Engineering topics

Clark, Jason

Publications and source records attributed to Clark, Jason.

5 records

DOE OSTI2024

Recombinant Vaccine Strain ASFV-G-Δ9GL/ΔUK Produced in the IPKM Cell Line Is Genetically Stable and Efficacious in Inducing Protection in Pigs Challenged with the Virulent African Swine Fever Virus Field Isolate Georgia 2010

We have previously reported that the recombinant African Swine Fever (ASF) vaccine candidate ASFV-G-Δ9GL/ΔUK efficiently induces protection in domestic pigs challenged with the virulent strain Georgia 2010 (ASFV-G). As reported, ASFV-G-Δ9GL/ΔUK induces protection, while intramuscularly (IM), administered at doses of 10 4 HAD 50 or higher, prevents ASF clinical disease in animals infected with the homologous ASFV g strain. Like other recombinant vaccine candidates obtained from ASFV field isolates, ASFV-G-Δ9GL/ΔUK stocks need to be produced in primary cultures of swine macrophages, which constitutes an important limitation in the production of large virus stocks at the industrial level. Here, we describe the development of ASFV-G-Δ9GL/ΔUK stocks using IPKM (Immortalized Porcine Kidney Macrophage) cells, which are derived from swine macrophages. We show that ten successive passages of ASFV-G-Δ9GL/ΔUK in IPKM cells induced small changes in the virus genome. The produced virus, ASFV-G-Δ9GL/ΔUKp10, presented a similar level of replication in swine macrophages cultures to that of the original ASFV-G-Δ9GL/ΔUK (ASFV-G-Δ9GL/ΔUKp0). The protective efficacy of ASFV-G-Δ9GL/ΔUKp10 was evaluated in pigs that were IM-inoculated with either 10 4 or 10 6 HAD 50 of ASFV-G-Δ9GL/ΔUKp10. While animals inoculated with 10 4 HAD 50 present a partial protection against the experimental infection with the virulent parental virus ASFV-G, those inoculated with 10 6 HAD 50 were completely protected. Therefore, as was just recently reported for another ASF vaccine candidate, ASFV-G-ΔI177L, IPKM cells are an effective alternative to produce stocks for vaccine strains which only grow in swine macrophages.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2024

Deletion of the EP402R Gene from the Genome of African Swine Fever Vaccine Strain ASFV-G-ΔI177L Provides the Potential Capability of Differentiating between Infected and Vaccinated Animals

The African swine fever virus (ASFV) mutant ASFV-G-ΔI177L is a safe and efficacious vaccine which induces protection against the challenge of its parental virus, the Georgia 2010 isolate. Although a genetic DIVA (differentiation between infected and vaccinated animals) assay has been developed for this vaccine, still there is not a serological DIVA test for differentiating between animals vaccinated with ASFV-G-ΔI177L and those infected with wild-type viruses. In this report, we describe the development of the ASFV-G-ΔI177L mutant having deleted the EP402R gene, which encodes for the viral protein responsible for mediating the hemadsorption of swine erythrocytes. The resulting virus, ASFV-G-ΔI177L/ΔEP402R, does not have a decreased ability to replicates in swine macrophages when compared with the parental ASFV-G-ΔI177L. Domestic pigs intramuscularly (IM) inoculated with either 10 2 or 10 6 HAD 50 of ASFV-G-ΔI177L/ΔEP402R remained clinically normal, when compared with a group of mock-vaccinated animals, indicating the absence of residual virulence. Interestingly, an infectious virus could not be detected in the blood samples of the ASFV-G-ΔI177L/ΔEP402R-inoculated animals in either group at any of the time points tested. Furthermore, while all of the mock-inoculated animals presented a quick and lethal clinical form of ASF after the intramuscular inoculation challenge with 10 2 HAD 50 of highly virulent parental field isolate Georgia 2010 (ASFV-G), all of the ASFV-G-ΔI177L/ΔEP402R-inoculated animals were protected, remaining clinically normal until the end of the observational period. Most of the ASFV-G-ΔI177L/ΔEP402R-inoculated pigs developed strong virus-specific antibody responses against viral antigens, reaching maximum levels at 28 days post inoculation. Importantly, all of the sera collected at that time point in the ASFV-G-ΔI177L/ΔEP402R-inoculated pigs did not react in a direct ELISA coated with the recombinant EP402R protein. Conversely, the EP402R protein was readily recognized by the pool of sera from the animals immunized with recombinant live attenuated vaccine candidates ASFV-G-ΔI177L, ASFV-G-ΔMGF, or ASFV-G-Δ9GL/ΔUK. Therefore, ASFV-G-ΔI177L/ΔEP402R is a novel, safe and efficacious candidate with potential to be used as an antigenically DIVA vaccine.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2024

