Develop and Test Fish Pot Cull Rings

Fish potting is a growing fishery in Virginia’s rivers and catfish is the primary targeted species. Demand for catfish is strong, and prices are good, but there is a lot of sorting and fish handling because the demand is for 2-8 pound fish. Traditionally, cull rings are used successfully in various traps/pots to let smaller fish/crabs escape and to reduce the labor and expense to manually sort and discard smaller animals. The use of cull rings in catfish pots, or hoop-nets, has not been studied in the Virginia catfish fishery. If cull rings could be successfully designed and placed within catfish pots to reduce the amount of small, les

COVID-19 Serological Diagnostic Development Using A SARS-CoV-2 RBD Foldon Fusion

Serological tests are conducted to assess humoral response against viral protein antigens, to assess viral exposure and protection from pathogens. The rapid development and modularity of serological assays have proven critical to managing the current SARS-CoV-2 pandemic. The receptor binding domain of SARS-CoV-2 is within the trimeric Spike protein and serves as a highly immunogenic target for potentially neutralizing antibodies. Current receptor binding domain serological assays use recombinant monomers or dimers of the receptor binding domain. The receptor binding domain is presented to the immune system natively in the context of the Spike protein trimer. Therefore, a recombinant trimeric receptor binding domain may be predictive of protection and improve antibody binding. For this thesis, using the trimerization domain from Bacteriophage T4 Fibritin, called Foldon, fused to the receptor binding domain, a novel antigen was produced. The antigen was expressed in and extracted from Nicotiana benthamiana plants, purified through immobilized metal affinity FPLC, and used to develop a serological ELISA. The antigen was tested with hospitalized (n=46), non-hospitalized (n=36), and negative (n=46) patient sera sample lots and batch reproducibility was examined. From these studies, it was concluded that this trimeric antigen can be consistently expressed, extracted, and purified and can be used to reliably detect responses to SARS-CoV-2 in sera. Additionally, fusion of the Foldon trimerization domain to trimeric viral proteins serves as a platform for the development of plant produced viral antigens to better detect host response

Effects of domain walls on hole motion in the two-dimensional t-J model at finite temperature

The t-J model on the square lattice, close to the t-J_z limit, is studied by quantum Monte Carlo techniques at finite temperature and in the underdoped regime. A variant of the Hoshen-Koppelman algorithm was implemented to identify the antiferromagnetic domains on each Trotter slice. The results show that the model presents at high enough temperature finite antiferromagnetic (AF) domains which collapse at lower temperatures into a single ordered AF state. While there are domains, holes would tend to preferentially move along the domain walls. In this case, there are indications of hole pairing starting at a relatively high temperature. At lower temperatures, when the whole system becomes essentially fully AF ordered, at least in finite clusters, holes would likely tend to move within phase separated regions. The crossover between both states moves down in temperature as doping increases and/or as the off-diagonal exchange increases. The possibility of hole motion along AF domain walls at zero temperature in the fully isotropic t-J is discussed.Comment: final version, to appear in Physical Review

Design and performance of beam test electronics for the PHENIX Multiplicity Vertex Detector

The system architecture and test results of the custom circuits and beam test system for the Multiplicity-Vertex Detector (MVD) for the PHENIX detector collaboration at the Relativistic Heavy Ion Collider (RHIC) are presented in this paper. The final detector per-channel signal processing chain will consist of a preamplifier-gain stage, a current-mode summed multiplicity discriminator, a 64-deep analog memory (simultaneous read-write), a post-memory analog correlator, and a 10-bit 5 {mu}s ADC. The Heap Manager provides all timing control, data buffering, and data formatting for a single 256-channel multi-chip module (MCM). Each chip set is partitioned into 32-channel sets. Beam test (16-cell deep memory) performance for the various blocks will be presented as well as the ionizing radiation damage performance of the 1.2 {mu} n-well CMOS process used for preamplifier fabrication

Isothermal Recombinase Polymerase amplification (RPA) of Schistosoma haematobium DNA and oligochromatographic lateral flow detection

© 2015 Rosser et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. The attached file is the published version of the article

Changes in Optical Conductivity due to Readjustments in Electronic Density of States

Within the model of elastic impurity scattering, we study how changes in the energy dependence of the electronic density of states (EDOS) $N(\epsilon)$ around the Fermi energy $\epsilon_F$ are reflected in the frequency-dependent optical conductivity $\sigma(\omega)$. While conserving the total number of states in $N(\epsilon)$ we compute the induced changes in $\sigma(\omega)$ as a function of $\omega$ and in the corresponding optical scattering rate $1/\tau_{\rm op}(\omega)$. These quantities mirror some aspects of the EDOS changes but the relationship is not direct. Conservation of optical oscillator strength is found not to hold, and there is no sum rule on the optical scattering rate although one does hold for the quasiparticle scattering. Temperature as well as increases in impurity scattering lead to additional changes in optical properties not seen in the constant EDOS case. These effects have their origin in an averaging of the EDOS around the Fermi energy $\epsilon_F$ on an energy scale set by the impurity scattering.Comment: 13 pages, 7 figure

RKKY interaction and Kondo screening cloud for correlated electrons

The RKKY law and the Kondo screening cloud around a magnetic impurity are investigated for correlated electrons in 1D (Luttinger liquid). We find slow algebraic distance dependences, with a crossover between both types of behavior. Monte Carlo simulations have been developed to study this crossover. In the strong coupling regime, the Knight shift is shown to increase with distance due to correlations.Comment: 5 pages REVTeX, incl two figures, to appear in Phys.Rev.