Membrane Antigens on AKR Mice Lymphocytes

This investigation is concerned with cell surface antigens present on murine AKR/J mice spleen and thymus cells which have been extracted with papain. Isolation of individual proteins was accomplished by granulated gel electrofocusing. Similar patterns recorded by both electrofocusing procedures identified several proteins limited to the AKR/J and C3Heb/FeJ spleen and thymus samples, which represent Murine Leukemia Virus-associated surface proteins

Surveys of Southern Flying Squirrel Activity Following Timber Harvest in Southern Indiana

Southern flying squirrels (Glaucomys volans) are gliding small mammals that are ecologically important seed dispersers and prey species across their wide range, which extends from southern Canada to Central America. Because of their reliance on forest structure for efficient movement and on forest composition for hard mast production to provide winter food items, habitat use by G. volans may be impacted by timber harvest. Responses of G. volans to timber harvests remains understudied throughout their range, and studies are especially lacking within the Central Hardwoods Region that includes Indiana. Our study in the Hardwood Ecosystem Experiment (HEE) in southern Indiana examined responses in G. volans activity to even- and uneven-aged forestry using passive acoustic sampling. We examined data from Anabat II recorders positioned within and around harvested areas for ultrasonic G. volans vocalizations to determine activity levels in uneven-aged, even-aged, and no harvest treatments in the year following treatment. We identified G. volans calls via comparison to a library of known calls. We used the mean number of calls per night as an estimate of G. volans activity. Our preliminary results found G. volans activity in the treatment area edge and surrounding forest for all treatment types. We found the greatest activity in the interior of uneven-aged patch cuts, whereas even-aged clearcuts and no harvest treatment interiors had lower levels of activity. We found no activity in the interior of even-aged shelterwoods. These results suggest that uneven-aged harvests have less impact on G. volans activity than even-aged forest management

Purification and structural characterization of the Na⁺-translocating ferredoxin: NAD⁺ reductase (Rnf) complex of Clostridium tetanomorphum

Various microbial metabolisms use H+/Na+-translocating ferredoxin:NAD+ reductase (Rnf) either to exergonically oxidize reduced ferredoxin by NAD+ for generating a transmembrane electrochemical potential or reversely to exploit the latter for producing reduced ferredoxin. For cryo-EM structural analysis, we elaborated a quick four-step purification protocol for the Rnf complex from Clostridium tetanomorphum and integrated the homogeneous and active enzyme into a nanodisc. The obtained 4.27 Å density map largely allows chain tracing and redox cofactor identification complemented by biochemical data from entire Rnf and single subunits RnfB, RnfC and RnfG. On this basis, we postulated an electron transfer route between ferredoxin and NAD via eight [4Fe-4S] clusters, one Fe ion and four flavins crossing the cell membrane twice related to the pathway of NADH:ubiquinone reductase. Redox-coupled Na+ translocation is provided by orchestrating Na+ uptake/release, electrostatic effects of the assumed membrane-integrated FMN semiquinone anion and accompanied polypeptide rearrangements mediated by different redox steps

Cross Section and Angular Distributions of the (d, p) and (d, n) Reactions in C12 from 1.8 to 6.1 Mev

The reaction C12(d, p)C13 has been studied from a deuteron bombarding energy of 1.8 to 6.1 Mev. Resonances were found at 2.47, 2.67, 2.99, 3.39, 4.00, 4.6, 4.8, 5.34, and 5.64 Mev. Angular distributions of protons leaving C13 in the ground state show a pronounced Butler peak at 25° over the entire deuteron energy range. The angular distributions can be explained by assuming small amplitudes for compound nucleus formation interfering with large stripping amplitudes. Angular distributions of the lower energy group of protons leaving C13 excited to 3.09 Mev show a pronounced Butler peak at 0° and an even smaller contribution of compound nucleus formation. The reaction C12(d, n)N13 was also studied, and showed similar resonances and angular distributions. An analysis is made of the phase difference between the resonant and nonresonant parts of the cross section for the (d, p) reaction near the resonance at 4.00 Mev

Analytical solution of a one-dimensional Ising model with zero temperature dynamics

The one-dimensional Ising model with nearest neighbour interactions and the zero-temperature dynamics recently considered by Lefevre and Dean -J. Phys. A: Math. Gen. {\bf 34}, L213 (2001)- is investigated. By introducing a particle-hole description, in which the holes are associated to the domain walls of the Ising model, an analytical solution is obtained. The result for the asymptotic energy agrees with that found in the mean field approximation.Comment: 6 pages, no figures; accepted in J. Phys. A: Math. Gen. (Letter to the Editor

Radio-Frequency Spectroscopy

Contains reports on three research projects

Dynamics of the frustrated Ising lattice gas

The dynamical properties of a three dimensional model glass, the frustrated Ising lattice gas (FILG) are studied by Monte Carlo simulations. We present results of compression experiments, where the chemical potential is either slowly or abruptly changed, as well as simulations at constant density. One time quantities like density and two time ones like correlations, responses and mean square displacements are measured, and the departure from equilibrium clearly characterized. The aging scenario, particularly in the case of density autocorrelations is reminiscent of spin glass phenomenology with violations of the Fluctuation-dissipation theorem, typical of systems with one replica symmetry breaking. The FILG, as a valid on-lattice model of structural glasses can be described with tools developed in spin glass theory and, being a finite dimensional model, can open the way for a systematic study of activated processes in glasses.Comment: to appear in Phys. Rev. E, november (2000

Radio-Frequency Spectroscopy

Contains reports on four research projects

Demonstrating vaccine effectiveness during a waning epidemic: A WHO/NIH meeting report on approaches to development and licensure of Zika vaccine candidates.

Since its peak in early 2016, the incidence of Zika virus (ZIKV) cases has declined to such low levels that Phase 3 field efficacy trials may be infeasible. While great progress was made to rapidly advance several vaccine candidates into Phase 1 and 2 clinical trials, in the absence of sustained viral transmission it may be difficult to evaluate the effectiveness of ZIKV vaccine candidates by conducting traditional clinical disease endpoint efficacy studies. However, ZIKV is still circulating at low levels in some areas and is likely to re-emerge in naïve populations or in sites of prior epidemics once population immunity wanes. Therefore, the public health need for a ZIKV vaccine remains. To facilitate continued ZIKV vaccine development efforts, the World Health Organization's Initiative for Vaccine Research and the National Institutes of Health's National Institute of Allergy and Infectious Diseases co-hosted a meeting of experts in March 2018 to identify strategies to demonstrate vaccine effectiveness in view of waning ZIKV disease incidence. This paper outlines points for consideration for developers, regulators, and other stakeholders working towards a licensed ZIKV vaccine. These deliberations may also be applicable to development of vaccines for other emerging infections where the size, unpredictability, and ephemeral nature of outbreaks makes clinical disease endpoint efficacy trials to demonstrate vaccine effectiveness infeasible