Determination of the spins and parities for the 0$^{+}_{4}$ and 0$^{+}_{5}$ states in 100 Zr

Here, two 0 + states at 1294.5 and 1774.0 keV, together with three 2 + and one 4 + levels, were identified or unambiguously spin-parity assigned for the first time in 100 Zr utilizing γ-ray spectroscopy and γ–γ angular correlation techniques with the Gammasphere spectrometer, following the β – decay of neutron-rich, mass-separated 100,100m Y isotopes. Comparisons with recent Monte Carlo shell-model calculations indicate that these two states are candidates for the bandhead of a sequence in a shape-coexisting spherical minimum predicted to be located around ≈1500 keV. According to the measured relative B(E2) relative transition probabilities, the 0$^+_5$ state exhibits decay properties which more closely align with those predicted for a spherical shape, while the 0$^+_4$ level is suggested to be associated with a weakly deformed shape similar to one related to the 0$^+_2$ state.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2023

Precise mass measurements of radioactive nuclides for astrophysics

Much of astrophysics is fueled by nuclear physics with observables, such as energy output and elements produced, that are heavily dependent on the masses of the nuclides. A mass precision of at least 50 keV/c 2 for many rare nuclides is needed to adequately discriminate models that explain the observables. In recent decades, the development of new facilities and mass-measurement techniques has made available a wealth of precise and accurate mass data. Further, the new data, in combination with novel codes and models, has greatly enhanced the understanding of astrophysical processes in the universe, but much is still to be learned.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2021

The LAKE model input dataset for three Arctic lakes

This dataset contains meteorological data collected for three Arctic lakes and compiled to satisfy input requirements of the LAKE 2.0 model. The dataset was generated to act as a benchmarking dataset for future model-data inter-comparisons. The LAKE 2.0 model simulates temperatures within the water later and the sedimentary layer of a lake. The LAKE2.0. is an open-source code and available to download via this weblike http://tesla.parallel.ru/Viktor/LAKE/-/wikis/LAKE-model (last visit July 14, 2021). The meteorological data are required to simulate the surface energy balance at the surface of a lake. This dataset includes a compilation of the meteorological data pulled from multiple data streams, including National Oceanic and Atmospheric Administration (NOAA) climate data, Circumarctic Lakes Observation Network (CALON) data, and the United States Geological Survey (USGS) data. The data were compiled for three Arctic lakes: FoxDen (66.55877, -164.45670), Atqasuk (70.452497, -156.951984), and Toolik (68.63150, -149.60740). Each meteorological data is in comma-delimited format (file extension ‘.dat’) and includes eight columns: Temperature [K], Pressure [Pa], longwave downward radiation [W/m2], shortwave downward radiation [W/m2], “U” wind speed [m/s], ”V” wind speed [m/s], humidity [kg/kg], precipitation [m/s]. In addition to the meteorological data file, we included setup and driver files. The Toolik lake is the deepest out of three lakes and has inflowing and outflowing groundwater data. InflowOutflowREADME.txt has more information about inflow and outflow flies. The other two lakes are much shallower and modeled as a closed system (i.e. no water inflow or outflow).

54 ENVIRONMENTAL SCIENCES↗