504 research outputs found
Development of modern auditing standards: the strange case of Raymond Marien and the fraud at Interstate Hosiery Mills, 1934-1937
In February 1938, the police arrested Raymond Marien, a small, bookish man, for forging checks at Interstate Hosiery Mills, Inc. During the ensuing investigation, the New York Attorney General\u27s office found that Marien had juggled the books of the corporation and that these accounting irregularities inflated Interstate Hosiery Mills\u27 assets by 2,000, Marien and others were exonerated from any financial gain in the fraud due to the increased value in Interstate\u27s shares. In the end, the fraud and the SEC rulings would serve as a foundation of many modern accounting and auditing principles related to auditor independence, supervision, and management responsibility
Isolation and characterization of centroacinar/terminal ductal progenitor cells in adult mouse pancreas
The question of whether dedicated progenitor cells exist in adult vertebrate pancreas remains controversial. Centroacinar cells and terminal duct (CA/TD) cells lie at the junction between peripheral acinar cells and the adjacent ductal epithelium, and are frequently included among cell types proposed as candidate pancreatic progenitors. However these cells have not previously been isolated in a manner that allows formal assessment of their progenitor capacities. We have found that a subset of adult CA/TD cells are characterized by high levels of ALDH1 enzymatic activity, related to high-level expression of both Aldh1a1 and Aldh1a7. This allows their isolation by FACS using a fluorogenic ALDH1 substrate. FACS-isolated CA/TD cells are relatively depleted of transcripts associated with differentiated pancreatic cell types. In contrast, they are markedly enriched for transcripts encoding Sca1, Sdf1, c-Met, Nestin, and Sox9, markers previously associated with progenitor populations in embryonic pancreas and other tissues. FACS-sorted CA/TD cells are uniquely able to form self-renewing 'pancreatospheres' in suspension culture, even when plated at clonal density. These spheres display a capacity for spontaneous endocrine and exocrine differentiation, as well as glucose-responsive insulin secretion. In addition, when injected into cultured embryonic dorsal pancreatic buds, these adult cells display a unique capacity to contribute to both the embryonic endocrine and exocrine lineages. Finally, these cells demonstrate dramatic expansion in the setting of chronic epithelial injury. These findings suggest that CA/TD cells are indeed capable of progenitor function and may contribute to the maintenance of tissue homeostasis in adult mouse pancreas
Biomass for thermochemical conversion: targets and challenges
Includes bibliographical references (pages 13-20).Bioenergy will be one component of a suite of alternatives to fossil fuels. Effective conversion of biomass to energy will require the careful pairing of advanced conversion technologies with biomass feedstocks optimized for the purpose. Lignocellulosic biomass can be converted to useful energy products via two distinct pathways: enzymatic or thermochemical conversion. The thermochemical pathways are reviewed and potential biotechnology or breeding targets to improve feedstocks for pyrolysis, gasification, and combustion are identified. Biomass traits influencing the effectiveness of the thermochemical process (cell wall composition, mineral and moisture content) differ from those important for enzymatic conversion and so properties are discussed in the language of biologists (biochemical analysis) as well as that of engineers (proximate and ultimate analysis). We discuss the genetic control, potential environmental influence, and consequences of modification of these traits. Improving feedstocks for thermochemical conversion can be accomplished by the optimization of lignin levels, and the reduction of ash and moisture content. We suggest that ultimate analysis and associated properties such as H:C, O:C, and heating value might be more amenable than traditional biochemical analysis to the high-throughput necessary for the phenotyping of large plant populations. Expanding our knowledge of these biomass traits will play a critical role in the utilization of biomass for energy production globally, and add to our understanding of how plants tailor their composition with their environment.Published with support from the Colorado State University Libraries Open Access Research and Scholarship Fund
Metabolomic and Functional Genomic Analyses Reveal Varietal Differences in Bioactive Compounds of Cooked Rice
