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The Examination of AES S-Box Implementations Using Composite Field Arithmetic on FPGAs
No full textThis paper presents an examination of the S-Box transformation in the Advanced Encryption Standard algorithm. The research examined the S-box implementation as a standard look-up table and implemented as combinational logic derived from Composite Field Arithmetic. The study was carried out using an Artix-7 xc7a100tcsg324-1 Xilinx FPGA, programmed using Verilog HDL in the Vivado design suite. The research suggests that using the Composite Field implementation, the s-box required less ram resources at the cost of more power consumption than the standard implementation requires. It also suggests there is further room for research in the effects the implementation has on possible cryptanalysis techniques and heat generation abatement
Emerging Technology for Mitigating Burden of Foodborne Bacteria of Public Health Concern
No full textDiseases caused by foodborne pathogens are serious public health challenge affecting many lives and creating challenges to the health of the individuals. People who are elderly, small children, the pregnant women, and the immunocompromised people are at greatest risk. It is creating problems both globally and nationally. The first chapter of this dissertation is focused on the studies related with the sensitivity of Staphylococcus aureus to elevated levels of hydrostatic pressure in the presence of antimicrobials such as nisin, carvacrol and caprylic acid. At high pressures, nisin had mild effects to enhance the decontamination efficacy of the pathogen. Mild heat enhanced the decontamination effect of this pathogen and also the antimicrobials were effective to reduce the pressure treatment time. The second chapter is about the studies related with the inactivation of pressure-stressed and wild-type Cronobacter sakazakii using pressure-based pasteurization. The application seems to be effective to enhance the pressure-based decontamination of Cronobacter sakazakii. The application of protamine and defensin were additionally effective to reduce the bacterial counts. The third chapter is focused on the studies related with the biofilm formation of pathogenic Listeria monocytogenes and Salmonella serovars and non-pathogenic Listeria innocua and Salmonella LT2 and their inactivation on stainless steel coupons. All treatments tested were found to be effective for eliminating the planktonic cells of pathogenic and non-pathogenic cells of Listeria spp. and Salmonella serovars. Overall, 5% acetic acid seems to be less effective compared to sodium hypochlorite and quaternary ammonium compounds. The last chapter is focused on the studies related with the decontamination of four bacterial spores using thermal assisted high-pressure processing. Bacterial spores usually show more resistance to harsh conditions unlike the vegetative cells of the bacteria. Modest reduction in the spore counts happened due to high-pressure treatments. The use of nisin at a very high concentration reduced the spore counts of the bacterium Bacillus amyloliquefaciens. When bacteriocin is combined with high-pressure processing, this could effectively reduce the bacterial spore counts by up to 99%
Functional Genomics Analysis of the Virus-Host Interaction in FV3-Infected Xenopus laevis
No full textThis dissertation was designed to provide better understanding on the amphibian interferon (IFN) complex and relevant antiviral regulation in a Xenopus model infected by a Frog Virus 3 (FV3). Four objectives were performed: (1) Determine differential expression of amphibian IFN genes and IFN-stimulated genes (ISGs) induced by FV3 infection in Xenopus laevis kidney cell line (A6); (2) Functionally evaluate antiviral activity of representative IFN peptides against FV3 infection; (3) Clone some IFN receptor genes into expression vectors for future functional analysis; and (4) Examine ranaviral antagonism against host IFN signaling using functional prediction and virus-targeting transcriptomic validation. Three groups of IFN genes (IFNX3, IFNX4 and IFNX6) and two ISG genes (IL11 and TNFAIP3) were significantly up-regulated post FV3 infection in A6 cells. Four type I IFN peptides (encoded by three intron-containing IFN genes of IFN4, IFN6, and IFN7, as well as one intronless IFNX4 gene) and one type III IFN peptide (encoded by the intron-containing gene of IFNL4), showed antiviral activity against FV3. Five expression constructs to express three isoforms of X. laevis IFN-α/β receptor subunit 1 (IFNAR1) and two isoforms of IFNAR subunit 2 (IFNAR2) were cloned in an episomal mammalian expression vector. A virus-targeting transcriptome analysis using several frog tissues infected by FV3 in vivo were performed. Several newly identified ranaviral mimicking-proteins, which are very likely to functionally interfere with host IFN response, were predicted. The viral microRNAs involved in IFN-mediated responses were detected. This indicates that ranaviruses have evolved diverse mechanisms to regulate the virus-host interaction
Nine Bright γ Doradus Variables Discovered with Ground-based Photometry
Get PDFWe have used precise photometric and high-dispersion spectroscopic observations to study nine candidate γ Doradus (γ Dor) stars, identified as optically variable comparison stars in our photometric studies of Sun-like stars. In this paper, we confirm these nine candidates as new γ Dor variables. All exhibit sinusoidal variability with amplitudes between 6 and 65 mmag in Johnson B and periods from 0.28 to 1.13 days. All lie in the same region of the H-R diagram as our previously confirmed γ Dor stars. Of the nine systems, one is a single-lined spectroscopic binary (SB1), two are double-lined spectroscopic binaries (SB2), and the remaining six are single stars. We present orbits for the three binary systems: HD 34415, HD 144839, and HD 182735. Their periods are 6400 days or 17.5 yr (adopted), 995 ± 7 days, and 1052.4 ± 0.2 days, respectively. We compare our photometric periods with those we derive for six of the nine stars observed with the Transiting Exoplanet Survey Satellite to strengthen the confirmation of these new γ Dor variables. Finally, because the distribution of γ Dor stars in the H-R diagram overlaps with the red edge of the δ Scuti (δ Sct) instability strip, we use our ground-based photometric results for the 73 γ Dor stars confirmed with our Automatic Photoelectric Telescopes over the past two decades to look at the incidence of hybrid δ Sct/γ Dor stars; these are highly valuable targets for asteroseismology
Carbon-sensitive pedotransfer functions for plant available water
Get PDFCurrently accepted pedotransfer functions show negligible effect of management-induced changes to soil organic carbon (SOC) on plant available water holding capacity (θAWHC), while some studies show the ability to substantially increase θAWHC through management. The Soil Health Institute\u27s North America Project to Evaluate Soil Health Measurements measured water content at field capacity using intact soil cores across 124 long-term research sites that contained increases in SOC as a result of management treatments such as reduced tillage and cover cropping. Pedotransfer functions were created for volumetric water content at field capacity (θFC) and permanent wilting point (θPWP). New pedotransfer functions had predictions of θAWHC that were similarly accurate compared with Saxton and Rawls when tested on samples from the National Soil Characterization database. Further, the new pedotransfer functions showed substantial effects of soil calcareousness and SOC on θAWHC. For an increase in SOC of 10 g kg–1 (1%) in noncalcareous soils, an average increase in θAWHC of 3.0 mm 100 mm–1 soil (0.03 m3 m–3) on average across all soil texture classes was found. This SOC related increase in θAWHC is about double previous estimates. Calcareous soils had an increase in θAWHC of 1.2 mm 100 mm–1 soil associated with a 10 g kg–1 increase in SOC, across all soil texture classes. New equations can aid in quantifying benefits of soil management practices that increase SOC and can be used to model the effect of changes in management on drought resilience
Dynamics and simulations of discretized Caputo-conformable fractional-order Lotka–Volterra models
Get PDFIn this article, a prey–predator system is considered in Caputo-conformable fractional-order derivatives. First, a discretization process, making use of the piecewise-constant approximation, is performed to secure discrete-time versions of the two fractional-order systems. Local dynamic behaviors of the two discretized fractional-order systems are investigated. Numerical simulations are executed to assert the outcome of the current work. Finally, a discussion is conducted to compare the impacts of the Caputo and conformable fractional derivatives on the discretized model
