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Sample records for brachypodium distachyon grain

  1. Starch bioengineering in Brachypodium distachyon

    DEFF Research Database (Denmark)

    Tanackovic, Vanja; Svensson, Jan Tommy; Glaring, Mikkel Andreas;

    2011-01-01

    identified starch biosynthesis genes including seven soluble starch synthases (SS), three granule bound starch syntheses (GBSS), four starch branching enzymes (SBE), two glucan- and one phosphoglucan- water dikinases (GWD, PWD). Phylogenetic analysis based on the SS genes provided evidence for a close......Brachypodium distachyon was recently introduced as a model plant for temperate cereals (Opanowicz et al., 2008). We aim to establish Brachypodium as a model for cereal starch metabolism. Grain starch from two lines: Bd21 and Bd21-3 are being characterized. Microscopic, chemical and structural data...... including amylopectin chain length distribution, phosphate content and amylose content provided further evidence for the close relationship to temperate cereals even though starch content and starch granule size were considerably lower than that for barley (Hordeum vulgare). Bioinformatics analyses...

  2. Brachypodium distachyon

    DEFF Research Database (Denmark)

    Tanackovic, Vanja

    Starch is one of the most abundant polysaccharides on the Earth, the principal energy storage of most plant species and of crucial significance for humans as a major nutrient in human diet. The majority of produced starch comes from cereals, domesticated grasses, characterized by specific en...... (Hordeum vulgare). This thesis focuses on domestication of grasses – the cereal ancestors, starch in the grass Brachypodium distachyon, and its comparison to domesticated cereal. Grasses can potentially be used for the reintroduction of the lost grass traits, like health-promoting carbohydrates. Therefore......, we compared grain starch metabolism in a wild grass, and in a cereal (Brachypodium and barley, respectively). Genes of Brachypodium starch metabolism were identified and annotated, including important motifs such as transit peptides and putative carbohydrate-binding modules (CBMs). Some...

  3. Effects of glyphosate on brachypodium distachyon

    OpenAIRE

    Altıntaş, Ayşegul; Altintas, Aysegul

    2010-01-01

    Glyphosate is a non-selective herbicide used widely as the most popular weed management tool, especially since the commercialization of glyphosate-resistant crops. Due to overuse, several weed species have evolved resistance towards glyphosate and this trend threatens the future of world food production. Brachypodium distachyon has been proposed as a model organism specifically for economically important crops such as wheat and barley. Thus, evaluating the effects of glyphosate on Brachypodiu...

  4. Agrobacterium-mediated transformation of Brachypodium distachyon.

    Science.gov (United States)

    Thole, Vera; Vain, Philippe

    2012-01-01

    Brachypodium distachyon is an attractive genomics and biological model system for grass research. Recently, the complete annotated genome sequence of the diploid line Bd21 has been released. Genetic transformation technologies are critical for the discovery and validation of gene function in Brachypodium. Here, we describe an efficient procedure enabling the Agrobacterium-mediated transformation of a range of diploid and polyploid genotypes of Brachypodium. The procedure relies on the transformation of compact embryogenic calli derived from immature embryos using either chemical selection alone or a combination of chemical and visual screening of transformed tissues and plants. Transformation efficiencies of around 20% can routinely be achieved using this protocol. In the context of the BrachyTAG programme (BrachyTAG.org), this procedure made possible the mass production of Bd21T-DNA mutant plant lines.

  5. Pathogenicity of Rice Blast Fungus Magnaporthe oryzae on Brachypodium distachyon

    Institute of Scientific and Technical Information of China (English)

    WANG Jiao-yu; WANG Xiao-yan; LI Ling; ZHANG Xin; WANG Yan-li; CHAI Rong-yao; SUN Guo-chang

    2012-01-01

    Inoculation methods for rice blast fungus Magnaporthe oryzae to Brachypodium distachyon were developed to investigate the infection process and symptom development in comparison with those on rice (Oryza sativa) and barley (Hordeum vulgare).M.oryzae could infect leaves,sheathes,stems and panicles of B.distachyon and cause blast disease.Spraying conidial suspension on either intact seedlings or leaf segments induced typical symptoms on B distachyon.During the intact seedling inoculation,the symptom developed on B.distachyon leaves closely resembled that on rice; but the lesions on B.distachyon had better uniformity in shapes and sizes than those on rice or barley.In the leaf segments inoculation,only initial and low-developed lesions could be found on rice,while normal symptoms on B.distachyon and barley.Inoculated with low-virulent mutants of M.oryzae,B.distachyon produced low-level symptoms.The symptom level of each mutant on B.distachyon corresponded well to that on rice.In addition,typical infection processes presented on B.distachyon leaves:forming melanized appressoria,penetrating into host epidermis and then forming hyphae in epidermal cells.According to these results,B.distachyon can be used as a candidate for studying fungus-plant interactions and as a probable source of disease resistance.

  6. Infection of Brachypodium distachyon with selected grass rust pathogens.

    Science.gov (United States)

    Ayliffe, Michael; Singh, Davinder; Park, Robert; Moscou, Matthew; Pryor, Tony

    2013-08-01

    The model temperate grass Brachypodium distachyon is considered a nonhost for wheat rust diseases caused by Puccinia graminis f. sp. tritici, P. triticina, and P. striiformis. Up to 140 Brachypodium accessions were infected with these three rust species, in addition to P. graminis ff. spp. avena and phalaridis. Related B. distachyon lines showed similar cytological nonhost resistance (NHR) phenotypes, and an inverse relationship between P. graminis f. sp. tritici and P. striiformis growth was observed in many lines, with accessions that allowed the most growth of P. graminis f. sp. tritici showing the least P. striiformis development and vice versa. Callose deposition patterns during infection by all three rust species showed similarity to the wheat basal defense response while cell death that resulted in autofluorescence did not appear to be a major component of the defense response. Infection of B. distachyon with P. graminis f. sp. avena and P. graminis f. sp. phalaridis produced much greater colonization, indicating that P. graminis rusts with Poeae hosts show greater ability to infect B. distachyon than those with Triticeae hosts. P. striiformis infection of progeny from two B. distachyon families demonstrated that these NHR phenotypes are highly heritable and appear to be under relatively simple genetic control, making this species a powerful tool for elucidating the molecular basis of NHR to cereal rust pathogens.

  7. Molecular characterization and expression profiling of the protein disulfide isomerase gene family in Brachypodium distachyon L.

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    Chong Zhu

    Full Text Available Protein disulfide isomerases (PDI are involved in catalyzing protein disulfide bonding and isomerization in the endoplasmic reticulum and functions as a chaperone to inhibit the aggregation of misfolded proteins. Brachypodium distachyon is a widely used model plant for temperate grass species such as wheat and barley. In this work, we report the first molecular characterization, phylogenies, and expression profiles of PDI and PDI-like (PDIL genes in B. distachyon in different tissues under various abiotic stresses. Eleven PDI and PDIL genes in the B. distachyon genome by in silico identification were evenly distributed across all five chromosomes. The plant PDI family has three conserved motifs that are involved in catalyzing protein disulfide bonding and isomerization, but a different exon/intron structural organization showed a high degree of structural differentiation. Two pairs of genes (BdPDIL4-1 and BdPDIL4-2; BdPDIL7-1 and BdPDIL7-2 contained segmental duplications, indicating each pair originated from one progenitor. Promoter analysis showed that Brachypodium PDI family members contained important cis-acting regulatory elements involved in seed storage protein synthesis and diverse stress response. All Brachypodium PDI genes investigated were ubiquitously expressed in different organs, but differentiation in expression levels among different genes and organs was clear. BdPDIL1-1 and BdPDIL5-1 were expressed abundantly in developing grains, suggesting that they have important roles in synthesis and accumulation of seed storage proteins. Diverse treatments (drought, salt, ABA, and H2O2 induced up- and down-regulated expression of Brachypodium PDI genes in seedling leaves. Interestingly, BdPDIL1-1 displayed significantly up-regulated expression following all abiotic stress treatments, indicating that it could be involved in multiple stress responses. Our results provide new insights into the structural and functional characteristics of the

  8. Cell wall composition and biomass recalcitrance differences within a set of Brachypodium distachyon inbred lines

    Science.gov (United States)

    Brachypodium distachyon (Brachypodium) has emerged as a useful model system for studying traits unique to graminaceous species, owing to its amenability to laboratory experimentation and the availability of extensive genetic and germplasm resources. We assessed the extent of natural variation for tr...

  9. Use of Agrobacterium rhizogenes Strain 18r12v and Paromomycin Selection for Transformation of Brachypodium distachyon and Brachypodium sylvaticum.

    Science.gov (United States)

    Collier, Ray; Bragg, Jennifer; Hernandez, Bryan T; Vogel, John P; Thilmony, Roger

    2016-01-01

    The genetic transformation of monocot grasses is a resource intensive process, the quality and efficiency of which is dependent in part upon the method of DNA introduction, as well as the ability to effectively separate transformed from wildtype tissue. Agrobacterium-mediated transformation of Brachypodium has relied mainly on Agrobacterium tumefaciens strain AGL1. Currently the antibiotic hygromycin B has been the selective agent of choice for robust identification of transgenic calli in Brachypodium distachyon and Brachypodium sylvaticum but few other chemicals have been shown to work as well for selection of transgenic Brachypodium cells in tissue culture. This study demonstrates that Agrobacterium rhizogenes strain 18r12v and paromomycin selection can be successfully used for the efficient generation of transgenic B. distachyon and B. sylvaticum. Additionally we observed that the transformation rates were similar to or higher than those obtained with A. tumefaciens strain AGL1 and hygromycin selection. The A. rhizogenes strain 18r12v harboring the pARS1 binary vector and paromomycin selection is an effective means of generating transgenic Brachypodium plants. This novel approach will facilitate the transgenic complementation of T-DNA knockout mutants of B. distachyon which were created using hygromycin selection, as well as aid the implementation of more complex genome manipulation strategies which require multiple rounds of transformation.

  10. Use of Agrobacterium rhizogenes Strain 18r12v and Paromomycin Selection for Transformation of Brachypodium distachyon and Brachypodium sylvaticum

    Science.gov (United States)

    Collier, Ray; Bragg, Jennifer; Hernandez, Bryan T.; Vogel, John P.; Thilmony, Roger

    2016-01-01

    The genetic transformation of monocot grasses is a resource intensive process, the quality and efficiency of which is dependent in part upon the method of DNA introduction, as well as the ability to effectively separate transformed from wildtype tissue. Agrobacterium-mediated transformation of Brachypodium has relied mainly on Agrobacterium tumefaciens strain AGL1. Currently the antibiotic hygromycin B has been the selective agent of choice for robust identification of transgenic calli in Brachypodium distachyon and Brachypodium sylvaticum but few other chemicals have been shown to work as well for selection of transgenic Brachypodium cells in tissue culture. This study demonstrates that Agrobacterium rhizogenes strain 18r12v and paromomycin selection can be successfully used for the efficient generation of transgenic B. distachyon and B. sylvaticum. Additionally we observed that the transformation rates were similar to or higher than those obtained with A. tumefaciens strain AGL1 and hygromycin selection. The A. rhizogenes strain 18r12v harboring the pARS1 binary vector and paromomycin selection is an effective means of generating transgenic Brachypodium plants. This novel approach will facilitate the transgenic complementation of T-DNA knockout mutants of B. distachyon which were created using hygromycin selection, as well as aid the implementation of more complex genome manipulation strategies which require multiple rounds of transformation. PMID:27252729

  11. Use of Agrobacterium rhizogenes strain 18r12v and paromomycin selection for transformation of Brachypodium distachyon and Brachypodium sylvaticum

    Directory of Open Access Journals (Sweden)

    Ray eCollier

    2016-05-01

    Full Text Available The genetic transformation of monocot grasses is a resource intensive process, the quality and efficiency of which is dependent in part upon the method of DNA introduction, as well as the ability to effectively separate transformed from wildtype tissue. Agrobacterium-mediated transformation of Brachypodium has relied mainly on Agrobacterium tumefaciens strain AGL1. Currently the antibiotic hygromycin B has been the selective agent of choice for robust identification of transgenic calli in Brachypodium distachyon and Brachypodium sylvaticum but few other chemicals have been shown to work as well for selection of transgenic Brachypodium cells in tissue culture. This study demonstrates that Agrobacterium rhizogenes strain 18r12v and paromomycin selection can be successfully used for the efficient generation of transgenic B. distachyon and B. sylvaticum. Additionally we observed that the transformation rates were similar to or higher than those obtained with A. tumefaciens strain AGL1 and hygromycin selection. The A. rhizogenes strain 18r12v harboring the pARS1 binary vector and paromomycin selection is an effective means of generating transgenic Brachypodium plants. This novel approach will facilitate the transgenic complementation of T-DNA knockout mutants of B. distachyon which were created using hygromycin selection, as well as aid the implementation of more complex genome manipulation strategies which require multiple rounds of transformation.

  12. QTLs for resistance to the false brome rust Puccinia brachypodii in the model grass Brachypodium distachyon L.

    NARCIS (Netherlands)

    Barbieri, M.; Marcel, T.C.; Niks, R.E.; Francia, E.; Pasquariello, M.; Mazzamurro, V.; Garvin, D.F.; Pecchioni, N.

    2012-01-01

    The potential of the model grass Brachypodium distachyon L. (Brachypodium) for studying grass–pathogen interactions is still underexploited. We aimed to identify genomic regions in Brachypodium associated with quantitative resistance to the false brome rust fungus Puccinia brachypodii. The inbred li

  13. Brachypodium distachyon as a model system for studies of copper transport in cereal crops

    Directory of Open Access Journals (Sweden)

    Ha-il eJung

    2014-05-01

    Full Text Available Copper (Cu is an essential micronutrient that performs a remarkable array of functions in plants including photosynthesis, cell wall remodeling, flowering, and seed set. Of the world's major cereal crops, wheat, barley, and oat are the most sensitive to Cu deficiency. Cu deficient soils include alkaline soils, which occupy approximately 30% of the world’s arable lands, and organic soils that occupy an estimated 19% of arable land in Europe. We used Brachypodium distachyon (brachypodium as a proxy for wheat and other grain cereals to initiate analyses of the molecular mechanisms underlying their increased susceptibility to Cu deficiency. In this report, we focus on members of the CTR/COPT family of Cu transporters because their homologs in A. thaliana are transcriptionally upregulated in Cu-limited conditions and are involved either in Cu uptake from soils into epidermal cells in the root, or long-distance transport and distribution of Cu in photosynthetic tissues. We found that of five COPT proteins in brachypodium, BdCOPT3 and BdCOPT4 localize to the plasma membrane and are transcriptionally upregulated in roots and leaves by Cu deficiency. We also found that BdCOPT3, BdCOPT4, and BdCOPT5 confer low affinity Cu transport, in contrast to their counterparts in A. thaliana that confer high affinity Cu transport. These data suggest that increased sensitivity to Cu deficiency in some grass species may arise from lower efficiency and, possibly, other properties of components of Cu uptake and tissue partitioning systems and reinforce the importance of using brachypodium as a model for the comprehensive analyses of Cu homeostasis in cereal crops.

  14. Diversity of morphology and function in arbuscular mycorrhizal symbioses in Brachypodium distachyon.

    Science.gov (United States)

    Hong, Jeon J; Park, Yong-Soon; Bravo, Armando; Bhattarai, Kishor K; Daniels, Dierdra A; Harrison, Maria J

    2012-09-01

    Brachypodium distachyon is a grass species that serves as a useful model for wheat and also for many of the grass species proposed as feedstocks for bioenergy production. Here, we monitored B. distachyon symbioses with five different arbuscular mycorrhizal (AM) fungi and identified symbioses that vary functionally with respect to plant performance. Three symbioses promoted significant increases in shoot phosphorus (P) content and shoot growth of Brachypodium, while two associations were neutral. The Brachypodium/Glomus candidum symbiosis showed a classic 'Paris-type' morphology. In the other four AM symbioses, hyphal growth was exclusively intracellular and linear; hyphal coils were not observed and arbuscules were abundant. Expression of the Brachypodium ortholog of the symbiosis-specific phosphate (Pi) transporter MtPT4 did not differ significantly in these five interactions indicating that the lack of apparent functionality did not result from a failure to express this gene or several other AM symbiosis-associated genes. Analysis of the expression patterns of the complete PHT1 Pi transporter gene family and AMT2 gene family in B. distachyon/G. intraradices mycorrhizal roots identified additional family members induced during symbiosis and again, transcript levels were similar in the different Brachypodium AM symbioses. This initial morphological, molecular and functional characterization provides a framework for future studies of functional diversity in AM symbiosis in B. distachyon.

  15. Genome sequence analysis of the model grass Brachypodium distachyon: insights into grass genome evolution

    Energy Technology Data Exchange (ETDEWEB)

    Schulman, Al

    2009-08-09

    Three subfamilies of grasses, the Erhardtoideae (rice), the Panicoideae (maize, sorghum, sugar cane and millet), and the Pooideae (wheat, barley and cool season forage grasses) provide the basis of human nutrition and are poised to become major sources of renewable energy. Here we describe the complete genome sequence of the wild grass Brachypodium distachyon (Brachypodium), the first member of the Pooideae subfamily to be completely sequenced. Comparison of the Brachypodium, rice and sorghum genomes reveals a precise sequence- based history of genome evolution across a broad diversity of the grass family and identifies nested insertions of whole chromosomes into centromeric regions as a predominant mechanism driving chromosome evolution in the grasses. The relatively compact genome of Brachypodium is maintained by a balance of retroelement replication and loss. The complete genome sequence of Brachypodium, coupled to its exceptional promise as a model system for grass research, will support the development of new energy and food crops

  16. Comparative analyses reveal potential uses of Brachypodium distachyon as a model for cold stress responses in temperate grasses

    Directory of Open Access Journals (Sweden)

    Li Chuan

    2012-05-01

    Full Text Available Abstract Background Little is known about the potential of Brachypodium distachyon as a model for low temperature stress responses in Pooideae. The ice recrystallization inhibition protein (IRIP genes, fructosyltransferase (FST genes, and many C-repeat binding factor (CBF genes are Pooideae specific and important in low temperature responses. Here we used comparative analyses to study conservation and evolution of these gene families in B. distachyon to better understand its potential as a model species for agriculturally important temperate grasses. Results Brachypodium distachyon contains cold responsive IRIP genes which have evolved through Brachypodium specific gene family expansions. A large cold responsive CBF3 subfamily was identified in B. distachyon, while CBF4 homologs are absent from the genome. No B. distachyon FST gene homologs encode typical core Pooideae FST-motifs and low temperature induced fructan accumulation was dramatically different in B. distachyon compared to core Pooideae species. Conclusions We conclude that B. distachyon can serve as an interesting model for specific molecular mechanisms involved in low temperature responses in core Pooideae species. However, the evolutionary history of key genes involved in low temperature responses has been different in Brachypodium and core Pooideae species. These differences limit the use of B. distachyon as a model for holistic studies relevant for agricultural core Pooideae species.

  17. Molecular characterization and evolutionary origins of farinin genes in Brachypodium distachyon L.

    Science.gov (United States)

    Subburaj, Saminathan; Luo, Nana; Lu, Xiaobing; Li, Xiaohui; Cao, Hui; Hu, Yingkao; Li, Jiarui; Yan, Yueming

    2016-08-01

    Farinins are one of the oldest members of the gluten family in wheat and Aegilops species, and they influence dough properties. Here, we performed the first detailed molecular genetic study on farinin genes in Brachypodium distachyon L., the model species for Triticum aestivum. A total of 51 b-type farinin genes were cloned and characterized, including 27 functional and 24 non-functional pseudogenes from 14 different B. distachyon accessions. All genes were highly similar to those previously reported from wheat and Aegilops species. The identification of deduced amino acid sequences showed that b-type farinins across Triticeae genomes could be classified as b1-, b2-, b3-, and b4-type farinins; however, B. distachyon had only b3- and b4-type farinins. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) revealed that farinin genes are transcribed into mRNA in B. distachyon at much lower levels than in Triticeae, despite the presence of cis-acting elements in promoter regions. Phylogenetic analysis suggested that Brachypodium farinins may have closer relationships with common wheat and further confirmed four different types of b-type farinins in Triticeae and Brachypodium genomes, corresponding to b1, b2, b3 (group 1), and b4 (group 2). A putative evolutionary origin model of farinin genes in Brachypodium, Triticum, and the related species suggests that all b-type farinins diverged from their common ancestor ~3.2 million years ago (MYA). The b3 and b4 types could be considered older in the farinin family. The results explain the loss of b1- and b2-type farinin alleles in Brachypodium. PMID:26519166

  18. Reduced susceptibility to Fusarium head blight in Brachypodium distachyon through priming with the Fusarium mycotoxin deoxynivalenol.

    Science.gov (United States)

    Blümke, Antje; Sode, Björn; Ellinger, Dorothea; Voigt, Christian A

    2015-06-01

    The fungal cereal pathogen Fusarium graminearum produces deoxynivalenol (DON) during infection. The mycotoxin DON is associated with Fusarium head blight (FHB), a disease that can cause vast grain losses. Whilst investigating the suitability of Brachypodium distachyon as a model for spreading resistance to F. graminearum, we unexpectedly discovered that DON pretreatment of spikelets could reduce susceptibility to FHB in this model grass. We started to analyse the cell wall changes in spikelets after infection with F. graminearum wild-type and defined mutants: the DON-deficient Δtri5 mutant and the DON-producing lipase disruption mutant Δfgl1, both infecting only directly inoculated florets, and the mitogen-activated protein (MAP) kinase disruption mutant Δgpmk1, with strongly decreased virulence but intact DON production. At 14 days post-inoculation, the glucose amounts in the non-cellulosic cell wall fraction were only increased in spikelets infected with the DON-producing strains wild-type, Δfgl1 and Δgpmk1. Hence, we tested for DON-induced cell wall changes in B. distachyon, which were most prominent at DON concentrations ranging from 1 to 100 ppb. To test the involvement of DON in defence priming, we pretreated spikelets with DON at a concentration of 1 ppm prior to F. graminearum wild-type infection, which significantly reduced FHB disease symptoms. The analysis of cell wall composition and plant defence-related gene expression after DON pretreatment and fungal infection suggested that DON-induced priming of the spikelet tissue contributed to the reduced susceptibility to FHB.

  19. DNA methylation patterns of Brachypodium distachyon chromosomes and their alteration by 5-azacytidine treatment

    OpenAIRE

    Borowska, Natalia; Idziak, Dominika; Hasterok, Robert

    2011-01-01

    Sequential immunolocalisation of 5-methylcytosine (5-MeC) and fluorescence in situ hybridisation with chromosome-specific BAC clones were performed on Brachypodium distachyon mitotic metaphase chromosomes to determine specific DNA methylation patterns of each chromosome in the complement. In the majority of cells examined, chromosomes Bd4 and Bd5, which bear the loci of 5S and 35S ribosomal DNA, respectively, had characteristic 5-MeC patterns. In contrast, the distribution of 5-MeC along the ...

  20. Memory of the Vernalized State in Plants including the Model Grass Brachypodium distachyon

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    Daniel P Woods

    2014-03-01

    Full Text Available Plant species that have a vernalization requirement exhibit variation in the ability to remember winter—i.e., variation in the stability of the vernalized state. Studies in Arabidopsis have demonstrated that molecular memory involves changes in the chromatin state and expression of the flowering repressor FLOWERING LOCUS C, and have revealed that single-gene differences can have large effects on the stability of the vernalized state. In the perennial Arabidopsis relative Arabis alpina, the lack of memory of winter is critical for its perennial life history. Our studies of flowering behavior in the model grass Brachypodium distachyon reveal extensive variation in the vernalization requirement, and studies of a particular Brachypodium accession that has a qualitative requirement for both cold exposure and inductive daylength reveals that Brachypodium can exhibit a highly stable vernalized state.

  1. Cell walls and the developmental anatomy of the Brachypodium distachyon stem internode.

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    Dominick A Matos

    Full Text Available While many aspects of plant cell wall polymer structure are known, their spatial and temporal distribution within the stem are not well understood. Here, we studied vascular system and fiber development, which has implication for both biofuel feedstock conversion efficiency and crop yield. The subject of this study, Brachypodium distachyon, has emerged as a grass model for food and energy crop research. Here, we conducted our investigation using B. distachyon by applying various histological approaches and Fourier transform infrared spectroscopy to the stem internode from three key developmental stages. While vascular bundle size and number did not change over time, the size of the interfascicular region increased dramatically, as did cell wall thickness. We also describe internal stem internode anatomy and demonstrate that lignin deposition continues after crystalline cellulose and xylan accumulation ceases. The vascular bundle anatomy of B. distachyon appears to be highly similar to domesticated grasses. While the arrangement of bundles within the stem is highly variable across grasses, B. distachyon appears to be a suitable model for the rind of large C4 grass crops. A better understanding of growth and various anatomical and cell wall features of B. distachyon will further our understanding of plant biomass accumulation processes.

  2. Brachypodium distachyon is a suitable host plant for study of Barley yellow dwarf virus.

    Science.gov (United States)

    Tao, Ye; Nadege, Soumou Wansim; Huang, Caiping; Zhang, Penghui; Song, Shuang; Sun, Liying; Wu, Yunfeng

    2016-04-01

    Barley yellow dwarf viruses (BYDVs) belong to the family Luteoviridae and cause disease in cereals. Because of the large and complex genome of cereal plants, it is difficult to study host-virus interactions. In order to establish a model host system for the studies on BYDVs, we examined the susceptibility of a monocot model plant, Brachypodium distachyon, to BYDV-GAV infection. Fourteen days after BYDV-GAV inoculation by aphid transmission, B. distachyon plants (inbred line Bd21-3) showed conspicuous disease symptoms such as leaf reddening, dwarfness and root stunting. Virus accumulation was detected in both shoots and roots using reverse transcription PCR and triple antibody sandwich ELISA. Compared with infected wheat plants, B. distachyon plants developed more severe disease symptoms and accumulated a higher level of BYDV-GAV. Under transmission electron microscope, we observed that virus particles accumulated in companion cells and BYDV-GAV infection was associated with the deformation of chloroplasts in the infected leaves of B. distachyon plants. Our results suggest that B. distachyon is a suitable and promising experimental model plant for the host-BYDV-GAV pathosystem and possibly for other BYDVs. PMID:26814813

  3. Brachypodium distachyon is a suitable host plant for study of Barley yellow dwarf virus.

    Science.gov (United States)

    Tao, Ye; Nadege, Soumou Wansim; Huang, Caiping; Zhang, Penghui; Song, Shuang; Sun, Liying; Wu, Yunfeng

    2016-04-01

    Barley yellow dwarf viruses (BYDVs) belong to the family Luteoviridae and cause disease in cereals. Because of the large and complex genome of cereal plants, it is difficult to study host-virus interactions. In order to establish a model host system for the studies on BYDVs, we examined the susceptibility of a monocot model plant, Brachypodium distachyon, to BYDV-GAV infection. Fourteen days after BYDV-GAV inoculation by aphid transmission, B. distachyon plants (inbred line Bd21-3) showed conspicuous disease symptoms such as leaf reddening, dwarfness and root stunting. Virus accumulation was detected in both shoots and roots using reverse transcription PCR and triple antibody sandwich ELISA. Compared with infected wheat plants, B. distachyon plants developed more severe disease symptoms and accumulated a higher level of BYDV-GAV. Under transmission electron microscope, we observed that virus particles accumulated in companion cells and BYDV-GAV infection was associated with the deformation of chloroplasts in the infected leaves of B. distachyon plants. Our results suggest that B. distachyon is a suitable and promising experimental model plant for the host-BYDV-GAV pathosystem and possibly for other BYDVs.

  4. Genome Wide Analysis of Nucleotide-Binding Site Disease Resistance Genes in Brachypodium distachyon

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    Shenglong Tan

    2012-01-01

    Full Text Available Nucleotide-binding site (NBS disease resistance genes play an important role in defending plants from a variety of pathogens and insect pests. Many R-genes have been identified in various plant species. However, little is known about the NBS-encoding genes in Brachypodium distachyon. In this study, using computational analysis of the B. distachyon genome, we identified 126 regular NBS-encoding genes and characterized them on the bases of structural diversity, conserved protein motifs, chromosomal locations, gene duplications, promoter region, and phylogenetic relationships. EST hits and full-length cDNA sequences (from Brachypodium database of 126 R-like candidates supported their existence. Based on the occurrence of conserved protein motifs such as coiled-coil (CC, NBS, leucine-rich repeat (LRR, these regular NBS-LRR genes were classified into four subgroups: CC-NBS-LRR, NBS-LRR, CC-NBS, and X-NBS. Further expression analysis of the regular NBS-encoding genes in Brachypodium database revealed that these genes are expressed in a wide range of libraries, including those constructed from various developmental stages, tissue types, and drought challenged or nonchallenged tissue.

  5. Brachypodium distachyon as a model for defining the allergen potential of non-prolamin proteins.

    Science.gov (United States)

    Juhász, A; Gell, Gy; Sebestyén, E; Haraszi, R; Tamás, L; Balázs, E

    2012-08-01

    Epitope databases and the protein sequences of published plant genomes are suitable to identify some of the proteins causing food allergies and sensitivities. Brachypodium distachyon, a diploid wild grass with a sequenced genome and low prolamin content, is the closest relative of the allergen cereals, such as wheat or barley. Using the Brachypodium genome sequence, a workflow has been developed to identify potentially harmful proteins which may cause either celiac disease or wheat allergy-related symptoms. Seed tissue-specific expression of the potential allergens has been determined, and intact epitopes following an in silico digestion with several endopeptidases have been identified. Molecular function of allergen proteins has been evaluated using Gene Ontology terms. Biologically overrepresented proteins and potentially allergen protein families have been identified.

  6. Annotation and comparative analysis of the glycoside hydrolase genes in Brachypodium distachyon

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, Ludmila [United States Department of Agriculture (USDA), Western Regional Research Center (WRRC), Albany; Bragg, Jennifer [United States Department of Agriculture (USDA), Western Regional Research Center (WRRC), Albany; Wu, Jiajie [United States Department of Agriculture (USDA), Western Regional Research Center (WRRC), Albany; Yang, Xiaohan [ORNL; Tuskan, Gerald A [ORNL; Vogel, John [United States Department of Agriculture (USDA), Western Regional Research Center (WRRC), Albany

    2010-01-01

    Background Glycoside hydrolases cleave the bond between a carbohydrate and another carbohydrate, a protein, lipid or other moiety. Genes encoding glycoside hydrolases are found in a wide range of organisms, from archea to animals, and are relatively abundant in plant genomes. In plants, these enzymes are involved in diverse processes, including starch metabolism, defense, and cell-wall remodeling. Glycoside hydrolase genes have been previously cataloged for Oryza sativa (rice), the model dicotyledonous plant Arabidopsis thaliana, and the fast-growing tree Populus trichocarpa (poplar). To improve our understanding of glycoside hydrolases in plants generally and in grasses specifically, we annotated the glycoside hydrolase genes in the grasses Brachypodium distachyon (an emerging monocotyledonous model) and Sorghum bicolor (sorghum). We then compared the glycoside hydrolases across species, both at the whole-genome level and at the level of individual glycoside hydrolase families. Results We identified 356 glycoside hydrolase genes in Brachypodium and 404 in sorghum. The corresponding proteins fell into the same 34 families that are represented in rice, Arabidopsis, and poplar, helping to define a glycoside hydrolase family profile which may be common to flowering plants. Examination of individual glycoside hydrolase familes (GH5, GH13, GH18, GH19, GH28, and GH51) revealed both similarities and distinctions between monocots and dicots, as well as between species. Shared evolutionary histories appear to be modified by lineage-specific expansions or deletions. Within families, the Brachypodium and sorghum proteins generally cluster with those from other monocots. Conclusions This work provides the foundation for further comparative and functional analyses of plant glycoside hydrolases. Defining the Brachypodium glycoside hydrolases sets the stage for Brachypodium to be a monocot model for investigations of these enzymes and their diverse roles in planta. Insights

  7. Comparative genomics of flowering time pathways using Brachypodium distachyon as a model for the temperate grasses.

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    Janet A Higgins

    Full Text Available Brachypodium distachyon (Brachypodium is a model for the temperate grasses which include important cereals such as barley, wheat and oats. Comparison of the Brachypodium genome (accession Bd21 with those of the model dicot Arabidopsis thaliana and the tropical cereal rice (Oryza sativa provides an opportunity to compare and contrast genetic pathways controlling important traits. We analysed the homologies of genes controlling the induction of flowering using pathways curated in Arabidopsis Reactome as a starting point. Pathways include those detecting and responding to the environmental cues of day length (photoperiod and extended periods of low temperature (vernalization. Variation in these responses has been selected during cereal domestication, providing an interesting comparison with the wild genome of Brachypodium. Brachypodium Bd21 has well conserved homologues of circadian clock, photoperiod pathway and autonomous pathway genes defined in Arabidopsis and homologues of vernalization pathway genes defined in cereals with the exception of VRN2 which was absent. Bd21 also lacked a member of the CO family (CO3. In both cases flanking genes were conserved showing that these genes are deleted in at least this accession. Segmental duplication explains the presence of two CO-like genes in temperate cereals, of which one (Hd1 is retained in rice, and explains many differences in gene family structure between grasses and Arabidopsis. The conserved fine structure of duplications shows that they largely evolved to their present structure before the divergence of the rice and Brachypodium. Of four flowering-time genes found in rice but absent in Arabidopsis, two were found in Bd21 (Id1, OsMADS51 and two were absent (Ghd7, Ehd1. Overall, results suggest that an ancient core photoperiod pathway promoting flowering via the induction of FT has been modified by the recruitment of additional lineage specific pathways that promote or repress FT expression.

  8. Investigations of barley stripe mosaic virus as a gene silencing vector in barley roots and in Brachypodium distachyon and oat

    DEFF Research Database (Denmark)

    Pacak, Andrzej; Geisler, Katrin; Jørgensen, Bodil;

    2010-01-01

    -expressed genes we wanted to explore the potential of BSMV for silencing genes in root tissues. Furthermore, the newly completed genome sequence of the emerging cereal model species Brachypodium distachyon as well as the increasing amount of EST sequence information available for oat (Avena species) have created...

  9. Analysis of saccharification in Brachypodium distachyon stems under mild conditions of hydrolysis

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    Statham Emily R

    2008-10-01

    Full Text Available Abstract Background Brachypodium distachyon constitutes an excellent model species for grasses. It is a small, easily propagated, temperate grass with a rapid life cycle and a small genome. It is a self-fertile plant that can be transformed with high efficiency using Agrobacteria and callus derived from immature embryos. In addition, considerable genetic and genomic resources are becoming available for this species in the form of mapping populations, large expressed sequence tag collections, T-DNA insertion lines and, in the near future, the complete genome sequence. The development of Brachypodium as a model species is of particular value in the areas of cell wall and biomass research, where differences between dicots and grasses are greatest. Here we explore the effect of mild conditions of pretreatment and hydrolysis in Brachypodium stem segments as a contribution for the establishment of sensitive screening of the saccharification properties in different genetic materials. Results The non-cellulosic monosaccharide composition of Brachypodium is closely related to grasses of agricultural importance and significantly different from the dicot model Arabidopsis thaliana. Diluted acid pretreatment of stem segments produced significant release of sugars and negatively affected the amount of sugars obtained by enzymatic hydrolysis. Monosaccharide and oligosaccharide analysis showed that the hemicellulose fraction is the main target of the enzymatic activity under the modest hydrolytic conditions used in our assays. Scanning electron microscopy analysis of the treated materials showed progressive exposure of fibrils in the stem segments. Conclusion Results presented here indicate that under mild conditions cellulose and hemicellulose are hydrolysed to differing extents, with hemicellulose hydrolysis predominating. We anticipate that the sub-optimal conditions for hydrolysis identified here will provide a sensitive assay to detect variations in

  10. Molecular Characterization and Expression Profiling of NAC Transcription Factors in Brachypodium distachyon L.

    Science.gov (United States)

    Zhu, Gengrui; Chen, Guanxing; Zhu, Jiantang; Zhu, Yan; Lu, Xiaobing; Li, Xiaohui; Hu, Yingkao; Yan, Yueming

    2015-01-01

    NAC (NAM, ATAF1/2, CUC2) transcription factors are involved in regulating plant developmental processes and response to environmental stresses. Brachypodium distachyon is an emerging model system for cereals, temperate grasses and biofuel crops. In this study, a comprehensive investigation of the molecular characterizations, phylogenetics and expression profiles under various abiotic stresses of the NAC gene family in Brachypodium distachyon was performed. In total, 118 BNAC genes in B. distachyon were identified, of which 22 (18.64%) were tandemly duplicated and segmentally duplicated, respectively. The Bayesian phylogenetic inference using Markov Chain Monte Carlo (MCMC) algorithms showed that they were divided into two clades and fourteen subfamilies, supported by similar motif compositions within one subfamily. Some critical amino acids detected using DIVERGE v3.0 might contribute to functional divergence among subfamilies. The different exon-intron organizations among subfamilies revealed structural differentiation. Promoter sequence predictions showed that the BNAC genes were involved in various developmental processes and diverse stress responses. Three NAC domain-encoding genes (BNAC012, BNAC078 and BNAC108), orthologous of NAC1, were targeted by five miRNA164 (Bdi-miR164a-c, e, f), suggesting that they might function in lateral organ enlargement, floral development and the responses to abiotic stress. Eleven (~9.32%) BNAC proteins containing α-helical transmembrane motifs were identified. 23 representative BNAC genes were analyzed by quantitative real-time PCR, showing different expression patterns under various abiotic stresses, of which 18, 17 and 11 genes were up-regulated significantly under drought, H2O2 and salt stresses, respectively. Only four and two genes were up-regulated under cold and cadmium stresses, respectively. Dynamic transcriptional expression analysis revealed that six genes showed constitutive expression and period

  11. Molecular Characterization and Expression Profiling of NAC Transcription Factors in Brachypodium distachyon L.

    Directory of Open Access Journals (Sweden)

    Gengrui Zhu

    Full Text Available NAC (NAM, ATAF1/2, CUC2 transcription factors are involved in regulating plant developmental processes and response to environmental stresses. Brachypodium distachyon is an emerging model system for cereals, temperate grasses and biofuel crops. In this study, a comprehensive investigation of the molecular characterizations, phylogenetics and expression profiles under various abiotic stresses of the NAC gene family in Brachypodium distachyon was performed. In total, 118 BNAC genes in B. distachyon were identified, of which 22 (18.64% were tandemly duplicated and segmentally duplicated, respectively. The Bayesian phylogenetic inference using Markov Chain Monte Carlo (MCMC algorithms showed that they were divided into two clades and fourteen subfamilies, supported by similar motif compositions within one subfamily. Some critical amino acids detected using DIVERGE v3.0 might contribute to functional divergence among subfamilies. The different exon-intron organizations among subfamilies revealed structural differentiation. Promoter sequence predictions showed that the BNAC genes were involved in various developmental processes and diverse stress responses. Three NAC domain-encoding genes (BNAC012, BNAC078 and BNAC108, orthologous of NAC1, were targeted by five miRNA164 (Bdi-miR164a-c, e, f, suggesting that they might function in lateral organ enlargement, floral development and the responses to abiotic stress. Eleven (~9.32% BNAC proteins containing α-helical transmembrane motifs were identified. 23 representative BNAC genes were analyzed by quantitative real-time PCR, showing different expression patterns under various abiotic stresses, of which 18, 17 and 11 genes were up-regulated significantly under drought, H2O2 and salt stresses, respectively. Only four and two genes were up-regulated under cold and cadmium stresses, respectively. Dynamic transcriptional expression analysis revealed that six genes showed constitutive expression and period

  12. Centromeres cluster de novo at the beginning of meiosis in Brachypodium distachyon.

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    Ruoyu Wen

    Full Text Available In most eukaryotes that have been studied, the telomeres cluster into a bouquet early in meiosis, and in wheat and its relatives and in Arabidopsis the centromeres pair at the same time. In Arabidopsis, the telomeres do not cluster as a typical telomere bouquet on the nuclear membrane but are associated with the nucleolus both somatically and at the onset of meiosis. We therefore assessed whether Brachypodium distachyon, a monocot species related to cereals and whose genome is approximately twice the size of Arabidopsis thaliana, also exhibited an atypical telomere bouquet and centromere pairing. In order to investigate the occurrence of a bouquet and centromere pairing in B distachyon, we first had to establish protocols for studying meiosis in this species. This enabled us to visualize chromosome behaviour in meiocytes derived from young B distachyon spikelets in three-dimensions by fluorescent in situ hybridization (FISH, and accurately to stage meiosis based on chromatin morphology in relation to spikelet size and the timing of sample collection. Surprisingly, this study revealed that the centromeres clustered as a single site at the same time as the telomeres also formed a bouquet or single cluster.

  13. The complete chloroplast genome sequence of Brachypodium distachyon: sequence comparison and phylogenetic analysis of eight grass plastomes

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    Anderson Olin D

    2008-07-01

    Full Text Available Abstract Background Wheat, barley, and rye, of tribe Triticeae in the Poaceae, are among the most important crops worldwide but they present many challenges to genomics-aided crop improvement. Brachypodium distachyon, a close relative of those cereals has recently emerged as a model for grass functional genomics. Sequencing of the nuclear and organelle genomes of Brachypodium is one of the first steps towards making this species available as a tool for researchers interested in cereals biology. Findings The chloroplast genome of Brachypodium distachyon was sequenced by a combinational approach using BAC end and shotgun sequences derived from a selected BAC containing the entire chloroplast genome. Comparative analysis indicated that the chloroplast genome is conserved in gene number and organization with respect to those of other cereals. However, several Brachypodium genes evolve at a faster rate than those in other grasses. Sequence analysis reveals that rice and wheat have a ~2.1 kb deletion in their plastid genomes and this deletion must have occurred independently in both species. Conclusion We demonstrate that BAC libraries can be used to sequence plastid, and likely other organellar, genomes. As expected, the Brachypodium chloroplast genome is very similar to those of other sequenced grasses. The phylogenetic analyses and the pattern of insertions and deletions in the chloroplast genome confirmed that Brachypodium is a close relative of the tribe Triticeae. Nevertheless, we show that some large indels can arise multiple times and may confound phylogenetic reconstruction.

  14. Investigations of barley stripe mosaic virus as a gene silencing vector in barley roots and in Brachypodium distachyon and oat

    DEFF Research Database (Denmark)

    Pacak, Andrzej; Geisler, Katrin; Jørgensen, Bodil;

    2010-01-01

    -expressed genes we wanted to explore the potential of BSMV for silencing genes in root tissues. Furthermore, the newly completed genome sequence of the emerging cereal model species Brachypodium distachyon as well as the increasing amount of EST sequence information available for oat (Avena species) have created...... the wealth of genome information in the new cereal model plant B. distachyon. On the other hand, the silencing induced by BSMV in oat seemed too weak to be of practical use. The new BSMV vectors modified for ligation-free cloning will allow rapid insertion of plant gene fragments for future experiments....

  15. Molecular and Physiological Analysis of Growth-Limiting Drought Stress in Brachypodium distachyon Leaves

    Institute of Scientific and Technical Information of China (English)

    Wim Verelst; Edoardo Bertolini; Stefanie De Bodt; Klaas Vandepoele; Marlies Demeulenaere; Mario Enrico Pè; Dirk Inzé

    2013-01-01

    The drought-tolerant grass Brachypodium distachyon is an emerging model species for temperate grasses and cereal crops.To explore the usefulness of this species for drought studies,a reproducible in vivo drought assay was developed.Spontaneous soil drying led to a 45% reduction in leaf size,and this was mostly due to a decrease in cell expansion,whereas cell division remained largely unaffected by drought.To investigate the molecular basis of the observed leaf growth reduction,the third Brachypodium leaf was dissected in three zones,namely proliferation,expansion,and mature zones,and subjected to transcriptome analysis,based on a whole-genome tiling array.This approach allowed us to highlight that transcriptome profiles of different developmental leaf zones respond differently to drought.Several genes and functional processes involved in drought tolerance were identified.The transcriptome data suggest an increased energy availability in the proliferation zones,along with an up-regulation of sterol synthesis that may influence membrane fluidity.This information may be used to improve the tolerance of temperate cereals to drought,which is undoubtedly one of the major environmental challenges faced by agriculture today and in the near future.

  16. Brachypodium distachyon-Cochliobolus sativus Pathosystem is a New Model for Studying Plant-Fungal Interactions in Cereal Crops.

    Science.gov (United States)

    Zhong, Shaobin; Ali, Shaukat; Leng, Yueqiang; Wang, Rui; Garvin, David F

    2015-04-01

    Cochliobolus sativus (anamorph: Bipolaris sorokiniana) causes spot blotch, common root rot, and kernel blight or black point in barley and wheat. However, little is known about the molecular mechanisms underlying the pathogenicity of C. sativus or the molecular basis of resistance and susceptibility in the hosts. This study aims to establish the model grass Brachypodium distachyon as a new model for studying plant-fungus interactions in cereal crops. Six B. distachyon lines were inoculated with five C. sativus isolates. The results indicated that all six B. distachyon lines were infected by the C. sativus isolates, with their levels of resistance varying depending on the fungal isolates used. Responses ranging from hypersensitive response-mediated resistance to complete susceptibility were observed in a large collection of B. distachyon (2n=2x=10) and B. hybridum (2n=4x=30) accessions inoculated with four of the C. sativus isolates. Evaluation of an F2 population derived from the cross between two of the B. distachyon lines, Bd1-1 and Bd3-1, with isolate Cs07-47-1 showed quantitative and transgressive segregation for resistance to C. sativus, suggesting that the resistance may be governed by quantitative trait loci from both parents. The availability of whole-genome sequences of both the host (B. distachyon) and the pathogen (C. sativus) makes this pathosystem an attractive model for studying this important disease of cereal crops.

  17. Final technical report for: Insertional Mutagenesis of Brachypodium distachyon DE-AI02-07ER64452

    Energy Technology Data Exchange (ETDEWEB)

    John, Vogel P. [DOE Joint Genome Institute, Walnut Creek, CA (United States)

    2015-10-29

    Several bioenergy grasses are poised to become a major source of energy in the United States. Despite their increasing importance, we know little about the basic biology underlying the traits that control the utility of grasses as energy crops. Better knowledge of grass biology (e.g. identification of the genes that control cell wall composition, plant architecture, cell size, cell division, reproduction, nutrient uptake, carbon flux, etc.) could be used to design rational strategies for crop improvement and shorten the time required to domesticate these species. The use of an appropriate model system is an efficient way to gain this knowledge. Brachypodium distachyon is a small annual grass with all the attributes needed to be a modern model organism including simple growth requirements, fast generation time, small stature, small genome size and self-fertility. These attributes led to the recommendation in the DOE’s “Breaking the Biological Barriers to Cellulosic Ethanol: A Joint Research Agenda” report to propose developing and using B. distachyon as a model for energy crops to accelerate their domestication. Strategic investments (e.g. genome sequencing) in B. distachyon by the DOE are now bearing fruit and B. distachyon is being used as a model grass by hundreds of laboratories worldwide. Sequence indexed insertional mutants are an extremely powerful tool for both forward and reverse genetics. They allow researchers to order mutants in any gene tagged in the collection by simply emailing a request. The goal of this project was to create a collection of sequence indexed insertional mutants (T-DNA lines) for the model grass Brachypodium distachyon in order to facilitate research by the scientific community. During the course of this grant we created a collection of 23,649 B. distachyon T-DNA lines and identified 26,112 unique insertion sites. The collection can be queried through the project website (http://jgi.doe.gov/our-science/science-programs/plant-genomics/brachypodium/brachypodium

  18. Evaluation of Brachypodium distachyon L-Tyrosine Decarboxylase Using L-Tyrosine Over-Producing Saccharomyces cerevisiae.

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    Shuhei Noda

    Full Text Available To demonstrate that herbaceous biomass is a versatile gene resource, we focused on the model plant Brachypodium distachyon, and screened the B. distachyon for homologs of tyrosine decarboxylase (TDC, which is involved in the modification of aromatic compounds. A total of 5 candidate genes were identified in cDNA libraries of B. distachyon and were introduced into Saccharomyces cerevisiae to evaluate TDC expression and tyramine production. It is suggested that two TDCs encoded in the transcripts Bradi2g51120.1 and Bradi2g51170.1 have L-tyrosine decarboxylation activity. Bradi2g51170.1 was introduced into the L-tyrosine over-producing strain of S. cerevisiae that was constructed by the introduction of mutant genes that promote deregulated feedback inhibition. The amount of tyramine produced by the resulting transformant was 6.6-fold higher (approximately 200 mg/L than the control strain, indicating that B. distachyon TDC effectively converts L-tyrosine to tyramine. Our results suggest that B. distachyon possesses enzymes that are capable of modifying aromatic residues, and that S. cerevisiae is a suitable host for the production of L-tyrosine derivatives.

  19. Comparative genome analysis between Agrostis stolonifera and members of the Pooideae subfamily, including Brachypodium distachyon.

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    Loreto Araneda

    Full Text Available Creeping bentgrass (Agrostis stolonifera, allotetraploid 2n = 4x = 28 is one of the major cool-season turfgrasses. It is widely used on golf courses due to its tolerance to low mowing and aggressive growth habit. In this study, we investigated genome relationships of creeping bentgrass relative to the Triticeae (a consensus map of Triticum aestivum, T. tauschii, Hordeum vulgare, and H. spontaneum, oat, rice, and ryegrass maps using a common set of 229 EST-RFLP markers. The genome comparisons based on the RFLP markers revealed large-scale chromosomal rearrangements on different numbers of linkage groups (LGs of creeping bentgrass relative to the Triticeae (3 LGs, oat (4 LGs, and rice (8 LGs. However, we detected no chromosomal rearrangement between creeping bentgrass and ryegrass, suggesting that these recently domesticated species might be closely related, despite their memberships to different Pooideae tribes. In addition, the genome of creeping bentgrass was compared with the complete genome sequence of Brachypodium distachyon in Pooideae subfamily using both sequences of the above-mentioned mapped EST-RFLP markers and sequences of 8,470 publicly available A. stolonifera ESTs (AgEST. We discovered large-scale chromosomal rearrangements on six LGs of creeping bentgrass relative to B. distachyon. Also, a total of 24 syntenic blocks based on 678 orthologus loci were identified between these two grass species. The EST orthologs can be utilized in further comparative mapping of Pooideae species. These results will be useful for genetic improvement of Agrostis species and will provide a better understanding of evolution within Pooideae species.

  20. Daily changes in temperature, not the circadian clock, regulate growth rate in Brachypodium distachyon.

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    Dominick A Matos

    Full Text Available Plant growth is commonly regulated by external cues such as light, temperature, water availability, and internal cues generated by the circadian clock. Changes in the rate of growth within the course of a day have been observed in the leaves, stems, and roots of numerous species. However, the relative impact of the circadian clock on the growth of grasses has not been thoroughly characterized. We examined the influence of diurnal temperature and light changes, and that of the circadian clock on leaf length growth patterns in Brachypodium distachyon using high-resolution time-lapse imaging. Pronounced changes in growth rate were observed under combined photocyles and thermocycles or with thermocycles alone. A considerably more rapid growth rate was observed at 28°C than 12°C, irrespective of the presence or absence of light. In spite of clear circadian clock regulated gene expression, plants exhibited no change in growth rate under conditions of constant light and temperature, and little or no effect under photocycles alone. Therefore, temperature appears to be the primary cue influencing observed oscillations in growth rate and not the circadian clock or photoreceptor activity. Furthermore, the size of the leaf meristem and final cell length did not change in response to changes in temperature. Therefore, the nearly five-fold difference in growth rate observed across thermocycles can be attributed to proportionate changes in the rate of cell division and expansion. A better understanding of the growth cues in B. distachyon will further our ability to model metabolism and biomass accumulation in grasses.

  1. Daily changes in temperature, not the circadian clock, regulate growth rate in Brachypodium distachyon.

    Science.gov (United States)

    Matos, Dominick A; Cole, Benjamin J; Whitney, Ian P; MacKinnon, Kirk J-M; Kay, Steve A; Hazen, Samuel P

    2014-01-01

    Plant growth is commonly regulated by external cues such as light, temperature, water availability, and internal cues generated by the circadian clock. Changes in the rate of growth within the course of a day have been observed in the leaves, stems, and roots of numerous species. However, the relative impact of the circadian clock on the growth of grasses has not been thoroughly characterized. We examined the influence of diurnal temperature and light changes, and that of the circadian clock on leaf length growth patterns in Brachypodium distachyon using high-resolution time-lapse imaging. Pronounced changes in growth rate were observed under combined photocyles and thermocycles or with thermocycles alone. A considerably more rapid growth rate was observed at 28°C than 12°C, irrespective of the presence or absence of light. In spite of clear circadian clock regulated gene expression, plants exhibited no change in growth rate under conditions of constant light and temperature, and little or no effect under photocycles alone. Therefore, temperature appears to be the primary cue influencing observed oscillations in growth rate and not the circadian clock or photoreceptor activity. Furthermore, the size of the leaf meristem and final cell length did not change in response to changes in temperature. Therefore, the nearly five-fold difference in growth rate observed across thermocycles can be attributed to proportionate changes in the rate of cell division and expansion. A better understanding of the growth cues in B. distachyon will further our ability to model metabolism and biomass accumulation in grasses.

  2. CG Methylation Covaries with Differential Gene Expression between Leaf and Floral Bud Tissues of Brachypodium distachyon.

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    Kyria Roessler

    Full Text Available DNA methylation has the potential to influence plant growth and development through its influence on gene expression. To date, however, the evidence from plant systems is mixed as to whether patterns of DNA methylation vary significantly among tissues and, if so, whether these differences affect tissue-specific gene expression. To address these questions, we analyzed both bisulfite sequence (BSseq and transcriptomic sequence data from three biological replicates of two tissues (leaf and floral bud from the model grass species Brachypodium distachyon. Our first goal was to determine whether tissues were more differentiated in DNA methylation than explained by variation among biological replicates. Tissues were more differentiated than biological replicates, but the analysis of replicated data revealed high (>50% false positive rates for the inference of differentially methylated sites (DMSs and differentially methylated regions (DMRs. Comparing methylation to gene expression, we found that differential CG methylation consistently covaried negatively with gene expression, regardless as to whether methylation was within genes, within their promoters or even within their closest transposable element. The relationship between gene expression and either CHG or CHH methylation was less consistent. In total, CG methylation in promoters explained 9% of the variation in tissue-specific expression across genes, suggesting that CG methylation is a minor but appreciable factor in tissue differentiation.

  3. Digital imaging approaches for phenotyping whole plant nitrogen and phosphorus response in Brachypodium distachyon

    Institute of Scientific and Technical Information of China (English)

    Richard Poir; Vincent Chochois; Xavier R.R.Sirault; John P.Vogel; Michelle Watt; Robert T.Furbank

    2014-01-01

    This work evaluates the phenotypic response of the model grass (Brachypodium distachyon (L.) P. Beauv.) to nitrogen and phosphorus nutrition using a combination of imaging techniques and destructive harvest of shoots and roots. Reference line Bd21-3 was grown in pots using 11 phosphorus and 11 nitrogen concentrations to establish a dose-response curve. Shoot biovolume and biomass, root length and biomass, and tissue phosphorus and nitrogen concentrations increased with nutrient concentration. Shoot biovolume, estimated by imaging, was highly correlated with dry weight (R2>0.92) and both biovolume and growth rate responded strongly to nutrient availability. Higher nutrient supply increased nodal root length more than other root types. Photochemical efficiency was strongly reduced by low phosphorus concentrations as early as 1 week after germination, suggesting that this measurement may be suitable for high throughput screening of phosphorus response. In contrast, nitrogen concentration had little effect on photochemical efficiency. Changes in biovolume over time were used to compare growth rates of four accessions in response to nitrogen and phosphorus supply. We demonstrate that a time series image-based approach coupled with mathematical modeling provides higher resolution of genotypic response to nutrient supply than traditional destructive techniques and shows promise for high throughput screening and determina-tion of genomic regions associated with superior nutrient use efficiency.

  4. An integrated physical, genetic and cytogenetic map of Brachypodium distachyon, a model system for grass research.

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    Melanie Febrer

    Full Text Available The pooid subfamily of grasses includes some of the most important crop, forage and turf species, such as wheat, barley and Lolium. Developing genomic resources, such as whole-genome physical maps, for analysing the large and complex genomes of these crops and for facilitating biological research in grasses is an important goal in plant biology. We describe a bacterial artificial chromosome (BAC-based physical map of the wild pooid grass Brachypodium distachyon and integrate this with whole genome shotgun sequence (WGS assemblies using BAC end sequences (BES. The resulting physical map contains 26 contigs spanning the 272 Mb genome. BES from the physical map were also used to integrate a genetic map. This provides an independent validation and confirmation of the published WGS assembly. Mapped BACs were used in Fluorescence In Situ Hybridisation (FISH experiments to align the integrated physical map and sequence assemblies to chromosomes with high resolution. The physical, genetic and cytogenetic maps, integrated with whole genome shotgun sequence assemblies, enhance the accuracy and durability of this important genome sequence and will directly facilitate gene isolation.

  5. Accelerated Growth Rate and Increased Drought Stress Resilience of the Model Grass Brachypodium distachyon Colonized by Bacillus subtilis B26.

    Science.gov (United States)

    Gagné-Bourque, François; Mayer, Boris F; Charron, Jean-Benoit; Vali, Hojatollah; Bertrand, Annick; Jabaji, Suha

    2015-01-01

    Plant growth-promoting bacteria (PGB) induce positive effects in plants, for instance, increased growth and reduced abiotic stresses susceptibility. The mechanisms by which these bacteria impact the host plant are numerous, diverse and often specific. Here, we studied the agronomical, molecular and biochemical effects of the endophytic PGB Bacillus subtilis B26 on the full life cycle of Brachypodium distachyon Bd21, an established model species for functional genomics in cereal crops and temperate grasses. Inoculation of Brachypodium with B. subtilis strain B26 increased root and shoot weights, accelerated growth rate and seed yield as compared to control plants. B. subtilis strain B26 efficiently colonized the plant and was recovered from roots, stems and blades as well as seeds of Brachypodium, indicating that the bacterium is able to migrate, spread systemically inside the plant, establish itself in the aerial plant tissues and organs, and is vertically transmitted to seeds. The presence of B. subtilis strain B26 in the seed led to systemic colonization of the next generation of Brachypodium plants. Inoculated Brachypodium seedlings and mature plants exposed to acute and chronic drought stress minimized the phenotypic effect of drought compared to plants not harbouring the bacterium. Protection from the inhibitory effects of drought by the bacterium was linked to upregulation of the drought-response genes, DREB2B-like, DHN3-like and LEA-14-A-like and modulation of the DNA methylation genes, MET1B-like, CMT3-like and DRM2-like, that regulate the process. Additionally, total soluble sugars and starch contents increased in stressed inoculated plants, a biochemical indication of drought tolerance. In conclusion, we show a single inoculation of Brachypodium with a PGB affected the whole growth cycle of the plant, accelerating its growth rates, shortening its vegetative period, and alleviating drought stress effects. These effects are relevant to grasses and cereal

  6. Accelerated Growth Rate and Increased Drought Stress Resilience of the Model Grass Brachypodium distachyon Colonized by Bacillus subtilis B26.

    Directory of Open Access Journals (Sweden)

    François Gagné-Bourque

    Full Text Available Plant growth-promoting bacteria (PGB induce positive effects in plants, for instance, increased growth and reduced abiotic stresses susceptibility. The mechanisms by which these bacteria impact the host plant are numerous, diverse and often specific. Here, we studied the agronomical, molecular and biochemical effects of the endophytic PGB Bacillus subtilis B26 on the full life cycle of Brachypodium distachyon Bd21, an established model species for functional genomics in cereal crops and temperate grasses. Inoculation of Brachypodium with B. subtilis strain B26 increased root and shoot weights, accelerated growth rate and seed yield as compared to control plants. B. subtilis strain B26 efficiently colonized the plant and was recovered from roots, stems and blades as well as seeds of Brachypodium, indicating that the bacterium is able to migrate, spread systemically inside the plant, establish itself in the aerial plant tissues and organs, and is vertically transmitted to seeds. The presence of B. subtilis strain B26 in the seed led to systemic colonization of the next generation of Brachypodium plants. Inoculated Brachypodium seedlings and mature plants exposed to acute and chronic drought stress minimized the phenotypic effect of drought compared to plants not harbouring the bacterium. Protection from the inhibitory effects of drought by the bacterium was linked to upregulation of the drought-response genes, DREB2B-like, DHN3-like and LEA-14-A-like and modulation of the DNA methylation genes, MET1B-like, CMT3-like and DRM2-like, that regulate the process. Additionally, total soluble sugars and starch contents increased in stressed inoculated plants, a biochemical indication of drought tolerance. In conclusion, we show a single inoculation of Brachypodium with a PGB affected the whole growth cycle of the plant, accelerating its growth rates, shortening its vegetative period, and alleviating drought stress effects. These effects are relevant to

  7. Brachypodium distachyon line Bd3-1 resistance is elicited by the barley stripe mosaic virus triple gene block 1 movement protein

    NARCIS (Netherlands)

    Lee, M.Y.; Yan, L.J.; Gorter, F.A.; Kim, B.Y.T.; Cui, Y.; Hu, Y.; Yuan, C.; Grindheim, J.; Ganesan, U.; Liu, Z.Y.; Han, C.G.; Yu, J.L.; Li, D.W.; Jackson, A.O.

    2012-01-01

    Barley stripe mosaic virus North Dakota 18 (ND18), Beijing (BJ), Xinjiang (Xi), Type (TY) and CV21 strains are unable to infect the Brachypodium distachyon Bd3-1 inbred line, which harbours a resistance gene designated Bsr1, but the Norwich (NW) strain is virulent on Bd3-1. Analysis of ND18 and NW g

  8. Functional conservation and diversification of APETALA1/FRUITFULL genes in Brachypodium distachyon.

    Science.gov (United States)

    Li, Qi; Wang, Ye; Wang, Fuxiang; Guo, Yuyu; Duan, Xueqing; Sun, Jinhao; An, Hailong

    2016-08-01

    The duplicated grass APETALA1/FRUITFULL (AP1/FUL) genes have distinct but overlapping patterns of expression, suggesting their discrete roles in transition to flowering, specification of spikelet meristem identity and specification of floral organ identity. In this study, we analyzed the expression patterns and functions of four AP1/FUL paralogs (BdVRN1, BdFUL2, BdFUL3 and BdFUL4) in Brachypodium distachyon, a model plant for the temperate cereals and related grasses. Among the four genes tested, only BdVRN1 could remember the prolonged cold treatment. The recently duplicated BdVRN1 and BdFUL2 genes were expressed in a highly consistent manner and ectopic expressions of them caused similar phenotypes such as extremely early flowering and severe morphological alterations of floral organs, indicating their redundant roles in floral transition, inflorescence development and floral organ identity. In comparison, ectopic expressions of BdFUL3 and BdFUL4 only caused a moderate early flowering phenotype, suggesting their divergent function. In yeast two-hybrid assay, both BdVRN1 and BdFUL2 physically interact with SEP proteins but only BdFUL2 is able to form a homodimer. BdVRN1 also interacts weakly with BdFUL2. Our results indicate that, since the separation of AP1/FUL genes in grasses, the process of sub- or neo-functionalization has occurred and paralogs function redundantly and/or separately in flowering competence and inflorescence development.

  9. Functional conservation and diversification of APETALA1/FRUITFULL genes in Brachypodium distachyon.

    Science.gov (United States)

    Li, Qi; Wang, Ye; Wang, Fuxiang; Guo, Yuyu; Duan, Xueqing; Sun, Jinhao; An, Hailong

    2016-08-01

    The duplicated grass APETALA1/FRUITFULL (AP1/FUL) genes have distinct but overlapping patterns of expression, suggesting their discrete roles in transition to flowering, specification of spikelet meristem identity and specification of floral organ identity. In this study, we analyzed the expression patterns and functions of four AP1/FUL paralogs (BdVRN1, BdFUL2, BdFUL3 and BdFUL4) in Brachypodium distachyon, a model plant for the temperate cereals and related grasses. Among the four genes tested, only BdVRN1 could remember the prolonged cold treatment. The recently duplicated BdVRN1 and BdFUL2 genes were expressed in a highly consistent manner and ectopic expressions of them caused similar phenotypes such as extremely early flowering and severe morphological alterations of floral organs, indicating their redundant roles in floral transition, inflorescence development and floral organ identity. In comparison, ectopic expressions of BdFUL3 and BdFUL4 only caused a moderate early flowering phenotype, suggesting their divergent function. In yeast two-hybrid assay, both BdVRN1 and BdFUL2 physically interact with SEP proteins but only BdFUL2 is able to form a homodimer. BdVRN1 also interacts weakly with BdFUL2. Our results indicate that, since the separation of AP1/FUL genes in grasses, the process of sub- or neo-functionalization has occurred and paralogs function redundantly and/or separately in flowering competence and inflorescence development. PMID:26856680

  10. Final technical report for Phenomic Analysis of Natural and Induced Variation in Brachypodium Distachyon DE-SC0001526

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, John P. [USDA ARS Western Regional Research Center, Albany, NY (United States)

    2014-12-17

    The goal of this project was to apply high-throughput, non-destructive phenotyping (phenomics) to collections of natural variants and induced mutants of the model grass Brachypodium distachyon and characterize a small subset of that material in detail. B. distachyon is well suited to this phenomic approach because its small size and rapid generation time allow researchers to grow many plants under carefully controlled conditions. In addition, the simple diploid genetics, high quality genome sequence and existence of numerous experimental tools available for B. distachyon allow us to rapidly identify genes affecting specific phenotypes. Our phenomic analysis revealed great diversity in biofuel-relevant traits like growth rate, biomass and photosynthetic rate. This clearly demonstrated the feasibility of applying a phenomic approach to the model grass B. distachyon. We also demonstrated the utility of B. distachyon for studying mature root system, something that is virtually impossible to do with biomass crops. We showed tremendous natural variation in root architecture that can potentially be used to design crops with superior nutrient and water harvesting capability. Finally, we demonstrated the speed with which we can link specific genes to specific phenotypes by studying two mutants in detail. Importantly, in both cases, the specific biological lessons learned were grass-specific and could not have been learned from a dicot model system. Furthermore, one of the genes affects cell wall integrity and thus may be a useful target in the context of biomass crop improvement. Ultimately, all this information can be used to accelerate the creation of improved biomass crops.

  11. High temperature stress and its effect on pollen development and morphological components of harvest index in the C3 model grass Brachypodium distachyon

    Science.gov (United States)

    Harsant, Jeffrey; Pavlovic, Lazar; Chiu, Greta; Sultmanis, Stefanie; Sage, Tammy L.

    2013-01-01

    The effect of high temperatures on harvest index (HI) and morphological components that contribute to HI was investigated in two lines (Bd21 and Bd21-3) of Brachypodium distachyon, a C3 grass recognized as a tractable plant, to address critical issues associated with enhancing cereal crop yields in the presence of global climate change. The results demonstrated that temperatures ≥32 °C eliminated HI. Reductions in yield at 32 °C were due primarily to declines in pollen viability, retention of pollen in anthers, and pollen germination, while abortion of microspores by the uninucleate stage that was correlated with abnormal tapetal development resulted in yield failure at 36 °C. Increasing temperatures from 24 to 32 °C resulted in reductions in tiller numbers but had no impact on axillary branch numbers per tiller. Grain developed at 24 and 28 °C primarily in tiller spikes, although spikes on axillary branches also formed grain. Grain quantity decreased in tiller spikes but increased in axillary branch spikes as temperatures rose from 24 to 28 °C. Differential patterns of axillary branching and floret development within spikelets between Bd21 and Bd21-3 resulted in higher grain yield in axillary branches of Bd21-3 at 28 °C. The response of male reproductive development and tiller branching patterns in B. distachyon to increasing temperatures mirrors that in other cereal crops, providing support for the use of this C3 grass in assessing the molecular control of HI in the presence of global warming. PMID:23771979

  12. Fine mapping of the Bsr1 barley stripe mosaic virus resistance gene in the model grass Brachypodium distachyon.

    Directory of Open Access Journals (Sweden)

    Yu Cui

    Full Text Available The ND18 strain of Barley stripe mosaic virus (BSMV infects several lines of Brachypodium distachyon, a recently developed model system for genomics research in cereals. Among the inbred lines tested, Bd3-1 is highly resistant at 20 to 25 °C, whereas Bd21 is susceptible and infection results in an intense mosaic phenotype accompanied by high levels of replicating virus. We generated an F(6:7 recombinant inbred line (RIL population from a cross between Bd3-1 and Bd21 and used the RILs, and an F(2 population of a second Bd21 × Bd3-1 cross to evaluate the inheritance of resistance. The results indicate that resistance segregates as expected for a single dominant gene, which we have designated Barley stripe mosaic virus resistance 1 (Bsr1. We constructed a genetic linkage map of the RIL population using SNP markers to map this gene to within 705 Kb of the distal end of the top of chromosome 3. Additional CAPS and Indel markers were used to fine map Bsr1 to a 23 Kb interval containing five putative genes. Our study demonstrates the power of using RILs to rapidly map the genetic determinants of BSMV resistance in Brachypodium. Moreover, the RILs and their associated genetic map, when combined with the complete genomic sequence of Brachypodium, provide new resources for genetic analyses of many other traits.

  13. Analysis of global gene expression in Brachypodium distachyon reveals extensive network plasticity in response to abiotic stress.

    Directory of Open Access Journals (Sweden)

    Henry D Priest

    Full Text Available Brachypodium distachyon is a close relative of many important cereal crops. Abiotic stress tolerance has a significant impact on productivity of agriculturally important food and feedstock crops. Analysis of the transcriptome of Brachypodium after chilling, high-salinity, drought, and heat stresses revealed diverse differential expression of many transcripts. Weighted Gene Co-Expression Network Analysis revealed 22 distinct gene modules with specific profiles of expression under each stress. Promoter analysis implicated short DNA sequences directly upstream of module members in the regulation of 21 of 22 modules. Functional analysis of module members revealed enrichment in functional terms for 10 of 22 network modules. Analysis of condition-specific correlations between differentially expressed gene pairs revealed extensive plasticity in the expression relationships of gene pairs. Photosynthesis, cell cycle, and cell wall expression modules were down-regulated by all abiotic stresses. Modules which were up-regulated by each abiotic stress fell into diverse and unique gene ontology GO categories. This study provides genomics resources and improves our understanding of abiotic stress responses of Brachypodium.

  14. Infection of Brachypodium distachyon by formae speciales of Puccinia graminis: early infection events and host-pathogen incompatibility.

    Directory of Open Access Journals (Sweden)

    Melania Figueroa

    Full Text Available Puccinia graminis causes stem rust, a serious disease of cereals and forage grasses. Important formae speciales of P. graminis and their typical hosts are P. graminis f. sp. tritici (Pg-tr in wheat and barley, P. graminis f. sp. lolii (Pg-lo in perennial ryegrass and tall fescue, and P. graminis f. sp. phlei-pratensis (Pg-pp in timothy grass. Brachypodium distachyon is an emerging genetic model to study fungal disease resistance in cereals and temperate grasses. We characterized the P. graminis-Brachypodium pathosystem to evaluate its potential for investigating incompatibility and non-host resistance to P. graminis. Inoculation of eight Brachypodium inbred lines with Pg-tr, Pg-lo or Pg-pp resulted in sporulating lesions later accompanied by necrosis. Histological analysis of early infection events in one Brachypodium inbred line (Bd1-1 indicated that Pg-lo and Pg-pp were markedly more efficient than Pg-tr at establishing a biotrophic interaction. Formation of appressoria was completed (60-70% of germinated spores by 12 h post-inoculation (hpi under dark and wet conditions, and after 4 h of subsequent light exposure fungal penetration structures (penetration peg, substomatal vesicle and primary infection hyphae had developed. Brachypodium Bd1-1 exhibited pre-haustorial resistance to Pg-tr, i.e. infection usually stopped at appressorial formation. By 68 hpi, only 0.3% and 0.7% of the Pg-tr urediniospores developed haustoria and colonies, respectively. In contrast, development of advanced infection structures by Pg-lo and Pg-pp was significantly more common; however, Brachypodium displayed post-haustorial resistance to these isolates. By 68 hpi the percentage of urediniospores that only develop a haustorium mother cell or haustorium in Pg-lo and Pg-pp reached 8% and 5%, respectively. The formation of colonies reached 14% and 13%, respectively. We conclude that Brachypodium is an apt grass model to study the molecular and genetic components of

  15. Quantitative trait loci associated with natural diversity in water-use efficiency and response to soil drying in Brachypodium distachyon.

    Science.gov (United States)

    Des Marais, David L; Razzaque, Samsad; Hernandez, Kyle M; Garvin, David F; Juenger, Thomas E

    2016-10-01

    All plants must optimize their growth with finite resources. Water use efficiency (WUE) measures the relationship between biomass acquisition and transpired water. In the present study, we performed two experiments to understand the genetic basis of WUE and other parameters of plant-water interaction under control and water-limited conditions. Our study used two inbred natural accessions of Brachypodium distachyon, a model grass species with close phylogenetic affinity to temperate forage and cereal crops. First, we identify the soil water content which causes a reduction in leaf relative water content and an increase in WUE. Second, we present results from a large phenotyping experiment utilizing a recombinant inbred line mapping population derived from these same two natural accessions. We identify QTLs associated with environmentally-insensitive genetic variation in WUE, including a pair of epistatically interacting loci. We also identify QTLs associated with constitutive differences in biomass and a QTL describing an environmentally-sensitive difference in leaf carbon content. Finally, we present a new linkage map for this mapping population based on new SNP markers as well as updated genomic positions for previously described markers. Our studies provide an initial characterization of plant-water relations in B. distachyon and identify candidate genomic regions involved in WUE.

  16. Addressing the Role of microRNAs in Reprogramming Leaf Growth during Drought Stress in Brachypodium distachyon

    Institute of Scientific and Technical Information of China (English)

    Edoardo Bertolini; Wim Verelst; David Stephen Horner; Luca Gianfranceschi; Viviana Piccolo; Dirk Inzé; Mario Enrico Pè

    2013-01-01

    Plant responses to drought are regulated by complex genetic and epigenetic networks leading to rapid reprogramming of plant growth,miRNAs have been widely indicated as key players in the regulation of growth and development.The role of miRNAs in drought response was investigated in young leaves of Brachypodium distachyon,a drought-tolerant monocot model species.Adopting an in vivo drought assay,shown to cause a dramatic reduction in leaf size,mostly due to reduced cell expansion,small RNA libraries were produced from proliferating and expanding leaf cells.Next-generation sequencing data were analyzed using an in-house bioinformatics pipeline allowing the identification of 66 annotated miRNA genes and 122 new high confidence predictions greatly expanding the number of known Brachypodium miRNAs.In addition,we identified four TAS3 loci and a large number of siRNA-producing loci that show characteristics suggesting that they may represent young miRNA genes.Most miRNAs showed a high expression level,consistent with their involvement in early leaf development and cell identity.Proliferating and expanding leaf cells respond differently to drought treatment and differential expression analyses suggest novel evidence for an miRNA regulatory network controlling cell division in both normal and stressed conditions and demonstrate that drought triggers a genetic reprogramming of leaf growth in which miRNAs are deeply involved.

  17. The family of DOF transcription factors in Brachypodium distachyon: phylogenetic comparison with rice and barley DOFs and expression profiling

    Directory of Open Access Journals (Sweden)

    Hernando-Amado Sara

    2012-11-01

    Full Text Available Abstract Background Transcription factors (TFs are proteins that have played a central role both in evolution and in domestication, and are major regulators of development in living organisms. Plant genome sequences reveal that approximately 7% of all genes encode putative TFs. The DOF (DNA binding with One Finger TF family has been associated with vital processes exclusive to higher plants and to their close ancestors (algae, mosses and ferns. These are seed maturation and germination, light-mediated regulation, phytohormone and plant responses to biotic and abiotic stresses, etc. In Hordeum vulgare and Oryza sativa, 26 and 30 different Dof genes, respectively, have been annotated. Brachypodium distachyon has been the first Pooideae grass to be sequenced and, due to its genomic, morphological and physiological characteristics, has emerged as the model system for temperate cereals, such as wheat and barley. Results Through searches in the B. distachyon genome, 27 Dof genes have been identified and a phylogenetic comparison with the Oryza sativa and the Hordeum vulgare DOFs has been performed. To explore the evolutionary relationship among these DOF proteins, a combined phylogenetic tree has been constructed with the Brachypodium DOFs and those from rice and barley. This phylogenetic analysis has classified the DOF proteins into four Major Cluster of Orthologous Groups (MCOGs. Using RT-qPCR analysis the expression profiles of the annotated BdDof genes across four organs (leaves, roots, spikes and seeds has been investigated. These results have led to a classification of the BdDof genes into two groups, according to their expression levels. The genes highly or preferentially expressed in seeds have been subjected to a more detailed expression analysis (maturation, dry stage and germination. Conclusions Comparison of the expression profiles of the Brachypodium Dof genes with the published functions of closely related DOF sequences from the cereal

  18. Investigations of barley stripe mosaic virus as a gene silencing vector in barley roots and in Brachypodium distachyon and oat

    Directory of Open Access Journals (Sweden)

    Nilsson Lena

    2010-11-01

    Full Text Available Abstract Background Gene silencing vectors based on Barley stripe mosaic virus (BSMV are used extensively in cereals to study gene function, but nearly all studies have been limited to genes expressed in leaves of barley and wheat. However since many important aspects of plant biology are based on root-expressed genes we wanted to explore the potential of BSMV for silencing genes in root tissues. Furthermore, the newly completed genome sequence of the emerging cereal model species Brachypodium distachyon as well as the increasing amount of EST sequence information available for oat (Avena species have created a need for tools to study gene function in these species. Results Here we demonstrate the successful BSMV-mediated virus induced gene silencing (VIGS of three different genes in barley roots, i.e. the barley homologues of the IPS1, PHR1, and PHO2 genes known to participate in Pi uptake and reallocation in Arabidopsis. Attempts to silence two other genes, the Pi transporter gene HvPht1;1 and the endo-β-1,4-glucanase gene HvCel1, in barley roots were unsuccessful, probably due to instability of the plant gene inserts in the viral vector. In B. distachyon leaves, significant silencing of the PHYTOENE DESATURASE (BdPDS gene was obtained as shown by photobleaching as well as quantitative RT-PCR analysis. On the other hand, only very limited silencing of the oat AsPDS gene was observed in both hexaploid (A. sativa and diploid (A. strigosa oat. Finally, two modifications of the BSMV vector are presented, allowing ligation-free cloning of DNA fragments into the BSMV-γ component. Conclusions Our results show that BSMV can be used as a vector for gene silencing in barley roots and in B. distachyon leaves and possibly roots, opening up possibilities for using VIGS to study cereal root biology and to exploit the wealth of genome information in the new cereal model plant B. distachyon. On the other hand, the silencing induced by BSMV in oat seemed too

  19. Imaging with the fluorogenic dye Basic Fuchsin reveals subcellular patterning and ecotype variation of lignification in Brachypodium distachyon.

    Science.gov (United States)

    Kapp, Nikki; Barnes, William J; Richard, Tom L; Anderson, Charles T

    2015-07-01

    Lignin is a complex polyphenolic heteropolymer that is abundant in the secondary cell walls of plants and functions in growth and defence. It is also a major barrier to the deconstruction of plant biomass for bioenergy production, but the spatiotemporal details of how lignin is deposited in actively lignifying tissues and the precise relationships between wall lignification in different cell types and developmental events, such as flowering, are incompletely understood. Here, the lignin-detecting fluorogenic dye, Basic Fuchsin, was adapted to enable comparative fluorescence-based imaging of lignin in the basal internodes of three Brachypodium distachyon ecotypes that display divergent flowering times. It was found that the extent and intensity of Basic Fuchsin fluorescence increase over time in the Bd21-3 ecotype, that Basic Fuchsin staining is more widespread and intense in 4-week-old Bd21-3 and Adi-10 basal internodes than in Bd1-1 internodes, and that Basic Fuchsin staining reveals subcellular patterns of lignin in vascular and interfascicular fibre cell walls. Basic Fuchsin fluorescence did not correlate with lignin quantification by acetyl bromide analysis, indicating that whole-plant and subcellular lignin analyses provide distinct information about the extent and patterns of lignification in B. distachyon. Finally, it was found that flowering time correlated with a transient increase in total lignin, but did not correlate strongly with the patterning of stem lignification, suggesting that additional developmental pathways might regulate secondary wall formation in grasses. This study provides a new comparative tool for imaging lignin in plants and helps inform our views of how lignification proceeds in grasses. PMID:25922482

  20. Large-scale collection and analysis of full-length cDNAs from Brachypodium distachyon and integration with Pooideae sequence resources.

    Directory of Open Access Journals (Sweden)

    Keiichi Mochida

    Full Text Available A comprehensive collection of full-length cDNAs is essential for correct structural gene annotation and functional analyses of genes. We constructed a mixed full-length cDNA library from 21 different tissues of Brachypodium distachyon Bd21, and obtained 78,163 high quality expressed sequence tags (ESTs from both ends of ca. 40,000 clones (including 16,079 contigs. We updated gene structure annotations of Brachypodium genes based on full-length cDNA sequences in comparison with the latest publicly available annotations. About 10,000 non-redundant gene models were supported by full-length cDNAs; ca. 6,000 showed some transcription unit modifications. We also found ca. 580 novel gene models, including 362 newly identified in Bd21. Using the updated transcription start sites, we searched a total of 580 plant cis-motifs in the -3 kb promoter regions and determined a genome-wide Brachypodium promoter architecture. Furthermore, we integrated the Brachypodium full-length cDNAs and updated gene structures with available sequence resources in wheat and barley in a web-accessible database, the RIKEN Brachypodium FL cDNA database. The database represents a "one-stop" information resource for all genomic information in the Pooideae, facilitating functional analysis of genes in this model grass plant and seamless knowledge transfer to the Triticeae crops.

  1. Identification of genes that regulate phosphate acquisition and plant performance during arbuscular my corrhizal symbiosis in medicago truncatula and brachypodium distachyon

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Maria J [Boyce Thompson Institute, Ithaca, NY (United States); Hudson, Matthew E [Univ. of Illinois, Champaign, IL (United States)

    2015-11-24

    Most vascular flowering plants have the ability to form symbiotic associations with arbuscular mycorrhizal (AM) fungi. The symbiosis develops in the roots and can have a profound effect on plant productivity, largely through improvements in plant mineral nutrition. Within the root cortical cells, the plant and fungus create novel interfaces specialized for nutrient transfer, while the fungus also develops a network of hyphae in the rhizosphere. Through this hyphal network, the fungus acquires and delivers phosphate and nitrogen to the root. In return, the plant provides the fungus with carbon. In addition, to enhancing plant mineral nutrition, the AM symbiosis has an important role in the carbon cycle, and positive effects on soil health. Here we identified and characterized plant genes involved in the regulation and functioning of the AM symbiosis in Medicago truncatula and Brachypodium distachyon. This included the identification and and characterization of a M. truncatula transcription factors that are required for symbiosis. Additionally, we investigated the molecular basis of functional diversity among AM symbioses in B. distachyon and analysed the transcriptome of Brachypodium distachyon during symbiosis.

  2. In silico sequence analysis and homology modeling of predicted beta-amylase 7-like protein in Brachypodium distachyon L.

    Directory of Open Access Journals (Sweden)

    ERTUĞRUL FILIZ

    2014-04-01

    Full Text Available Beta-amylase (β-amylase, EC 3.2.1.2 is an enzyme that catalyses hydrolysis of glucosidic bonds in polysaccharides. In this study, we analyzed protein sequence of predicted beta-amylase 7-like protein in Brachypodium distachyon. pI (isoelectric point value was found as 5.23 in acidic character, while the instability index (II was found as 50.28 with accepted unstable protein. The prediction of subcellular localization was revealed that the protein may reside in chloroplast by using CELLO v.2.5. The 3D structure of protein was performed using comparative homology modeling with SWISS-MODEL. The accuracy of the predicted 3D structure was checked using Ramachandran plot analysis showed that 95.4% in favored region. The results of our study contribute to understanding of β-amylase protein structure in grass species and will be scientific base for 3D modeling of beta-amylase proteins in further studies.

  3. Integrative proteome analysis of Brachypodium distachyon roots and leaves reveals a synergetic responsive network under H2O2 stress.

    Science.gov (United States)

    Bian, Yan-Wei; Lv, Dong-Wen; Cheng, Zhi-Wei; Gu, Ai-Qin; Cao, Hui; Yan, Yue-Ming

    2015-10-14

    The plant oxidative stress response is vital for defense against various abiotic and biotic stresses. In this study, ultrastructural changes and the proteomic response to H2O2 stress in roots and leaves of the model plant Brachypodium distachyon were studied. Transmission electron microscopy (TEM) showed that the ultrastructural damage in roots was more serious than in leaves. Particularly, the ultrastructures of organelles and the nucleus in root tip cells were damaged, leading to the inhibition of normal biological activities of roots, which then spread throughout the plant. Based on two-dimensional electrophoresis (2-DE) and MALDI-TOF/TOF-MS, 84 and 53 differentially accumulated protein (DAP) spots representing 75 and 45 unique proteins responsive to H2O2 stress in roots and leaves, respectively, were identified. These protein species were mainly involved in signal transduction, energy metabolism, redox homeostasis/stress defense, protein folding/degradation, and cell wall/cell structure. Interestingly, two 14-3-3 proteins (GF14-B and GF14-D) were identified as DAPs in both roots and leaves. Protein-protein interaction (PPI) analysis revealed a synergetic H2O2-responsive network.

  4. Analysis of two heterologous flowering genes in ¤Brachypodium distachyon¤ demonstrates its potential as a grass model plant

    DEFF Research Database (Denmark)

    Olsen, P.; Lenk, I.; Jensen, Christian S.;

    2006-01-01

    date up to 10 weeks in plants of the T, generation. Furthermore, a positive correlation between Terminal Flower 1 expression level and delay in heading date was apparent for most of the lines. The short life cycle and fast transformation system of B. distachyon allowed heading date analyses in the T-1......Despite the great contribution of model organisms, such as Arabidopsis and rice to understand biological processes in plants, these models are less valuable for functional studies of particular genes from temperate grass crop species. Therefore a new model plant is required, displaying features...... including close phylogenetic relationship to the temperate grasses, vernalisation requirement, high transformation efficiency, small genome size and a rapid life cycle. These requirements are all fulfilled by the small annual grass Brachypodium distachyon. As a first step towards implementing this plant as...

  5. Evaluation of the use of the polyubiquitin genes, Ubi4 and Ubi10 as reference genes for expression studies in Brachypodium distachyon.

    Directory of Open Access Journals (Sweden)

    John P Chambers

    Full Text Available BACKGROUND: Brachypodium distachyon is emerging as the model plant for temperate grass research and the genome of the community line Bd21 has been sequenced. Additionally, techniques have been developed for Agrobacterium-mediated transformation for the generation of T-DNA insertional lines. Recently, it was reported that expression of the polyubiquitin genes, Ubi4 and Ubi10 are stable in different tissues and growth hormone-treated plant samples, leading to the conclusion that both Ubi4 and Ubi10 are good reference genes for normalization of gene expression data using real-time, quantitative PCR (qPCR. PRINCIPAL FINDINGS: Mining of the Joint Genome Institute (JGI 8X Brachypodium distachyon genome assembly showed that Ubi4 and Ubi10 share a high level of sequence identity (89%, and in silico analyses of the sequences of Ubi4 (Bradi3g04730 and Ubi10 (Bradi1g32860 showed that the primers used previously exhibit multiple binding sites within the coding sequences arising from the presence of tandem repeats of the coding regions. This can potentially result in over-estimation of steady-state levels of Ubi4 and Ubi10. Additionally, due to the high level of sequence identity between both genes, primers used previously for amplification of Ubi4 can bind to Ubi10 and vice versa, resulting in the formation of non-specific amplification products. CONCLUSIONS: The results from this study indicate that the primers used previously were not sufficiently robust and specific. Additionally, their use would result in over-estimation of the steady-state expression levels of Ubi4. Our results question the validity of using the previously proposed primer sets for qPCR amplification of Ubi4 and Ubi10. We demonstrate that primers designed to target the 3'-UTRs of Ubi4 and Ubi10 are better suited for real-time normalization of steady-state expression levels in Brachypodium distachyon.

  6. High-Throughput Sequencing Reveals H2O2 Stress-Associated MicroRNAs and a Potential Regulatory Network in Brachypodium distachyon Seedlings

    Science.gov (United States)

    Lv, Dong-Wen; Zhen, Shoumin; Zhu, Geng-Rui; Bian, Yan-Wei; Chen, Guan-Xing; Han, Cai-Xia; Yu, Zi-Tong; Yan, Yue-Ming

    2016-01-01

    Oxidative stress in plants can be triggered by many environmental stress factors, such as drought and salinity. Brachypodium distachyon is a model organism for the study of biofuel plants and crops, such as wheat. Although recent studies have found many oxidative stress response-related proteins, the mechanism of microRNA (miRNA)-mediated oxidative stress response is still unclear. Using next generation high-throughput sequencing technology, the small RNAs were sequenced from the model plant B. distachyon 21 (Bd21) under H2O2 stress and normal growth conditions. In total, 144 known B. distachyon miRNAs and 221 potential new miRNAs were identified. Further analysis of potential new miRNAs suggested that 36 could be clustered into known miRNA families, while the remaining 185 were identified as B. distachyon-specific new miRNAs. Differential analysis of miRNAs from the normal and H2O2 stress libraries identified 31 known and 30 new H2O2 stress responsive miRNAs. The expression patterns of seven representative miRNAs were verified by reverse transcription quantitative polymerase chain reaction (RT-qPCR) analysis, which produced results consistent with those of the deep sequencing method. Moreover, we also performed RT-qPCR analysis to verify the expression levels of 13 target genes and the cleavage site of 5 target genes by known or novel miRNAs were validated experimentally by 5′ RACE. Additionally, a miRNA-mediated gene regulatory network for H2O2 stress response was constructed. Our study identifies a set of H2O2-responsive miRNAs and their target genes and reveals the mechanism of oxidative stress response and defense at the post-transcriptional regulatory level.

  7. Phylogeny in defining model plants for lignocellulosic ethanol production: a comparative study of Brachypodium distachyon, wheat, maize, and Miscanthus x giganteus leaf and stem biomass.

    Directory of Open Access Journals (Sweden)

    Till Meineke

    Full Text Available The production of ethanol from pretreated plant biomass during fermentation is a strategy to mitigate climate change by substituting fossil fuels. However, biomass conversion is mainly limited by the recalcitrant nature of the plant cell wall. To overcome recalcitrance, the optimization of the plant cell wall for subsequent processing is a promising approach. Based on their phylogenetic proximity to existing and emerging energy crops, model plants have been proposed to study bioenergy-related cell wall biochemistry. One example is Brachypodium distachyon, which has been considered as a general model plant for cell wall analysis in grasses. To test whether relative phylogenetic proximity would be sufficient to qualify as a model plant not only for cell wall composition but also for the complete process leading to bioethanol production, we compared the processing of leaf and stem biomass from the C3 grasses B. distachyon and Triticum aestivum (wheat with the C4 grasses Zea mays (maize and Miscanthus x giganteus, a perennial energy crop. Lambda scanning with a confocal laser-scanning microscope allowed a rapid qualitative analysis of biomass saccharification. A maximum of 108-117 mg ethanol·g(-1 dry biomass was yielded from thermo-chemically and enzymatically pretreated stem biomass of the tested plant species. Principal component analysis revealed that a relatively strong correlation between similarities in lignocellulosic ethanol production and phylogenetic relation was only given for stem and leaf biomass of the two tested C4 grasses. Our results suggest that suitability of B. distachyon as a model plant for biomass conversion of energy crops has to be specifically tested based on applied processing parameters and biomass tissue type.

  8. Arabidopsis and Brachypodium distachyon transgenic plants expressing Aspergillus nidulans acetylesterases have decreased degree of polysaccharide acetylation and increased resistance to pathogens.

    Science.gov (United States)

    Pogorelko, Gennady; Lionetti, Vincenzo; Fursova, Oksana; Sundaram, Raman M; Qi, Mingsheng; Whitham, Steven A; Bogdanove, Adam J; Bellincampi, Daniela; Zabotina, Olga A

    2013-05-01

    The plant cell wall has many significant structural and physiological roles, but the contributions of the various components to these roles remain unclear. Modification of cell wall properties can affect key agronomic traits such as disease resistance and plant growth. The plant cell wall is composed of diverse polysaccharides often decorated with methyl, acetyl, and feruloyl groups linked to the sugar subunits. In this study, we examined the effect of perturbing cell wall acetylation by making transgenic Arabidopsis (Arabidopsis thaliana) and Brachypodium (Brachypodium distachyon) plants expressing hemicellulose- and pectin-specific fungal acetylesterases. All transgenic plants carried highly expressed active Aspergillus nidulans acetylesterases localized to the apoplast and had significant reduction of cell wall acetylation compared with wild-type plants. Partial deacetylation of polysaccharides caused compensatory up-regulation of three known acetyltransferases and increased polysaccharide accessibility to glycosyl hydrolases. Transgenic plants showed increased resistance to the fungal pathogens Botrytis cinerea and Bipolaris sorokiniana but not to the bacterial pathogens Pseudomonas syringae and Xanthomonas oryzae. These results demonstrate a role, in both monocot and dicot plants, of hemicellulose and pectin acetylation in plant defense against fungal pathogens.

  9. Mannans and endo-β-mannanases (MAN) in Brachypodium distachyon: expression profiling and possible role of the BdMAN genes during coleorhiza-limited seed germination.

    Science.gov (United States)

    González-Calle, Virginia; Barrero-Sicilia, Cristina; Carbonero, Pilar; Iglesias-Fernández, Raquel

    2015-07-01

    Immunolocalization of mannans in the seeds of Brachypodium distachyon reveals the presence of these polysaccharides in the root embryo and in the coleorhiza in the early stages of germination (12h), decreasing thereafter to the point of being hardly detected at 27h. Concurrently, the activity of endo-β-mannanases (MANs; EC 3.2.1.78) that catalyse the hydrolysis of β-1,4 bonds in mannan polymers, increases as germination progresses. The MAN gene family is represented by six members in the Brachypodium genome, and their expression has been explored in different organs and especially in germinating seeds. Transcripts of BdMAN2, BdMAN4 and BdMAN6 accumulate in embryos, with a maximum at 24-30h, and are detected in the coleorhiza and in the root by in situ hybridization analyses, before root protrusion (germination sensu stricto). BdMAN4 is not only present in the embryo root and coleorhiza, but is abundant in the de-embryonated (endosperm) imbibed seeds, while BdMAN2 and BdMAN6 are faintly expressed in endosperm during post-germination (36-42h). BdMAN4 and BdMAN6 transcripts are detected in the aleurone layer. These data indicate that BdMAN2, BdMAN4 and BdMAN6 are important for germination sensu stricto and that BdMAN4 and BdMAN6 may also influence reserve mobilization. Whether the coleorhiza in monocots and the micropylar endosperm in eudicots have similar functions, is discussed.

  10. Characterization of Phosphate Transporters BdPT4 and BdPT8 in Mycorrhizal and Non-Mychorrhizal Brachypodium distachyon

    DEFF Research Database (Denmark)

    Clausen, Signe Sandbech

    drain of plant carbon. The aim of this thesis was to explore the alternative hypothesis that such growth depressions are caused by Pi limitation under conditions where a repressed direct Pi uptake in AM plants is not fully compensated by the AM-mediated Pi uptake. The hypothesized relationship between P...... limitation and growth depression was investigated by manipulation of the transcript levels of BdPT4 and BdPT8, two putative direct Brachypodium distachyon phosphate transporters (BdPT). Using a reverse genetic transformation approach, over-expression (OE) lines and knock-down (RNAi) lines of each BdPT gene...... be involved in uptake of Pi via the AM pathway, which correlates with the slightly decreased AM-mediated uptake in BdPT4-RNAi plants. Since mitigation of AM-related growth depression was not achieved by OE of the assumed direct uptake pathway transporter genes BdPT4 and BdPT8, the alternative hypothesis...

  11. Análisis de la diversidad genética en una colección de poblaciones españolas de "Brachypodium distachyon" como material de base para la mejora y aplicaciones biotecnológica

    OpenAIRE

    Hammami, Rifka

    2011-01-01

    Contiene: Tesis doctoral. No contiene los 4 ficheros Excel (Matrices), en CD-ROM En este trabajo se ha llevado a cabo la evaluación de la diversidad genética que encierra una colección de 23 poblaciones naturales de Brachypodium distachyon recogidas en diversas regiones de la Península Ibérica. Se ha utilizado como referencia dos líneas domesticadas y comercializadas. Esta especie presenta variabilidad en el número de cromosomas por lo que el primer objetivo fue el de caracterizar la const...

  12. Genome-Wide Identification, Evolution, and Co-expression Network Analysis of Mitogen-Activated Protein Kinase Kinase Kinases in Brachypodium distachyon

    Science.gov (United States)

    Feng, Kewei; Liu, Fuyan; Zou, Jinwei; Xing, Guangwei; Deng, Pingchuan; Song, Weining; Tong, Wei; Nie, Xiaojun

    2016-01-01

    Mitogen-activated protein kinase (MAPK) cascades are the conserved and universal signal transduction modules in all eukaryotes, which play the vital roles in plant growth, development, and in response to multiple stresses. In this study, we used bioinformatics methods to identify 86 MAPKKK protein encoded by 73 MAPKKK genes in Brachypodium. Phylogenetic analysis of MAPKKK family from Arabidopsis, rice, and Brachypodium has classified them into three subfamilies, of which 28 belonged to MEKK, 52 to Raf, and 6 to ZIK subfamily, respectively. Conserved protein motif, exon-intron organization, and splicing intron phase in kinase domains supported the evolutionary relationships inferred from the phylogenetic analysis. And gene duplication analysis suggested the chromosomal segment duplication happened before the divergence of the rice and Brachypodium, while all of three tandem duplicated gene pairs happened after their divergence. We further demonstrated that the MAPKKKs have evolved under strong purifying selection, implying the conservation of them. The splicing transcripts expression analysis showed that the splicesome translating longest protein tended to be adopted. Furthermore, the expression analysis of BdMAPKKKs in different organs and development stages as well as heat, virus and drought stresses revealed that the MAPKKK genes were involved in various signaling pathways. And the circadian analysis suggested there were 41 MAPKKK genes in Brachypodium showing cycled expression in at least one condition, of which seven MAPKKK genes expressed in all conditions and the promoter analysis indicated these genes possessed many cis-acting regulatory elements involved in circadian and light response. Finally, the co-expression network of MAPK, MAPKK, and MAPKKK in Brachypodium was constructed using 144 microarray and RNA-seq datasets, and ten potential MAPK cascades pathway were predicted. To conclude, our study provided the important information for evolutionary and

  13. Pushing the boundaries of resistance: insights from Brachypodium-rust interactions

    Directory of Open Access Journals (Sweden)

    Melania eFigueroa

    2015-07-01

    Full Text Available The implications of global population growth urge transformation of current food and bioenergy production systems to sustainability. Members of the family Poaceae are of particular importance both in food security and for their applications as biofuel substrates. For centuries, rust fungi have threatened the production of valuable crops such as wheat, barley, oat and other small grains; similarly, biofuel crops can also be susceptible to these pathogens. Emerging rust pathogenic races with increased virulence and recurrent rust epidemics around the world point out the vulnerability of monocultures. Basic research in plant immunity, especially in model plants, can make contributions to understanding plant resistance mechanisms and improve disease management strategies. The development of the grass Brachypodium distachyon as a genetically tractable model for monocots, especially temperate cereals and grasses, offers the possibility to overcome the experimental challenges presented by the genetic and genomic complexities of economically valuable crop plants. The numerous resources and tools available in Brachypodium have opened new doors to investigate the underlying molecular and genetic bases of plant-microbe interactions in grasses and evidence demonstrating the applicability and advantages of working with B. distachyon is increasing. Importantly, several interactions between B. distachyon and devastating plant pathogens, such rust fungi, have been examined in the context of non-host resistance. Here, we discuss the use of B. distachyon in these various pathosystems. Exploiting B. distachyon to understand the mechanisms underpinning disease resistance to non-adapted rust fungi may provide effective and durable approaches to fend off these pathogens. The close phylogenetic relationship among Brachypodium spp. and grasses with industrial and agronomic value support harnessing this model plant to improve cropping systems and encourage its use in

  14. Pushing the boundaries of resistance: insights from Brachypodium-rust interactions.

    Science.gov (United States)

    Figueroa, Melania; Castell-Miller, Claudia V; Li, Feng; Hulbert, Scot H; Bradeen, James M

    2015-01-01

    The implications of global population growth urge transformation of current food and bioenergy production systems to sustainability. Members of the family Poaceae are of particular importance both in food security and for their applications as biofuel substrates. For centuries, rust fungi have threatened the production of valuable crops such as wheat, barley, oat, and other small grains; similarly, biofuel crops can also be susceptible to these pathogens. Emerging rust pathogenic races with increased virulence and recurrent rust epidemics around the world point out the vulnerability of monocultures. Basic research in plant immunity, especially in model plants, can make contributions to understanding plant resistance mechanisms and improve disease management strategies. The development of the grass Brachypodium distachyon as a genetically tractable model for monocots, especially temperate cereals and grasses, offers the possibility to overcome the experimental challenges presented by the genetic and genomic complexities of economically valuable crop plants. The numerous resources and tools available in Brachypodium have opened new doors to investigate the underlying molecular and genetic bases of plant-microbe interactions in grasses and evidence demonstrating the applicability and advantages of working with B. distachyon is increasing. Importantly, several interactions between B. distachyon and devastating plant pathogens, such rust fungi, have been examined in the context of non-host resistance. Here, we discuss the use of B. distachyon in these various pathosystems. Exploiting B. distachyon to understand the mechanisms underpinning disease resistance to non-adapted rust fungi may provide effective and durable approaches to fend off these pathogens. The close phylogenetic relationship among Brachypodium spp. and grasses with industrial and agronomic value support harnessing this model plant to improve cropping systems and encourage its use in translational

  15. Variation in Adult Plant Phenotypes and Partitioning among Seed and Stem-Borne Roots across Brachypodium distachyon Accessions to Exploit in Breeding Cereals for Well-Watered and Drought Environments.

    Science.gov (United States)

    Chochois, Vincent; Vogel, John P; Rebetzke, Gregory J; Watt, Michelle

    2015-07-01

    Seedling roots enable plant establishment. Their small phenotypes are measured routinely. Adult root systems are relevant to yield and efficiency, but phenotyping is challenging. Root length exceeds the volume of most pots. Field studies measure partial adult root systems through coring or use seedling roots as adult surrogates. Here, we phenotyped 79 diverse lines of the small grass model Brachypodium distachyon to adults in 50-cm-long tubes of soil with irrigation; a subset of 16 lines was droughted. Variation was large (total biomass, ×8; total root length [TRL], ×10; and root mass ratio, ×6), repeatable, and attributable to genetic factors (heritabilities ranged from approximately 50% for root growth to 82% for partitioning phenotypes). Lines were dissected into seed-borne tissues (stem and primary seminal axile roots) and stem-borne tissues (tillers and coleoptile and leaf node axile roots) plus branch roots. All lines developed one seminal root that varied, with branch roots, from 31% to 90% of TRL in the well-watered condition. With drought, 100% of TRL was seminal, regardless of line because nodal roots were almost always inhibited in drying topsoil. Irrigation stimulated nodal roots depending on genotype. Shoot size and tillers correlated positively with roots with irrigation, but partitioning depended on genotype and was plastic with drought. Adult root systems of B. distachyon have genetic variation to exploit to increase cereal yields through genes associated with partitioning among roots and their responsiveness to irrigation. Whole-plant phenotypes could enhance gain for droughted environments because root and shoot traits are coselected.

  16. Genome-wide Identification and Analysis of WRKY Gene Family Members from Brachypodium distachyon%二穗短柄草WRKY基因家族成员的鉴定和分析

    Institute of Scientific and Technical Information of China (English)

    蒋明; 尹龙飞; 张志仙; 余沁欣; 罗礼礼

    2012-01-01

    WRKY转录因子以基因家族形式存在,在植物生长、发育和逆境反应中起着重要作用。二穗短柄草是大麦、小麦和禾本科牧草的模式植物,为了给基因表达和功能鉴定奠定基础,本研究利用生物信息学方法鉴定和分析其WRKY转录因子。结果表明,二穗短柄草有76个WRKY基因,它们具有0~6个内含子,编码区全长396~2 847 bp,基因分布在5条染色体上;进化分析结果表明,二穗短柄草WRKY在系统发生树上聚为3组,分属于I、II和III类转录因子;核心序列除WRKYGQK外,还有WKKYGQK、WRKYGKK、WRKY-GEK、WRKYGQT和WKKYGPK等多种变异类型;锌指模体也存在多种变异,它们是C-X4-C-X21-H-X1-H、C-X3-C-X22-H-X1-H、C-X7-C-X28-H-X1-C、C-X7-C-X24-H-X1-C、C-X7-C-X26-H-X1-C、C-X6-C-X24-H-X1-C、C-X7-C-X33-H-X1-C、C-X6-C-X32-H-X1-C和C-X7-C-X32-H-X1-C。%WRKY transcription factors belong to a gene family,and play important roles in plant growth,development as well as stress responses.Brachypodium distachyonacts as a model plant for Hordeum vulgare,Triticum aestivum and Gramineae grasses.To provide a basis for gene expression and functional characterization of genes,bioinformatic techniques were performed to identify WRKY transcription factors.Results indicated that there were 76 WRKY genes in B.distachyon with 0~6 introns.The coding sequences were 396~2 847 bp in length,and the genes distributed in 5 different chromosomes.Phylogenetic analysis revealed that the WRKYs were clustered into 3 groups and they belonged to I,II and III transcription factors,respectively.Besides WRKYGQK,several core sequence variants as WKKYGQK,WRKYGKK,WRKYGEK,WRKYGQT and WKKYGPK were identified.Mutations in zinc finger motifs were also observed,the variants included C-X4-C-X21-H-X1-H,C-X3-C-X22-H-X1-H,C-X7-C-X28-H-X1-C,C-X7-C-X24-H-X1-C,C-X7-C-X26-H-X1-C,C-X6-C-X24-H-X1-C,C-X7-C-X33-H-X1-C,C-X6-C-X32-H-X1-C and C-X7-C-X32-H-X1-C.

  17. Reconstructing the Evolution of Brachypodium Genomes Using Comparative Chromosome Painting.

    Directory of Open Access Journals (Sweden)

    Alexander Betekhtin

    Full Text Available Brachypodium distachyon is a model for the temperate cereals and grasses and has a biology, genomics infrastructure and cytogenetic platform fit for purpose. It is a member of a genus with fewer than 20 species, which have different genome sizes, basic chromosome numbers and ploidy levels. The phylogeny and interspecific relationships of this group have not to date been resolved by sequence comparisons and karyotypical studies. The aims of this study are not only to reconstruct the evolution of Brachypodium karyotypes to resolve the phylogeny, but also to highlight the mechanisms that shape the evolution of grass genomes. This was achieved through the use of comparative chromosome painting (CCP which hybridises fluorescent, chromosome-specific probes derived from B. distachyon to homoeologous meiotic chromosomes of its close relatives. The study included five diploids (B. distachyon 2n = 10, B. sylvaticum 2n = 18, B. pinnatum 2n = 16; 2n = 18, B. arbuscula 2n = 18 and B. stacei 2n = 20 three allotetraploids (B. pinnatum 2n = 28, B. phoenicoides 2n = 28 and B. hybridum 2n = 30, and two species of unknown ploidy (B. retusum 2n = 38 and B. mexicanum 2n = 40. On the basis of the patterns of hybridisation and incorporating published data, we propose two alternative, but similar, models of karyotype evolution in the genus Brachypodium. According to the first model, the extant genome of B. distachyon derives from B. mexicanum or B. stacei by several rounds of descending dysploidy, and the other diploids evolve from B. distachyon via ascending dysploidy. The allotetraploids arise by interspecific hybridisation and chromosome doubling between B. distachyon and other diploids. The second model differs from the first insofar as it incorporates an intermediate 2n = 18 species between the B. mexicanum or B. stacei progenitors and the dysploidic B. distachyon.

  18. Orthology between genomes of Brachypodium, wheat and rice

    Directory of Open Access Journals (Sweden)

    Balyan Harindra S

    2009-05-01

    Full Text Available Abstract Background In the past, rice genome served as a good model for studies involving comparative genomics of grass species. More recently, however, Brachypodium distachyon genome has emerged as a better model system for genomes of temperate cereals including wheat. During the present study, Brachypodium EST contigs were utilized to resolve orthologous relationships among the genomes of Brachypodium, wheat and rice. Findings Comparative sequence analysis of 3,818 Brachypodium EST (bEST contigs and 3,792 physically mapped wheat EST (wEST contigs revealed that as many as 449 bEST contigs were orthologous to 1,154 wEST loci that were bin-mapped on all the 21 wheat chromosomes. Similarly 743 bEST contigs were orthologous to specific rice genome sequences distributed on all the 12 rice chromosomes. As many as 183 bEST contigs were orthologous to both wheat and rice genome sequences, which harbored as many as 17 SSRs conserved across the three species. Primers developed for 12 of these 17 conserved SSRs were used for a wet-lab experiment, which resolved relatively high level of conservation among the genomes of Brachypodium, wheat and rice. Conclusion The present study confirmed that Brachypodium is a better model than rice for analysis of the genomes of temperate cereals like wheat and barley. The whole genome sequence of Brachypodium, which should become available in the near future, will further facilitate greatly the studies involving comparative genomics of cereals.

  19. 以色列二穗短柄草休眠及遗传多样性分析%Seed Dormancy and Genetic Diversity of Brachypodium distachyon from Israel

    Institute of Scientific and Technical Information of China (English)

    黄青; 薛文韬; 严俊; 赵钢; 程剑平

    2015-01-01

    [Objective]To estimate the seed dormancy and its genetic diversity of B .distachyon in Israel,B .distachyon of 13 genotypes from different areas of Israel were tested for their dormancy depth and EST-SSR diversity.[Method]In the dormancy measurements,the maximum germina-tion rate (Gmax )was measured and the equation of Gmax dynamic was fitted.The fragments ampli-fied by SSR were separated by PEGA gel with develop method of silver staining.[Results]A-mong the 13 genotypes,seed dormancy of EG5 was the deepest but the seeds of Ko12 and SB2 germinated faster compared to the others.The cluster results of SSR amplified fragments showed that there was similar genetic structure between Bd and Sha4 population.[Conclusion]Large differences were found in seed dormancy among the different genotypes in Israel.The genotype from Shlomi of north area of Israel was related to the B .distachyon populations from Turkey.%【目的】为探讨以色列地区二穗短柄草的休眠及其遗传多样性,对来自以色列不同地区的13个基因型二穗短柄草进行籽粒休眠深度和 EST-SSR 标记遗传位点多态性分析。【方法】休眠深度分别测定籽粒在40℃高温不同贮藏时间下的最大发芽率(Gmax ),并对其 Gmax 进行动态方程拟合;SSR 标记的扩增片段采用 PEGA 凝胶电泳分离并用银染法进行显影。【结果】13个基因型中,EG5休眠最深,而基因型 Ko12和 SB2休眠较浅。SSR 标记扩增片段的聚类分析中,Sha4与 Bd 群体的基因型遗传结构较类似。【结论】以色列不同地区籽粒休眠深度差异较大;北部Shlomi 地区的基因型与土耳其地区的二穗短柄草有较近的亲缘关系。

  20. Genome-Wide Analysis of miRNA targets in Brachypodium and Biomass Energy Crops

    Energy Technology Data Exchange (ETDEWEB)

    Green, Pamela J. [Univ. of Delaware, Newark, DE (United States)

    2015-08-11

    MicroRNAs (miRNAs) contribute to the control of numerous biological processes through the regulation of specific target mRNAs. Although the identities of these targets are essential to elucidate miRNA function, the targets are much more difficult to identify than the small RNAs themselves. Before this work, we pioneered the genome-wide identification of the targets of Arabidopsis miRNAs using an approach called PARE (German et al., Nature Biotech. 2008; Nature Protocols, 2009). Under this project, we applied PARE to Brachypodium distachyon (Brachypodium), a model plant in the Poaceae family, which includes the major food grain and bioenergy crops. Through in-depth global analysis and examination of specific examples, this research greatly expanded our knowledge of miRNAs and target RNAs of Brachypodium. New regulation in response to environmental stress or tissue type was found, and many new miRNAs were discovered. More than 260 targets of new and known miRNAs with PARE sequences at the precise sites of miRNA-guided cleavage were identified and characterized. Combining PARE data with the small RNA data also identified the miRNAs responsible for initiating approximately 500 phased loci, including one of the novel miRNAs. PARE analysis also revealed that differentially expressed miRNAs in the same family guide specific target RNA cleavage in a correspondingly tissue-preferential manner. The project included generation of small RNA and PARE resources for bioenergy crops, to facilitate ongoing discovery of conserved miRNA-target RNA regulation. By associating specific miRNA-target RNA pairs with known physiological functions, the research provides insights about gene regulation in different tissues and in response to environmental stress. This, and release of new PARE and small RNA data sets should contribute basic knowledge to enhance breeding and may suggest new strategies for improvement of biomass energy crops.

  1. The Brachypodium-Puccinia graminis system: Solving a puzzle to uncover the underlying mechanisms of non-host resistance and plant immunity

    Science.gov (United States)

    Brachypodium distachyon is regarded as non-host to the causal agent of stem rust in wheat and barley, P. graminis f. sp. tritici (Pgt), and a near-host to the pathogens of forage grasses, P. graminis f. sp. lolii (Pgl) and P. graminis f. sp. phlei-pratensis (Pgp). Given the devastating effect of ste...

  2. Genome Sequencing and Analysis of the Model Grass Brachypodium Distachyon.

    Science.gov (United States)

    Three subfamilies of grasses, the Ehrhartoideae (rice), the Panicoideae (maize, sorghum, sugar cane and millet), and the Pooideae (wheat, barley and cool season forage grasses) provide the basis of human nutrition and are poised to become major sources of renewable energy. Here we describe the compl...

  3. Deep sequencing of Brachypodium small RNAs at the global genome level identifies microRNAs involved in cold stress response

    Directory of Open Access Journals (Sweden)

    Chong Kang

    2009-09-01

    Full Text Available Abstract Background MicroRNAs (miRNAs are endogenous small RNAs having large-scale regulatory effects on plant development and stress responses. Extensive studies of miRNAs have only been performed in a few model plants. Although miRNAs are proved to be involved in plant cold stress responses, little is known for winter-habit monocots. Brachypodium distachyon, with close evolutionary relationship to cool-season cereals, has recently emerged as a novel model plant. There are few reports of Brachypodium miRNAs. Results High-throughput sequencing and whole-genome-wide data mining led to the identification of 27 conserved miRNAs, as well as 129 predicted miRNAs in Brachypodium. For multiple-member conserved miRNA families, their sizes in Brachypodium were much smaller than those in rice and Populus. The genome organization of miR395 family in Brachypodium was quite different from that in rice. The expression of 3 conserved miRNAs and 25 predicted miRNAs showed significant changes in response to cold stress. Among these miRNAs, some were cold-induced and some were cold-suppressed, but all the conserved miRNAs were up-regulated under cold stress condition. Conclusion Our results suggest that Brachypodium miRNAs are composed of a set of conserved miRNAs and a large proportion of non-conserved miRNAs with low expression levels. Both kinds of miRNAs were involved in cold stress response, but all the conserved miRNAs were up-regulated, implying an important role for cold-induced miRNAs. The different size and genome organization of miRNA families in Brachypodium and rice suggest that the frequency of duplication events or the selection pressure on duplicated miRNAs are different between these two closely related plant species.

  4. Transcriptome-wide Analysis Of Vernalization Reveals Conserved and Species-specific Mechanisms in Brachypodium

    Institute of Scientific and Technical Information of China (English)

    Qing Huan; Zhiwei Mao; Jingyu Zhang; Yunyuan Xu; Kang Chong

    2013-01-01

    Several temperate cereals need vernalization to promote flowering.Little,however,is known about the vernalization-memory-related genes,and almost no comparative analysis has been performed.Here,RNA-Seq was used for transcriptome analysis in non-vernalized,vernalized and post-vernalized Brachypodium distachyon (L.) Beauv.seedlings.In total,the expression of 1,665 genes showed significant changes (fold change ≥4) in response to vernalization.Among them,674 putative vernalization-memory-related genes with a constant response to vernalization were significantly enriched in transcriptional regulation and monooxygenase-mediated biological processes.Comparative analysis of vernalization-memory-related genes with barley demonstrated that the oxidative-stress response was the most conserved pathway between these two plant species.Moreover,Brachypodium preferred to regulate transcription and protein phosphorylation processes,while vernalization-memory-related genes,whose products are cytoplasmic membrane-bound-vesicle-located proteins,were preferred to be regulated in barley.Correlation analysis of the vernalization-related genes with barley revealed that the vernalization mechanism was conserved between these two plant species.In summary,vernalization,including its memory mechanism,is conserved between Brachypodium and barley,although several species-specific features also exist.The data reported here will provide primary resources for subsequent functional research in vernalization.

  5. Accelerated rates of protein evolution in barley grain and pistil biased genes might be legacy of domestication.

    Science.gov (United States)

    Shi, Tao; Dimitrov, Ivan; Zhang, Yinling; Tax, Frans E; Yi, Jing; Gou, Xiaoping; Li, Jia

    2015-10-01

    Traits related to grain and reproductive organs in grass crops have been under continuous directional selection during domestication. Barley is one of the oldest domesticated crops in human history. Thus genes associated with the grain and reproductive organs in barley may show evidence of dramatic evolutionary change. To understand how artificial selection contributes to protein evolution of biased genes in different barley organs, we used Digital Gene Expression analysis of six barley organs (grain, pistil, anther, leaf, stem and root) to identify genes with biased expression in specific organs. Pairwise comparisons of orthologs between barley and Brachypodium distachyon, as well as between highland and lowland barley cultivars mutually indicated that grain and pistil biased genes show relatively higher protein evolutionary rates compared with the median of all orthologs and other organ biased genes. Lineage-specific protein evolutionary rates estimation showed similar patterns with elevated protein evolution in barley grain and pistil biased genes, yet protein sequences generally evolve much faster in the lowland barley cultivar. Further functional annotations revealed that some of these grain and pistil biased genes with rapid protein evolution are related to nutrient biosynthesis and cell cycle/division. Our analyses provide insights into how domestication differentially shaped the evolution of genes specific to different organs of a crop species, and implications for future functional studies of domestication genes.

  6. The Effects of High Steady State Auxin Levels on Root Cell Elongation in Brachypodium.

    Science.gov (United States)

    Pacheco-Villalobos, David; Díaz-Moreno, Sara M; van der Schuren, Alja; Tamaki, Takayuki; Kang, Yeon Hee; Gujas, Bojan; Novak, Ondrej; Jaspert, Nina; Li, Zhenni; Wolf, Sebastian; Oecking, Claudia; Ljung, Karin; Bulone, Vincent; Hardtke, Christian S

    2016-05-01

    The long-standing Acid Growth Theory of plant cell elongation posits that auxin promotes cell elongation by stimulating cell wall acidification and thus expansin action. To date, the paucity of pertinent genetic materials has precluded thorough analysis of the importance of this concept in roots. The recent isolation of mutants of the model grass species Brachypodium distachyon with dramatically enhanced root cell elongation due to increased cellular auxin levels has allowed us to address this question. We found that the primary transcriptomic effect associated with elevated steady state auxin concentration in elongating root cells is upregulation of cell wall remodeling factors, notably expansins, while plant hormone signaling pathways maintain remarkable homeostasis. These changes are specifically accompanied by reduced cell wall arabinogalactan complexity but not by increased proton excretion. On the contrary, we observed a tendency for decreased rather than increased proton extrusion from root elongation zones with higher cellular auxin levels. Moreover, similar to Brachypodium, root cell elongation is, in general, robustly buffered against external pH fluctuation in Arabidopsis thaliana However, forced acidification through artificial proton pump activation inhibits root cell elongation. Thus, the interplay between auxin, proton pump activation, and expansin action may be more flexible in roots than in shoots. PMID:27169463

  7. The Effects of High Steady State Auxin Levels on Root Cell Elongation in Brachypodium[OPEN

    Science.gov (United States)

    Pacheco-Villalobos, David; Tamaki, Takayuki; Gujas, Bojan; Jaspert, Nina; Oecking, Claudia; Bulone, Vincent; Hardtke, Christian S.

    2016-01-01

    The long-standing Acid Growth Theory of plant cell elongation posits that auxin promotes cell elongation by stimulating cell wall acidification and thus expansin action. To date, the paucity of pertinent genetic materials has precluded thorough analysis of the importance of this concept in roots. The recent isolation of mutants of the model grass species Brachypodium distachyon with dramatically enhanced root cell elongation due to increased cellular auxin levels has allowed us to address this question. We found that the primary transcriptomic effect associated with elevated steady state auxin concentration in elongating root cells is upregulation of cell wall remodeling factors, notably expansins, while plant hormone signaling pathways maintain remarkable homeostasis. These changes are specifically accompanied by reduced cell wall arabinogalactan complexity but not by increased proton excretion. On the contrary, we observed a tendency for decreased rather than increased proton extrusion from root elongation zones with higher cellular auxin levels. Moreover, similar to Brachypodium, root cell elongation is, in general, robustly buffered against external pH fluctuation in Arabidopsis thaliana. However, forced acidification through artificial proton pump activation inhibits root cell elongation. Thus, the interplay between auxin, proton pump activation, and expansin action may be more flexible in roots than in shoots. PMID:27169463

  8. Range of cell-wall alterations enhance saccharification in Brachypodium distachyon mutants

    DEFF Research Database (Denmark)

    Marriott, Poppy E; Sibout, Richard; Lapierre, Catherine;

    2014-01-01

    Lignocellulosic plant biomass is an attractive feedstock for the production of sustainable biofuels, but the commercialization of such products is hampered by the high costs of processing this material into fermentable sugars (saccharification). One approach to lowering these costs is to produce ...

  9. Natural genetic variation in water-use efficiency and responses to soil drying in Brachypodium distachyon

    Science.gov (United States)

    All plants must optimize their growth with finite resources. Water use efficiency (WUE) measures the relationship between biomass acquisition and transpired water. In the present study, we performed two experiments to understand the genetic basis of WUE and other parameters of plant-water interact...

  10. Molecular genetic investigations of root gravitropism and other complex growth behaviors using Arabidopsis and Brachypodium as models

    Science.gov (United States)

    Masson, Patrick; Barker, Richard; Miller, Nathan; Su, Shih-Hao; Su, Shih-Heng

    2016-07-01

    When growing on hard surfaces, Arabidopsis roots tend to grown downward, as dictated by positive gravitropism. At the same time, surface-derived stimuli promote a wavy pattern of growth that is superimposed to a rightward root-skewing trend. This behavior is believed to facilitate obstacle avoidance in soil. To better understand these complex behaviors, we have isolated and characterized mutations that affect them. Some of these mutations were shown to affect gravitropism whereas others did not. Within the latter group, most of the mutations affected mechanisms that control anisotropic cell expansion. We have also characterized mutations that affect early steps of gravity signal transduction within the gravity-sensing columella cells of the root cap. Upon reorientation within the gravity field, starch-filled plastids sediment to the bottom-side of these cells, triggering a pathway that leads to re-localization of auxin efflux facilitators to the bottom membrane. Lateral auxin transport toward the bottom flank ensues, leading to gravitropic curvature. Several of the mutations we characterized affect genes that encode proteins associated with the vesicle trafficking pathway needed for this cell polarization. Other mutations were shown to affect components of the plastid outer envelope protein import complex (TOC). Their functional analysis suggests an active role for plastids in gravity signal transduction, beyond a simple contribution as sedimenting gravity susceptors. Because most cultivated crops are monocots, not dicots like Arabidopsis, we have also initiated studies of root-growth behavior with Brachypodium distachyon. When responding to a gravistimulus, the roots of Brachypodium seedlings develop a strong downward curvature that proceeds until the tip reaches a ~50-degree curvature. At that time, an oscillatory tip movement occurs while the root continues its downward reorientation. These root-tip oscillations also occur if roots are allowed to simply grow

  11. Protein (Viridiplantae): 357121016 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available EDICTED: major pollen allergen Hol l 1-like Brachypodium distachyon MASSSSTSTLLLAAAILATLASSSFKPRMNLRDQHQTTNG...VIIQTYLLYKHPSHINNTAQHREKTKPQPTKMASSSSSTLLLAASILATLASSAHGIPKVPPGPNITATYGDKWLDAKSTW

  12. Protein (Viridiplantae): 357158162 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available EDICTED: L-ascorbate oxidase-like Brachypodium distachyon MELLGANPRLLCCLFLCFFSSLAMSQAKTVHEKWDISYHFKSPDCVRKLA...HYGMQRSAGLNGMIIVSPAEPEPFSYDGEHDVFLNDWWHKSTYEQAAGLASVPIEWVGEPKSLLINGRGRFNCSALAASGGAAAACNATSPDCAVQVFAVVPGRTYRF

  13. Protein (Viridiplantae): 357118651 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 15368:1608 PREDICTED: uncharacterized protein LOC100826717 Brachypodium distachyon MGACVSRPSACVGKPNTPRSGDAARAGGARRRRRRGKGRRTAPSRAASM...ETIQEAEGSVSPSAAAASASGDCRTYSNPAFQVTGSLEEAWYDSFAISESDGEDDF

  14. Protein (Viridiplantae): 357159140 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 2 PREDICTED: thiosulfate sulfurtransferase, chloroplastic-like Brachypodium distachyon MATADNKEQAILPMVDADEARALLSSGHGYLDARMPEDFDKGHAPG...ARNIPYYVYVAPGQGREKNPHFEQEVAALYGKEDHLIVGCFTGTRSKLATSDLLKAGFKNVRNLQGGYRAFLQSASQQQPVNDQQPSAN ...

  15. Update on the genomics and basic biology of Brachypodium

    DEFF Research Database (Denmark)

    Catalan, Pilar; Chalhoub, Boulos; Chochois, Vincent;

    2014-01-01

    , abiotic and biotic stress, comparative genomics, natural diversity, and cell walls) demonstrates that the Brachypodium research community has achieved a critical mass of tools and has transitioned from resource development to addressing biological questions, particularly those unique to grasses...

  16. A Brachypodium UDP-Glycosyltransferase Confers Root Tolerance to Deoxynivalenol and Resistance to Fusarium Infection.

    Science.gov (United States)

    Pasquet, Jean-Claude; Changenet, Valentin; Macadré, Catherine; Boex-Fontvieille, Edouard; Soulhat, Camille; Bouchabké-Coussa, Oumaya; Dalmais, Marion; Atanasova-Pénichon, Vessela; Bendahmane, Abdelhafid; Saindrenan, Patrick; Dufresne, Marie

    2016-09-01

    Fusarium head blight (FHB) is a cereal disease caused by Fusarium graminearum, a fungus able to produce type B trichothecenes on cereals, including deoxynivalenol (DON), which is harmful for humans and animals. Resistance to FHB is quantitative, and the mechanisms underlying resistance are poorly understood. Resistance has been related to the ability to conjugate DON into a glucosylated form, deoxynivalenol-3-O-glucose (D3G), by secondary metabolism UDP-glucosyltransferases (UGTs). However, functional analyses have never been performed within a single host species. Here, using the model cereal species Brachypodium distachyon, we show that the Bradi5g03300 UGT converts DON into D3G in planta. We present evidence that a mutation in Bradi5g03300 increases root sensitivity to DON and the susceptibility of spikes to F. graminearum, while overexpression confers increased root tolerance to the mycotoxin and spike resistance to the fungus. The dynamics of expression and conjugation suggest that the speed of DON conjugation rather than the increase of D3G per se is a critical factor explaining the higher resistance of the overexpressing lines. A detached glumes assay showed that overexpression but not mutation of the Bradi5g03300 gene alters primary infection by F. graminearum, highlighting the involvement of DON in early steps of infection. Together, these results indicate that early and efficient UGT-mediated conjugation of DON is necessary and sufficient to establish resistance to primary infection by F. graminearum and highlight a novel strategy to promote FHB resistance in cereals. PMID:27378816

  17. Imaging with the fluorogenic dye Basic Fuchsin reveals subcellular patterning and ecotype variation of lignification in Brachypodium distachyon

    OpenAIRE

    Kapp, Nikki; Barnes, William J.; Richard, Tom L.; Anderson, Charles T.

    2015-01-01

    Lignin is a complex polyphenolic heteropolymer that is abundant in the secondary cell walls of plants and functions in growth and defence. It is also a major barrier to the deconstruction of plant biomass for bioenergy production, but the spatiotemporal details of how lignin is deposited in actively lignifying tissues and the precise relationships between wall lignification in different cell types and developmental events, such as flowering, are incompletely understood. Here, the lignin-detec...

  18. Cell wall composition and digestibility alterations in Brachypodium distachyon achieved through reduced expression of the UDP-arabinopyranose mutase

    Science.gov (United States)

    Nucleotide-activated sugars are essential substrates for plant cell wall carbohydrate-polymer biosynthetic glycosyltransferase enzymes. The most prevalent sugars in grass cell walls include glucose (Glc), xylose (Xyl), and arabinose (Ara). These sugars are biosynthetically related via the uridine di...

  19. Using the Model Perennial Grass Brachypodium sylvaticum to Engineer Resistance to Multiple Abiotic Stresses

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, Sean; Reguera, Maria; Sade, Nir; Cartwright, Amy; Tobias, Christian; Thilmony, Roger; Blumwald, Eduardo; Vogel, John

    2015-03-20

    We are using the perennial model grass Brachypodium sylvaticum to identify combinations of transgenes that enhance tolerance to multiple, simultaneous abiotic stresses. The most successful transgene combinations will ultimately be used to create improved switchgrass (Panicum virgatum L.) cultivars. To further develop B. sylvaticum as a perennial model grass, and facilitate our planned transcriptional profiling, we are sequencing and annotating the genome. We have generated ~40x genome coverage using PacBio sequencing of the largest possible size selected libraries (18, 22, 25 kb). Our initial assembly using only long-read sequence contained 320 Mb of sequence with an N50 contig length of 315 kb and an N95 contig length of 40 kb. This assembly consists of 2,430 contigs, the largest of which was 1.6 Mb. The estimated genome size based on c-values is 340 Mb indicating that about 20 Mb of presumably repetitive DNA remains yet unassembled. Significantly, this assembly is far superior to an assembly created from paired-end short-read sequence, ~100x genome coverage. The short-read-only assembly contained only 226 Mb of sequence in 19k contigs. To aid the assembly of the scaffolds into chromosome-scale assemblies we produced an F2 mapping population and have genotyped 480 individuals using a genotype by sequence approach. One of the reasons for using B. sylvaticum as a model system is to determine if the transgenes adversely affect perenniality and winter hardiness. Toward this goal, we examined the freezing tolerance of wild type B. sylvaticum lines to determine the optimal conditions for testing the freezing tolerance of the transgenics. A survey of seven accessions noted significant natural variation in freezing tolerance. Seedling or adult Ain-1 plants, the line used for transformation, survived an 8 hour challenge down to -6 oC and 50% survived a challenge down to -9 oC. Thus, we will be able to easily determine if the transgenes compromise freezing tolerance. In the

  20. Structure and Dynamics of Brachypodium Primary Cell Wall Polysaccharides from Two-Dimensional 13C Solid-State Nuclear Magnetic Resonance Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tuo [Ames Lab., Ames, IA (United States); Salazar, Andre [Iowa State Univ., Ames, IA (United States); Zabotina, Olga A. [Iowa State Univ., Ames, IA (United States); Hong, Mei [Ames Lab., Ames, IA (United States)

    2014-04-10

    The polysaccharide structure and dynamics in the primary cell wall of the model grass Brachypodium distachyon are investigated for the first time using solid-state nuclear magnetic resonance (NMR). While both grass and non-grass cell walls contain cellulose as the main structural scaffold, the former contains xylan with arabinose and glucuronic acid substitutions as the main hemicellulose, with a small amount of xyloglucan (XyG) and pectins, while the latter contains XyG as the main hemicellulose and significant amounts of pectins. We labeled the Brachypodium cell wall with 13C to allow two-dimensional (2D) 13C correlation NMR experiments under magic-angle spinning. Well-resolved 2D spectra are obtained in which the 13C signals of cellulose, glucuronoarabinoxylan (GAX), and other matrix polysaccharides can be assigned. The assigned 13C chemical shifts indicate that there are a large number of arabinose and xylose linkages in the wall, and GAX is significantly branched at the developmental stage of 2 weeks. 2D 13C–13C correlation spectra measured with long spin diffusion mixing times indicate that the branched GAX approaches cellulose microfibrils on the nanometer scale, contrary to the conventional model in which only unbranched GAX can bind cellulose. The GAX chains are highly dynamic, with average order parameters of 0.4. Biexponential 13C T1 and 1H T relaxation indicates that there are two dynamically distinct domains in GAX: the more rigid domain may be responsible for cross-linking cellulose microfibrils, while the more mobile domain may fill the interfibrillar space. This dynamic heterogeneity is more pronounced than that of the non-grass hemicellulose, XyG, suggesting that GAX adopts the mixed characteristics of XyG and pectins. Moderate differences in cellulose rigidity are observed between the Brachypodium and Arabidopsis cell walls

  1. Brachypodium sylvaticum, a model for perennial grasses: transformation and inbred line development.

    Directory of Open Access Journals (Sweden)

    Michael A Steinwand

    Full Text Available Perennial species offer significant advantages as crops including reduced soil erosion, lower energy inputs after the first year, deeper root systems that access more soil moisture, and decreased fertilizer inputs due to the remobilization of nutrients at the end of the growing season. These advantages are particularly relevant for emerging biomass crops and it is projected that perennial grasses will be among the most important dedicated biomass crops. The advantages offered by perennial crops could also prove favorable for incorporation into annual grain crops like wheat, rice, sorghum and barley, especially under the dryer and more variable climate conditions projected for many grain-producing regions. Thus, it would be useful to have a perennial model system to test biotechnological approaches to crop improvement and for fundamental research. The perennial grass Brachypodiumsylvaticum is a candidate for such a model because it is diploid, has a small genome, is self-fertile, has a modest stature, and short generation time. Its close relationship to the annual model Brachypodiumdistachyon will facilitate comparative studies and allow researchers to leverage the resources developed for B. distachyon. Here we report on the development of two keystone resources that are essential for a model plant: high-efficiency transformation and inbred lines. Using Agrobacterium tumefaciens-mediated transformation we achieved an average transformation efficiency of 67%. We also surveyed the genetic diversity of 19 accessions from the National Plant Germplasm System using SSR markers and created 15 inbred lines.

  2. Brachypodium sylvaticum, a model for perennial grasses: transformation and inbred line development.

    Science.gov (United States)

    Steinwand, Michael A; Young, Hugh A; Bragg, Jennifer N; Tobias, Christian M; Vogel, John P

    2013-01-01

    Perennial species offer significant advantages as crops including reduced soil erosion, lower energy inputs after the first year, deeper root systems that access more soil moisture, and decreased fertilizer inputs due to the remobilization of nutrients at the end of the growing season. These advantages are particularly relevant for emerging biomass crops and it is projected that perennial grasses will be among the most important dedicated biomass crops. The advantages offered by perennial crops could also prove favorable for incorporation into annual grain crops like wheat, rice, sorghum and barley, especially under the dryer and more variable climate conditions projected for many grain-producing regions. Thus, it would be useful to have a perennial model system to test biotechnological approaches to crop improvement and for fundamental research. The perennial grass Brachypodiumsylvaticum is a candidate for such a model because it is diploid, has a small genome, is self-fertile, has a modest stature, and short generation time. Its close relationship to the annual model Brachypodiumdistachyon will facilitate comparative studies and allow researchers to leverage the resources developed for B. distachyon. Here we report on the development of two keystone resources that are essential for a model plant: high-efficiency transformation and inbred lines. Using Agrobacterium tumefaciens-mediated transformation we achieved an average transformation efficiency of 67%. We also surveyed the genetic diversity of 19 accessions from the National Plant Germplasm System using SSR markers and created 15 inbred lines. PMID:24073248

  3. Protein (Viridiplantae): 357120817 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 7:3537 15368:3537 PREDICTED: uncharacterized protein LOC100824467 Brachypodium distachyon MGAMTMASSSLALRPRASASSSSPPSRPPHDAAALPARRRPAT...ENTLRRLSASVEPDRRPAAAETTSAMRLYSVAPYPLLLAALLPGAEPVASAFAPFV

  4. Protein (Viridiplantae): 357168562 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available TED: LOW QUALITY PROTEIN: dihydroflavonol-4-reductase-like, partial Brachypodium distachyon KVGADHDTRITPMSSE...LIYVIKGGPNAISDMSWHIVDVHDVADALLLVYEKPELSGRYICAPNXISTKVVLELLKKTYPDYNYVMCKVGADHDTRITPISSKKLRNLGWKPRKLEETLLDSVEYCXETGILQDVEGRAYRLPNVFLFFHAIEE ...

  5. Protein (Viridiplantae): 357112535 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 368:1152 PREDICTED: putative calmodulin-like protein 6-like Brachypodium distachyon MCPGGRYAGLDIPAGAGAADLRPAFDVLDADHD...GRISREDLKSFYAKAGAHEPFDDDDIAAMIAAADADHDGFVQYDEFEGLLGRAAATGTAGGCRSAMEDAFRLMDRDGDGKVGFEDLKAYLGWAGMPVADDEIRAMIGMAGDVDGGVGLEAFARVLAVDLDGIL ...

  6. Dicty_cDB: SHB481 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 5_075 Brachypodium distachyon developing spike EST library Brachypodium distachyon cDNA clone 5484_C09_E18, ...257_H11_P21, mRNA sequence. 42 7.6 1 DV474787 |DV474787.1 5484_C09_E18ZE5_075 Brachypodium distachyon developing

  7. Genetic structure and diversity of the selfing model grass Brachypodium stacei (Poaceae) in Western Mediterranean: out of the Iberian Peninsula and into the islands.

    Science.gov (United States)

    Shiposha, Valeriia; Catalán, Pilar; Olonova, Marina; Marques, Isabel

    2016-01-01

    Annual Mediterranean species of the genus Brachypodium are promising model plants for energy crops since their selfing nature and short-life cycles are an advantage in breeding programs. The false brome, B. distachyon, has already been sequenced and new genomic initiatives have triggered the de-novo genome sequencing of its close relatives such as B. stacei, a species that was until recently mistaken for B. distachyon. However, the success of these initiatives hinges on detailed knowledge about the distribution of genetic variation within and among populations for the effective use of germplasm in a breeding program. Understanding population genetic diversity and genetic structure is also an important prerequisite for designing effective experimental populations for genomic wide studies. However, population genetic data are still limited in B. stacei. We therefore selected and amplified 10 nuclear microsatellite markers to depict patterns of population structure and genetic variation among 181 individuals from 19 populations of B. stacei occurring in its predominant range, the western Mediterranean area: mainland Iberian Peninsula, continental Balearic Islands and oceanic Canary Islands. Our genetic results support the occurrence of a predominant selfing system with extremely high levels of homozygosity across the analyzed populations. Despite the low level of genetic variation found, two different genetic clusters were retrieved, one clustering all SE Iberian mainland populations and the island of Minorca and another one grouping all S Iberian mainland populations, the Canary Islands and all Majorcan populations except one that clustered with the former group. These results, together with a high sharing of alleles (89%) suggest different colonization routes from the mainland Iberian Peninsula into the islands. A recent colonization scenario could explain the relatively low levels of genetic diversity and low number of alleles found in the Canary Islands

  8. Factores transcripcionales de la clase DOF en Brachypodium distachyon: caracterización molecular de BdDOF24 durante la germinación de las semillas

    OpenAIRE

    González de la Calle, Virginia

    2014-01-01

    La semilla es el órgano que garantiza la propagación y continuidad evolutiva de las plantas espermatofitas y constituye un elemento indispensable en la alimentación humana y animal. La semilla de cereales acumula en el endospermo durante la maduración, mayoritariamente, almidón y proteínas de reserva. Estas reservas son hidrolizadas en la germinación por hidrolasas sintetizadas en la aleurona en respuesta a giberelinas (GA), siendo la principal fuente de energía hasta que la plántula emergent...

  9. Protein (Viridiplantae): 357167833 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available PREDICTED: C2 and GRAM domain-containing protein At5g50170-like Brachypodium distachyon MRLYVCVLEARGLPAPPHCAHGGCGCGAVYTRVKVGAQRARTRA...VELAGPGSAAAWNEEFVFPVGVEEEGDEVVEVGVARRLEGAGREVLGRVKLPVPAV

  10. Protein (Viridiplantae): 357120636 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 8 15368:3518 PREDICTED: fatty acyl-CoA reductase 2-like Brachypodium distachyon MGSSPCVNLSRAAARRPAAGRGFAHRRS...NPDVGKIYVVIKAKDSEAALQRLRNEVVDTELFRCLQEIHGKDYHSFVAAKLVPVVGDVREANIGIAPELADEIAERVDIIVNSAANTTFDERYDVAMDINTVGPFRIMSFAHR

  11. Protein (Viridiplantae): 357123379 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available :497 PREDICTED: BTB/POZ and MATH domain-containing protein 2-like Brachypodium distachyon MEKDCKSITNVARWVKLLKIDGYCAAKTMGNEDC...PSPEKSVSCIFNRSWISRCLEMCSPFVNEDCSLPVCLKSTGELAASGYLRNDSFTVQCTITVLKEDVPAARIPVKEVSVSSPSLQHHLAELLHNKTGTDVTFLVSGKS

  12. Genome-wide distribution and organization of microsatellites in plants: an insight into marker development in Brachypodium.

    Directory of Open Access Journals (Sweden)

    Humira Sonah

    Full Text Available Plant genomes are complex and contain large amounts of repetitive DNA including microsatellites that are distributed across entire genomes. Whole genome sequences of several monocot and dicot plants that are available in the public domain provide an opportunity to study the origin, distribution and evolution of microsatellites, and also facilitate the development of new molecular markers. In the present investigation, a genome-wide analysis of microsatellite distribution in monocots (Brachypodium, sorghum and rice and dicots (Arabidopsis, Medicago and Populus was performed. A total of 797,863 simple sequence repeats (SSRs were identified in the whole genome sequences of six plant species. Characterization of these SSRs revealed that mono-nucleotide repeats were the most abundant repeats, and that the frequency of repeats decreased with increase in motif length both in monocots and dicots. However, the frequency of SSRs was higher in dicots than in monocots both for nuclear and chloroplast genomes. Interestingly, GC-rich repeats were the dominant repeats only in monocots, with the majority of them being present in the coding region. These coding GC-rich repeats were found to be involved in different biological processes, predominantly binding activities. In addition, a set of 22,879 SSR markers that were validated by e-PCR were developed and mapped on different chromosomes in Brachypodium for the first time, with a frequency of 101 SSR markers per Mb. Experimental validation of 55 markers showed successful amplification of 80% SSR markers in 16 Brachypodium accessions. An online database 'BraMi' (Brachypodium microsatellite markers of these genome-wide SSR markers was developed and made available in the public domain. The observed differential patterns of SSR marker distribution would be useful for studying microsatellite evolution in a monocot-dicot system. SSR markers developed in this study would be helpful for genomic studies in Brachypodium

  13. Interstellar Grains

    OpenAIRE

    Draine, B. T.

    2000-01-01

    Our current understanding of interstellar dust is summarized at an introductory level. Submicron-sized interstellar dust grains absorb and scatter light, and reradiate the absorbed energy in the infrared. The grain population spans a range of sizes, from molecules containing only tens of atoms, to particles containing 10^{10} atoms. Most of the grain mass appears to be due to two types of solid, in approximately equal amounts: amorphous silicate mineral, and carbonaceous material. Approximate...

  14. Testing assumptions of the enemy release hypothesis: generalist versus specialist enemies of the grass Brachypodium sylvaticum.

    Science.gov (United States)

    Halbritter, Aud H; Carroll, George C; Güsewell, Sabine; Roy, Bitty A

    2012-01-01

    The enemy release hypothesis (ERH) suggests greater success of species in an invaded range due to release from natural enemies. The ERH assumes there will be more specialist enemies in the native range and that generalists will have an equal effect in both ranges. We tested these assumptions with the grass Brachypodium sylvaticum in the native range (Switzerland) and invaded range (Oregon, USA). We assessed all the kinds of damage present (caused by fungi, insects, mollusk and deer) on both leaves and seeds at 10 sites in each range and correlated damage with host fitness. Only two of the 20 fungi found on leaves were specialist pathogens, and these were more frequent in the native range. Conversely there was more insect herbivory on leaves in the invaded range. All fungi and insects found on seeds were generalists. More species of fungi were found on seeds in the native range, and a higher proportion of them were pathogenic than in the invaded range. There were more kinds of enemies in the native range, where the plants had lower fitness, in accordance with the ERH. However, contrary to assumptions of the ERH, generalists appear to be equally or more important than specialists in reducing host fitness.

  15. Population regulation by enemies of the grass Brachypodium sylvaticum: demography in native and invaded ranges.

    Science.gov (United States)

    Roy, Bitty A; Coulson, Tim; Blaser, Wilma; Policha, Tobias; Stewart, Julie L; Blaisdell, G Kai; Güsewell, Sabine

    2011-03-01

    The enemy-release hypothesis (ERH) states that species become more successful in their introduced range than in their native range because they leave behind natural enemies in their native range and are thus "released" from enemy pressures in their introduced range. The ERH is popularly cited to explain the invasive properties of many species and is the underpinning of biological control. We tested the prediction that plant populations are more strongly regulated by natural enemies (herbivores and pathogens) in their native range than in their introduced range with enemy-removal experiments using pesticides. These experiments were replicated at multiple sites in both the native and invaded ranges of the grass Brachypodium sylvaticum. In support of the ERH, enemies consistently regulated populations in the native range. There were more tillers and more seeds produced in treated vs. untreated plots in the native range, and few seedlings survived in the native range. Contrary to the ERH, total measured leaf damage was similar in both ranges, though the enemies that caused it differed. There was more damage by generalist mollusks and pathogens in the native range, and more damage by generalist insect herbivores in the invaded range. Demographic analysis showed that population growth rates were lower in the native range than in the invaded range, and that sexually produced seedlings constituted a smaller fraction of the total in the native range. Our removal experiment showed that enemies regulate plant populations in their native range and suggest that generalist enemies, not just specialists, are important for population regulation.

  16. Microbiota of kefir grains

    Directory of Open Access Journals (Sweden)

    Tomislav Pogačić

    2013-03-01

    Full Text Available Kefir grains represent the unique microbial community consisting of bacteria, yeasts, and sometimes filamentous moulds creating complex symbiotic community. The complexity of their physical and microbial structures is the reason that the kefir grains are still not unequivocally elucidated. Microbiota of kefir grains has been studied by many microbiological and molecular approaches. The development of metagenomics, based on the identification without cultivation, is opening new possibilities for identification of previously nonisolated and non-identified microbial species from the kefir grains. Considering recent studies, there are over 50 microbial species associated with kefir grains. The aim of this review is to summarise the microbiota composition of kefir grains. Moreover, because of technological and microbiological significance of the kefir grains, the paper provides an insight into the microbiological and molecular methods applied to study microbial biodiversity of kefir grains.

  17. Marketing Farm Grain Crops.

    Science.gov (United States)

    Ridenour, Harlan E.

    This vocational agriculture curriculum on grain marketing contains three parts: teacher guide, student manual, and student workbook. All three are coordinated and cross-referenced. The course is designed to give students of grain marketing a thorough background in the subject and provide practical help in developing grain marketing strategies for…

  18. Interstellar grains in elliptical galaxies grain evolution

    CERN Document Server

    Tsai, J C; Tsai, John C; Mathews, William G

    1995-01-01

    We consider the lifecycle of dust introduced into the hot interstellar medium in isolated elliptical galaxies. Dust grains are ejected into galactic-scale cooling flows in large ellipticals by normal mass loss from evolving red giants. Newly introduced dust rapidly enters the hot gas environment and is sputtered away by thermal collisions with ions. Before the grains are completely sputtered away, they emit prodigious amounts of infrared radiation which may contribute to the large far infrared luminosities observed in ellipticals. In order to study the global properties of grains in ellipticals we construct a new series of King-type galactic models which are consistent with the fundamental plane, galactic mass to light ratios and other relevant observational correlations. We describe a new ``continuity'' procedure to construct simple time-dependent gas dynamic models for cooling flows. In all galaxy models, although grains can flow a considerable distance from their radius of origin before being sputtered awa...

  19. GrainSpotter

    DEFF Research Database (Denmark)

    Schmidt, Søren

    2014-01-01

    A new approach for indexing multigrain diffraction data is presented. It is based on the use of a monochromatic beam simultaneously illuminating all grains. By operating in sub-volumes of Rodrigues space, a powerful vertex-finding algorithm can be applied, with a running time that is compatible...... with online analysis. The resulting program, GrainSpotter, is sufficiently fast to enable online analysis during synchrotron sessions. The program applies outlier rejection schemes, leading to more robust and accurate data. By simulations it is shown that several thousand grains can be retrieved. A new...... method to derive partial symmetries, called pseudo-twins, is introduced. Uniquely, GrainSpotter includes an analysis of pseudo-twins, which is shown to be critical to avoid erroneous grains resulting from the indexing....

  20. Syntenic relationships between the U and M genomes of Aegilops, wheat and the model species Brachypodium and rice as revealed by COS markers.

    Science.gov (United States)

    Molnár, István; Šimková, Hana; Leverington-Waite, Michelle; Goram, Richard; Cseh, András; Vrána, Jan; Farkas, András; Doležel, Jaroslav; Molnár-Láng, Márta; Griffiths, Simon

    2013-01-01

    Diploid Aegilops umbellulata and Ae. comosa and their natural allotetraploid hybrids Ae. biuncialis and Ae. geniculata are important wild gene sources for wheat. With the aim of assisting in alien gene transfer, this study provides gene-based conserved orthologous set (COS) markers for the U and M genome chromosomes. Out of the 140 markers tested on a series of wheat-Aegilops chromosome introgression lines and flow-sorted subgenomic chromosome fractions, 100 were assigned to Aegilops chromosomes and six and seven duplications were identified in the U and M genomes, respectively. The marker-specific EST sequences were BLAST-ed to Brachypodium and rice genomic sequences to investigate macrosyntenic relationships between the U and M genomes of Aegilops, wheat and the model species. Five syntenic regions of Brachypodium identified genome rearrangements differentiating the U genome from the M genome and from the D genome of wheat. All of them seem to have evolved at the diploid level and to have been modified differentially in the polyploid species Ae. biuncialis and Ae. geniculata. A certain level of wheat-Aegilops homology was detected for group 1, 2, 3 and 5 chromosomes, while a clearly rearranged structure was showed for the group 4, 6 and 7 Aegilops chromosomes relative to wheat. The conserved orthologous set markers assigned to Aegilops chromosomes promise to accelerate gene introgression by facilitating the identification of alien chromatin. The syntenic relationships between the Aegilops species, wheat and model species will facilitate the targeted development of new markers specific for U and M genomic regions and will contribute to the understanding of molecular processes related to allopolyploidization.

  1. Syntenic relationships between the U and M genomes of Aegilops, wheat and the model species Brachypodium and rice as revealed by COS markers.

    Directory of Open Access Journals (Sweden)

    István Molnár

    Full Text Available Diploid Aegilops umbellulata and Ae. comosa and their natural allotetraploid hybrids Ae. biuncialis and Ae. geniculata are important wild gene sources for wheat. With the aim of assisting in alien gene transfer, this study provides gene-based conserved orthologous set (COS markers for the U and M genome chromosomes. Out of the 140 markers tested on a series of wheat-Aegilops chromosome introgression lines and flow-sorted subgenomic chromosome fractions, 100 were assigned to Aegilops chromosomes and six and seven duplications were identified in the U and M genomes, respectively. The marker-specific EST sequences were BLAST-ed to Brachypodium and rice genomic sequences to investigate macrosyntenic relationships between the U and M genomes of Aegilops, wheat and the model species. Five syntenic regions of Brachypodium identified genome rearrangements differentiating the U genome from the M genome and from the D genome of wheat. All of them seem to have evolved at the diploid level and to have been modified differentially in the polyploid species Ae. biuncialis and Ae. geniculata. A certain level of wheat-Aegilops homology was detected for group 1, 2, 3 and 5 chromosomes, while a clearly rearranged structure was showed for the group 4, 6 and 7 Aegilops chromosomes relative to wheat. The conserved orthologous set markers assigned to Aegilops chromosomes promise to accelerate gene introgression by facilitating the identification of alien chromatin. The syntenic relationships between the Aegilops species, wheat and model species will facilitate the targeted development of new markers specific for U and M genomic regions and will contribute to the understanding of molecular processes related to allopolyploidization.

  2. Folding of Pollen Grains

    Science.gov (United States)

    Katifori, Eleni; Alben, Silas; Cerda, Enrique; Nelson, David; Dumais, Jacques

    2008-03-01

    At dehiscence, which occurs when the anther reaches maturity and opens, pollen grains dehydrate and their volume is reduced. The pollen wall deforms to accommodate the volume loss, and the deformation pathway depends on the initial turgid pollen grain geometry and the mechanical properties of the pollen wall. We demonstrate, using both experimental and theoretical approaches, that the design of the apertures (areas on the pollen wall where the stretching and the bending modulus are reduced) is critical for controlling the folding pattern, and ensures the pollen grain viability. An excellent fit to the experiments is obtained using a discretized version of the theory of thin elastic shells.

  3. Artabas of grain or artabas of grains?

    OpenAIRE

    Clarysse, Willy

    2014-01-01

    Survey of the use of the singular and plural with Greek words for grain. The original plural gives way to the singular in the course of the Hellenistic period, but the plural reappears in the later Roman period for barley, whereas wheat, for which σῖτος is then used rather than πυρός, occurs in the singular. There are, however, a number of exceptions to the general picture, often depending on the case in which the words occur.

  4. Fingering phenomena during grain-grain displacement

    Science.gov (United States)

    Mello, Nathália M. P.; Paiva, Humberto A.; Combe, G.; Atman, A. P. F.

    2016-05-01

    Spontaneous formation of fingered patterns during the displacement of dense granular assemblies was experimentally reported few years ago, in a radial Hele-Shaw cell. Here, by means of discrete element simulations, we have recovered the experimental findings and extended the original study to explore the control parameters space. In particular, using assemblies of grains with different geometries (monodisperse, bidisperse, or polydisperse), we measured the macroscopic stress tensor in the samples in order to confirm some conjectures proposed in analogy with Saffman-Taylor viscous fingering phenomena for immiscible fluids. Considering an axial setup which allows to control the discharge of grains and to follow the trajectory and the pressure gradient along the displacing interface, we have applied the Darcy law for laminar flow in fluids in order to measure an "effective viscosity" for each assembly combination, in an attempt to mimic variation of the viscosity ratio between the injected/displaced fluids in the Saffman-Taylor experiment. The results corroborate the analogy with the viscous fluids displacement, with the bidisperse assembly corresponding to the less viscous geometry. But, differently to fluid case, granular fingers only develop for a specific combination of displaced/injected geometries, and we have demonstrated that it is always related with the formation of a force chain network along the finger direction.

  5. Composite circumstellar dust grains

    Science.gov (United States)

    Gupta, Ranjan; Vaidya, Dipak B.; Dutta, Rajeshwari

    2016-10-01

    We calculate the absorption efficiencies of composite silicate grains with inclusions of graphite and silicon carbide in the spectral range 5-25 μm. We study the variation in absorption profiles with volume fractions of inclusions. In particular we study the variation in the wavelength of peak absorption at 10 and 18 μm. We also study the variation of the absorption of porous silicate grains. We use the absorption efficiencies to calculate the infrared flux at various dust temperatures and compare with the observed infrared emission flux from the circumstellar dust around some M-type and asymptotic giant branch stars obtained from IRAS and a few stars from Spitzer satellite. We interpret the observed data in terms of the circumstellar dust grain sizes, shape, composition and dust temperature.

  6. Composite Circumstellar Dust Grains

    CERN Document Server

    Gupta, Ranjan; Dutta, Rajeshwari

    2016-01-01

    We calculate the absorption efficiencies of composite silicate grains with inclusions of graphite and silicon carbide in the spectral range 5--25$\\rm \\mu m$. We study the variation in absorption profiles with volume fractions of inclusions. In particular we study the variation in the wavelength of peak absorption at 10 and 18$\\rm \\mu m$. We also study the variation of the absorption of porous silicate grains. We use the absorption efficiencies to calculate the infrared flux at various dust temperatures and compare with the observed infrared emission flux from the circumstellar dust around some M-Type \\& AGB stars obtained from IRAS and a few stars from Spitzer satellite. We interpret the observed data in terms of the circumstellar dust grain sizes; shape; composition and dust temperature.

  7. Grain Boundary Segregation in Metals

    CERN Document Server

    Lejcek, Pavel

    2010-01-01

    Grain boundaries are important structural components of polycrystalline materials used in the vast majority of technical applications. Because grain boundaries form a continuous network throughout such materials, their properties may limit their practical use. One of the serious phenomena which evoke these limitations is the grain boundary segregation of impurities. It results in the loss of grain boundary cohesion and consequently, in brittle fracture of the materials. The current book deals with fundamentals of grain boundary segregation in metallic materials and its relationship to the grain boundary structure, classification and other materials properties.

  8. Grain Marketing Tools: A Survey of Illinois Grain Elevators

    OpenAIRE

    Whitacre, Rick C.; Spaulding, Aslihan D.

    2007-01-01

    As with most sectors of the agriculture economy, the U. S. country grain elevator industry has experienced considerable consolidation and concentration. By the same token, the country elevator's customer base (grain producers and landlords) has also changed rather dramatically as grain production takes place on larger and fewer farms. The profitability of operating a country elevator is directly related to the volume of grain the country elevator purchases over the course of a marketing year....

  9. Grain alcohol study: summary

    Energy Technology Data Exchange (ETDEWEB)

    The study has concentrated upon a detailed examination of all considerations involved in the production, use, and marketing of ethyl alcohol (Ethanol) as produced from the fermentation of agricultural grains. Each parameter was examined in the light of current energy markets and trends; new sources and technological, and processes for fermentation, the capability of the agricultural industry to support fermentaton demand; the optimization of value of agricultureal crops; and the efficiencies of combining related industries. Anhydrous (200 proof) ethanol makes an excellent blending component for all present automotive fuels and an excellent octane additive for unleaded fuels in proportions up to 35% without requiring modifications to current engines. There is no difference between ethanol produced by fermentation and ethanol produced synthetically from petroleum. The decision to produce ethanol one way or the other is purely economic. The agricultural industry can support a major expansion in the fermentation industry. The residue (distillers grains) from the fermentation of corn for ethanol is an excellent and economical feed for livestock and poultry. A reliable supply of distillers grains can assist in making the large beef feedlot operations more economically viable. The source materials, fuels, products and by-products of an ethanol plant, beef feedlot, gas biodigester plant, municipal waste recovery plant and a steam generated electrical plant are interrelated and mutually beneficial for energy efficiencies and economic gains when co-located. The study concludes that the establishment of such agricultural-environment industrial energy complexes, would provide a broad range of significant benefits to Indiana.

  10. Grain alcohol study: summary

    Energy Technology Data Exchange (ETDEWEB)

    The study has concentrated upon a detailed examination of all considerations involved in the production, use, and marketing of ethyl alcohol (ethanol) as produced from the fermentation of agricultural grains. Each parameter was examined in the light of current energy markets and trends; new sources and technological, and processes for fermentation, the capability of the agricultural industry to support fermentation demand; the optimizaton of value of agricultural crops; and the efficiencies of combining related industries. Ahydrous (200 proof) ethanol makes an excellent blending component for all present automotive fuels and an excellent octane additive for unleaded fuels in proportions up to 35% without requiring modifications to current engines. There is no difference between ethanol produced by fermentation and ethanol produced synthetically from petroleum. The decision to produce ethanol one way or the other is purely economic. The agricultural industry can support a major expansion in the fermentation industry. The residue (distillers grains) from the fermentation of corn for ethanol is an excellent and economical feed for livestock and poultry. A reliable supply of distillers grain can assist in making the large beef feedlot operations more economically viable. The source materials, fuels, products and by-products of an ethanol plant, beef feedlot, gas biodigester plant, municipal waste recovery plant and a steam generated electrical plant are interrelated and mutually beneficial for energy efficiencies and economic gains when co-located. The study concludes that the establishment of such agricultural- environment industrial energy complexes, would provide a broad range of significant benefits to Indiana.

  11. Clinical application of minimally invasive Brachypodium hip replacement in treatment of avascular necrosis of femoral head%微创短柄人工髋关节置换术治疗股骨头坏死的临床应用

    Institute of Scientific and Technical Information of China (English)

    张明辉; 李国军; 陈欣欣; 王晓

    2015-01-01

    目的::评价微创短柄人工髋关节置换术治疗股骨头坏死的临床效果。方法:对我院2008年3月~2010年3月23例无菌性股骨头坏死病人行微创短柄人工髋关节置换术治疗,术后进行临床结果分析和评价。结果:23例均获得随访,平均随访36个月,按照Harris[1]评分标准评分:优18,良4,可1,差0.优良率为95.6%。结论:保留了股骨颈的短柄人工髋关节置换术,更符合人体生物力学特点,术后并发症低,为中青年股骨头坏死患者的治疗提供了一个新方法。%Objective:To evaluate the clinical effect of minimally invasive Brachypodium hip replacement in the treatment of avascular necrosis of the femoral head. Methods:23 aseptic osteonecrosis cases were treated with Brachypodium hip replacement surgery from March 2008 to March 2010, and analysis and evaluate the operation outcomes. Results:All cases were followed up for an average 36 months, ac-cording to Harris[1] Grading rating:18 excellent, 4 good,1 ok, no poor, excellent rate 95. 6%. Conclusion:The minimally invasive Brachypodium hip arthroplasty could retain femoral neck, which conform to biomechanics, reduce postoperative complications. It might be a new approach for young patients with osteonecrosis.

  12. Economics of Grain Irradiation

    International Nuclear Information System (INIS)

    After three years, in which preliminary designs were prepared, a grain irradiation plant has been designed and is being built into an existing silo installation. From this experience actual costs of plant construction are available for a plant using cobalt-60 and this experience is incorporated in estimates for machine installations for high grain throughput. Costs are compared for plants of comparable complexity and they indicate those areas in which each type of plant is pre-eminently suitable and those areas where either type may be best, dependent upon local site conditions, the standard of local technology and methods of operation. The two plants compared are described in sufficient detail to enable the precise extent of the equipment supply covered by the costs to be appreciated. The accounting methods employed have been discussed with industrial accountants to ensure that they are acceptable to the potential users. The methods employed are explained so that they can be applied to problems of a similar nature. (author)

  13. COOPERATIVE MARKETING IN SPECIALTY GRAINS AND IDENTITY PRESERVED GRAIN MARKETS

    OpenAIRE

    Janzen, Edward L.; Wilson, William W.

    2002-01-01

    Marketing of specialty and identity preserved grains has become an important strategy in the grain marketing industry and is being driven, in part, by consumer and processor demand and an interest in non-GM products. This study provides background and practices of numerous organizations involved in marketing of specialty/identity preserved grains. Supporting marketing activities are reviewed. Key factors in the success (or failure) of their efforts are identified. Major challenges facing the ...

  14. Botanicals as Grain Protectants

    Directory of Open Access Journals (Sweden)

    Yallappa Rajashekar

    2012-01-01

    Full Text Available Prevention of food losses during postharvest storage is of paramount economic importance. Integrated pest management is now a widely accepted strategy in pest control including postharvest infestation control which involves the use of chemical (contact/residual insecticides along with fumigants. The use of synthetic chemical insecticides is either not permitted or used restrictively because of the residue problem and health risks to consumers. In view of the above, there is a need for plants that may provide potential alternatives to the currently used insect control agents as they constitute a rich source of bioactive molecules. Available literature indicates that plant could be source for new insecticides. Therefore, there is a great potential for a plant-derived insecticidal compounds. This paper focuses on the current state of the botanical insecticides as grain protectants and its mode of action.

  15. Grain charging in protoplanetary discs

    OpenAIRE

    Ilgner, Martin

    2011-01-01

    Recent work identified a growth barrier for dust coagulation that originates in the electric repulsion between colliding particles. Depending on its charge state, dust material may have the potential to control key processes towards planet formation such as MHD (magnetohydrodynamic) turbulence and grain growth which are coupled in a two-way process. We quantify the grain charging at different stages of disc evolution and differentiate between two very extreme cases: compact spherical grains a...

  16. Grain Flow at High Stresses

    Science.gov (United States)

    McSaveney, M. J.

    2015-12-01

    The transport mechanism of rapid long-runout rock avalanches was a hotly debated topic when I came on the scene in 1967. So how come it is still debated today? My explanation is that it is the expected outcome of peer review, poor comprehension, and technological advances outpacing intellectual advances. Why think about the problem when we can model it! So let us think about the problem. Shreve thought that rock avalanches fell upon and trapped a layer of air. What physics was he thinking about? It is how feathers and tissue papers fall. When my rock avalanches fly, they fly like unlubricated bricks using the physics of projectiles and ballistics. But the main transport mechanism is not flight. The dominant impression from watching a rock avalanche in motion is of fluid flow, as Heim described it in 1882. A rock avalanche is a very large grain flow. Bagnold studied dispersive grain flows, but why should one assume that rock avalanches are dispersive grain flows as many do. The more common grain flow type is a dense grain flow and rock avalanches are dense grain flows in which the weight can and does generate very high stresses at grain contacts. Brittle rock deforms elastically up to its compressive strength, whereupon it breaks, releasing elastic strain as transient elastic strain (seismic energy to a seismologist, acoustic energy to a physicist). Melosh and others have shown that acoustic energy can fluidize a grain mass. There is no exotic physics behind grain flow at high stress. When grains break, the released elastic strain has to go somewhere, and it goes somewhere principally by transmission though grain contacts. Depending on the state of stress at the grain contact, the contact will pass the stress or will slip at conventional values of Coulomb friction. Enough thinking! A physical model of the entire process is too big for any laboratory. So whose numerical model will do it?

  17. Ionizing radiation for insect control in grain and grain products

    International Nuclear Information System (INIS)

    A technical review summarizes and discusses information on various aspects of the use of ionizing radiation for the control of insect infestation in grains and grain products. Topics include: the effects of ionizing radiation on insects infesting stored-grain products; the 2 main types of irradiators (electron accelerators; radioisotopes (e.g.: Co-60; Cs-137); dosimetry systems and methodology; variations in radiation resistance by stored-product pests; the proper selection of radiation dose; the effects of combining various treatments (temperature, infrared/microwave radiation, hypoxia, chemicals) with ionizing radiation; sublethal radiation for controlling bulk grain insects; the feeding capacity of irradiated insects; the susceptibility of insecticide-resistant insects to ionizing radiation; and the possible resistance of insects to ionizing radiation. Practical aspects of removing insects from irradiated grain also are discussed

  18. The Perennial Ryegrass GenomeZipper – Targeted Use of Genome Resources for Comparative Grass Genomics

    DEFF Research Database (Denmark)

    Pfeiffer, Matthias; Martis, Mihaela; Asp, Torben;

    2013-01-01

    (Lolium perenne) genome on the basis of conserved synteny to barley (Hordeum vulgare) and the model grass genome Brachypodium (Brachypodium distachyon) as well as rice (Oryza sativa) and sorghum (Sorghum bicolor). A transcriptome-based genetic linkage map of perennial ryegrass served as a scaffold to...... assignment of 3,315 out of 8,876 previously unmapped genes to the respective chromosomes. In total, the GenomeZipper incorporates 4,035 conserved grass gene loci, which were used for the first genome-wide sequence divergence analysis between perennial ryegrass, barley, Brachypodium, rice, and sorghum. The...

  19. The Antinutritional Components of Grains

    DEFF Research Database (Denmark)

    Madsen, Claus Krogh; Brinch-Pedersen, Henrik

    2016-01-01

    Grains provide humans and farmed animals with a very large proportion of the energy and macro- and micronutrients they need. Unfortunately, grains also contain compounds that interfere with the utilization of the nutrients by animals. These so-called antinutritionals may result in poor resource...

  20. Coarse Grained Quantum Dynamics

    CERN Document Server

    Agon, Cesar; Kasko, Skyler; Lawrence, Albion

    2014-01-01

    We consider coarse graining a quantum system divided between short distance and long distance degrees of freedom, which are coupled by the Hamiltonian. Observations using purely long distance observables can be described by the reduced density matrix that arises from tracing out the short-distance observables. The dynamics of this density matrix is that of an open quantum system, and is nonlocal in time, on the order of some short time scale. We describe these dynamics in a model system with a simple hierarchy of energy gaps $\\Delta E_{UV} > \\Delta E_{IR}$, in which the coupling between high-and low-energy degrees of freedom is treated to second order in perturbation theory. We then describe the equations of motion under suitable time averaging, reflecting the limited time resolution of actual experiments, and find an expansion of the master equation in powers of $\\Delta E_{IR}/\\Delta E_{UV}$, in which the failure of the system to be Hamiltonian or even Markovian appears at higher orders in this ratio. We com...

  1. Urbanization and Grain Production Efficiency

    Institute of Scientific and Technical Information of China (English)

    Xiaoyang; LI; Dongge; LIU

    2015-01-01

    Based on DEA-Malmquist method,this paper calculated the integrated technology efficiency of grain production and total factor productivity and analyzed factors influencing the grain production technology efficiency using working documents of panel structure. Research results indicate that grain production integrated technology efficiency of China is relatively low,technology utilization level is low,and it remains at the stage of decreasing returns to scale,and the pure technology efficiency still has space to increase. Total factor productivity is declining and the total factor productivity of many provinces is relatively low. Since the total factor productivity of eastern areas is higher than central and western areas,it is required to strengthen technological support for grain production. The implementation of urbanization is helpful for promoting increase of grain production technology efficiency in central and eastern areas,but it will exert negative influence on western areas.

  2. Autonomous grain combine control system

    Science.gov (United States)

    Hoskinson, Reed L.; Kenney, Kevin L.; Lucas, James R.; Prickel, Marvin A.

    2013-06-25

    A system for controlling a grain combine having a rotor/cylinder, a sieve, a fan, a concave, a feeder, a header, an engine, and a control system. The feeder of the grain combine is engaged and the header is lowered. A separator loss target, engine load target, and a sieve loss target are selected. Grain is harvested with the lowered header passing the grain through the engaged feeder. Separator loss, sieve loss, engine load and ground speed of the grain combine are continuously monitored during the harvesting. If the monitored separator loss exceeds the selected separator loss target, the speed of the rotor/cylinder, the concave setting, the engine load target, or a combination thereof is adjusted. If the monitored sieve loss exceeds the selected sieve loss target, the speed of the fan, the size of the sieve openings, or the engine load target is adjusted.

  3. Methods of assessing grain-size distribution during grain growth

    DEFF Research Database (Denmark)

    Tweed, Cherry J.; Hansen, Niels; Ralph, Brian

    1985-01-01

    This paper considers methods of obtaining grain-size distributions and ways of describing them. In order to collect statistically useful amounts of data, an automatic image analyzer is used, and the resulting data are subjected to a series of tests that evaluate the differences between two related...... distributions (before and after grain growth). The distributions are measured from two-dimensional sections, and both the data and the corresponding true three-dimensional grain-size distributions (obtained by stereological analysis) are collected. The techniques described here are illustrated by reference to...

  4. Prevalence of IgE antibodies to grain and grain dust in grain elevator workers

    International Nuclear Information System (INIS)

    IgE-mediated allergic reactions have been postulated to contribute to respiratory reactions seen in workers exposed to grain dusts. In an attempt better to define the prevalence of IgE antibodies in workers exposed to grain dusts, we performed the radioallergosorbent test (RAST) on worker sera using both commercial allergens prepared from grain and worksite allergens prepared from grain dust samples collected at the worksite. We found that the two types of reagents identified different populations with respect to the specificity of IgE antibodies present. The RAST assay performed using worksite allergens correlated well with skin test procedures. These results may allow us to gain better understanding of allergy associated with grain dust exposure, and document the utility of the RAST assay in assessment of occupational allergies

  5. Protein (Viridiplantae): 357130727 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available ectional sugar transporter SWEET6a-like Brachypodium distachyon MTEQRFPQNGNTSVPAGNS...24:4295 3398:4295 4447:4380 4734:4380 38820:4380 4479:4380 359160:3487 147368:3422 147385:3422 15367:3422 15368:3422 PREDICTED: bidir

  6. Protein (Viridiplantae): 357135133 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available ectional sugar transporter SWEET2a-like Brachypodium distachyon MASLGLPGVSSYHDLCCYG...24:4295 3398:4295 4447:4380 4734:4380 38820:4380 4479:4380 359160:3487 147368:3422 147385:3422 15367:3422 15368:3422 PREDICTED: bidir

  7. Protein (Viridiplantae): 357168326 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 2 3398:112 4447:10886 4734:10886 38820:10886 4479:10886 359160:6892 147368:7145 147385:7145 15367:7145 15368:7145 PREDICTED: craniofa...cial development protein 2-like Brachypodium distachyon MKPKRISLGRNPLSDAPYRNPGVVSNG

  8. Protein (Viridiplantae): 357132051 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 15368:4872 PREDICTED: craniofacial development protein 1-like Brachypodium distachyon MASRSSASEAGGSGAKVVAAD...58024:4234 3398:4234 4447:6074 4734:6074 38820:6074 4479:6074 359160:4801 147368:4872 147385:4872 15367:4872

  9. Protein (Viridiplantae): 357112985 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 58024:7047 3398:7047 4447:4465 4734:4465 38820:4465 4479:4465 359160:2518 147368:2334 147385:2334 15367:2334... 15368:2334 PREDICTED: josephin-like protein-like Brachypodium distachyon MEPGAKSEANQNEEGSGAVGSSGGSSKVYHERQR

  10. Protein (Viridiplantae): 357126612 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 24:2780 3398:2780 4447:228 4734:228 38820:228 4479:228 359160:2357 147368:2136 147385:2136 15367:2136 15368:...2136 PREDICTED: random slug protein 5-like Brachypodium distachyon MGSSGGGDAGEGEWLKVAELRAMAEAQDPHVKEVDNMSLRR

  11. Protein (Viridiplantae): 357148126 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 5 15368:6125 PREDICTED: IMPACT family member in pol 5'region-like Brachypodium distachyon MAAVRVVTPRLRSIPLLL...8024:15552 3398:15552 4447:7995 4734:7995 38820:7995 4479:7995 359160:5958 147368:6125 147385:6125 15367:612

  12. Protein (Viridiplantae): 357134432 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 8024:5377 3398:5377 4447:5981 4734:5981 38820:5981 4479:5981 359160:5029 147368:5115 147385:5115 15367:5115 15368:5115 PREDICTED: bor...on transporter 4-like Brachypodium distachyon MEHKKTLFKGVIEDFRGRAACYKQDWHNGFSSGFRIL

  13. Protein (Viridiplantae): 357135844 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 8024:5377 3398:5377 4447:5981 4734:5981 38820:5981 4479:5981 359160:5029 147368:5115 147385:5115 15367:5115 15368:5115 PREDICTED: bor...on transporter 4-like Brachypodium distachyon MDLLRNPFKGVVADVKGRASWYKDDWVAGLRAGFRIL

  14. Protein (Viridiplantae): 357130643 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 121 3398:3121 4447:340 4734:340 38820:340 4479:340 359160:3145 147368:3033 147385:3033 15367:3033 15368:3033 PREDICTED: Werner Syndro...me-like exonuclease-like Brachypodium distachyon MATDTYVTDVTFEENVIITTVTSSGVAVEGWLRE

  15. Protein (Viridiplantae): 357120544 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 121 3398:3121 4447:340 4734:340 38820:340 4479:340 359160:3145 147368:3033 147385:3033 15367:3033 15368:3033 PREDICTED: Werner Syndro...me-like exonuclease-like Brachypodium distachyon MTTARYTVRFSSALIDTTVTSDAAAADEWARSVR

  16. Protein (Viridiplantae): 357130647 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

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  1. Quantitative characterisation of sedimentary grains

    Science.gov (United States)

    Tunwal, Mohit; Mulchrone, Kieran F.; Meere, Patrick A.

    2016-04-01

    Analysis of sedimentary texture helps in determining the formation, transportation and deposition processes of sedimentary rocks. Grain size analysis is traditionally quantitative, whereas grain shape analysis is largely qualitative. A semi-automated approach to quantitatively analyse shape and size of sand sized sedimentary grains is presented. Grain boundaries are manually traced from thin section microphotographs in the case of lithified samples and are automatically identified in the case of loose sediments. Shape and size paramters can then be estimated using a software package written on the Mathematica platform. While automated methodology already exists for loose sediment analysis, the available techniques for the case of lithified samples are limited to cases of high definition thin section microphotographs showing clear contrast between framework grains and matrix. Along with the size of grain, shape parameters such as roundness, angularity, circularity, irregularity and fractal dimension are measured. A new grain shape parameter developed using Fourier descriptors has also been developed. To test this new approach theoretical examples were analysed and produce high quality results supporting the accuracy of the algorithm. Furthermore sandstone samples from known aeolian and fluvial environments from the Dingle Basin, County Kerry, Ireland were collected and analysed. Modern loose sediments from glacial till from County Cork, Ireland and aeolian sediments from Rajasthan, India have also been collected and analysed. A graphical summary of the data is presented and allows for quantitative distinction between samples extracted from different sedimentary environments.

  2. Why Is It Important to Eat Grains, Especially Whole Grains?

    Science.gov (United States)

    ... Drink Matters Variety Amount Nutrition Other Ingredients Choosing Foods and Beverages Saturated, Unsaturated, and Trans Fats Sodium Added Sugars ... may reduce the risk of heart disease. Consuming foods containing fiber, ... weight management. Eating grain products fortified with folate before and ...

  3. Export Rebates on Grain Finished

    Institute of Scientific and Technical Information of China (English)

    Liu; Xinwen

    2008-01-01

      According to the State Statistics Bureau, China's consumer price index (CPI) jumped by 6.9 percent year-on-year last November, approaching the high levels seen at the end of 1996, one of the largest areas of increase was the price of grain,which rose by 6.6 percent. There is no doubt the growth in CPI can be mainly attributed to soaring food prices and the diffusion effect of oil price adjustments. Large orders for grain exports have put Chinese grain suppliers under tremendous pressure. In order to solve this problem, the Finance Ministry and State Administration of Taxation together announced that 84 categories of export tax rebates on major types of grain will be eliminated.……

  4. Export Rebates on Grain Finished

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ According to the State Statistics Bureau, China's consumer price index (CPI) jumped by 6.9 percent year-on-year last November, approaching the high levels seen at the end of 1996, one of the largest areas of increase was the price of grain,which rose by 6.6 percent. There is no doubt the growth in CPI can be mainly attributed to soaring food prices and the diffusion effect of oil price adjustments. Large orders for grain exports have put Chinese grain suppliers under tremendous pressure. In order to solve this problem, the Finance Ministry and State Administration of Taxation together announced that 84 categories of export tax rebates on major types of grain will be eliminated.

  5. MYCOTOXIN CONTROL DURING GRAIN PROCESSING.

    Science.gov (United States)

    Controlling mycotoxin formation by fungi growing in and on cereal grains involves a multifactorial approach for defining multiple variables. The scope includes varietial (maturity, date, GMO) selection, tillage (time, depth), planting (density, spacing), fertilizion (type, amount, timing), irrigati...

  6. Applied Thermodynamics: Grain Boundary Segregation

    OpenAIRE

    Pavel Lejček; Lei Zheng; Siegfried Hofmann; Mojmír Šob

    2014-01-01

    Chemical composition of interfaces—free surfaces and grain boundaries—is generally described by the Langmuir–McLean segregation isotherm controlled by Gibbs energy of segregation. Various components of the Gibbs energy of segregation, the standard and the excess ones as well as other thermodynamic state functions—enthalpy, entropy and volume—of interfacial segregation are derived and their physical meaning is elucidated. The importance of the thermodynamic state functions of grain boundary se...

  7. GRAIN BOUNDARIES IN POLYPHASE CERAMICS

    OpenAIRE

    Clarke, D

    1985-01-01

    The majority of polyphase ceramics contain a residual glass phase at their grain boundaries. The stability of these phases, particularly at the two-grain boundaries, is of significance since they affect the properties of the material as a whole. Drawing analogies with soap films, the stability of a continuous intergranular phase is considered in terms of the balance between the capillarity and disjoining pressures. The individual components to the disjoining pressures are discussed. It is arg...

  8. Superconductivity of small metal grains

    Institute of Scientific and Technical Information of China (English)

    ZHENG; Renrong; CHEN; Zhiqian; ZHU; Shunquan

    2005-01-01

    The formulas of the energy gap and superconducting critical temperature appropriate for systems with both odd and even number of electrons are derived; the bases of the derivations are BCS theory and energy level statistics. Numerical results qualitatively agree with the experimental phenomena. i.e., the superconductivity of small metallic grains will first enhance then decrease to zero when the grain are getting smaller and smaller. The calculations indicate that the above phenomena happen in the metallic grains belonging to Gaussian Orthogonal Ensemble (GOE) and Gaussian Unitary ensemble (GUE) with zero spin; The superconductivity of small metallic grains in Gaussian Symplectic Ensemble (GSE) will monotonically decrease to zero with the decreasing of the grain size. The analyses suggest that the superconductivity enhancements come from pairing and the balance of the strengths between spin-orbital coupling and external magnetic field. In order to take the latter into account, it is necessary to include the level statistics given by Random Matrix Theory (RMT) in describing small metallic grains.

  9. Complex Chemistry on Interstellar Grains

    Science.gov (United States)

    Widicus Weaver, Susanna L.; Kelley, Matthew J.; Blake, Geoffrey A.

    Early interstellar chemical models considered complex molecule formation on grains [Allen & Robinson (1977)], but current models assume that simple molecules form on grains and subsequent gas phase ion-molecule reactions produce the more complex species [Ruffle & Herbst (2001), Charnley (2001)]. It has been shown, however, that gas phase ion-molecule reactions are insufficient for the production of such complex organic species as ethanol (CH3CH2OH) and methyl formate (CH3OCHO) [Horn et al. (2004)]. Organics such as acetaldehyde (CH3CHO), ethanol, methyl formate, acetic acid (CH3COOH), and glycolaldehyde (CH2OHCHO) have also been detected in high abundance in regions of grain mantle disruption or evaporation, indicating that these species are formed on grain surfaces [see Chengalur & Kanekar (2003), Bottinelli et al. (2004), Hollis et al. (2001)]. The mechanisms for complex molecule production on grains are clearly much more important, and much more complex, than has been recognized. Recent observational studies of these types of species have offered insight into the mechanisms for their possible grain surface synthesis. The relative hot core abundances of the 2C structural isomers methyl formate, acetic acid, and glycolaldehyde (52:2:1, respectively [Hollis et al. (2001)]) indicate that if they form on grains it is not from kinetically-controlled single-atom addition reactions. Likewise, the 3C aldose sugar, glyceraldehyde (CH2OHCHOHCHO), was not detected in Sgr B2(N-LMH) [Hollis et al. (2004)] while the 3C ketose sugar, dihydroxyacetone (CO(CH2OH)2) was detected in this source [Widicus Weaver & Blake (2005)]. Chemical pathways favoring the more stable carbonates over acids and aldehydes are required to explain these results. Interestingly, all of these species can be formed from reactions involving the abundant grain mantle constituents CO, HCOOH, and CH3OH and their radical precursors. A model has been developed to investigate this type of chemical network, and

  10. Deformation strain inhomogeneity in columnar grain nickel

    DEFF Research Database (Denmark)

    Wu, G.L.; Godfrey, A.; Juul Jensen, D.;

    2005-01-01

    A method is presented for determination of the local deformation strain of individual grains in the bulk of a columnar grain sample. The method, based on measurement of the change in grain area of each grain, is applied to 12% cold rolled nickel. Large variations are observed in the local strain...

  11. Interstellar Grains: 50 Years On

    CERN Document Server

    Wickramasinghe, N Chandra

    2011-01-01

    Our understanding of the nature of interstellar grains has evolved considerably over the past half century with the present author and Fred Hoyle being intimately involved at several key stages of progress. The currently fashionable graphite-silicate-organic grain model has all its essential aspects unequivocally traceable to original peer-reviewed publications by the author and/or Fred Hoyle. The prevailing reluctance to accept these clear-cut priorities may be linked to our further work that argued for interstellar grains and organics to have a biological provenance - a position perceived as heretical. The biological model, however, continues to provide a powerful unifying hypothesis for a vast amount of otherwise disconnected and disparate astronomical data.

  12. Fractal dust grains in plasma

    Energy Technology Data Exchange (ETDEWEB)

    Huang, F. [College of Science, China Agricultural University, Beijing 100083 (China); Peng, R. D. [State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Beijing 100083 (China); Liu, Y. H. [Institute of Complexity Science, Qingdao University, Qingdao 266071 (China); Chen, Z. Y. [Department of Physics, Beijing University of Chemical Technology, Beijing 100029 (China); Ye, M. F.; Wang, L. [Institute of Physics, Chinese Academy of Science, Beijing 100190 (China)

    2012-09-15

    Fractal dust grains of different shapes are observed in a radially confined magnetized radio frequency plasma. The fractal dimensions of the dust structures in two-dimensional (2D) horizontal dust layers are calculated, and their evolution in the dust growth process is investigated. It is found that as the dust grains grow the fractal dimension of the dust structure decreases. In addition, the fractal dimension of the center region is larger than that of the entire region in the 2D dust layer. In the initial growth stage, the small dust particulates at a high number density in a 2D layer tend to fill space as a normal surface with fractal dimension D = 2. The mechanism of the formation of fractal dust grains is discussed.

  13. Grain centre mapping - 3DXRD measurements of average grain characteristics

    DEFF Research Database (Denmark)

    Oddershede, Jette; Schmidt, Søren; Lyckegaard, Allan;

    2014-01-01

    Three-Dimensional X-ray Diraction (3DXRD) Microscopy is a generic term covering a variety of dierent techniques for characterising the mi- crostructure within the bulk of polycrystalline materials. One strategy | namely grain centre mapping | enables fast measurements of the av- erage characteris...

  14. Applied Thermodynamics: Grain Boundary Segregation

    Directory of Open Access Journals (Sweden)

    Pavel Lejček

    2014-03-01

    Full Text Available Chemical composition of interfaces—free surfaces and grain boundaries—is generally described by the Langmuir–McLean segregation isotherm controlled by Gibbs energy of segregation. Various components of the Gibbs energy of segregation, the standard and the excess ones as well as other thermodynamic state functions—enthalpy, entropy and volume—of interfacial segregation are derived and their physical meaning is elucidated. The importance of the thermodynamic state functions of grain boundary segregation, their dependence on volume solid solubility, mutual solute–solute interaction and pressure effect in ferrous alloys is demonstrated.

