Принципы построения сетевых систем обнаружения вторжений на базе ПЛИС

The common principles of FPGA-based NIDS (Network Intrusion Detection Systems) construction are investigated. The main requirements and characteristics of such systems are discussed. The generalized structure of a reconfigurable NIDS is described

A foundation for provitamin A biofortification of maize: genome-wide association and genomic prediction models of carotenoid levels.

Efforts are underway for development of crops with improved levels of provitamin A carotenoids to help combat dietary vitamin A deficiency. As a global staple crop with considerable variation in kernel carotenoid composition, maize (Zea mays L.) could have a widespread impact. We performed a genome-wide association study (GWAS) of quantified seed carotenoids across a panel of maize inbreds ranging from light yellow to dark orange in grain color to identify some of the key genes controlling maize grain carotenoid composition. Significant associations at the genome-wide level were detected within the coding regions of zep1 and lut1, carotenoid biosynthetic genes not previously shown to impact grain carotenoid composition in association studies, as well as within previously associated lcyE and crtRB1 genes. We leveraged existing biochemical and genomic information to identify 58 a priori candidate genes relevant to the biosynthesis and retention of carotenoids in maize to test in a pathway-level analysis. This revealed dxs2 and lut5, genes not previously associated with kernel carotenoids. In genomic prediction models, use of markers that targeted a small set of quantitative trait loci associated with carotenoid levels in prior linkage studies were as effective as genome-wide markers for predicting carotenoid traits. Based on GWAS, pathway-level analysis, and genomic prediction studies, we outline a flexible strategy involving use of a small number of genes that can be selected for rapid conversion of elite white grain germplasm, with minimal amounts of carotenoids, to orange grain versions containing high levels of provitamin A

Rare genetic variation at Zea mays crtRB1 increases β-carotene in maize grain

Breeding to increase β-carotene levels in cereal grains, termed provitamin A biofortification, is an economical approach to address dietary vitamin A deficiency in the developing world. Experimental evidence from association and linkage populations in maize (Zea maysL.) demonstrate that the gene encoding β-carotene hydroxylase 1 (crtRB1) underlies a principal quantitative trait locus associated with β-carotene concentration and conversion in maize kernels. crtRB1 alleles associated with reduced transcript expression correlate with higher β-carotene concentrations. Genetic variation at crtRB1 also affects hydroxylation efficiency among encoded allozymes, as observed by resultant carotenoid profiles in recombinant expression assays. The most favorable crtRB1 alleles, rare in frequency and unique to temperate germplasm, are being introgressed via inexpensive PCR marker-assisted selection into tropical maize germplasm adapted to developing countries, where it is most needed for human health

Genetic dissection of carotenoid concentration and compositional traits in maize grain

Carotenoid compounds are derivatives of a well described secondary metabolic pathway in plants, participating in a diverse array of physiological functions, and are nutritionally valued vitamin precursors in the human diet. With the goal of enhancing the quantity (concentration) and quality (composition) of carotenoids in consumable plant tissues such as grain, breeding approaches have sampled from the extensive phenotypic variation that exists for these traits among maize inbreds. The predominant carotenoids in maize grain include lutein and zeaxanthin, which are collectively called di-hydroxy xanthophyll carotenoids, as well as alpha-carotene, beta-carotene and beta-cryptoxanthin, which are proVitamin A carotenoids. While phenotypic sampling and recombination across diverse maize germplasm has been successful, response to phenotypic selection has not been large enough to satisfy target nutritional levels. Greater phenotypic gain may be more predictably achieved if: 1) the genetic network regulating biological functions which contribute to carotenoid accumulation was better understood; and 2) the relative effect of the genetic loci controlling this quantitative trait was known, especially in varying genetic backgrounds. To this end, an investigation of the genetic basis for variation in carotenoid concentration and composition was performed in the studies presented here. Two QTL analyses revealed gene networks likely involved in carotenoid biosynthesis, conversion, and degradation as the primary drivers of variation in carotenoid concentration and composition. Investigation of one QTL hotspot on maize chromosome 9, observed to account for significant phenotypic variation in almost all carotenoid intermediates, revealed an allelic series associated with a large reduction in the major carotenoid intermediates of maize grain. This QTL, encoding carotenoid cleavage dioxygenase 1 (ccd1), showed a substrate preference for all measured carotenoids except beta-carotene. We further evaluated allelic variation affecting carotenoid composition focusing on two genes within the carotenoid biosynthesis pathway at lycopene epsilon cyclase (lcye) and beta-carotene hydroxylase (crtRB1). Variation at each of these genes was found to significantly affect carotenoid ratios or intermediates hypothesized to change through predicted substrate-enzyme interactions. Several other traits including total carotenoid concentration, were unexpectedly affected. Using allele-specific marker assisted selection at lcye and crtRB1 in synthetic populations developed for high total carotenoid content lead to a 3.95-11.33-fold improvement in beta-carotene and 1.45-3.22-fold improvement in proVitamin A for the favorable genotypes. The combined information from these studies highlights new genetic targets for further improvement of carotenoid concentration and composition, and provides guidelines for the selection and recombination of desirable genetic variation in breeding germplasm

Modeling Departures From Abiotic Expectations During the Calcium Carbonate Precipitation Process

83 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007.Although many investigators have described factors responsible for the formation of calcium carbonate (CaCO3) in natural systems, quantifying the extent to which biological influences drive precipitation in carbonate depositional environments remains an unresolved problem. Thus, a quantitative understanding of biological-mineral-aqueous interactions is needed to determine the most influential aspects of these biogeochemical systems on precipitation. This investigation distinguishes mechanistic influences on CaCO3 mineralization and isotope fractionation by: performing kinetic experiments directly within a modern carbonate spring; determining the carbon and oxygen isotopic composition of aragonite and coexisting spring water; and modeling these experimental results to establish whether precipitation and isotopic fractionation are consistent with abiotic CaCO3 mineralization or better explained via alternative processes. At an aragonite saturation state (O) consistent with modern seawater (3.63 +/- 0.09), controlled in situ kinetic experiments show that: (1) the natural steady state aragonite precipitation rate is more than twice that determined when microbial biomass on the aragonite mineral surface is depleted by 0.2 mum filtration; and (2) inhibiting microbial viability with UV irradiation has no significant effect on the mean precipitation rate. Kinetic modeling of the CaCO3 precipitation process also reveals that microbial biomass catalyzes aragonite precipitation and can increase the empirical rate constant by more than an order of magnitude relative to filtered controls. Furthermore, aqueous and solid phase carbon isotope determinations demonstrate that previously documented abiotic fractionation mechanisms and equilibrium fractionation models, which account for temperature and speciation effects, are insufficient to explain isotope fractionation in carbonate depositional systems. These findings strongly suggest that microbial biomass influences the mechanism of aragonite precipitation and imply that changes in CaCO3 mineralization rates and carbon isotopic composition may be intimately linked with changes in local microbial biomass concentration throughout geologic history.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD