitor enantiomers bind with comparable affinity and equivalent binding modes. The structure of this inhibitor/RNA complex suggests that the small molecule rearranges the base stacking in the bulge and introduces a significant conformational change that eliminates the bent RNA helical trajectory. This suggests a iv possible mechanism of inhibition involving the displacement of the domain II terminus from the mRNA cleft on the ribosomal E site. Perhaps most importantly, this structure may serve as a guide in the development of second-generation higher affinity inhibitors of the hepatitis C IRES as well as provide general insights into small molecule inhibitor interactions with RNA

Mixed cropping systems for biological control of weeds and pests in organic oilseed crops

Agricultural advantages of mixed cropping are gained by biological effects like light competition, offering weed-suppressing capacities or by diversification of plant covers to break development cycles of pests. In a two-year project on mixed cropping with organic oilseed crops these effects were measured. It was found that weeds can be efficiently suppressed in organic linseed (Linum usitatissivum) in crop combinations with wheat (Triticum aestivum) or false flax (Camelina sativa). But linseed development was strictly limited. Also in organic pea production (Pisum sativum) the introduction of mixtures with the oil crop false flax led to a significant decrease of weed population. Either culture showed a balanced plant development. In winter rape (Brassica napus) hints were found that infestation by insect pests can be directly reduced in mixtures with cereals or legumes and that parasitoids of insect pests are supported

Mixed cropping systems for control of weeds and pests in organic oilseed crops

Agricultural advantages of mixed cropping are gained from biological effects like light competition offering weed-suppressing capacities, or by diversification of plant covers to break development cycles of pests. These effects were measured in a two-year project on mixed cropping with organic oilseed crops. It was found that weeds can be efficiently suppressed in organic linseed (Linum usitatissivum) grown in combination with wheat (Triticum aestivum) or false flax (Camelina sativa). Linseed growth was, however, impaired. In organic pea production (Pisum sativum) also, growing the crop as a mixture with false flax led to a significant decrease of weed population. Either culture showed a balanced plant development. In winter rape (Brassica napus) there were suggestions that infestation by insect pests can be directly reduced in mixtures with cereals or legumes and that parasitoids of insect pests are supported

Intrinsic avalanches and collective phenomena in a Mn(II)-free radical ferrimagnetic chain

Magnetic hysteresis loops below 300 mK on single crystals of the Mn(II) - nitronyl nitroxide free radical chain (Mn(hfac)_2({\it R})-3MLNN) present abrupt reversals of the magnetization, or avalanches. We show that, below 200 mK, the avalanches occur at a constant field, independent of the sample and so propose that this avalanche field is an intrinsic property. We compare this field to the energy barrier existing in the sample and conclude that the avalanches are provoked by multiple nucleation of domain-walls along the chains. The different avalanche field observed in the zero field cooled magnetization curves suggests that the avalanche mechanisms are related to the competition between ferromagnetic and antiferromagnetic order in this compound.Comment: 9 pages, 7 fig, to be published in Phys. Rev.

Classical and nonclassical randomness in quantum measurements

The space of positive operator-valued measures on the Borel sets of a compact (or even locally compact) Hausdorff space with values in the algebra of linear operators acting on a d-dimensional Hilbert space is studied from the perspectives of classical and non-classical convexity through a transform $\Gamma$ that associates any positive operator-valued measure with a certain completely positive linear map of the homogeneous C*-algebra $C(X)\otimes B(H)$ into $B(H)$. This association is achieved by using an operator-valued integral in which non-classical random variables (that is, operator-valued functions) are integrated with respect to positive operator-valued measures and which has the feature that the integral of a random quantum effect is itself a quantum effect. A left inverse $\Omega$ for $\Gamma$ yields an integral representation, along the lines of the classical Riesz Representation Theorem for certain linear functionals on $C(X)$, of certain (but not all) unital completely positive linear maps $\phi:C(X)\otimes B(H) \rightarrow B(H)$. The extremal and C*-extremal points of the space of POVMS are determined.Comment: to appear in Journal of Mathematical Physic

A collaborative chain out of phase

Purpose: To understand the needs of information in the collaboration between health personnel in hospitals and care nursing personnel in municipal care in the process of discharging care-needing older patients from hospitals. Theory: The analytical perspective is a process of patient transition, in which responsible actors in health and municipal care have to collaborate in certain patterns, within a tight time schedule, restricted by the different organizational framework of a hospital or a municipality within which individual actors are situated. Methods: Step 1: Qualitative studies with nursing personnel in six municipalities and nurses in the hospitals serving the actual municipalities. Step 2: A survey addressed to key informants in municipal care in a representative sample of Norwegian municipalities. Results: The formal routines of information exchange associated with these kinds of discharges are too slow and out of phase with informational needs. Seventy percent of our respondent stated that information delivered through formal routines had already been collected by informal contacts. Formal routines were usually weakest for patients to be taken care of in their own homes—where the need for information in many cases was greater than for patients going to local institutions

Organizational Knowledge Transfer: Introducing A Multi-Level Perspective

Posten inneholder presentasjon og tilhørende artikkel presentert på Academy of Management Annual Meeting i 2010Research on organizational knowledge transfer is burgeoning, due to the critical role of external knowledge as a source of advantages for firms as well as public sector organizations. Our study investigates knowledge transfer in the context of a Norwegian benchmarking project in which a majority of the country‟s municipality organizations participated over a period of two years. The explicit purpose of the project was to encourage the project groups to learn from the experiences of their partner organizations. A field sample of 82 benchmarking groups and 274 individual municipality managers were examined to test antecedents to knowledge transfer in this setting. Specifically, the relationships between knowledge transfer and group autonomy, group intensity of effort, absorptive capacity and cognitive distance were hypothesized in the current study, and possible moderator effects from group autonomy were tested on an exploratory basis. Our study was deliberately conducted using a composite multi-level design, in order to test individual and group level relationships simultaneously. The study detected a positive relationship between group intensity, group autonomy and knowledge transfer as well as a negative relationship between individual cognitive distance and knowledge transfer

Occasional Paper No. 091-1: Small Towns Lack Capacity For Successful Development Efforts

Smalltown residents in Nebraska put a high premium on the need for economic development efforts, yet most think their towns\u27 efforts fall short. Some towns, especially the smallest, don\u27t even try to put together a development project. And those that do try often need help of a kind that State and Federal agencies do not offer. Nonetheless, Nebraska is trying some new programs that match State aid with a town\u27s needs and willingness for self-help. Based on a survey of 135 small towns in Nebraska

A study on various methods of supplying propellant to an orbit insertion rocket engine

Various types of pumps and pump drives were evaluated to determine the lightest weight system for supplying propellants to a planetary orbit insertion rocket engine. From these analyses four candidate propellant feed systems were identified. Systems Nos. 1 and 2 were both battery powered (lithium-thionyl-chloride or silver-zinc) motor driven pumps. System 3 was a monopropellant gas generator powered turbopump. System 4 was a bipropellant gas generator powered turbopump. Parameters considered were pump break horsepower, weight, reliability, transient response and system stability. Figures of merit were established and the ranking of the candidate systems was determined. Conceptual designs were prepared for typical motor driven pumps and turbopump configurations for a 1000 lbf thrust rocket engine