  15. AGB stars and presolar grains

    CERN Document Server

    Busso, M; Maiorca, E; Palmerini, S

    2013-01-01

    Among presolar materials recovered in meteorites, abundant SiC and Al$_{2}$O$_{3}$ grains of AGB origins were found. They showed records of C, N, O, $^{26}$Al and s-element isotopic ratios that proved invaluable in constraining the nucleosynthesis models for AGB stars \\cite{zin,gal}. In particular, when these ratios are measured in SiC grains, they clearly reveal their prevalent origin in cool AGB circumstellar envelopes and provide information on both the local physics and the conditions at the nucleosynthesis site (the H- and He-burning layers deep inside the structure). Among the properties ascertained for the main part of the SiC data (the so-called {\\it mainstream} ones), we mention a large range of $^{14}$N/$^{15}$N ratios, extending below the solar value \\cite{mar}, and $^{12}$C/$^{13}$C ratios $\\gtrsim$ 30. Other classes of grains, instead, display low carbon isotopic ratios ($\\gtrsim 10$) and a huge dispersion for N isotopes, with cases of large $^{15}$N excess. In the same grains, isotopes currently...

  16. Grain Refinement of Deoxidized Copper

    Science.gov (United States)

    Balart, María José; Patel, Jayesh B.; Gao, Feng; Fan, Zhongyun

    2016-10-01

    This study reports the current status of grain refinement of copper accompanied in particular by a critical appraisal of grain refinement of phosphorus-deoxidized, high residual P (DHP) copper microalloyed with 150 ppm Ag. Some deviations exist in terms of the growth restriction factor ( Q) framework, on the basis of empirical evidence reported in the literature for grain size measurements of copper with individual additions of 0.05, 0.1, and 0.5 wt pct of Mo, In, Sn, Bi, Sb, Pb, and Se, cast under a protective atmosphere of pure Ar and water quenching. The columnar-to-equiaxed transition (CET) has been observed in copper, with an individual addition of 0.4B and with combined additions of 0.4Zr-0.04P and 0.4Zr-0.04P-0.015Ag and, in a previous study, with combined additions of 0.1Ag-0.069P (in wt pct). CETs in these B- and Zr-treated casts have been ascribed to changes in the morphology and chemistry of particles, concurrently in association with free solute type and availability. No further grain-refining action was observed due to microalloying additions of B, Mg, Ca, Zr, Ti, Mn, In, Fe, and Zn (~0.1 wt pct) with respect to DHP-Cu microalloyed with Ag, and therefore are no longer relevant for the casting conditions studied. The critical microalloying element for grain size control in deoxidized copper and in particular DHP-Cu is Ag.

  17. Grain Refinement of Deoxidized Copper

    Science.gov (United States)

    Balart, María José; Patel, Jayesh B.; Gao, Feng; Fan, Zhongyun

    2016-08-01

    This study reports the current status of grain refinement of copper accompanied in particular by a critical appraisal of grain refinement of phosphorus-deoxidized, high residual P (DHP) copper microalloyed with 150 ppm Ag. Some deviations exist in terms of the growth restriction factor (Q) framework, on the basis of empirical evidence reported in the literature for grain size measurements of copper with individual additions of 0.05, 0.1, and 0.5 wt pct of Mo, In, Sn, Bi, Sb, Pb, and Se, cast under a protective atmosphere of pure Ar and water quenching. The columnar-to-equiaxed transition (CET) has been observed in copper, with an individual addition of 0.4B and with combined additions of 0.4Zr-0.04P and 0.4Zr-0.04P-0.015Ag and, in a previous study, with combined additions of 0.1Ag-0.069P (in wt pct). CETs in these B- and Zr-treated casts have been ascribed to changes in the morphology and chemistry of particles, concurrently in association with free solute type and availability. No further grain-refining action was observed due to microalloying additions of B, Mg, Ca, Zr, Ti, Mn, In, Fe, and Zn (~0.1 wt pct) with respect to DHP-Cu microalloyed with Ag, and therefore are no longer relevant for the casting conditions studied. The critical microalloying element for grain size control in deoxidized copper and in particular DHP-Cu is Ag.

  18. Concepts on Low Temperature Mechanical Grain Growth

    Energy Technology Data Exchange (ETDEWEB)

    Sharon, John Anthony [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Metallurgy and Materials Joining Dept.; Boyce, Brad Lee [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Metallurgy and Materials Joining Dept.

    2013-11-01

    In metals, as grain size is reduced below 100nm, conventional dislocation plasticity is suppressed resulting in improvements in strength, hardness, and wears resistance. Existing and emerging components use fine grained metals for these beneficial attributes. However, these benefits can be lost in service if the grains undergo growth during the component’s lifespan. While grain growth is traditionally viewed as a purely thermal process that requires elevated temperature exposure, recent evidence shows that some metals, especially those with nanocrystalline grain structure, can undergo grain growth even at room temperature or below due to mechanical loading. This report has been assembled to survey the key concepts regarding how mechanical loads can drive grain coarsening at room temperature and below. Topics outlined include the atomic level mechanisms that facilitate grain growth, grain boundary mobility, and the impact of boundary structure, loading scheme, and temperature.

  19. Cool Down!——The State Administration of Grain Lower Expectation of Grain Price

    Institute of Scientific and Technical Information of China (English)

    He Jun

    2010-01-01

    @@ The rising grain price in the first half of the year,coupled with the news that China's summer grain output fell for the first time in seven years,has enhanced market expectation for the grain price to rise.

  20. Three Dimension Monte Carlo Simulation of Austenite Grain Growth in CGHAZ of an Ultrafine Grain Steel

    Institute of Scientific and Technical Information of China (English)

    Dong CHEN; Yongping LEI; Xiaoyan LI; Yaowu SHI; Zhiling TIAN

    2003-01-01

    In the present research Monte Carlo technique was used to simulate the grain growth in heat-affected zone(HAZ) of an ultrafine grain steel. An experimental data based (EBD) model proposed by Gao was used to establish the relation between tMCS and real time temperature kinetics in our simulation. The simulations give out the evolution of grain structure and grain size distribution in HAZ of the ultrafine grain steel. A Microsoft Window based on computer program for the simulation of grain growth in the HAZ of weldment in three dimensions has been developed using Monte Carlo technique. For the system, inputting the temperature field data and material properties, the evolution of grain structure, both image of simulated grain structure and numerical datum reflecting grain size distribution can be produced by the program. The system was applied to the ultrafine grain steel welding, and the simulated results show that the ultrafine grain steel has large tendency of grain growth.

  1. China's Grain Demand and Supply: Trade Implications

    OpenAIRE

    Wu, Harry X.; Christopher Findlay

    1997-01-01

    This study reviews research on China's grain demand and supply. The purpose is to comment on the outlook for China's trade in grain and grain-based food, but also to identify the sensitivities of the projections of China's grain demand to key parameters. The paper will therefore 1) review a set of projections of grain demand and trade, 2) examine studies of major factors considered to affect grain demand in China, 3) comment on some trade and production policy issues based on a new projection...

  2. Spinodal decomposition in fine grained materials

    Indian Academy of Sciences (India)

    H Ramanarayan; T A Abinandanan

    2003-01-01

    We have used a phase field model to study spinodal decomposition in polycrystalline materials in which the grain size is of the same order of magnitude as the characteristic decomposition wavelength ($\\lambda_{SD}$). In the spirit of phase field models, each grain () in our model has an order parameter ($\\eta_i$) associated with it; $\\eta_i$ has a value of unity inside the th grain, decreases smoothly through the grain boundary region to zero outside the grain. For a symmetric alloy of composition, = 0.5, our results show that microstructural evolution depends largely on the difference in the grain boundary energies, $\\gamma_{gb}$, of A-rich () and B-rich () phases. If $\\gamma^{\\alpha}_{gb}$ is lower, we find that the decomposition process is initiated with an layer being formed at the grain boundary. If the grain size is sufficiently small (about the same as $\\lambda_{SD}$), the interior of the grain is filled with the phase. If the grain size is large (say, about 10 $\\lambda_{SD}$ or greater), the early stage microstructure exhibits an A-rich grain boundary layer followed by a B-rich layer; the grain interior exhibits a spinodally decomposed microstructure, evolving slowly. Further, grain growth is suppressed completely during the decomposition process.

  3. Coarse-graining complex dynamics

    DEFF Research Database (Denmark)

    Sibani, Paolo

    2013-01-01

    Continuous Time Random Walks (CTRW) are widely used to coarse-grain the evolution of systems jumping from a metastable sub-set of their configuration space, or trap, to another via rare intermittent events. The multi-scaled behavior typical of complex dynamics is provided by a fat-tailed distribu......Continuous Time Random Walks (CTRW) are widely used to coarse-grain the evolution of systems jumping from a metastable sub-set of their configuration space, or trap, to another via rare intermittent events. The multi-scaled behavior typical of complex dynamics is provided by a fat......-law and logarithmic relaxation behaviors ubiquitous in complex dynamics, together with the sub-diffusive time dependence of the Mean Square Displacement characteristic of single particles moving in a complex environment....

  4. Solid Propellant Grain Structural Integrity Analysis

    Science.gov (United States)

    1973-01-01

    The structural properties of solid propellant rocket grains were studied to determine the propellant resistance to stresses. Grain geometry, thermal properties, mechanical properties, and failure modes are discussed along with design criteria and recommended practices.

  5. Conception, definition, measuring procedure of grain size

    International Nuclear Information System (INIS)

    The conception, definition, measuring procedure of ''Grain Size'' were surveyed. A concept ''grain diameter'' was introduced after deriving a calculation formula for the grain diameter for using the Comparison (simple) and Intercept(detailed) procedure. As an example and putting into practice, the grain diameter determination was carried out by means of the Comparison procedure for a UO2 pellet used in a densification experiment. (auth.)

  6. Grain nucleation and growth during phase transformations

    DEFF Research Database (Denmark)

    Offerman, S.E.; Dijk, N.H. van; Sietsma, J.;

    2002-01-01

    of individual grains. Our measurements show that the activation energy for grain nucleation is at least two orders of magnitude smaller than that predicted by thermodynamic models. The observed growth curves of the newly formed grains confirm the parabolic growth model but also show three...... fundamentally different types of growth. Insight into the grain nucleation and growth mechanisms during phase transformations contributes to the development of materials with optimal mechanical properties....

  7. Ancient whole grain gluten-free flatbreads

    Science.gov (United States)

    The USDA food guide recommends that at least ½ of all the grains eaten should be whole grains. The FDA allows food Health Claim labels for food containing 51% whole gains and 11 g of dietary fiber. This is the only report demonstrating innovative ancient whole grain gluten-free (no yeast or chemical...

  8. Whole grain gluten-free flat breads

    Science.gov (United States)

    The USDA food guide recommends that at least ½ of all the grains eaten should be whole grains. The FDA allows food health claim labels for food containing 51% whole gains and 11 g of dietary fiber. This is the only report demonstrating innovative whole grain gluten free (without yeast or chemicals) ...

  9. Determination of grain boundary geometry using TEM

    NARCIS (Netherlands)

    Jang, H.; Farkas, D.; Hosson, J.T.M. De

    1992-01-01

    An experimental method to obtain the grain boundary geometry using the transmission electron microscope is presented. The method allows Σ determination including grain boundary plane orientation. In order to determine the specialness of the grain boundary, three different criteria for maximum allowa

  10. Bioactive compounds in whole grain wheat

    NARCIS (Netherlands)

    Mateo Anson, N.

    2010-01-01

    Bread can be healthier! Consuming whole-grain foods can prevent cardiovascular diseases, type-2 diabetes and metabolic syndrome. This is due to bioactive compounds in whole grain, such as antioxidants and anti-inflammatory compounds. We found that the different fractions of a wheat grain vary much i

  11. 75 FR 76254 - Official Performance and Procedural Requirements for Grain Weighing Equipment and Related Grain...

    Science.gov (United States)

    2010-12-08

    ... Performance and Procedural Requirements for Grain Weighing Equipment and Related Grain Handling Systems AGENCY... reviewed under Executive Order 12988, Civil Justice Reform. This action is not intended to have retroactive... PROCEDURAL REQUIREMENTS FOR GRAIN WEIGHING EQUIPMENT AND RELATED GRAIN HANDLING SYSTEMS 0 1. The...

  12. Grain-size sorting and slope failure in experimental subaqueous grain flows

    NARCIS (Netherlands)

    Kleinhans, M.G.; Asch, Th.W.J. van

    2005-01-01

    Grain-size sorting in subaqueous grain flows of a continuous range of grain sizes is studied experimentally with three mixtures. The observed pattern is a combination of stratification and gradual segregation. The stratification is caused by kinematic sieving in the grain flow. The segregation is ca

  13. Airborne Pollen Grains Of Afyon, Turkey

    Institute of Scientific and Technical Information of China (English)

    Adem BICAKCI; Süheyla ERGUN; Sevcan TATLIDIL; Hulusi MALYER; Sabri OZYURT; Ahmet AKKAYA; Nihat SAPAN

    2002-01-01

    The airborne pollen grains of Afyon have been studied for a two-year period (1999-2000) with a Durham sampler. A total of 14 367 pollen grains belonging to 40 taxa have been identified and recorded with some unidentified ones. Of them, 6 732 were identified in 1999 and 7 635 in 2000. Of the total pollen grains, 69.67% were arboreal, 26.64% non-arboreal and 3.68 % unidentified. The majority of the investigated pollen grains were from Pinus, Gramineae, Cupressaceae, Platanus, Chenopodiaceae/Amaranthaceae, Quercus, Ailanthus, Moraceae, Juglans, Salix, Cedrus and Rosaceae. The highest level of pollen grains was in May.

  14. Establishment of Grain Farmers’ Supply Response Model and Empirical Analysis under Minimum Grain Purchase Price Policy

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Based on farmers’ supply behavior theory and price expectations theory,this paper establishes grain farmers’ supply response model of two major grain varieties (early indica rice and mixed wheat) in the major producing areas,to test whether the minimum grain purchase price policy can have price-oriented effect on grain production and supply in the major producing areas. Empirical analysis shows that the minimum purchase price published annually by the government has significant positive impact on farmers’ grain supply in the major grain producing areas. In recent years,China steadily raises the level of minimum grain purchase price,which has played an important role in effectively protecting grain farmers’ interests,mobilizing the enthusiasm of farmers’ grain production,and ensuring the market supply of key grain varieties.

  15. Nonresonant Grain Acceleration in MHD Turbulence

    CERN Document Server

    Yan, Huirong

    2009-01-01

    We discuss a new type of dust acceleration mechanism that acts in a turbulent magnetized medium. The magnetohydrodynamic (MHD) turbulence can accelerate grains through resonant as well as nonresonant interactions. We show that the magnetic compression provides higher velocities for super-Alfv\\'enic turbulence and can accelerate an extended range of grains in warm media compared to gyroresonance. While fast modes dominate the acceleration for the large grains, slow modes can be important for sub-micron grains. We provide comprehensive discussion of all the possible grain acceleration mechanisms in interstellar medium. We show that supersonic velocities are attainable for Galactic dust grains. We discuss the consequence of the acceleration. The implications for extinction curve, grain alignment, chemical abundance, etc, are provided.

  16. Method of preventing contamination by grain molder

    International Nuclear Information System (INIS)

    Object: To prevent contamination by scattering of radioactive substance from a uranium dioxide grain molder used within a hot cell while readily removing the contamination by a simple means. Structure: Scattering of grain from a grain molder for press molding grain having intense radioactivity and comprising a hammer, mortar, hammer plunger, agitating motor and feeder is prevented by a cover. Also, grain within the cover and grain within the feeder are removed by jetting air from nozzle pipes provided on the top and sides of the molder. After removal, air is switched over to rinsing liquid issued to wash off grain having been attached to the molder, followed by jetting of hot air for drying. (Kamimura, M.)

  17. Study on Fluctuation of Grain Yield in China’s Major Grain Producing Areas

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    By using the statistical data of grain yield in China’s major grain producing areas from 1949 to 2008,and fluctuation theory,the historical process and main cause of fluctuation of grain yield in China’s major grain producing areas are analyzed.The results of research show that the grain yield in China’s major grain producing areas grows in unstable fluctuation,with high-frequency fluctuation cycle and regular length;the amplitude of fluctuation,on the whole,is moderate,with not strong stability;the fluctuation of grain yield has correspondence,reflecting the N-shape developmental trend of grain production at present;the fluctuation of grain yield has gradient characteristics;in the process of comparison of grain yield,the average growth rate annually of grain yield in China’s major grain producing areas is higher than that of the national average,but the relative fluctuation coefficient is also higher than that of the national average.From five aspects,namely natural disaster,agricultural policy,production input,grain price and grain circulation,the cause of fluctuation of grain yield in China’s major grain producing areas is analyzed,and measures of preventing and arresting super-long fluctuation of grain yield are put forward.Firstly,stick to strict farmland protection system,and strive to promote farmland quality;secondly,strengthen infrastructure construction of grain production and beef up the ability of preventing natural disaster;thirdly,quicken the pace of agricultural technology and establish robust technology supporting system;fourthly,lay stress on innovation of agricultural organization system and provide implementation path and vehicle for application of agricultural technology measures;fifthly,perfect disaster precaution system and grain market system,and strengthen the ability of preventing risk of grain production.

  18. Electronic properties of grains and grain boundaries in graphene grown by chemical vapor deposition

    OpenAIRE

    Jauregui, Luis A.; Cao, Helin; Wu, Wei; Yu, Qingkai; Chen, Yong P.

    2011-01-01

    We synthesize hexagonal shaped single-crystal graphene, with edges parallel to the zig-zag orientations, by ambient pressure CVD on polycrystalline Cu foils. We measure the electronic properties of such grains as well as of individual graphene grain boundaries, formed when two grains merged during the growth. The grain boundaries are visualized using Raman mapping of the D band intensity, and we show that individual boundaries between coalesced grains impede electrical transport in graphene a...

  19. More than Rising Grain Prices

    Institute of Scientific and Technical Information of China (English)

    Hu Junhua

    2010-01-01

    @@ According to the bulletin of the National Bureau of Statistics,the summer harvest nationwide this year was 246.2billion jin,a decline of 0.3% compared to last year.The cold spell in late spring and high temperatures afterwards are considered as the main causes for this round of rising grain prices.However,"natural disasters"are dwarfed by another worrisome picture: young and strong farming hands flooding out of the rural areas and the elderly,the weak,females and children are made the mainstay of the tilling army.

  20. Direct imaging of grain boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Gronsky, R.

    1979-09-01

    There are currently two types of microscopes which, in principle, are capable of imaging atom positions at grain boundaries. One, the field ion microscope (FIM), yields a projection of the specimen surface (approximately stereographic) by field ionization of an imaging gas at protruding atom sites, and provides topographic information in high-index pole regions which may be interpreted atom-by-atom. The other, a transmission electron microscope (TEM), yields a projection (approximately linear) of the entire specimen thickness by electron optical imaging, and provides atomic resolution detail throughout the illuminated area. In this paper, both methods are described and compared, using examples from practical materials systems.

  1. Whole grains and health: from theory to practice--highlights of The Grains for Health Foundation's Whole Grains Summit 2012.

    Science.gov (United States)

    McKeown, Nicola M; Jacques, Paul F; Seal, Chris J; de Vries, Jan; Jonnalagadda, Satya S; Clemens, Roger; Webb, Densie; Murphy, Lee Anne; van Klinken, Jan-Willem; Topping, David; Murray, Robyn; Degeneffe, Dennis; Marquart, Leonard F

    2013-05-01

    The Grains for Health Foundation's Whole Grains Summit, held May 19-22, 2012 in Minneapolis, was the first meeting of its kind to convene >300 scientists, educators, food technologists, grain breeders, food manufacturers, marketers, health professionals, and regulators from around the world. Its goals were to identify potential avenues for collaborative efforts and formulate new approaches to whole-grains research and health communications that support global public health and business. This paper summarizes some of the challenges and opportunities that researchers and nutrition educators face in expanding the knowledge base on whole grains and health and in translating and disseminating that knowledge to consumers. The consensus of the summit was that effective, long-term, public-private partnerships are needed to reach across the globe and galvanize the whole-grains community to collaborate effectively in translating whole-grains science into strategies that increase the availability and affordability of more healthful, grain-based food products. A prerequisite of that is the need to build trust among diverse multidisciplinary professionals involved in the growing, producing, marketing, and regulating of whole-grain products and between the grain and public health communities. PMID:23514771

  2. High Temperature at Grain-filling Stage Affects Nitrogen Metabolism Enzyme Activities in Grains and Grain Nutritional Quality in Rice

    Institute of Scientific and Technical Information of China (English)

    LIANG Cheng-gang; CHEN Li-ping; WANG Yan; LIU Jia; Xu Guang-li; LI Tian

    2011-01-01

    Rice plants would more frequently suffer from high temperature (HT) stress at the grain-filling stage in future.A japonica rice variety Koshihikari and an indica rice variety IR72 were used to study the effect of high temperature on dynamic changes of glutamine synthetase (GS) activity,glutamate synthase (GOGAT) activity,glutamic oxalo-acetic transminase (GOT) activity,glutamate pyruvate transminase (GPT) activity in grains and grain nutritional quality at the grain-filling stage.Under HT,the activities of GOGAT,GOT,GPT and soluble protein content in grains significantly increased,whereas GS activity significantly decreased at the grain-filling stage.In addition to the increase of protein and amino acids contents,it was suggested that GOGAT,GOT and GPT in grains played important roles in nitrogen metabolism at the grain-filling stage.Since the decrease of GS activity in grains did not influence the accumulations of amino acids and protein,it is implied that GS might not be the key enzyme in regulating glutamine content in grains.

  3. Grain Growth in Collapsing Clouds

    Science.gov (United States)

    Rossi, S. C. F.; Benevides-Soares, P.; Barbuy, B.

    1990-11-01

    RESUMEN. Se ha considerado un proceso de coagulaci6n de granos en nubes colapsantes de diferentes metalicidades. Se aplicaron los calculos al intervalo de densidades n = lO to , forrespondiendo a la fase isotermica de contracci6n de nubes. A lo largo de esta fase en el colap- so, la temperatura es por lo tanto constante, en donde se alcanza T Q lOKpara nubes de metalicidad solar y T 100 K para nubes de baja metalicidad. El tamano final del grano es mayor para las mayores metali- cidades. ABSTRACT. A process of grain coagulation in collapsing clouds of different metallicities is considered. The calculations are applied to the density range n = 1O to , corresponding to the isothermal phase of cloud contraction. Along this phase in the collapse, the temperature is thus a constant, where T % 10 K for solar-metallicity clouds, and T % 100 K for low metallicity clouds is reached. The final grain size is larger for the higher metallicities. Keq : INTERSTELLAR-CLOUDS - INTERSTELLAR-CRAINS

  4. Study on grain growth of fine grained WC-Co hardmetal by numerical calculation

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, N. [Kobe Steel, Ltd., Kobe (Japan); Hayashi, K. [The University of Tokyo, Tokyo (Japan). Institute of industrial Science

    2000-12-15

    This paper reviews our simulation study by numerical calculation based on two-, three- and multi-grain-size models on WC grain growth in fine grained WC-Co hardmetal doped with VC. The study aimed to presume or predict the following: (1) the cause and conditions for the abnormal grain growth which occurs in some cases in the fine grained hardmetal prepared from fine WC powders with mean grain size below about 0.2{mu}m, and (2) how the mean grain size of the hardmetal varies with decreasing mean grain size of the WC starting powder to 0.1 pm or nano-meter size. The calculation results by these three kinds of models suggested the following, respectively: (1) the occurrence of the abnormal grain growth is generally substantial for WC starting powder with bimodal size-distribution and mean gram size below 0.1 - 0.2{mu}m, and not due to the non-uniform distribution of the grain growth inhibitor, (2) the introduction of middle grains caused the disappearance of small (fine) grains during sintering, leading to abruptly increase of the mean grain size of alloy, and (3) the mean grain size of alloy becomes so large as about 0.3 - 0.4{mu}m, even when the WC starting powders with nano-size as well as 0.1 {mu}m are used. (author)

  5. Quasiclassical Coarse Graining and Thermodynamic Entropy

    CERN Document Server

    Gell-Mann, Murray; Gell-Mann, Murray; Hartle, James

    2006-01-01

    Our everyday descriptions of the universe are highly coarse-grained, following only a tiny fraction of the variables necessary for a perfectly fine-grained description. Coarse graining in classical physics is made natural by our limited powers of observation and computation. But in the modern quantum mechanics of closed systems, some measure of coarse graining is inescapable because there are no non-trivial, probabilistic, fine-grained descriptions. This essay explores the consequences of that fact: Quantum theory allows for various coarse-grained descriptions some of which are mutually incompatible. For most purposes, however, we are interested in the small subset of ``quasiclassical descriptions'' defined by ranges of values of averages over small volumes of densities of conserved quantities such as energy and momentum and approximately conserved quantities such as baryon number. The near-conservation of these quasiclassical quantities results in approximate decoherence, predictability, and local equilibriu...

  6. Determination of grain boundary geometry using TEM

    Energy Technology Data Exchange (ETDEWEB)

    Jang, H.; Farkas, D. (Department of Materials Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0237 (United States)); De Hosson, J.T.M. (Department of Applied Physics, University of Groningen, Nijenborgh 18, 9747 AG, Groningen (Netherlands))

    1992-07-01

    An experimental method to obtain the grain boundary geometry using the transmission electron microscope is presented. The method allows {Sigma} determination including grain boundary plane orientation. In order to determine the specialness of the grain boundary, three different criteria for maximum allowable deviations from exact CSL misorientations were examined. We tested these three criteria from a statistical distribution of grain boundary types in terms of {Sigma}. We compared grain boundary distributions from other studies in Ni{sub 3}Al and found discrepancies among them. It seems that the discrepancy came from the different criteria for special boundaries in {Sigma} determination and different experimental procedures they used. The statistical distribution of grain boundary plane orientations showed that low {Sigma} boundaries ({Sigma}{lt}11) were oriented to the plane of high density of coincident sites.

  7. Grain Alignment and CMB Polarization Studies

    CERN Document Server

    Lazarian, A

    2008-01-01

    Polarized microwave emission from dust is an important foreground that may contaminate polarized CMB studies unless carefully accounted for. Modeling of polarization from dust requires a quantitative understanding of grain alignment. I review the current status of grain alignment theory outlining recent advances in quantitative description of the alignment. In particular, I show that the grain-alignment theory is a predictive one, and its results nicely match observations. Those indicate that the most important process of alignment is related to radiative torques acting on irregular grains. The recently developed analytical model of radiative torque alignment has proven to be a very efficient tool for predicting the degree of grain alignment. We expect the alignment theory to further mature before CMBPol flight, which would ensure a better accounting for the dust-related polarization. At the same time, CMBPol should provide the additional testing of grain alignment, clarifying the reliability of polarimetry f...

  8. Grain refinement of AZ31 magnesium alloy by electromagnetic stirring under effect of grain-refiner

    Indian Academy of Sciences (India)

    S Y Gao; Q C Le; Z Q Zhang; J Z Cui

    2012-08-01

    The effects of electromagnetic stirring and Al4C3 grain refiner on the grain refinement of semicontinuously cast AZ31 magnesium alloy were discussed in this investigation. The results indicate that electromagnetic stirring has an effective refining effect on the grain size of AZ31 magnesium alloy under the effect of Al4C3 grain refiner. Electromagnetic stirring can `activate’ the Al4C3 particles, resulting in more heterogeneous nucleation sites for the primary -Mg grains. But, longer holding time can `deactivate’ the Al4C3 particles and poison the grain refining effect.

  9. Prediction of HAZ grain size in welding of ultra fine grained steel with different parameters

    Institute of Scientific and Technical Information of China (English)

    Zhao Hongyun; Zhang Hongtao; Li Dongqing; Wang Guodong

    2010-01-01

    The temperature field and thermal cycling curve in the heat-affected zone during welding 400 MPa ultra fine grained steel by plasma arc were simulated using finite element method.The principle of grain growth kinetics was used to predict the grain size in the heat-affected zone under different welding parameters.The simulation results show that the growing tendency of HAZ grain could be controlled by adjusting the welding parameters,but the growth of HAZ grain could not be eliminated at all.The HAZ grain size became small with increasing of the cooling rate and added with increasing of welding current,arc voltage and welding speed.

  10. Perennial Grain and Oilseed Crops.

    Science.gov (United States)

    Kantar, Michael B; Tyl, Catrin E; Dorn, Kevin M; Zhang, Xiaofei; Jungers, Jacob M; Kaser, Joe M; Schendel, Rachel R; Eckberg, James O; Runck, Bryan C; Bunzel, Mirko; Jordan, Nick R; Stupar, Robert M; Marks, M David; Anderson, James A; Johnson, Gregg A; Sheaffer, Craig C; Schoenfuss, Tonya C; Ismail, Baraem; Heimpel, George E; Wyse, Donald L

    2016-04-29

    Historically, agroecosystems have been designed to produce food. Modern societies now demand more from food systems-not only food, fuel, and fiber, but also a variety of ecosystem services. And although today's farming practices are producing unprecedented yields, they are also contributing to ecosystem problems such as soil erosion, greenhouse gas emissions, and water pollution. This review highlights the potential benefits of perennial grains and oilseeds and discusses recent progress in their development. Because of perennials' extended growing season and deep root systems, they may require less fertilizer, help prevent runoff, and be more drought tolerant than annuals. Their production is expected to reduce tillage, which could positively affect biodiversity. End-use possibilities involve food, feed, fuel, and nonfood bioproducts. Fostering multidisciplinary collaborations will be essential for the successful integration of perennials into commercial cropping and food-processing systems. PMID:26789233

  11. Superfluidity of grain boundaries and supersolid behavior.

    Science.gov (United States)

    Sasaki, S; Ishiguro, R; Caupin, F; Maris, H J; Balibar, S

    2006-08-25

    When two communicating vessels are filled to a different height with liquid, the two levels equilibrate because the liquid can flow. We have looked for such equilibration with solid (4)He. For crystals with no grain boundaries, we see no flow of mass, whereas for crystals containing several grain boundaries, we detect a mass flow. Our results suggest that the transport of mass is due to the superfluidity of grain boundaries. PMID:16873608

  12. A Comprehensive Rail Rate Index for Grain

    OpenAIRE

    Sparger, Adam; Prater, Marvin E.

    2012-01-01

    Several annual rail rate indices depict changes in the prices paid for rail service. Although accurate for general analyses, each of these indices falls short in capturing the three major components of total railroad grain rates: tariff rates, fuel surcharges, and secondary railcar market costs. Bids in the secondary grain railcar market can affect whether the actual rate paid by shippers is above or below the published tariff rate. The seasonality of rates inherent in grain transportation is...

  13. Runaway growth of fractal dust grains

    CERN Document Server

    Mattsson, Lars

    2015-01-01

    Fractal grains have large surface area, which leads to more efficient condensation. The special limit case where the volume-area ratio is constant (corresponding to, e.g., a very rough grain surface or non-compacts aggregates) is particularly interesting, as well as convenient, from a mathematical point of view. If dust grains from AGB stars have `rough surfaces', it may have important implications for our understanding of dust and wind formation in AGB stars.

  14. 7 CFR 868.310 - Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice...

    Science.gov (United States)

    2010-01-01

    ... Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled Rice. (See also Â... Milled Rice Principles Governing Application of Standards § 868.310 Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled...

  15. Grain interaction effects in polycrystalline Cu

    DEFF Research Database (Denmark)

    Thorning, C.; Somers, Marcel A.J.; Wert, John A.

    2005-01-01

    Crystal orientation maps for a grain in a deformed Cu polycrystal have been analysed with the goal of understanding the effect of grain interactions on orientation subdivision. The polycrystal was incrementally strained in tension to 5, 8, 15 and 25% extension; a crystal orientation map was measu......Crystal orientation maps for a grain in a deformed Cu polycrystal have been analysed with the goal of understanding the effect of grain interactions on orientation subdivision. The polycrystal was incrementally strained in tension to 5, 8, 15 and 25% extension; a crystal orientation map...

  16. The Effects of Grain Size and Texture on Dynamic Abnormal Grain Growth in Mo

    Science.gov (United States)

    Noell, Philip J.; Taleff, Eric M.

    2016-07-01

    This is the first report of abnormal grain morphologies specific to a Mo sheet material produced from a commercial-purity arc-melted ingot. Abnormal grains initiated and grew during plastic deformation of this material at temperatures of 1793 K and 1813 K (1520 °C and 1540 °C). This abnormal grain growth during high-temperature plastic deformation is termed dynamic abnormal grain growth, DAGG. DAGG in this material readily consumes nearly all grains near the sheet center while leaving many grains near the sheet surface unconsumed. Crystallographic texture, grain size, and other microstructural features are characterized. After recrystallization, a significant through-thickness variation in crystallographic texture exists in this material but does not appear to directly influence DAGG propagation. Instead, dynamic normal grain growth, which may be influenced by texture, preferentially occurs near the sheet surface prior to DAGG. The large grains thus produced near the sheet surface inhibit the subsequent growth of the abnormal grains produced by DAGG, which preferentially consume the finer grains near the sheet center. This produces abnormal grains that span the sheet center but leave unconsumed polycrystalline microstructure near the sheet surface. Abnormal grains are preferentially oriented with the new evidence that boundary curvature is the primary driving force for DAGG in Mo.

  17. Supercube grains leading to a strong cube texture and a broad grain size distribution after recrystallization

    Science.gov (United States)

    Lin, F. X.; Zhang, Y. B.; Pantleon, W.; Jensen, D. Juul

    2015-08-01

    This work revisits the classical subject of recrystallization of cold-rolled copper. Two characterization techniques are combined: three-dimensional X-ray diffraction using synchrotron X-rays, which is used to measure the growth kinetics of individual grains in situ, and electron backscatter diffraction, which is used for statistical analysis of the microstructural evolution. As the most striking result, the strong cube texture after recrystallization is found to be related to a few super large cube grains, which were named supercube grains. These few supercube grains become large due to higher growth rates. However, most other cube grains do not grow preferentially. Because of the few supercube grains, the grain size distribution after recrystallization is broad. Reasons for the higher growth rates of supercube grains are discussed, and are related to the local deformed microstructure.

  18. Supercube grains leading to a strong cube texture and a broad grain size distribution after recrystallization

    DEFF Research Database (Denmark)

    Lin, F.X.; Zhang, Y. B.; Pantleon, W.;

    2015-01-01

    diffraction, which is used for statistical analysis of the microstructural evolution. As the most striking result, the strong cube texture after recrystallization is found to be related to a few super large cube grains, which were named supercube grains. These few supercube grains become large due to higher......This work revisits the classical subject of recrystallization of cold-rolled copper. Two characterization techniques are combined: three-dimensional X-ray diffraction using synchrotron X-rays, which is used to measure the growth kinetics of individual grains in situ, and electron backscatter...... growth rates. However, most other cube grains do not grow preferentially. Because of the few supercube grains, the grain size distribution after recrystallization is broad. Reasons for the higher growth rates of supercube grains are discussed, and are related to the local deformed microstructure....

  19. Establishment of Grain Farmers' Supply Response Model and Empirical Analysis under Minimum Grain Purchase Price Policy

    OpenAIRE

    Shuang ZHANG

    2012-01-01

    Based on farmers' supply behavior theory and price expectations theory, this paper establishes grain farmers' supply response model of two major grain varieties (early indica rice and mixed wheat) in the major producing areas, to test whether the minimum grain purchase price policy can have price-oriented effect on grain production and supply in the major producing areas. Empirical analysis shows that the minimum purchase price published annually by the government has significant positive imp...

  20. Grain size effect on deformation twinning propensity in ultrafine-grained hexagonal close-packed titanium

    International Nuclear Information System (INIS)

    The deformation behaviour of ultrafine-grained hexagonal close-packed Ti processed by dynamic plastic deformation was investigated using electron microscopy techniques. Results show that the deformation twinning propensity in ultrafine-grained Ti decreases monotonously while the number of dislocations having the 〈c〉 component increases with decreasing grain size, indicating that the transformation of the deformation mechanism from twinning to slip occurs and that the twinning mechanism does not change within the observed grain size range

  1. Superior grains determined by grain weight are not fully correlated with the lfowering order in rice

    Institute of Scientific and Technical Information of China (English)

    PENG Ting; ZHAO Quan-zhi; L Qiang; ZHAO Ya-fan; SUN Hong-zheng; HAN Ying-chun; DU Yan-xiu; ZHANG Jing; LI Jun-zhou; WANG Lin-lin

    2015-01-01

    Rice panicles are composed of many branches with two types of extreme grains, the superior and the inferior. Traditional y, it has been wel accepted that earlier lfowers result in superior grains and late lfowers generate inferior grains. However, these correlations have never been strictly examined in practice. In order to determine the accurate relationship between superior and inferior grains and the lfowering order, we localized al the seeds in a panicle in four distinct rice species and systematical y documented the rice lfowering order, lfower locations and the ifnal grain weight for their relationships. Our results demonstrated that the grain weight is more heavily determined by the position of the seeds than by the lfowering order. Despite earlier lfowering has a positive correlation with the grain weight in general, grains from lfowers blooming on the second day after anthesis general y gained the highest weight. This suggests earlier lfowers may not result in superior grains. Therefore, we concluded that superior and inferior grains, commonly determined by grain weight, are not ful y cor-related with the lfowering order in rice. Fol owing the order of the grain weight, the superior grains are general y localized at the middle parts of the primary branches, whereas inferior grains were mainly on the last two secondary branches of the lower half part of the panicle. In addition, the weight of inferior grains were affected by spikelet thinning and spraying with exogenous plant growth regulators, indicating that physiological incompetence might be the major reason for the occurrence of the inferior grains.

  2. Grain-grain contact geometry and the propagation of elastic waves in granular media

    Science.gov (United States)

    Jones, B. W.

    1974-01-01

    It is shown that the compliance of an orthogonal grain-grain contact is so insensitive to the grain geometry in the contact region that this geometry is not at present an important parameter in theories of the speed of propagation of elastic waves in granular media, such as occur in the earth and in the moon.

  3. Irradiation-induced grain growth and defect evolution in nanocrystalline zirconia with doped grain boundaries.

    Science.gov (United States)

    Dey, Sanchita; Mardinly, John; Wang, Yongqiang; Valdez, James A; Holesinger, Terry G; Uberuaga, Blas P; Ditto, Jeff J; Drazin, John W; Castro, Ricardo H R

    2016-06-22

    Grain boundaries are effective sinks for radiation-induced defects, ultimately impacting the radiation tolerance of nanocrystalline materials (dense materials with nanosized grains) against net defect accumulation. However, irradiation-induced grain growth leads to grain boundary area decrease, shortening potential benefits of nanostructures. A possible approach to mitigate this is the introduction of dopants to target a decrease in grain boundary mobility or a reduction in grain boundary energy to eliminate driving forces for grain growth (using similar strategies as to control thermal growth). Here we tested this concept in nanocrystalline zirconia doped with lanthanum. Although the dopant is observed to segregate to the grain boundaries, causing grain boundary energy decrease and promoting dragging forces for thermally activated boundary movement, irradiation induced grain growth could not be avoided under heavy ion irradiation, suggesting a different growth mechanism as compared to thermal growth. Furthermore, it is apparent that reducing the grain boundary energy reduced the effectiveness of the grain boundary as sinks, and the number of defects in the doped material is higher than in undoped (La-free) YSZ. PMID:27282392

  4. Stabilisation of the grain market by the flexible use of grain for bioethanol

    NARCIS (Netherlands)

    Helming, J.F.M.; Pronk, A.; Woltjer, I.

    2010-01-01

    This report reviews whether the grain market and grain price can be stabilised by the variation of the use of grain in the EU-27's production of bioethanol. The time horizon of this study is 2020, whereby account is taken of the minimum 10% obligation for biofuel use in the EU-27. An economic comput

  5. Insect Population Dynamics in Commercial Grain Elevators

    Science.gov (United States)

    Data were collected in 1998-2002 from wheat stored in commercial grain elevators in south-central Kansas. Storage bins at these elevators had concrete walls and were typically 6-9 m in diameter and 30-35 m tall. A vacuum-probe sampler was used to collect ten 3-kg grain samples in the top 12 m of the...

  6. An Atmospheric Structure Equation for Grain Growth

    CERN Document Server

    Ormel, Chris W

    2014-01-01

    We present a method to include the evolution of the grain size and grain opacity $\\kappa_\\mathrm{gr}$ in the equations describing the structure of protoplanetary atmospheres. The key assumption of this method is that a single grain size dominates the grain size distribution at any height $r$. In addition to following grain growth, the method accounts for mass deposition by planetesimals and grain porosity. We illustrate this method by computation of a simplified atmosphere structure model. In agreement with previous works, grain coagulation is seen to be very efficient. The opacity drops to values much below the often-used `ISM-opacities' ($\\sim$$1\\ \\mathrm{cm^2\\ g}^{-1}$) and the atmosphere structure profiles for temperature and density resemble that of the grain-free case. Deposition of planetesimals in the radiative part of the atmosphere hardly influences this outcome as the added surface is quickly coagulated away. We observe a modest dependence on the internal structure (porosity), but show that filling...

  7. SEGMENTATION AND GRAIN SIZE OF CERAMICS

    Directory of Open Access Journals (Sweden)

    Xavier Arnould

    2011-05-01

    Full Text Available This paper presents some methods to automatically extract the grain boundaries of materials in order to develop an automatic method to determine the grain size and morphological parameters of ceramic materials. Results are presented in the case of sintered cerine (CeO2 materials.

  8. Topological Transformation during Normal Grain Growth

    Institute of Scientific and Technical Information of China (English)

    Chaogang LOU; Michael A.Player

    2004-01-01

    This paper investigates topological transformation during normal grain growth by carrying out a computer vertex simulation.Results show that topological correlation agrees with the models proposed by Blanc et al. and Weaire. Topological transformation occurs more often on grains with some topological classes instead of equal probability on each boundary. This can be qualitatively explained by topological correlation.

  9. Grain transport mechanics in shallow overland flow

    Science.gov (United States)

    A physical model based on continuum multiphase flow is described to represent saltating transport of grains in shallow overland flow. The two phase continuum flow of water and sediment considers coupled St.Venant type equations. The interactive cumulative effect of grains is incorporated by a disper...

  10. Grain transport mechanics in shallow flow

    Science.gov (United States)

    A physical model based on continuum multiphase flow is described to represent saltating transport of grains in shallow overland flows. The two-phase continuum flow of water and sediment considers coupled St.Venant type equations. The interactive cumulative effect of grains is incorporated by a dispe...

  11. Advances in ultrafine-grained materials

    Directory of Open Access Journals (Sweden)

    Yi Huang

    2013-03-01

    Full Text Available This review addresses new developments in the processing and properties of ultrafine-grained (UFG materials. These materials are produced through the application of severe plastic deformation to conventional coarse-grained metals and typically they have grain sizes within the submicrometer or even the nanometer range. Although several techniques are now available for achieving excellent homogeneity and high fractions of high-angle grain boundaries, this review concentrates on the major procedures of equal-channel angular pressing and high-pressure torsion. It is shown that UFG materials exhibit both excellent strength at ambient temperature and, if the grains are reasonably stable, outstanding superplastic properties at elevated temperatures. These materials also have a high innovation potential for use in commercial applications.

  12. Grain boundary strengthening in austenitic nitrogen steels

    International Nuclear Information System (INIS)

    The effect of nitrogen and carbon on the strengthening of the austenitic steel Cr18Ni16Mn10 by grain boundaries is studied. It is established in accordance with previous results that contrary to carbon nitrogen increases the coefficient k in the Hall-Petch equation markedly. Because of a pronounced planar slip induced by nitrogen and the absence of any noticeable segregation of nitrogen atoms at the grain boundaries, nitrogen austenite presents an excellent object for testing different existing models of grain boundary strengthening (pile-up, grain boundary dislocation sources, work hardening theories). Based on the analysis of available data and measurements of interaction between nitrogen (carbon) atoms and dislocations it is shown that the nitrogen effect can be attributed to a strong blocking of dislocation sources in grains adjacent to those where the slip started. (orig.)

  13. Grain Boundary Engineering of Electrodeposited Thin Films

    DEFF Research Database (Denmark)

    Alimadadi, Hossein

    Grain boundary engineering aims for a deliberate manipulation of the grain boundary characteristics to improve the properties of polycrystalline materials. Despite the emergence of some successful industrial applications, the mechanism(s) by which the boundary specific properties can be improved...... to engineer new materials. In this study, one of the most widely used electrolytes for electrodeposition is chosen for the synthesis of nickel films and based on thorough characterization of the boundaries the potentials in grain boundary engineering are outlined. The internal structure of the nickel films...... of the favorable boundaries that break the network of general grain boundaries. Successful dedicated synthesis of a textured nickel film fulfilling the requirements of grain boundary engineered materials, suggests improved boundary specific properties. However, the textured nickel film shows fairly low...

  14. ISOCHRONS IN PRESOLAR GRAPHITE GRAINS FROM ORGUEIL

    Energy Technology Data Exchange (ETDEWEB)

    Zinner, Ernst; Jadhav, Manavi, E-mail: ekz@wustl.edu [Laboratory for Space Sciences and the Physics Department, Washington University, One Brookings Drive, St. Louis, MO 63130 (United States)

    2013-05-10

    Primitive meteorites contain tiny dust grains that condensed in stellar outflows and explosions. These stardust grains can be extracted from their host meteorites and studied in detail in the laboratory. We investigated depth profiles of the Al-Mg, Ca-K, and Ti-Ca isotopic systems obtained during NanoSIMS isotopic analysis of presolar graphite grains from the CI carbonaceous meteorite Orgueil. Large {sup 26}Al/{sup 27}Al, {sup 41}Ca/{sup 40}Ca, and {sup 44}Ti/{sup 48}Ti ratios, inferred from {sup 26}Mg, {sup 41}K, and {sup 44}Ca excesses from the decay of the short-lived radioisotopes {sup 26}Al, {sup 41}Ca, and {sup 44}Ti, indicate a supernova (SN) origin. From the depth distribution of the radiogenic isotopes and the stable isotopes of their parent elements we constructed isochron-type correlation plots. The plots indicate quantitative retention of radiogenic {sup 26}Mg, {sup 41}K, and {sup 44}Ca in most grains. Deviations from straight lines in the Al-Mg and Ca-K plots can be explained by contamination with {sup 27}Al and isotopically normal Ca, respectively. For the Ti-Ca system in some grains, the lack of parent-daughter correlation indicates either redistribution of radiogenic {sup 44}Ca or heterogeneity in the initial {sup 44}Ti/{sup 48}Ti ratio. We also obtained Si isotopic depth profiles in three graphite grains with large {sup 29}Si and {sup 30}Si excesses, for which a SN origin has been proposed. In two grains no Si-rich subgrains are observed; in the third grain with an apparent Si-rich subgrain the anomalous Si isotopic ratios in the subgrain are the same as in the rest of the graphite host. Our studies show that by measuring depth profiles, information on presolar grains can be obtained that cannot be obtained by whole-grain analysis.

  15. Grain Boundary Effects in Solid Oxide Electrolytes

    Science.gov (United States)

    Ng, Mai

    Ion conducting ceramics are essential in applications such as solid oxide fuel cells and oxygen sensors. Traditional 8 mol% yttria-stabilized zirconia (8YSZ) solid oxide electrolytes operate at high temperatures (850°C-1000°C) to achieve high ionic conductivity (> 0.1 Scm-1 at 1000°C) by oxygen ion diffusion via vacancies. Operation at such temperatures requires high temperature electrode materials and shortens device lifetime due to interdiffusion and reactions at electrode/electrolyte interfaces. These concerns drive research in current systems and alternative materials to improve ionic conductivity at reduced operating temperatures. This research considers how grain size and grain boundary phases affect three electrolyte materials with different ion diffusion mechanisms. First, the conductivity of ultra-fine grained two-step sintered and large grained conventional sintered 8YSZ are compared to determine if enhanced ionic conductivity occurs supporting the theory that ion blocking impurities in grain boundaries are diluted with decreasing grain size. Second, apatite-type lanthanide silicates (Ln9.33(SiO4)6O2) which exhibit anisotropic interstitial oxygen diffusion at intermediate temperatures (400°C-800°C) are studied to determine whether grain boundaries detrimentally affect conductivity. Lastly, proton conducting La-monazite (LaPO4) is evaluated to determine the role of Sr-doping (up to 10% substitution of La with Sr) on grain size and conductivity as well as the effect of sintering in air or water vapor on the formation of intergranular phases rich in Sr and P. This research investigates grain boundary effects in three solid oxide electrolyte materials with the goal of understanding how grain boundaries affect ionic conductivity and the atomistic behavior governing these different diffusion mechanisms.

  16. Influence of China’s Grain Industrial Market Structure over Grain Pricing Power

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    From the point of view of industrial market structure,we analyze the influence of market structure on grain production,circulation,and processing,and on the grain pricing power of entities along China’s grain industrial chain.Through analysis,it is indicated that different features of market structure play a significant role in pricing power of such microeconomic entities as farmers and grain enterprises in grain production and transaction.And the market structure determines welfare distribution model of consumers’ surplus and producers’ surplus at the market.

  17. Abnormal grain growth in Ni-5at.%W

    Science.gov (United States)

    Witte, M.; Belde, M.; Barrales Mora, L.; de Boer, N.; Gilges, S.; Klöwer, J.; Gottstein, G.

    2012-12-01

    The growth of abnormally large grains in textured Ni-5at.%W substrates for high-temperature superconductors deteriorates the sharp texture of these materials and thus has to be avoided. Therefore the growth of abnormal grains is investigated and how it is influenced by the grain orientation and the annealing atmosphere. Texture measurements and grain growth simulations show that the grain orientation only matters so far that a high-angle grain boundary exists between an abnormally growing grain and the Cube-orientated matrix grains. The annealing atmosphere has a large influence on abnormal grain growth which is attributed to the differences in oxygen partial pressure.

  18. Phloem Transport of Arsenic Species from Flag Leaf to Grain During Grain Filling

    Energy Technology Data Exchange (ETDEWEB)

    A Carey; G Norton; C Deacon; K Scheckel; E Lombi; T Punshon; M Guerinot; A Lanzirotti; M Newville; et al.

    2011-12-31

    Strategies to reduce arsenic (As) in rice grain, below concentrations that represent a serious human health concern, require that the mechanisms of As accumulation within grain be established. Therefore, retranslocation of As species from flag leaves into filling rice grain was investigated. Arsenic species were delivered through cut flag leaves during grain fill. Spatial unloading within grains was investigated using synchrotron X-ray fluorescence (SXRF) microtomography. Additionally, the effect of germanic acid (a silicic acid analog) on grain As accumulation in arsenite-treated panicles was examined. Dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA) were extremely efficiently retranslocated from flag leaves to rice grain; arsenate was poorly retranslocated, and was rapidly reduced to arsenite within flag leaves; arsenite displayed no retranslocation. Within grains, DMA rapidly dispersed while MMA and inorganic As remained close to the entry point. Germanic acid addition did not affect grain As in arsenite-treated panicles. Three-dimensional SXRF microtomography gave further information on arsenite localization in the ovular vascular trace (OVT) of rice grains. These results demonstrate that inorganic As is poorly remobilized, while organic species are readily remobilized, from leaves to grain. Stem translocation of inorganic As may not rely solely on silicic acid transporters.

  19. A constitutive model of nanocrystalline metals based on competing grain boundary and grain interior deformation mechanisms

    KAUST Repository

    Gurses, Ercan

    2011-12-01

    In this work, a viscoplastic constitutive model for nanocrystalline metals is presented. The model is based on competing grain boundary and grain interior deformation mechanisms. In particular, inelastic deformations caused by grain boundary diffusion, grain boundary sliding and dislocation activities are considered. Effects of pressure on the grain boundary diffusion and sliding mechanisms are taken into account. Furthermore, the influence of grain size distribution on macroscopic response is studied. The model is shown to capture the fundamental mechanical characteristics of nanocrystalline metals. These include grain size dependence of the strength, i.e., both the traditional and the inverse Hall-Petch effects, the tension-compression asymmetry and the enhanced rate sensitivity. © 2011 Elsevier B.V. All rights reserved.

  20. Photoluminescence Imaging of Large-Grain CdTe for Grain Boundary Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, Steve; Allende Motz, Alyssa; Reese, Matthew O.; Burst, James M.; Metzger, Wyatt K.

    2015-06-14

    In this work, we use photoluminescence (PL) imaging to characterize CdTe grain boundary recombination. We use a silicon megapixel camera and green (532 nm) laser diodes for excitation. A microscope objective lens system is used for high spatial resolution and a field of view down to 190 um x 190 um. PL images of large-grain (5 to 50 um) CdTe samples show grain boundary and grain interior features that vary with processing conditions. PL images of samples in the as-deposited state show distinct dark grain boundaries that suggest high excess carrier recombination. A CdCl2 treatment leads to PL images with very little distinction at the grain boundaries, which illustrates the grain boundary passivation properties. Other process conditions are also shown, along with comparisons of PL images to high spatial resolution time-resolved PL carrier lifetime maps.

  1. Transfer of radioiodine into rice grains

    International Nuclear Information System (INIS)

    It is known that 129I levels near the spent fuel reprocessing plants are obviously higher than those in the other areas. At present commercial spent fuel reprocessing plant is under planning in the north of Japan mainland. For the safety assessment before the new-construction of the plant, it is required to obtain transfer factors of the nuclide to rice grains through deposition-translocation and rootuptake routes. Results obtained showed that contribution from dry deposition (I2 gas deposition)-translocation should be more significant than that from wet-deposition-translocation, but sometimes comparable or preferably less significant than that from root uptake route. In this paper, however, discussion is focused on I2 gas deposition translocation to rice grains, gaseous iodine deposition to hull surfaces and subsequent infiltration to brown rice should be more critical than leaf absorption-translocation. Excretion of the nuclide from hull surfaces was hardly recognized. Thus the transfer factor of gaseous 129I to rice grains was successfully obtained by using grain number deposition velocity (Vs) and distribution ratio of I between rough rice and rice grain. Ther Vs is given as following: Vs = the amount of iodine deposited on unit number of rough rice per unit time divided by iodine concentration in unit volume of air. Experimentally obtained Vs is about 5x10-3cm3.(grain.sec)-1. And the transfer factor of gaseous iodine (I2) to polished rice is calculated as about 4x102cm3.(grain)-1

  2. Interstellar chemical differentiation across grain sizes

    Science.gov (United States)

    Ge, J. X.; He, J. H.; Li, Aigen

    2016-07-01

    In this work, we investigate the effects of ion accretion and size-dependent dust temperatures on the abundances of both gas-phase and grain-surface species. While past work has assumed a constant areal density for icy species, we show that this assumption is invalid and the chemical differentiation over grain sizes is significant. We use a gas-grain chemical code to demonstrate this numerically for two typical interstellar conditions: a dark cloud (DC) and a cold neutral medium (CNM). It is shown that, although the grain-size distribution variation (but with the total grain surface area unchanged) has little effect on the gas-phase abundances, it can alter the abundances of some surface species by up to ∼2-4 orders of magnitude. The areal densities of ice species are larger on smaller grains in the DC model as a consequence of ion accretion. However, the surface areal density evolution tracks are more complex in the CNM model due to the combined effects of ion accretion and dust temperature variation. The surface areal density differences between the smallest ( ∼ 0.01 μm) and the biggest ( ∼ 0.2 μm) grains can reach ∼1 and ∼5 orders of magnitude in the DC and CNM models, respectively.

  3. Densification and grain coarsening of melting snow

    Institute of Scientific and Technical Information of China (English)

    周石硚; 中尾正义; 桥本重将; 坂井亚规子; 成田英器; 石川信敬

    2003-01-01

    A field work was conducted at Moshiri in Japan.The work included intensive snow pit work, taking snow grain photos, recording snow and air temperatures, as well as measuring snow water content.By treating the snow as a viscous fluid, it is found that the snow compactive viscosity decreases as the density increases, which is opposite to the relation for dry snow.Based on the measurements of snow grain size, it is shown that, similar to the water-saturated snow, the frequency distributions of grain size at different times almost have the same shape.This reveals that the water-unsaturated melting snow holds the same grain-coarsening behavior as the water-saturated snow does.It is also shown that the water-unsaturated melting snow coarsens much more slowly than the water-saturated snow.The C value, which is the viscosity when the snow density is zero, is related to the mean grain size and found to decrease with increasing grain size.The decreasing rate of C value increases with decreasing grain-coarsening rate.

  4. The Search for Interstellar Sulfide Grains

    Science.gov (United States)

    Keller, Lindsay P.; Messenger, Scott

    2010-01-01

    The lifecycle of sulfur in the galaxy is poorly understood. Fe-sulfide grains are abundant in early solar system materials (e.g. meteorites and comets) and S is highly depleted from the gas phase in cold, dense molecular cloud environments. In stark contrast, sulfur is essentially undepleted from the gas phase in the diffuse interstellar medium, indicating that little sulfur is incorporated into solid grains in this environment. It is widely believed that sulfur is not a component of interstellar dust grains. This is a rather puzzling observation unless Fe-sulfides are not produced in significant quantities in stellar outflows, or their lifetime in the ISM is very short due to rapid destruction. Fe sulfide grains are ubiquitous in cometary samples where they are the dominant host of sulfur. The Fe-sulfides (primarily pyrrhotite; Fe(1-x)S) are common, both as discrete 0.5-10 micron-sized grains and as fine (5-10 nm) nanophase inclusions within amorphous silicate grains. Cometary dust particles contain high abundances of well-preserved presolar silicates and organic matter and we have suggested that they should contain presolar sulfides as well. This hypothesis is supported by the observation of abundant Fe-sulfides grains in dust around pre- and post-main sequence stars inferred from astronomical spectra showing a broad 23 micron IR feature due to FeS. Fe-sulfide grains also occur as inclusions in bona fide circumstellar amorphous silicate grains and as inclusions within deuterium-rich organic matter in cometary dust samples. Our irradiation experiments show that FeS is far more resistant to radiation damage than silicates. Consequently, we expect that Fe sulfide stardust should be as abundant as silicate stardust in solar system materials.

  5. Tracing magnetic fields with aligned grains

    Energy Technology Data Exchange (ETDEWEB)

    Lazarian, A. [Astronomy Department, University of Wisconsin-Madison, 475 N. Charter St., Madison, WI 53706 (United States)]. E-mail: lazarian@astro.wisc.edu

    2007-07-15

    Magnetic fields play a crucial role in various astrophysical processes, including star formation, accretion of matter, transport processes (e.g., transport of heat), and cosmic rays. One of the easiest ways to determine the magnetic field direction is via polarization of radiation resulting from extinction or/and emission by aligned dust grains. Reliability of interpretation of the polarization maps in terms of magnetic fields depends on how well we understand the grain-alignment theory. Explaining what makes grains aligned has been one of the big issues of the modern astronomy. Numerous exciting physical effects have been discovered in the course of research undertaken in this field. As both the theory and observations matured, it became clear that the grain-alignment phenomenon is inherent not only in diffuse interstellar medium or molecular clouds but also is a generic property of the dust in circumstellar regions, interplanetary space and cometary comae. Currently the grain-alignment theory is a predictive one, and its results nicely match observations. Among its predictions is a subtle phenomenon of radiative torques. This phenomenon, after having stayed in oblivion for many years after its discovery, is currently viewed as the most powerful means of alignment. In this article, I shall review the basic physical processes involved in grain alignment, and the currently known mechanisms of alignment. I shall also discuss possible niches for different alignment mechanisms. I shall dwell on the importance of the concept of grain helicity for understanding of many properties of grain alignment, and shall demonstrate that rather arbitrarily shaped grains exhibit helicity when they interact with gaseous and radiative flows.

  6. Static Recrystallized Grain Size of Coarse-Grained Austenite in an API-X70 Pipeline Steel

    Science.gov (United States)

    Sha, Qingyun; Li, Guiyan; Li, Dahang

    2013-12-01

    The effects of initial grain size and strain on the static recrystallized grain size of coarse-grained austenite in an API-X70 steel microalloyed with Nb, V, and Ti were investigated using a Gleeble-3800 thermomechanical simulator. The results indicate that the static recrystallized grain size of coarse-grained austenite decreases with decreasing initial grain size and increasing applied strain. The addition of microalloying elements can lead to a smaller initial grain size for hot deformation due to the grain growth inhibition during reheating, resulting in decreasing of static recrystallized grain size. Based on the experimental data, an equation for the static recrystallized grain size was derived using the least square method. The grain sizes calculated using this equation fit well with the measured ones compared with the equations for fine-grained austenite and for coarse-grained austenite of Nb-V microalloyed steel.

  7. RF installation for the grain disinfestation

    CERN Document Server

    Zajtzev, B V; Kobetz, A F; Rudiak, B I

    2001-01-01

    The ecologically pure method of grain product disinfestations through the grain treatment with the RF electric field is described. The experimental data obtained showed that with strengths of the electrical RF field of E=5 kV/cm and frequency of 80 MHz the relative death rate is 100%.The time of the grain treatment it this case is 1 sec. The pulses with a duration of 600 mu s and repetition rate of 2 Hz were used, the duration of the front was 10 mu s. The schematic layout of installation with a productivity of 50 tones/h and power of 10 kW is given.

  8. CASS Ferrite and Grain Structure Relationship

    Energy Technology Data Exchange (ETDEWEB)

    Ruud, Clayton O. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ramuhalli, Pradeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Meyer, Ryan M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Diaz, Aaron A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Anderson, Michael T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-07-13

    This document summarizes the results of research conducted at Pacific Northwest National Laboratory (PNNL) to determine whether, based on experimental measurements, a correlation existed between grain structure in cast austenitic stainless steel (CASS) piping and ferrite content of the casting alloy. The motivation for this research lies in the fact that ultrasonic testing (UT) is strongly influenced by CASS grain structure; knowledge of this grain structure may help improve the ability to interpret UT responses, thereby improving the overall reliability of UT inspections of CASS components.

  9. EQUATIONS FOR GRAIN SIZE DISTRIBUTION CURVE

    Institute of Scientific and Technical Information of China (English)

    Prabhata K.SWAMEE; Nimisha SWAMEE

    2004-01-01

    The grain size distribution of particulate material is of particular interest in the field of sediment transport. The size distribution is described by various equations, however no equation is flexible enough to satisfy the grain size distribution data faithfully. Presented herein are the equations for unimodal and multimodal grain size distribution curves. A graphical method has been given to evaluate the parameters involved in these equations. The size distribution equation can be used to estimate many properties of sediment sample like number of sediment particles, surface area of the particles and hydraulic conductivity. It is hoped that the equations will find many applications in studying sedimentation processes.

  10. Analysis of airborne pollen grains in Denizli

    OpenAIRE

    GÜVENSEN, Aykut; ÇELİK, Ali; TOPUZ, Bülent; ÖZTÜRK, Münir

    2013-01-01

    Airborne pollen distribution in Denizli Province was measured volumetrically during 2 consecutive years, 2005 and 2006, on a weekly basis. A total of 11,981 pollen grains/m3 belonging to 42 taxa were determined. In 2005 the total was 5368 pollen grains/m3 and in 2006 it was 6613 pollen grains/m3. Among the taxa recorded, 26 belonged to arboreal and 16 to nonarboreal taxa. At the end of the 2 years total pollen counts comprised 79.68% arboreal, 19.48% nonarboreal, and 0.84% unidentified taxa. ...

  11. Optical sizing of irregular snow grains

    Directory of Open Access Journals (Sweden)

    A. A. Kokhanovsky

    2011-09-01

    Full Text Available We discuss a possibility of snow grain size determination using spectral reflectance measurements in the near-infrared part of the electromagnetic spectrum. Errors related to often made assumption of the sphericity of grains are studied. Also we introduce a new method for the snow albedo and snow pollution monitoring using measurements in the visible part of the electromagnetic theory. Both exact and approximate methods of the radiative transfer are used for the solution of corresponding inverse problem. It is assumed that snow grains can be presented as randomly distributed irregular fractal particles. The developed techniques are applied to both ground and satellite data.

  12. Parsing abnormal grain growth in specialty aluminas

    Science.gov (United States)

    Lawrence, Abigail Kremer

    Grain growth in alumina is strongly affected by the impurities present in the material. Certain impurity elements are known to have characteristic effects on abnormal grain growth in alumina. Specialty alumina powders contain multiple impurity species including MgO, CaO, SiO2, and Na 2O. In this work, sintered samples made from alumina powders containing various amounts of the impurities in question were characterized by their grain size and aspect ratio distributions. Multiple quantitative methods were used to characterize and classify samples with varying microstructures. The grain size distributions were used to partition the grain size population into subpopulations depending on the observed deviation from normal behavior. Using both grain size and aspect ratio a new visual representation for a microstructure was introduced called a morphology frequency map that gives a fingerprint for the material. The number of subpopulations within a sample and the shape of the distribution on the morphology map provided the basis for a classification scheme for different types of microstructures. Also using the two parameters a series of five metrics were calculated that describe the character of the abnormal grains in the sample, these were called abnormal character values. The abnormal character values describe the fraction of grains that are considered abnormal, the average magnitude of abnormality (including both grain size and aspect ratio), the average size, and variance in size. The final metric is the correlation between grain size and aspect ratio for the entire population of grains. The abnormal character values give a sense of how different from "normal" the sample is, given the assumption that a normal sample has a lognormal distribution of grain size and a Gaussian distribution of aspect ratios. In the second part of the work the quantified measures of abnormality were correlated with processing parameters such as composition and heat treatment conditions. A

  13. The use of cover crops to increase soil organic carbon in Mediterranean vineyards

    Science.gov (United States)

    García-Díaz, Andrés; Bienes Allas, Ramón; Sastre Rodriguez, Blanca

    2016-04-01

    In Central Spain the vineyards are commonly managed with conventional tillage (CT) to remove water and nutrient competition between the spontaneous vegetation and the vine plants. The continuous tillage promotes high mineralization rates resulting in soils with low organic matter content and prone to erosion. Consequently the increase of soil organic carbon (SOC) in Mediterranean soils has been a main concern in the last years. It is necessary to carry out different soil managements to enhance soil fertility and reduce erosion through the increase of SOC. The aim of this study was to assess the capacity of cover crops (CC) to increase SOC in vineyards in Mediterranean climate. The experiment consisted in four vineyards in four different locations (different type of soil and microclimate), in the same region, to analyze the influence of CC on different conditions. A seeded CC (Brachypodium distachyon L. P. Beauv) and spontaneous vegetation were performed to compare to CT. The Brachypodium distachyon cover was seeded in December, 2012. We analyzed the organic carbon content and bulk density after three agronomy seasons. The samples were taken in the summer of 2015 at the depth of 0-5 cm. The bulk density of Brachypodium distachyon was 1.42 t•m-3, which was statistically significant comparing to both CT (1.33 t•m-3) and spontaneous vegetation (1.34 t•m-3). The SOC percentage of CT, Brachypodium distachyon and spontaneous vegetation was 0.82, 0.96 and 1.10 respectively. Only spontaneous vegetation showed statistically significant differences compared to CT. The results were highly variable depending on the vineyard. The spontaneous vegetation was the most effective CC increasing SOC with an average of 2 t•ha-1 more than CT in three agronomy seasons. These results point out the different efficiency of CC and the high influence of local conditions on SOC increase.

  14. Hard-core thinnings of germ-grain models with power-law grain sizes

    CERN Document Server

    Kuronen, Mikko

    2012-01-01

    Random sets with long-range dependence can be generated using a Boolean model with power-law grain sizes. We study thinnings of such Boolean models which have the hard-core property that no grains overlap in the resulting germ-grain model. A fundamental question is whether long-range dependence is preserved under such thinnings. To answer this question we study four natural thinnings of a Poisson germ-grain model where the grains are spheres with a regularly varying size distribution. We show that a thinning which favors large grains preserves the slow correlation decay of the original model, whereas a thinning which favors small grains does not. Our most interesting finding concerns the case where only disjoint grains are retained, which corresponds to the well-known Mat\\'ern type I thinning. In the resulting germ-grain model, typical grains have exponentially small sizes, but rather surprisingly, the long-range dependence property is still present. As a byproduct, we obtain new mechanisms for generating hom...

  15. Global Goss grain growth and grain boundary characteristics in magnetostrictive Galfenol sheets

    International Nuclear Information System (INIS)

    Single Goss grains were globally grown in magnetostrictive Galfenol thin sheets via an abnormal grain growth (AGG) process. The sample behaves like single crystal Galfenol, exhibiting large magnetostriction along the 〈100〉 axes. Small variations in surface energy conditions, which were governed by different flow rates of 0.5% H2S gas in argon during annealing, had a significant impact of the development of AGG. AGG with a fully developed Goss (011) grain over 95% of the sample surface is very reproducible and feasible for a broad range of annealing conditions. In addition, the 〈100〉 orientation of the single-crystal-like Galfenol sheet aligns exactly with the rolling direction, and produces magnetostriction values of ∼300 ppm. AGG often produces isolated grains inside Goss grains due to anisotropic properties of grain boundaries. To better understand island formation mechanisms, grain orientation and grain boundary characteristics of island grains in Goss-oriented Galfenol thin sheets were also investigated. We examined samples annealed either under an argon atmosphere or under a sulfur atmosphere, and characterized the observed island grain boundaries in terms of grain misorientation angles. Trends in measured and simulated data on misorientation angles indicate that the presence of (001) island grain boundaries with angles higher than 45° can be explained by the high energy grain boundary (HEGB) model, whereas (111) boundaries with intermediate angles (20°–45°) cannot. The role of low energy coincident site lattice (CSL) boundaries on AGG in both annealing cases was found to be negligible. (paper)

  16. Scale effect and geometric shapes of grains

    Institute of Scientific and Technical Information of China (English)

    GUO Hui; GUO Xing-ming

    2007-01-01

    The rule-of-mixture approach has become one of the widely spread ways to investigate the mechanical properties of nano-materials and nano-structures, and it is very important for the simulation results to exactly compute phase volume fractions. The nanocrystalline (NC) materials are treated as three-phase composites consisting of grain core phase, grain boundary (GB) phase and triple junction phase, and a two-dimensional three-phase mixture regular polygon model is established to investigate the scale effect of mechanical properties of NC materials due to the geometrical polyhedron characteristics of crystal grain. For different multi-sided geometrical shapes of grains, the corresponding regular polygon model is adopted to obtain more precise phase volume fractions and exactly predict the mechanical properties of NC materials.

  17. Transient solute drag in migrating grain boundaries

    International Nuclear Information System (INIS)

    Understanding the solute drag in migrating grain boundaries or interfaces has been a topic in materials research since Cahn's seminal paper in 1962. However, mostly steady-state solutions for solute segregation and drag in a migrating interface have been investigated. Here a new concept, based on the thermodynamic extremal principle, is introduced, which allows a detailed study of the transient processes in the migrating interface starting from a given initial configuration. The system is then described by two parameters, the first representing the amount of segregated solute in the grain boundary and the second the grain boundary position. Stability studies are performed using the perturbation concept. The model is demonstrated by simulations for a Fe-0.1 at.% Ni alloy taking different values for the grain boundary mobility and the driving force.

  18. Grain sedimentation inside giant planet embryos

    CERN Document Server

    Nayakshin, Sergei

    2010-01-01

    In the context of massive fragmenting protoplanetary discs, Boss (1998) suggested that grains can grow and sediment inside giant planet embryos formed at R ~ 5 AU away from the star. Several authors since then criticised the suggestion. Convection may prevent grain sedimentation, and the embryos cannot even form so close to the parent star as cooling is too inefficient at these distances. Here we reconsider the grain sedimentation process suggested by Boss (1998) but inside an embryo formed, as expected in the light of the cooling constraints, at R ~ 100 AU. Such embryos are much less dense and are also cooler. We make analytical estimates of the process and also perform simple spherically symmetric radiation hydrodynamics simulations to test these ideas. We find that convection in our models does not become important before a somewhat massive (~ an Earth mass, this is clarified in a followup paper) solid core is built. Turbulent mixing slows down dust sedimentation but is overwhelmed by grain sedimentation w...

  19. The NGDC Seafloor Sediment Grain Size Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NGDC (now NCEI) Seafloor Sediment Grain Size Database contains particle size data for over 17,000 seafloor samples worldwide. The file was begun by NGDC in 1976...

  20. Grain operator miffed at port administration

    Index Scriptorium Estoniae

    2006-01-01

    Ventspils Grain Terminal saatis president Vaira Vike-Freibergale ja mitmetele ministritele kirja sõnumiga, et Ventspilsi Vabasadama (Ventspils Free Port) administratsiooni tegevus takistab terminali äritegevust

  1. Topological and metrical aspects of normal and abnormal grain growth

    Directory of Open Access Journals (Sweden)

    Paulo Rangel Rios

    2007-12-01

    Full Text Available Grain growth theories normally describe a grain using the concept of ‘grain radius’. However, this assumption bypasses all topological information relating to the grain, viz., the number of its faces, edges, etc. This study, by contrast, introduces a new methodology, treating normal and abnormal grain growth in three dimensions in terms of both metrical and topological properties of the grains.

  2. Analysis on Stability Factors of Grain Price in China

    Institute of Scientific and Technical Information of China (English)

    Li Cui-xia; Zhang Yu-ling

    2012-01-01

    To make grain price stable is an important goal for the Chinese government. The paper compared the grain supply elasticity and demand elasticity to determine the grain price stability in China; used "k value" method to analyze the grain price fluctuation from 1985 to 2010; divided the grain price volatility into three stages; and analyzed the factors in each phase. On the base, it put forward some countermeasures to guarantee the stability of the grain price.

  3. Thermomagnetic Stability in Pseudo Single Domain Grains

    Science.gov (United States)

    Nagy, Lesleis; Williams, Wyn; Muxworthy, Adrian; Fabian, Karl; Conbhuí, Pádraig Ó.

