Electron paramagnetic resonance studies of slowly tumbling vanadyl spin probes in nematic liquid crystals

An analysis of EPR line shapes by the method of Polnaszek, Bruno, and Freed is made for slowly tumbling vanadyl spin probes in viscous nematic liquid crystals. The use of typical vanadyl complexes as spin probes for nematic liquid crystals is shown to simplify the theoretical analysis and the subsequent interpretation. Rotational correlation times tau and orientational ordering parameters S sub Z where slow tumbling effects are expected to be observed in vanadyl EPR spectra are indicated in a plot. Analysis of the inertial effects on the probe reorientation, which are induced by slowly fluctuating torque components of the local solvent structure, yield quantitative values for tau and S sub Z. The weakly ordered probe VOAA is in the slow tumbling region and displays these inertial effects throughout the nematic range of BEPC and Phase V. VOAA exhibits different reorientation behavior near the isotropic-nematic transition temperature than that displayed far below this transition temperature

ESR studies of the slow tumbling of vanadyl spin probes in nematic liquid crystals

ESR line shapes that are appropriate for slowly tumbling vanadyl spin probes in viscous nematic liquid crystals were calculated by the stochastic Liouville method. Because of the symmetry possessed by vanadyl, the analysis and interpretation of these line shapes was simplified considerably. Spectral line shapes agreed well with experimental spectra of VOAcAc in the nematic liquid crystal Phase V and BEPC. Deviations from Brownian rotational diffusion were noted. A slowly fluctuating torque analysis yielded good agreement with the experimental spectra

Coaching in the sales profession: what part can coaching with literature play in dealing with a contemporary "Bartleby"?

This article makes a case for using Herman Melville’s 1853 short story “Bartleby the Scrivener, A Tale of Wall-Street” to support new sales staff. Rock and Schwartz’s (2006) ideas on brain-based coaching have been reinforced by an exploration of a literary approach to coaching in order to demonstrate how to support sales people. The study used feedback from salespeople in mainly the recruitment and publishing industries. Data collected suggest that new sales recruits are frustrated at not knowing what standards they are expected to meet. Findings also suggest that there was merit in using literature as part of a coaching development exercise and that literature such as “Bartleby” could be a source of help in navigating work situations

Bolometric light curves of supernovae and post-explosion magnetic fields

The various effects leading to diversity in the bolometric light curves of supernovae are examined: nucleosynthesis, kinematic differences, ejected mass, degree of mixing, and configuration and intensity of the magnetic field are discussed. In Type Ia supernovae, a departure in the bolometric light curve from the full-trapping decline of $^{56}$Co can occur within the two and a half years after the explosion, depending on the evolutionary path followed by the WD during the accretion phase. If convection has developed in the WD core during the presupernova evolution, starting several thousand years before the explosion, a tangled magnetic field close to the equipartition value should have grown in the WD. Such an intense magnetic field would confine positrons where they originate from the $^{56}$Co decays, and preclude a strong departure from the full-trapping decline, as the supernova expands. This situation is expected to occur in C+O Chandrasekhar WDs as opposed to edge-lit detonated sub-Chandrasekhar WDs. If the pre-explosion magnetic field of the WD is less intense than 10$^{5-8}$G, a lack of confinement of the positrons emitted in the $^{56}$Co decay and a departure from full-trapping decline would occur. The time at which it takes place can provide estimates of the original magnetic field of the WD, its configuration, and also of the mass of the supernova ejecta. In SN 1991bg, the bolometric light curve suggests absence of a significant tangled magnetic field (intensity lower than $10^{3}$ G). Chandrasekhar-mass models do not reproduce the bolometric light curve of this supernova. For SN 1972E, on the contrary, there is evidence for a tangled configuration of the magnetic field and its light curve is well reproduced by a Chandrasekhar WD explosion.Comment: 54 pages, including 8 figures. To appear in Ap