Emerging evidence supports that cooked rice (Oryza sativa L.) contains metabolites with biomedical activities, yet little is known about the genetic diversity that is responsible for metabolite variation and differences in health traits. Metabolites from ten diverse varieties of cooked rice were detected using ultra performance liquid chromatography coupled to mass spectrometry. A total of 3,097 compounds were detected, of which 25% differed among the ten varieties. Multivariate analyses of the metabolite profiles showed that the chemical diversity among the varieties cluster according to their defined subspecies classifications: indica, japonica, and aus. Metabolite-specific genetic diversity in rice was investigated by analyzing a collection of single nucleotide polymorphisms (SNPs) in genes from biochemical pathways of nutritional importance. Two classes of bioactive compounds, phenolics and vitamin E, contained nonsynonymous SNPs and SNPs in the 5′ and 3′ untranslated regions for genes in their biosynthesis pathways. Total phenolics and tocopherol concentrations were determined to examine the effect of the genetic diversity among the ten varieties. Per gram of cooked rice, total phenolics ranged from 113.7 to 392.6 µg (gallic acid equivalents), and total tocopherols ranged between 7.2 and 20.9 µg. The variation in the cooked rice metabolome and quantities of bioactive components supports that the SNP-based genetic diversity influenced nutritional components in rice, and that this approach may guide rice improvement strategies for plant and human health
Genome assembly and characterization of a complex zfBED-NLR gene-containing disease resistance locus in Carolina Gold Select rice with Nanopore sequencing
Long-read sequencing facilitates assembly of complex genomic regions. In plants, loci containing nucleotide-binding, leucine-rich repeat (NLR) disease resistance genes are an important example of such regions. NLR genes constitute one of the largest gene families in plants and are often clustered, evolving via duplication, contraction, and transposition. We recently mapped the Xo1 locus for resistance to bacterial blight and bacterial leaf streak, found in the American heirloom rice variety Carolina Gold Select, to a region that in the Nipponbare reference genome is NLR gene-rich. Here, toward identification of the Xo1 gene, we combined Nanopore and Illumina reads and generated a high-quality Carolina Gold Select genome assembly. We identified 529 complete or partial NLR genes and discovered, relative to Nipponbare, an expansion of NLR genes at the Xo1 locus. One of these has high sequence similarity to the cloned, functionally similar Xa1 gene. Both harbor an integrated zfBED domain, and the repeats within each protein are nearly perfect. Across diverse Oryzeae, we identified two sub-clades of NLR genes with these features, varying in the presence of the zfBED domain and the number of repeats. The Carolina Gold Select genome assembly also uncovered at the Xo1 locus a rice blast resistance gene and a gene encoding a polyphenol oxidase (PPO). PPO activity has been used as a marker for blast resistance at the locus in some varieties; however, the Carolina Gold Select sequence revealed a loss-of-function mutation in the PPO gene that breaks this association. Our results demonstrate that whole genome sequencing combining Nanopore and Illumina reads effectively resolves NLR gene loci. Our identification of an Xo1 candidate is an important step toward mechanistic characterization, including the role(s) of the zfBED domain. Finally, the Carolina Gold Select genome assembly will facilitate identification of other useful traits in this historically important variety. Author summary Plants lack adaptive immunity, and instead contain repeat-rich, disease resistance genes that evolve rapidly through duplication, recombination, and transposition. The number, variation, and often clustered arrangement of these genes make them challenging to sequence and catalog. The US heirloom rice variety Carolina Gold Select has resistance to two important bacterial diseases. Toward identifying the responsible gene(s), we combined long- and short-read sequencing technologies to assemble the whole genome and identify the resistance gene repertoire. We previously narrowed the location of the gene(s) to a region on chromosome four. The region in Carolina Gold Select is larger than in the rice reference genome (Nipponbare) and contains twice as many resistance genes. One shares unusual features with a known bacterial disease resistance gene, suggesting that it confers the resistance. Across diverse varieties and related species, we identified two widely-distributed groups of such genes. The results are an important step toward mechanistic characterization and deployment of the bacterial disease resistance. The genome assembly also identified a resistance gene for a fungal disease and predicted a marker phenotype used in breeding for resistance. Thus, the Carolina Gold Select genome assembly can be expected to aid in the identification and deployment of other valuable traits
An operon for production of bioactive gibberellin A4 phytohormone with wide distribution in the bacterial rice leaf streak pathogen Xanthomonas oryzae pv. oryzicola
• Phytopathogens have developed elaborate mechanisms to attenuate the defense response of their host plants, including convergent evolution of complex pathways for production of the gibberellin (GA) phytohormones, which were actually first isolated from the rice fungal pathogen Gibberella fujikuroi. The rice bacterial pathogen Xanthomonas oryzae pv. oryzicola (Xoc) has been demonstrated to contain a biosynthetic operon with cyclases capable of producing the universal GA precursor ent-kaurene. Genetic (knock-out) studies indicate that the derived diterpenoid serves as a virulence factor for this rice leaf streak pathogen, serving to reduce the jasmonic acid (JA) mediated defense response.
• Here the function of the remaining genes in the Xoc operon are elucidated and the distribution of the operon in X. oryzae investigated in over 100 isolates.
• The Xoc operon leads to production of the bioactive GA4, an additional step beyond production of the penultimate precursor GA9 mediated by the homologous operons recently characterized from rhizobia. Moreover, this GA biosynthetic operon was found to be widespread in Xoc (\u3e90%), but absent in the other major oryzae pathovar.
• These results indicate selective pressure for production of GA4 in the distinct lifestyle of Xoc, and the importance of GA to both fungal and bacterial pathogens of rice
Rice Galaxy: An open resource for plant science
Background: Rice molecular genetics, breeding, genetic diversity, and allied research (such as rice-pathogen interaction) have adopted sequencing technologies and high-density genotyping platforms for genome variation analysis and gene discovery. Germplasm collections representing rice diversity, improved varieties, and elite breeding materials are accessible through rice gene banks for use in research and breeding, with many having genome sequences and high-density genotype data available. Combining phenotypic and genotypic information on these accessions enables genome-wide association analysis, which is driving quantitative trait loci discovery and molecular marker development. Comparative sequence analyses across quantitative trait loci regions facilitate the discovery of novel alleles. Analyses involving DNA sequences and large genotyping matrices for thousands of samples, however, pose a challenge to non−computer savvy rice researchers. Findings: The Rice Galaxy resource has shared datasets that include high-density genotypes from the 3,000 Rice Genomes project and sequences with corresponding annotations from 9 published rice genomes. The Rice Galaxy web server and deployment installer includes tools for designing single-nucleotide polymorphism assays, analyzing genome-wide association studies, population diversity, rice−bacterial pathogen diagnostics, and a suite of published genomic prediction methods. A prototype Rice Galaxy compliant to Open Access, Open Data, and Findable, Accessible, Interoperable, and Reproducible principles is also presented. Conclusions: Rice Galaxy is a freely available resource that empowers the plant research community to perform state-of-the-art analyses and utilize publicly available big datasets for both fundamental and applied science
Нефтяное загрязнение берегов Севастополя
Приводятся результаты изучения загрязнения береговых структур при низких уровнях нефтяных углеводородов в морской воде. В прибрежных водах и берегах на границе с морем нефтяные углеводороды в концентрациях, не достигающих поражающего уровня для морской биоты вступают в сложные взаимодействия с гидробионтами. Первым этапом этого процесса является накопление или поверхностное загрязнение морских организмов-обрастателей. Такие данные являются составной частью мониторинга прибрежных акваторий и первым этапом изучения роли биопотоков нефтяных углеводородов в общем потоке нефтяного загрязнения у морских берегов.Наводяться результати вивчення забруднення берегових структур при низьких рівнях нафтових вуглеводнів в морській воді. У прибережних водах і берегах на кордоні з морем нафтові вуглеводні в концентраціях, що не досягають вражаючого рівня для морської біоти вступають в складні взаємодії з гідробіонтами. Першим етапом цього процесу є накопичення або поверхневе забруднення морських організмів-обрастателей. Такі дані є складовою частиною моніторингу прибережних акваторій і першим етапом вивчення ролі біопотоков нафтових вуглеводнів в загальному потоці нафтового забруднення морських берегів.The results of the study of coastal structures pollution at low levels of oil hydrocarbons in the sea water are given. Oil hydrocarbons at concentrations that do not reach damaging levels for marine biota enter into complex interactions with marine life in coastal waters and sea shores. The first step of this process is the accumulation or surface contamination of marine fouling organisms. These data are a part of the monitoring of coastal waters and the first step in studying the role of oil hydrocarbons bioflows in the general flow of the oil pollution at sea coast
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