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Islamovic E.,University of Georgia | Islamovic E.,BASF | Garcia-Pedrajas M.D.,University of Malaga | Chacko N.,University of Georgia | And 5 more authors.
Molecular Plant-Microbe Interactions | Year: 2015

Ustilago maydis, causal agent of corn smut disease, is a dimorphic fungus alternating between a saprobic budding haploid and an obligate pathogenic filamentous dikaryon. Maize responds to U. maydis colonization by producing tumorous structures, and only within these does the fungus sporulate, producing melanized sexual teliospores. Previously we identified Ust1, an APSES (Asm1p, Phd1p, Sok2p, Efg1p, and StuAp) transcription factor, whose deletion led to filamentous haploid growth and the production of highly pigmented teliospore-like structures in culture. In this study, we analyzed the transcriptome of a ust1 deletion mutant and functionally characterized two highly upregulated genes with potential roles in melanin biosynthesis: um05361, encoding a putative laccase (lac1), and um06414, encoding a polyketide synthase (pks1). The Δlac1 mutant strains showed dramatically reduced virulence on maize seedlings and fewer, less-pigmented teliospores in adult plants. The Δpks1 mutant was unaffected in seedling virulence but adult plant tumors generated hyaline, nonmelanized teliospores. Thus, whereas pks1 appeared to be restricted to the synthesis of melanin, lac1 showed a broader role in virulence. In conclusion, the ust1 deletion mutant provided an in vitro model for sporulation in U. maydis, and functional analysis supports the efficacy of this in vitro mutant analysis for identification of genes involved in in planta teliosporogenesis. © 2015 The American Phytopathological Society.


Baeza-Montanez L.,University of Malaga | Gold S.E.,Russell Research Center | Espeso E.A.,CSIC - Biological Research Center | Garcia-Pedrajas M.D.,University of Malaga
Molecular Plant-Microbe Interactions | Year: 2015

Ustilago maydis, causal agent of corn smut, can proliferate saprobically in a yeast form but its infectious filamentous form is an obligate parasite. Previously, we showed that Ust1, the first APSES (Asm1p, Phd1p, Sok2p, Efg1p, and StuAp) transcription factor functionally characterized in the phylum Basidiomycota, controlled morphogenesis and virulence in this species. Here, we further analyzed Ust1 function using multiple experimental approaches and determined that i) Ust1 activity was able to partially reverse stuA- conidiophore defects in Aspergillus nidulans; ii) in U. maydis, normal development and virulence were strongly dependent on precise induction or repression of Ust1 activity; iii) consistent with its role as a transcription factor regulating multiple processes, Ust1 accumulated in the nucleus at various stages of the life cycle; iv) however, it was undetectable at specific stages of pathogenic growth, indicating that Ust1 repression is part of normal development in planta; v) StuA response elements upstream of the ust1 open reading frame exhibited affinity for U. maydis DNAbinding proteins; vi) however, loss of regulated ust1 transcription had minor phenotypic effects; and vii) Ust1 was subject to post-translational phosphorylation but is not a target of cAMP signaling. Thus, the broad functional conservation between Ust1 and Ascomycota APSES proteins does not extend to the mechanisms regulating their activity. © 2015 The American Phytopathological Society.


PubMed | Russell Research Center, Beltsville Area Research Center and United States National Poultry Research Center
Type: Journal Article | Journal: Genome announcements | Year: 2016

We report here the draft genome sequences of two Salmonella enterica serovar Kentucky eBurstGroup 15 isolates collected from poultry carcasses in Georgia (USA).


Kandala C.V.,U.S. Department of Agriculture | Sundaram J.,Russell Research Center | Settaluri V.,New Mexico State University | Puppala N.,New Mexico State University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

A Custom made NIR spectroscope was used to determine the moisture content of in-shell peanuts of two different market type peanuts namely Virginia and Valencia. Peanuts were conditioned to different moisture levels between 6 and 26 % (wet basis). Samples from the different moisture levels were separated into two groups one for calibration and the other for validation. NIR absorption spectral data from 1000 nm to 2500 nm were collected on the peanuts from the calibration and validation groups. Measurements were obtained on 30 replicates within each moisture level. Reference moisture data were developed using standard air-oven method on calibration set samples. Partial Least Square (PLS) analysis was performed on the calibration set with certain pretreatments on the measured data and models were developed using the reference moisture data. The Standard Error of Calibration (SEC) and R2 of the calibration models were computed to select the best calibration model for each of the two peanut types. Both Valencia and Virginia types gave R2 of 0.99 for the pretreated as well as for the raw spectral data. The selected models were used to predict the moisture content of peanuts in the validation sample set. Predicted moisture contents of the validation samples were compared with their air-oven moisture values determined similarly as for the calibration samples. Goodness of fit was determined based on the lowest Standard Error of Prediction (SEP) and highest R2 value obtained for the prediction models. The model, with reflectance plus normalization spectral data with an SEP of 0.74 for Valencia and 1.57 for Virginia type in-shell peanuts was selected as the best model. The corresponding R2 values were 0.98 for both peanut types. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).


Cho S.H.,Agri. Machinery Certification Team | Choi S.,Russell Research Center | Le N.H.,United International University Dhanmondi | Kim S.J.,Sungkyunkwan University | Hwang H.,Sungkyunkwan University
Applied Engineering in Agriculture | Year: 2015

To automatically evaluate beef quality, a system must be developed to properly segment lean tissue in a sectional image of the 13th beef rib. To this end, a mobile color computer vision system and its corresponding image processing algorithms were developed for on-site application. The algorithms implement Rényi entropy and a texture index to provide adaptive thresholding. Automatic smoothing and modification followed boundary extraction, and binary morphological approaches were also taken. When 54 images of beef cut samples were assessed without manual intervention, the proposed algorithms exhibited an average boundary extraction error of 3% and an average pixel distance error of 1.8 pixels relative to assessments made by a human expert. The computing time for these sample images was of approximately 5.5 s. In addition, a user-friendly interactive man-machine interface was also developed to allow for a human expert to modify the extracted boundary.


Liu C.-K.,U.S. Department of Agriculture | Liu C.-K.,Eastern Regional Research Center | Latona N.P.,U.S. Department of Agriculture | Latona N.P.,Eastern Regional Research Center | And 2 more authors.
Journal of the American Leather Chemists Association | Year: 2013

Animal hides are important agricultural commodities closely associated with rural economics and the well being of rural farmers in the United States. Approximately 90% of the hides produced in the United States are being exported; the remaining 10% are mostly tanned into leather. At the present time hides and leather are visually inspected and ranked for quality, usable area, and sale price. However, visual inspection is not reliable for detecting defects, which are usually hidden inside the material or under the hair in fresh hides. This manual assessment is not uniform among operators, and often leads to disputes over fair price. Development of a non-contact nondestructive method to accurately evaluate the quality of hides and leather is urgently needed. We previously reported the research results for airborne ultrasonic (AU) testing using non-contact transducers to evaluate the quality of hides and leather. We demonstrated the ability of AU to reveal defects in hides and leather that are difficult to be found during visual inspection. In this paper, we present new results on AU inspection, particularly using a statistical data/cluster analysis technique, in which leather and hide defects are depicted as color-coded amplitude maps, or "C-scans.".


Holser R.,Russell Research Center
Biocatalysis and Agricultural Biotechnology | Year: 2012

Encapsulation of structurally sensitive compounds within a solid lipid matrix provides a barrier to prooxidant compounds and effectively limits the extent of oxidative degradation. Encapsulated docosahexaenoic acid (DHA) methyl ester was examined as a model compound for functional foods and feeds. Solid lipid particles were prepared from triacylglycerols and evaluated by differential scanning calorimetry. Thermal characteristics of the lipids used to form the particle were related to structure and could be adjusted by selection of the appropriate component fatty acids. Encapsulation by solid lipid particles provides a method to inhibit oxidation and improve shelf life of products formulated with DHA. © 2012.


Holser R.,Russell Research Center | Hinton Jr. A.,Russell Research Center
Lipid Insights | Year: 2010

The ability of α-tocopherol to prevent the degradation of the polyunsaturated fatty acids, docosahexaenoic acid (DHA) and linolenic acid (ALA) at elevated temperature was investigated in a series of laboratory experiments. DHA is known to promote nervous system function and health, however, DHA and other highly unsaturated fatty compounds are readily oxidized with loss of bioactivity. Mixtures of DHA or ALA and α-tocopherol were incubated at 70 °C. Samples of these mixtures were analyzed by gas chromatography. After 72 hours at 70 °C mixtures with 0.25mg α-tocopherol/mg retained 79.6% of the initial amount of DHA and 94.2% of the ALA. When α-tocopherol was present at 2.5mg/mg the amount of DHA decreased to 62.5% and ALA decreased to 87.4%. Control samples that did not contain α-tocopherol retained 43% DHA and 52.6% ALA. These results indicate that α-tocopherol can limit the degradation of these polyunsaturated fatty acids at elevated temperature. However, the greatest protective effect was not obtained with the highest level of α-tocopherol. This relationship needs to be considered when formulating feeds where elevated process temperatures are likely to occur. © the author(s).


Park B.,Russell Research Center | Hinton A.,Jr. | Lawrence K.C.,Russell Research Center
Transactions of the ASABE | Year: 2015

An acousto-optic tunable filter (AOTF)-based hyperspectral microscope imaging (HMI) method has potential for rapid identification of foodborne pathogenic bacteria from micro-colonies with a cell level. In this study, we successfully developed a method to acquire quality hyperspectral microscopic images from various gram-negative and grampositive bacteria live cells. Among the contiguous spectral images from the visible/NIR region between 450 and 800 nm, the scattering intensity of spectral images was distinct at mostly visible wavelengths. Specifically, the scattering peak intensity was distinct at 458, 498, 522, 546, 574, 590, 646, 670, and 690 nm for Staphylococcus. Similarly, distinct peak spectra were observed at 462, 498, 522, 546, 574, 598, 642, 670, and 690 nm for Salmonella. For both cases, the scattering intensity of outer cell membranes was brighter than that of inner membranes except at 546 nm, which was possibly caused by excitation of the metal-halide lighting source. The scattering intensity from a single cell varied with the wavelength as well as the type of bacteria. The overall variability of intensity was 31.2% for gram-negative (Salmonella) and 42.7% for gram-positive (Staphylococcus) bacteria. With scattering intensity data from five serotypes of Salmonella (Kentucky, Enteritidis, Typhimurium, Infantis, and Heidelberg) and five species of Staphylococcus (aureus, haemolyticus, hyicus, simulans, and sciuri) bacterial cells, a classification accuracy of 99.9% with a kappa coefficient of 0.9998 was obtained from the support vector machine (SVM) classification algorithm. ©2015 American Society of Agricultural and Biological Engineers.


Sundaram J.,Russell Research Center | Park B.,Russell Research Center | Kwon Y.,Plant and Fisheries Quarantine and Inspection Agency
Journal of Nanoscience and Nanotechnology | Year: 2013

Silver/biopolymer nanoparticles were prepared by adding 100 mg silver nitrate to 2% polyvinyl alcohol solution and reduced the silver nitrate using 2% trisodium citrate for high performance Surface Enhanced Raman Scattering (SERS) substrates. Optical properties of nanoparticle were measured using UV/VIS spectroscopy and hyperspectral imaging microscopy. Nanoparticle morphology was analyzed using transmission electron microscopy. Substrate reproducibility and repeatability was checked by measuring SERS signals of trans-1,2-bis(4-pyridyl) ethylene (BPE) and Rhodamine 6G. Copyright © 2013 American Scientific Publishers All rights reserved.

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