Academic Libraries, Government Information, and the Persistent Problem of Jargon

The shift to born-digital and digitized materials has ultimately increased access and convenience for users, but in many ways it has also complicated the process of finding information. While users may struggle with catalog interfaces or reading call numbers, most have a basic understanding of how to locate a physical book. But in the digital environment, users have no built-in model for what sequence of clicks or keywords will get them to the information they need. This problem is exacerbated for specialized areas like government information, where more and more data and documents are readily available online via a variety of public web portals. Libraries often curate these portals using research guides or other domain-specific reference websites, providing major points of access for users. However, designing these specialized sites to be user-centered, rather than domaincentered, presents numerous challenges. For instance, how should the needs of different user groups be balanced? How should complex information be structured to support domain experts, while also helping orient and remove barriers for new users? Answering these questions is especially important to Utah State University Libraries (USU), which serve as a Regional Depository for the Federal Depository Library Program (FDLP). USU’s Government Information Department supports not only our community of 25,000 undergraduate and 3,000 graduate students, many of whom learn at a distance, but also local and regional communities as a matter of public access. To be successful, these users need to understand and be able to effectively navigate the “library within a library” that is government information. To support this broad community and their range of needs, our websites need to strike the right balance between straightforward, content-focused design and more supportive, instruction-heavy design

Kynurenine pathway inhibition reduces central nervous system inflammation in a model of human African trypanosomiasis

Human African trypanosomiasis, or sleeping sickness, is caused by the protozoan parasites <i>Trypanosoma brucei rhodesiense</i> or <i>Trypanosoma brucei gambiense</i>, and is a major cause of systemic and neurological disability throughout sub-Saharan Africa. Following early-stage disease, the trypanosomes cross the blood-brain barrier to invade the central nervous system leading to the encephalitic, or late stage, infection. Treatment of human African trypanosomiasis currently relies on a limited number of highly toxic drugs, but untreated, is invariably fatal. Melarsoprol, a trivalent arsenical, is the only drug that can be used to cure both forms of the infection once the central nervous system has become involved, but unfortunately, this drug induces an extremely severe post-treatment reactive encephalopathy (PTRE) in up to 10% of treated patients, half of whom die from this complication. Since it is unlikely that any new and less toxic drug will be developed for treatment of human African trypanosomiasis in the near future, increasing attention is now being focussed on the potential use of existing compounds, either alone or in combination chemotherapy, for improved efficacy and safety. The kynurenine pathway is the major pathway in the metabolism of tryptophan. A number of the catabolites produced along this pathway show neurotoxic or neuroprotective activities, and their role in the generation of central nervous system inflammation is well documented. In the current study, Ro-61-8048, a high affinity kynurenine-3-monooxygenase inhibitor, was used to determine the effect of manipulating the kynurenine pathway in a highly reproducible mouse model of human African trypanosomiasis. It was found that Ro-61-8048 treatment had no significant effect (P = 0.4445) on the severity of the neuroinflammatory pathology in mice during the early central nervous system stage of the disease when only a low level of inflammation was present. However, a significant (P = 0.0284) reduction in the severity of the neuroinflammatory response was detected when the inhibitor was administered in animals exhibiting the more severe, late central nervous system stage, of the infection. <i>In vitro</i> assays showed that Ro-61-8048 had no direct effect on trypanosome proliferation suggesting that the anti-inflammatory action is due to a direct effect of the inhibitor on the host cells and not a secondary response to parasite destruction. These findings demonstrate that kynurenine pathway catabolites are involved in the generation of the more severe inflammatory reaction associated with the late central nervous system stages of the disease and suggest that Ro-61-8048 or a similar drug may prove to be beneficial in preventing or ameliorating the PTRE when administered as an adjunct to conventional trypanocidal chemotherap

Examining Retailer And Consumer Perceptions In Determining Economic Expectations: A Demonstration With The 2008 Holiday Season

Two stratified probability samples were conducted in the southeastern United States, one of consumers and one of retailers, to measure economic perceptions in the fall of 2008. Direct comparisons were made between consumers’ and retailers’ perceptions in the areas of the economy, financial soundness, cost of living, and planned consumer holiday spending.  The results suggested that retailers and consumers held similar negative perceptions in terms of the state of the economy.  Consumers though felt less financially sound than retailers did.  Additionally, consumers felt the cost of living has increased to a greater degree than retailers felt their cost of operating had.  Finally, there was a considerable difference in consumers’ planned holiday spending and retailers’ expectations of holiday spending as retailers better predicted that consumers were planning to spend less. The managerial implications for retailers based on these predictions are presented