    2016-04-01

    The reliability of paleomagnetic remanences are well understood for fine grains of magnetite that are single-domain (SD, uniformly magnetized). In particular Néel's theory [1] outlined the thermal energies required to block and unblock magnetic remanences. This lead to determination of thermal stability for magnetization in fine grains as outlined in Pullaiah et. al. [2] and a comprehensive understanding of SD paleomagnetic recordings. It has been known for some time that single domain magnetite is possible only in the grain size range 30 - 80nm, which may only account for a small fraction of the grain size distribution in any rock sample. Indeed rocks are often dominated by grains in the pseudo single domain (PSD) size range, at approximately 80 - 1000nm. Toward the top end of this range multi-domain features begin to dominate. In order to determine thermomagnetic stability in PSD grains we need to identify the energy barriers between all possible pairs of local energy minima (LEM) domain states as a function of both temperature and grain size. We have attempted to do this using the nudged elastic band (NEB) method [3] which searches for minimum energy paths between any given pair of LEM states. Using this technique we have determined, for the first time, complete thermomagnetic stability curves for PSD magnetite. The work presented is at a preliminary stage. However it can be shown that PSD grains of magnetite with simple geometries (e.g. cubes or cuboctahedra) have very few low energy transition paths and the stability is likely to be similar to that observed for SD grains (as expected form experimental observations). The results will provide a basis for a much more rigorous understanding of the fidelity of paleomagnetic signals in assemblages of PSD grains and their ability to retain ancient recordings of the geomagnetic field. References: [1] Néel, Louis. "Théorie du traînage magnétique des ferromagnétiques en grains fins avec applications aux terres

  4. Lifetime grain consumption and breast cancer risk.

    Science.gov (United States)

    Farvid, Maryam S; Cho, Eunyoung; Eliassen, A Heather; Chen, Wendy Y; Willett, Walter C

    2016-09-01

    We evaluated individual grain-containing foods and whole and refined grain intake during adolescence, early adulthood, and premenopausal years in relation to breast cancer risk in the Nurses' Health Study II. Grain-containing food intakes were reported on a baseline dietary questionnaire (1991) and every 4 years thereafter. Among 90,516 premenopausal women aged 27-44 years, we prospectively identified 3235 invasive breast cancer cases during follow-up to 2013. 44,263 women reported their diet during high school, and from 1998 to 2013, 1347 breast cancer cases were identified among these women. Cox proportional hazards regression was used to estimate relative risks (RR) and 95 % confidence intervals (95 % CI) of breast cancer for individual, whole and refined grain foods. After adjusting for known breast cancer risk factors, adult intake of whole grain foods was associated with lower premenopausal breast cancer risk (highest vs. lowest quintile: RR 0.82; 95 % CI 0.70-0.97; P trend = 0.03), but not postmenopausal breast cancer. This association was no longer significant after further adjustment for fiber intake. The average of adolescent and early adulthood whole grain food intake was suggestively associated with lower premenopausal breast cancer risk (highest vs lowest quintile: RR 0.74; 95 % CI 0.56-0.99; P trend = 0.09). Total refined grain food intake was not associated with risk of breast cancer. Most individual grain-containing foods were not associated with breast cancer risk. The exceptions were adult brown rice which was associated with lower risk of overall and premenopausal breast cancer (for each 2 servings/week: RR 0.94; 95 % CI 0.89-0.99 and RR 0.91; 95 % CI 0.85-0.99, respectively) and adult white bread intake which was associated with increased overall breast cancer risk (for each 2 servings/week: RR 1.02; 95 % CI 1.01-1.04), as well as breast cancer before and after menopause. Further, pasta intake was inversely associated with

  5. Combining ability of white grain popcorn populations

    OpenAIRE

    Carlos Alberto Scapim; Ronald José Barth Pinto; Antônio Teixeira do Amaral Júnior; Freddy Mora; Thatiana Silva Dandolini

    2006-01-01

    The objectives of this study were to indicate the best improvement strategy and select parents to begin animprovement program of white grain popcorn based on the combining ability and heterosis of eight populations selected inexperiments in the northwestern region of Paraná. The traits plant and ear height, grain yield and popping expansion wereevaluated. The base populations, the F1 and five controls were evaluated in Maringá, state of Paraná, over the course of twoyears. Heterosis for poppi...

  6. Antioxidant Properties of Whole Grain Cereals

    OpenAIRE

    Čukelj, Nikolina; Novotny, Dubravka; Ćurić, Duška

    2010-01-01

    Cereals have a long history of use by humans. Cereals and cereal products are staple foods, and are important source of energy, carbohydrate, protein, fibre, vitamins (E, B) and minerals (Zn, Mg, Fe) in both developed and developing countries. The health aspects of whole grain cereals have long been known, but the antioxidant profile of whole grains has only recently been introduced to the antioxidant research community where mostly fruits and vegetables are in focus. In vitro experiments con...

  7. Whole Grain Intake Reduces Pancreatic Cancer Risk

    OpenAIRE

    Lei, Qiucheng; Zheng, Huazhen; Bi, Jingcheng; Wang, Xinying; Jiang, Tingting; Gao, Xuejin; Tian, Feng; Xu, Min; Wu, Chao; Zhang, Li; Ning LI; Li, Jieshou

    2016-01-01

    Abstract Mounting evidence from epidemiology studies suggests that whole grain intake may reduce pancreatic cancer risk, but convincing evidence is scarce. We conducted a meta-analysis to assess the association between whole grain intake and pancreatic cancer risk. Relevant observational studies were identified by searching PubMed, Embase, Scopus, and Cochrane library databases for the period from January 1980 to July 2015, with no restrictions. We calculated the summary odds ratios (ORs) for...

  8. Coarse graining lessons from simple examples

    CERN Document Server

    Akritas, P; Yarevsky, E

    2001-01-01

    We assess Coarse Graining by studying different partitions of the phase space of the Baker transformation and the periodic torus automorphisms. It turns out that the shape of autocorrelation functions for the Baker transformation is more or less reproduced. However, for certain partitions the decay rates turn out to be irrelevant, even decay may stop in a finite time. For the periodic torus automorphisms, Coarse Graining introduces artificial dumping.

  9. THE ECONOMICS OF GRAIN PRODUCER CARTELS

    OpenAIRE

    Gleckler, James; Tweeten, Luther G.

    1994-01-01

    The objective of this study is to measure economic payoffs from a grain cartel. Two basic approaches to extract economic rents are considered: (i) Mandatory supply controls to restrict production and raise grain price, and (2) export price discrimination using export taxes or subsidies. The economic impacts of different producer cartel scenarios were estimated using a long-term, nine-region world trade simulation model incorporating the assumptions of neoclassical trade theory. The SWOPSIM pr...

  10. Optical sizing of irregular snow grains

    OpenAIRE

    Kokhanovsky, A. A.

    2011-01-01

    We discuss a possibility of snow grain size determination using spectral reflectance measurements in the near-infrared part of the electromagnetic spectrum. Errors related to often made assumption of the sphericity of grains are studied. Also we introduce a new method for the snow albedo and snow pollution monitoring using measurements in the visible part of the electromagnetic theory. Both exact and approximate methods of the radiative transfer are used for the solution of corresponding inve...

  11. Interstellar chemical differentiation across grain sizes

    CERN Document Server

    Ge, Jixing; Li, Aigen

    2016-01-01

    In this work we investigate the effects of ion accretion and size-dependent dust temperatures on the abundances of both gas-phase and grain-surface species. While past work has assumed a constant areal density for icy species, we show that this assumption is invalid and the chemical differentiation over grain sizes are significant. We use a gas-grain chemical code to numerically demonstrate this in two typical interstellar conditions: dark cloud (DC) and cold neutral medium (CNM). It is shown that, although the grain size distribution variation (but with the total grain surface area unchanged) has little effect on the gas-phase abundances, it can alter the abundances of some surface species by factors up to $\\sim2-4$ orders of magnitude. The areal densities of ice species are larger on smaller grains in the DC model as the consequence of ion accretion. However, the surface areal density evolution tracks are more complex in the CNM model due to the combined effects of ion accretion and dust temperature variati...

  12. GRAIN-BOUNDARY PRECIPITATION UNDER IRRADIATION IN DILUTE BINARY ALLOYS

    Institute of Scientific and Technical Information of China (English)

    S.H. Song; Z.X. Yuan; J. Liu; R.G.Faulkner

    2003-01-01

    Irradiation-induced grain boundary segregation of solute atoms frequently bring about grain boundary precipitation of a second phase because of its making the solubility limit of the solute surpassed at grain boundaries. Until now the kinetic models for irradiation-induced grain boundary precipitation have been sparse. For this reason, we have theoretically treated grain boundary precipitation under irradiation in dilute binary alloys. Predictions ofγ'-Ni3Si precipitation at grain boundaries ave made for a dilute Ni-Si alloy subjected to irradiation. It is demonstrated that grain boundary silicon segregation under irradiation may lead to grain boundaryγ'-Ni3 Si precipitation over a certain temperature range.

  13. Effect of grain size distribution on attenuation and backscattered grain noise

    International Nuclear Information System (INIS)

    The attenuation and backscattered grain noises in pure irons were measured. From the backscattered grain noise FOM (Figure-of-merit) which is a material dependent parameter were obtained by using independent scattering model. Attenuation coefficients and FOM's were compared with the results calculated by LPM theory and the general scattering model, respectively. Although the absolute values were not exactly same between measured and calculated results, the dependencies of them on the average grain size could be confirmed. The effect of grain size distribution on attenuation and backscattered grain noise was analyzed. The different scattering mechanisms according to the ratio of wavelength to grain size were applied to the analysis of the attenuation and backscattering even in a specimen.

  14. BHQ revisited (1) - Looking at grain size

    Science.gov (United States)

    Heilbronner, Renée; Kilian, Rüdiger; Tullis, Jan

    2016-04-01

    Black Hills Quartzite (BHQ) has been used extensively in experimental rock deformation for numerous studies. Coaxial and general shear experiments have been carried out, for example, to define the dislocation creep regimes of quartz (Hirth & Tullis, 1992), to determine the effect of annealing (Heilbronner & Tullis, 2002) or to study the development of texture and microstructure with strain (Heilbronner & Tullis, 2006). BHQ was also used to determine the widely used quartz piezometer by Stipp & Tullis (2003). Among the microstructure analyses that were performed in those original papers, grain size was usually determined using CIP misorientation images. However, the CIP method (= computer-integrated polarization microscopy, details in Heilbronner and Barrett, 2014) is only capable of detecting the c-axis orientation of optically uniaxial materials and hence is only capable of detecting grain boundaries between grains that differ in c-axis orientation. One of the puzzling results we found (Heilbronner & Tullis, 2006) was that the recrystallized grain size seemed to depend on the crystallographic preferred orientation of the domain. In other words the grain size did not only depend on the flow stress but also on the orientation of the c-axis w/r to the shear direction. At the time, no EBSD analysis (electron back scatter diffraction) was carried out and hence the full crystallographic orientation was not known. In principle it is therefore possible that we missed some grain boundaries (between grains with parallel c-axes) and miscalculated our grain sizes. In the context of recent shear experiments on quartz gouge at the brittle-viscous transition (see Richter et al., this conference), where EBSD is used to measure the recrystallized grain size, we wanted to re-measure the CIP grain sizes of our 2006 samples (deformed in regime 1, 2 and 3 of dislocation) in exactly the same way. In two companion posters we use EBSD orientation imaging to repeat, refine and expand the

  15. Microtexture investigation of orientation gradients and grain subdivision in rolled coarse-grained niobium

    OpenAIRE

    Sandim, H.; Raabe, D.

    2004-01-01

    Orientation effects concerning grain subdivision and further annealing behavior of three neighboring grains were observed in 80% cold-rolled coarse-grained niobium. The present study which was conducted as a cooperation on the basis of DAAD and CAPES funding attempts to clarify the microstructural evolution of deformed niobium and the differences in terms of stored energy (boundary distribution) using high-resolution electron backscattering diffraction (FE-EBSD).

  16. Selection of common bean lines with high grain yield and high grain calcium and iron concentrations

    Directory of Open Access Journals (Sweden)

    Nerinéia Dalfollo Ribeiro

    2014-02-01

    Full Text Available Genetic improvement of common bean nutritional quality has advantages in marketing and can contribute to society as a food source. The objective of this study was to evaluate the genetic variability for grain yield, calcium and iron concentrations in grains of inbred common bean lines obtained by different breeding methods. For this, 136 F7 inbred lines were obtained using the Pedigree method and 136 F7 inbred lines were obtained using the Single-Seed Descent (SSD method. The lines showed genetic variability for grain yield, and concentrations of calcium and iron independently of the method of advancing segregating populations. The Pedigree method allows obtaining a greater number of lines with high grain yield. Selection using the SSD method allows the identification of a larger number of lines with high concentrations of calcium and iron in grains. Weak negative correlations were found between grain yield and calcium concentration (r = -0.0994 and grain yield and iron concentration (r = -0.3926. Several lines show genetic superiority for grain yield and concentrations of calcium and iron in grains and their selection can result in new common bean cultivars with high nutritional quality.

  17. SIMULATIVE INVESTIGATION OF GRAIN BOUNDARIES IN NiAl ALLOY

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Using embedded atom potentials and molecular static relaxation method or Monte Carlo relaxation method, the grain boundary atomic structures of a series of [100], [110] and [111] symmetric tilt grain boundaries in NiAl with different geometrical indexes and compositions were studied. The grain boundary energies, grain boundary cohesive energies and point defects formation energies at the grain boundary were calculated. The results show that the grain boundaries of NiAl alloy have a periodic unit structure. Grain boundary energies of Al rich grain boundary is very high, but the cohesive energies are lower than those of others. The interaction of point defects and grain boundaries shows that grain boundaries incline to absorb point defects to decrease their orders and to relax the distortions caused by point defects. The boundary atomic structures relaxed by Monte Carlo method show that the disorder of them, grain boundary energies and cohesive energies increase with increasing temperature.

  18. Organic Wheat Farming Improves Grain Zinc Concentration.

    Science.gov (United States)

    Helfenstein, Julian; Müller, Isabel; Grüter, Roman; Bhullar, Gurbir; Mandloi, Lokendra; Papritz, Andreas; Siegrist, Michael; Schulin, Rainer; Frossard, Emmanuel

    2016-01-01

    Zinc (Zn) nutrition is of key relevance in India, as a large fraction of the population suffers from Zn malnutrition and many soils contain little plant available Zn. In this study we compared organic and conventional wheat cropping systems with respect to DTPA (diethylene triamine pentaacetic acid)-extractable Zn as a proxy for plant available Zn, yield, and grain Zn concentration. We analyzed soil and wheat grain samples from 30 organic and 30 conventional farms in Madhya Pradesh (central India), and conducted farmer interviews to elucidate sociological and management variables. Total and DTPA-extractable soil Zn concentrations and grain yield (3400 kg ha-1) did not differ between the two farming systems, but with 32 and 28 mg kg-1 respectively, grain Zn concentrations were higher on organic than conventional farms (t = -2.2, p = 0.03). Furthermore, multiple linear regression analyses revealed that (a) total soil zinc and sulfur concentrations were the best predictors of DTPA-extractable soil Zn, (b) Olsen phosphate taken as a proxy for available soil phosphorus, exchangeable soil potassium, harvest date, training of farmers in nutrient management, and soil silt content were the best predictors of yield, and (c) yield, Olsen phosphate, grain nitrogen, farmyard manure availability, and the type of cropping system were the best predictors of grain Zn concentration. Results suggested that organic wheat contained more Zn despite same yield level due to higher nutrient efficiency. Higher nutrient efficiency was also seen in organic wheat for P, N and S. The study thus suggests that appropriate farm management can lead to competitive yield and improved Zn concentration in wheat grains on organic farms. PMID:27537548

  19. The HEALTHGRAIN definition of 'whole grain'.

    Science.gov (United States)

    van der Kamp, Jan Willem; Poutanen, Kaisa; Seal, Chris J; Richardson, David P

    2014-01-01

    Most cereal products, like white bread, pasta, and biscuits, are based on flour after removal of bran and germ, the two parts of grain kernels containing most of the dietary fibre and other bioactive components. In the past decade, consumers have been rediscovering whole grain-based products and the number of wholegrain products has increased rapidly. In most countries in Europe and worldwide, however, no legally endorsed definition of wholegrain flour and products exists. Current definitions are often incomplete, lacking descriptions of the included grains and the permitted flour manufacturing processes. The consortium of the HEALTHGRAIN EU project (FP6-514008, 2005-2010) identified the need for developing a definition of whole grain with the following scope: 1) more comprehensive than current definitions in most EU countries; 2) one definition for Europe - when possible equal to definitions outside Europe; 3) reflecting current industrial practices for production of flours and consumer products; 4) useful in the context of nutritional guidelines and for labelling purposes. The definition was developed in a range of discussion meetings and consultations and was launched in 2010 at the end of the HEALTHGRAIN project. The grains included are specified: a wide range of cereal grains from the Poaceae family, and the pseudo-cereals amaranth, buckwheat, quinoa, and wild rice. The definition also describes manufacturing processes allowed for producing wholegrain flours. This paper compares the HEALTHGRAIN definition with previous definitions, provides more comprehensive explanations than in the definition itself regarding the inclusion of specific grains, and sets out the permitted flour manufacturing processes. PMID:24505218

  20. Effect of coarse-grain contents on strength and fracture toughness of fine-grained graphite

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Tsuneo; Ishihara, Masahiro; Baba, Shinichi; Hayashi, Kimio [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Arai, Taketoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Konishi, Takashi [Toyo Tanso Co. Ltd., Osaka (Japan)

    2001-03-01

    To investigate the effect of the coarse-grain content on strength and fracture toughness of fine-grained graphite, bending and fracture toughness tests were conducted for specimens with different contents of coarse-grains. In the study the standard specimen was made of fine-grained isotropic graphite (IG-11) with a mean grain size of 20 {mu}m, and two kinds of different grain size specimens were prepared by 20 and 40% mixing of coarse-grains with a mean grain size of 125 {mu}m. The bending test revealed a strength increase for the 40% specimen with a small deviation compared with that for the standard specimen. As for the fracture toughness, two kinds of fracture toughnesses were investigated on the basis of the crack initiation load and the maximum applied load. The initiation load based fracture toughness for the 20% and 40% specimens was higher than that for the standard one; however, the difference for the 20% and 40% specimens was not observed clearly. These results suggest that the fracture toughness tends to saturate at a relatively low coarse-grain content, which is below 20% in the present study. On the other hand, the maximum load based fracture toughness increased with increasing coarse-grain content; thus the difference with different coarse-grain contents was observed. Moreover, the present authors applied a probabilistic strength model to the bending test results, using the pore size distributions obtained by image analysis of microstructures observed by optical microscopy. The model had been proposed by Burchell under uniaxial stress conditions, in consideration of pore size distributions. The prediction by the present model indicated a good correlation with the experimental results. (author)

  1. Effect of coarse-grain contents on strength and fracture toughness of fine-grained graphite

    International Nuclear Information System (INIS)

    To investigate the effect of the coarse-grain content on strength and fracture toughness of fine-grained graphite, bending and fracture toughness tests were conducted for specimens with different contents of coarse-grains. In the study the standard specimen was made of fine-grained isotropic graphite (IG-11) with a mean grain size of 20 μm, and two kinds of different grain size specimens were prepared by 20 and 40% mixing of coarse-grains with a mean grain size of 125 μm. The bending test revealed a strength increase for the 40% specimen with a small deviation compared with that for the standard specimen. As for the fracture toughness, two kinds of fracture toughnesses were investigated on the basis of the crack initiation load and the maximum applied load. The initiation load based fracture toughness for the 20% and 40% specimens was higher than that for the standard one; however, the difference for the 20% and 40% specimens was not observed clearly. These results suggest that the fracture toughness tends to saturate at a relatively low coarse-grain content, which is below 20% in the present study. On the other hand, the maximum load based fracture toughness increased with increasing coarse-grain content; thus the difference with different coarse-grain contents was observed. Moreover, the present authors applied a probabilistic strength model to the bending test results, using the pore size distributions obtained by image analysis of microstructures observed by optical microscopy. The model had been proposed by Burchell under uniaxial stress conditions, in consideration of pore size distributions. The prediction by the present model indicated a good correlation with the experimental results. (author)

  2. Performance of organic grain legumes in Tuscany

    Directory of Open Access Journals (Sweden)

    Valentina Moschini

    2014-03-01

    Full Text Available In 2005-2007 growing season, few varieties of field bean, high protein pea and white lupin were compared in an organic farm of Central Italy (Mugello area, Tuscany, to evaluate their agronomic performance in terms of grain yield, nutritional quality and competitive ability against weeds. The experiment was performed under rain-fed conditions. Furthermore, grain legumes features were compared between two different sowing seasons (autumnal vs late-winter for two years, in order to get information on the best time of sowing of these species, and the stability of yields of different genotypes in those climatic and soil conditions. These legumes could be an alternative protein source to external soybean, a high-risk alimentary source of genetically modified organisms, in the organic livestock sector. The main findings indicate that higher yields in grain and crude protein were obtained with the pea species and in particular with cultivars Hardy (4.0 t/ha grain yield; 626 kg/ha crude protein yield and Classic (3.1 t/ha grain yield; 557 kg/ha crude protein yield; followed by field bean cv. Chiaro di Torre Lama (2.9 t/ha grain yield; 624 kg/ha crude protein yield and cv. Vesuvio (2.5 t/ha grain yield; 549 kg/ha crude protein yield. Furthermore the field bean is interesting for the stability of yield in both years despite climatic conditions rather different. The white lupin has showed the lower yield but the best values of grain quality, with higher values in lupin Multitalia for dry matter, crude protein and ether extract and in lupin Luxe also for crude fibre, respect to the other legumes analysed. Among lupin varieties, lupin Multitalia showed the best yield results for the pedo-climatic conditions of Mugello area (0.9 t/ha lupin Multitalia; 0.2 t/ha lupin Luxe. The total yield of organic grain legumes, in the experimental site, is resulted higher with an autumnal seeding respect to the late-winter seeding (2.8 t/ha vs 1.9 t/ha.

  3. Photoemission from glass dust grains: First measurements

    Science.gov (United States)

    Nouzak, Libor; Pechal, Radim; Pavlu, Jiri; Safrankova, Jana; Nemecek, Zdenek

    2014-05-01

    Dust grains are present in the interstellar space and also on surfaces of space objects like the Moon. The grains are charged by photoemission caused by solar UV radiation and by charged particles from the ambient plasma (solar wind, planetary magnetospheres). A balance of different charging processes on both sunlit and night sides of the Moon causes interesting phenomena as dust horizon glow, dust fountains, and dust levitation. To contribute to a better understanding of these processes, we present laboratory investigations that use a single SiO2 grain of micron size (an archetype of the lunar dust) caught in the electrodynamic trap. We irradiate it by HeI (21.2 eV) photons and electrons and discuss a contribution of these two processes to the grain charge. The grain specific charge is evaluated by an analysis of its motion and position in the trap. We compare equilibrium charge-to-mass ratios given by the electron emissions induced by electrons and by the UV photons from the HeI lamp. First measurements indicate that the resulting charge is about twice larger for photoemission than that caused by an electron impact.

  4. Grain Boundaries From Theory to Engineering

    CERN Document Server

    Priester, Louisette

    2013-01-01

    Grain boundaries are a main feature of crystalline materials. They play a key role in determining the properties of materials, especially when grain size decreases and even more so with the current improvements of  processing tools and methods that allow us to control various elements in a polycrystal. This book presents the theoretical basis of the study of  grain boundaries and aims to open up new lines of research in this area. The treatment is light on mathematical approaches while emphasizing practical examples; the issues they raise are discussed with reference to theories. The general approach of the book has two main goals: to lead the reader from the concept of ‘ideal’ to ‘real’ grain boundaries; to depart from established knowledge and address the opportunities emerging through "grain boundary engineering",  the control of morphological and crystallographic features that affect material properties. The book is divided in three parts:  I ‘From interganular order to disorder’ deals wit...

  5. Interstellar grain chemistry and organic molecules

    Science.gov (United States)

    Allamandola, L. J.; Sandford, S. A.

    1990-01-01

    The detection of prominant infrared absorption bands at 3250, 2170, 2138, 1670 and 1470 cm(-1) (3.08, 4.61, 4.677, 5.99 and 6.80 micron m) associated with molecular clouds show that mixed molecular (icy) grain mantles are an important component of the interstellar dust in the dense interstellar medium. These ices, which contain many organic molecules, may also be the production site of the more complex organic grain mantles detected in the diffuse interstellar medium. Theoretical calculations employing gas phase as well as grain surface reactions predict that the ices should be dominated only by the simple molecules H2O, H2CO, N2, CO, O2, NH3, CH4, possibly CH3OH, and their deuterated counterparts. However, spectroscopic observations in the 2500 to 1250 cm(-1)(4 to 8 micron m) range show substantial variation from source reactions alone. By comparing these astronomical spectra with the spectra of laboratory-produced analogs of interstellar ices, one can determine the composition and abundance of the materials frozen on the grains in dense clouds. Experiments are described in which the chemical evolution of an interstellar ice analog is determined during irradiation and subsequent warm-up. Particular attention is paid to the types of moderately complex organic materials produced during these experiments which are likely to be present in interstellar grains and cometary ices.

  6. Advantageous grain boundaries in iron pnictide superconductors

    Science.gov (United States)

    Katase, Takayoshi; Ishimaru, Yoshihiro; Tsukamoto, Akira; Hiramatsu, Hidenori; Kamiya, Toshio; Tanabe, Keiichi; Hosono, Hideo

    2011-01-01

    High critical temperature superconductors have zero power consumption and could be used to produce ideal electric power lines. The principal obstacle in fabricating superconducting wires and tapes is grain boundaries—the misalignment of crystalline orientations at grain boundaries, which is unavoidable for polycrystals, largely deteriorates critical current density. Here we report that high critical temperature iron pnictide superconductors have advantages over cuprates with respect to these grain boundary issues. The transport properties through well-defined bicrystal grain boundary junctions with various misorientation angles (θGB) were systematically investigated for cobalt-doped BaFe2As2 (BaFe2As2:Co) epitaxial films fabricated on bicrystal substrates. The critical current density through bicrystal grain boundary (JcBGB) remained high (>1 MA cm−2) and nearly constant up to a critical angle θc of ∼9°, which is substantially larger than the θc of ∼5° for YBa2Cu3O7–δ. Even at θGB>θc, the decay of JcBGB was much slower than that of YBa2Cu3O7–δ. PMID:21811238

  7. H2 recombination on interstellar grains

    International Nuclear Information System (INIS)

    From a consideration of relevant theoretical and experimental data it is concluded that H atoms (but not H2 molecules) will be chemisorbed on interstellar graphite grains, with H2 formation proceeding efficiently for graphite grain temperatures less than 70 K. It is argued that graphite grains will act as the principle sites for H2 formation, with a formation rate of Rapprox. =4 x 10/sup -17/ cm3 s/sup -1/. Heating by H2 molecules formed by surface recombination is analyzed in the context of the available experimental data, and a heating rate is derived and compared with other suggested cloud heating mechanisms. We conclude that H2 recombination will provide the largest heat source in diffuse clouds if the albedo of interstellar dust in the 912--1200 A region is high (approx.0.9), whereas if the albedo in this wavelength region is lower (approx.0.5), photoelectron ejection from grains will tend to predominate, and can explain observed cloud temperatures with a carbon depletion factor of approximately 2, a factor attributable to a normal interstellar abundance of graphite grains

  8. Control and characterization of individual grains and grain boundaries in graphene grown by chemical vapour deposition

    Science.gov (United States)

    Yu, Qingkai; Jauregui, Luis A.; Wu, Wei; Colby, Robert; Tian, Jifa; Su, Zhihua; Cao, Helin; Liu, Zhihong; Pandey, Deepak; Wei, Dongguang; Chung, Ting Fung; Peng, Peng; Guisinger, Nathan P.; Stach, Eric A.; Bao, Jiming; Pei, Shin-Shem; Chen, Yong P.

    2011-06-01

    The strong interest in graphene has motivated the scalable production of high-quality graphene and graphene devices. As the large-scale graphene films synthesized so far are typically polycrystalline, it is important to characterize and control grain boundaries, generally believed to degrade graphene quality. Here we study single-crystal graphene grains synthesized by ambient chemical vapour deposition on polycrystalline Cu, and show how individual boundaries between coalescing grains affect graphene’s electronic properties. The graphene grains show no definite epitaxial relationship with the Cu substrate, and can cross Cu grain boundaries. The edges of these grains are found to be predominantly parallel to zigzag directions. We show that grain boundaries give a significant Raman ‘D’ peak, impede electrical transport, and induce prominent weak localization indicative of intervalley scattering in graphene. Finally, we demonstrate an approach using pre-patterned growth seeds to control graphene nucleation, opening a route towards scalable fabrication of single-crystal graphene devices without grain boundaries.

  9. Evolution of orientations and deformation structures within individual grains in cold rolled columnar grained nickel

    DEFF Research Database (Denmark)

    Wu, G.L.; Godfrey, A.; Winther, Grethe;

    2011-01-01

    Columnar grained Ni is used as a model material allowing simultaneous non-surface investigations of the evolution of crystallographic orientations and deformation microstructures within individual grains as a function of rolling strain up to ε=0.7. Electron channelling contrast and electron...

  10. A unified model of grain alignment: Radiative Alignment of Interstellar Grains with magnetic inclusions

    CERN Document Server

    Hoang, Thiem

    2016-01-01

    The radiative torque (RAT) alignment of interstellar grains with ordinary paramagnetic susceptibilities has been supported by a number of earlier studies. The alignment of such grains depends on the so-called RAT parameter $q^{\\max}$ that is determined by the grain shape. For interstellar grains with a broad range of $q^{\\max}$, a significant fraction of grains is expected to get aligned with low angular momentum at the so-called low-J attractor points, which entail degrees of alignment between 20 or 30 percent, irrespectively of the strength of RATs. The latter value may not be sufficient for explaining the observed interstellar alignment in the diffuse medium. In this paper, we elaborate our model of radiative alignment for grains with enhanced magnetic susceptibility due to magnetic inclusions, such that both Magnetic torque and RAdiative Torque (MRAT) play a role in grain alignment. Such grains can get aligned with high angular momentum at the so-called high-J attractor points, which achieve a high degree...

  11. China’s Price System Jeopardizes its Grain Reserves

    Institute of Scientific and Technical Information of China (English)

    李宾

    2008-01-01

    2008 is a year of bumper harvest in summer grain across China. The failure of numerous state-owned grain depots to purchase grain in times of bumper harvest, however, directly threatens grain reserve security and state control over grain prices in the upcoming year. An important factor underpinning the difficulty of state grain depots to purchase grain is the unwillingness of farmers to sell grain due to the excess of the current market price over the government "protected price" aimed at preventing cheap grain from harming farmers. When grassroots grain depots find themselves in trouble, foreign capital stealthily moves in by taking advantage of this situation. To fulfill grain storage tasks and receive various state subsidies, some state-owned grain depots have no alternative but to surreptitiously raise the purchase price. By contrast, some not so courageous state-owned grain depots can only borrow money to finance the purchase of commodity grain at market prices and subsequently figure out a way to pay back such loans. Behind such distorted grain purchase behavior lies a rough and rugged history of grain price reform in China.

  12. Whole grain gluten-free egg-free pasta

    Science.gov (United States)

    The USDA food guide recommends that at least ½ of all the grains eaten should be whole grains. The FDA allows food Health Claim labels for food containing 51% whole grains and 11 g of dietary fiber. This is the only report demonstrating innovative whole grain gluten free, egg free (no chemicals adde...

  13. Evaluation of an in situ Grain Moisture Sensor

    Science.gov (United States)

    Grain storage managers could improve the quality of stored grain if they could directly monitor grain moisture content in storage bins, which is a key indicator of stored grain quality and an early indicator of deterioration. However, the necessary sensors are not commercially available. A new capa...

  14. The Evolution of the Whole Grain Partnership in Denmark

    DEFF Research Database (Denmark)

    Greve, Carsten; Neess, Rikke Iben

    the Danish Whole Grain Partnership was established in January 2008, Danes ate on average only 36 grams of whole grain per day per 10MJ (mega joules). Today, Danes eat on average 63 grams of whole grain per day per 10MJ. 30% of the population now eats the recommended intake of 75 grams of whole grain per day...

  15. Overview of Studies on Grain Security in China

    Institute of Scientific and Technical Information of China (English)

    Shuhua; CAO; Weipeng; MA; Lei; NIE

    2014-01-01

    Through overview of relevant literature and on the basis of basically grasping frontier study and development trend,this paper discussed the grain security from industrial structure,farmland protection,grain import,urbanization and industrialization,grain reserve,ecological protection,and grain security pre-warning,in the hope of providing some convenience and reference for future related researches.

  16. A Model for Evaluation of Grain Sizes of Aluminum Alloys with Grain Refinement Additions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the assumption that the nucleation substrates are activated by constitutional undercooling generated by an adjacent grain growth and solute distribution during the initial solidification, a model for calculation of the grain size of aluminum alloys with the grain refinement is developed, where the nucleation is dominated by two parameters, I.e. Growth restriction factor Q and the undercooling parameter P. The growth restriction factor Q is proportional to the initial rate of constitutional undercooling development and can be used directly as a criterion of the grain refinement in the alloys with strong potential nucleation particles. The undercooling parameter P can be regarded as the maximum of constitutional undercooling △TC. For weak potential nucleation particles, the use of RGS would be more accurate. The experimental data of the grain refinement of pure aluminum and AISi7 alloys are coincident predicted results with the model.

  17. INFLUENCE OF ABNORMAL AUSTENITE GRAIN GRAIN GROWTH IN QUENCHED ABNT 5135 STEEL

    Directory of Open Access Journals (Sweden)

    Camila de Brito Ferreira

    2015-03-01

    Full Text Available Grain size in the steels is a relevant aspect in quenching and tempering heat treatments. It is known that high austenitizing temperature and long time provide an increase in austenitic grain sizes. Likewise, after hardening of low alloy steel, the microstructure consists of martensite and a volume fraction of retained austenite. This paper evaluates the influence of austenite grain size on the volume fraction of retained austenite measured by metallographic analyses and X-ray diffraction. The Mi and Mf temperatures were calculated using an empirical equation and experimentally determined by differential thermal analysis. The mechanical behavior of the steel was evaluated by Vickers microhardness testing. Differently from other results published in the literature that steel hardenability increases with the austenite grain size, it was observed that the increase in austenite grain promotes greater volume fraction of retained austenite after water quenching.

  18. Fatigue In Tension Perpendicular to the Grain

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Uhre; Hoffmeyer, Preben;

    2004-01-01

    Traditionally fatigue resistance is quantified as number of cycles to failure at a given stress level. A previous study by the authors showed that fatigue in compression parallel to the grain is governed partly by duration of load and partly by an effect of loading, i.e. a combination of a creep...... mechanism and a mechanism connected to damage introduced in the loading sequences. The purpose of the present study is to disentangle the effect of duration of load from the effect of load oscillation in fatigue in tension perpendicular to the grain. Fatigue experiments are made on small specimens and on...... made on dowel type connections that have tension perpendicular to the grain as limiting strength parameter. It is concluded that no significant influence of duration of load is observed w hen the fatigue resistance of small specimens at 0.01 Hz and 0.1 Hz are compared. A weak but inconclusive time...

  19. Radiative torques on interstellar grains; 1, superthermal spinup

    CERN Document Server

    Draine, B T; Weingartner, Joseph C

    1996-01-01

    Irregular dust grains are subject to radiative torques when irradiated by interstellar starlight. It is shown how these radiative torques may be calculated using the discrete dipole approximation. Calculations are carried out for one irregular grain geometry, and three different grain sizes. It is shown that radiative torques can play an important dynamical role in spinup of interstellar dust grains, resulting in rotation rates which may exceed even those expected from H_2 formation on the grain surface. Because the radiative torque on an interstellar grain is determined by the overall grain geometry rather than merely the state of the grain surface, the resulting superthermal rotation is expected to be long-lived. By itself, long-lived superthermal rotation would permit grain alignment by normal paramagnetic dissipation on the "Davis-Greenstein" timescale. However, radiative torques arising from anisotropy of the starlight background can act directly to alter the grain alignment on much shorter timescales, a...

  20. Systematic Comparisons of Orthologous Selenocysteine Methyltransferase and Homocysteine Methyltransferase Genes from Seven Monocots Species

    Directory of Open Access Journals (Sweden)

    De-yong ZHAO

    2015-06-01

    Full Text Available Identifying and manipulating genes underlying selenium metabolism could be helpful for increasing selenium content in crop grain, which is an important way to overcome diseases resulted from selenium deficiency. A reciprocal smallest distance algorithm (RSD approach was applied using two experimentally confirmed Homocysteine S-Methyltransferases genes (HMT1 and HMT2 and a putative Selenocysteine Methyltransferase (SMT from dicots plant Arabidopsis thaliana, to explore their orthologs in seven sequenced diploid monocot species: Oryza sativa, Zea mays, Sorghum bicolor, Brachypodium distachyon, Hordeum vulgare, Aegilops tauschii (the D-genome donor of common wheat and Triticum urartu (the A-genome donor of common wheat. HMT1 was apparently diverged from HMT2 and most of SMT orthologs were the same with that of HMT2 in this study, leading to the hypothesis that SMT and HMT originate from one common ancestor gene. Identifying orthologs provide candidates for further experimental confirmation; also it could be helpful in designing primers to clone SMT or HMT orthologs in other crops.

  1. Malta and the Nineteenth Century Grain Trade

    DEFF Research Database (Denmark)

    Sharp, Paul Richard

    2009-01-01

    It is often assumed that Britain's colonies followed the British doctrine of free trade in the second half of the nineteenth century. Malta, which became a British colony in 1814, did indeed become an early free trader. However, she failed to liberalize the grain trade, even when the mother country....... The duties on grain in Malta were therefore not protectionist, but rather for revenue purposes, in contrast to the UK Corn Laws. Taxing an inelastic demand for foreign wheat by Maltese, who were unable to grow enough food to support themselves, was certainly an effective way of raising revenue, but probably...

  2. Malta and the Nineteenth Century Grain Trade

    DEFF Research Database (Denmark)

    Sharp, Paul Richard

    It is often assumed that Britain's colonies followed the British doctrine of free trade in the second half of the nineteenth century. Malta, which became a British colony in 1814, did indeed become an early free trader. However, she failed to liberalize the grain trade, even when the mother country....... The duties on grain in Malta were therefore not protectionist, but rather for revenue purposes, in contrast to the UK Corn Laws. Taxing an inelastic demand for foreign wheat by Maltese, who were unable to grow enough food to support themselves, was certainly an effective way of raising revenue, but probably...

  3. Fatigue in tension perpendicular to the grain

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben;

    1999-01-01

    Traditinally fatigue resistance is quantified as number of cycles to failure at a given stress level. A previous study by the authors showed that fatigue in compression parallel to the grain is governed partly by duration of load and partly by an effect of loading, i.e. a combination of a creep...... are made on dowel type connections that have tension perpendicular to the grain as limiting strength parameter. Is is concluded that no significant influence of duration of load is observed when the fatigue resistance of small specimens at 0.01 Hz and 0.1 Hz are compared. A weak but inconclusive time...

  4. A Granular Model of Rolling Grain Ripples

    CERN Document Server

    Andersen, K H

    1999-01-01

    A simple model is presented for the formation of rolling grain ripples on a flat sand bed by the oscillatory flow from a surface wave. The model is related to physical parameters of the problem, and is solved for the equilibrium spacing and height of the ripples. Good agreement between the model and measurements of rolling grain ripples is demonstrated. It is found that the length of the ripples scale with the square-root of the non-dimensional shear stress on a flat bed.

  5. Mining the Change of the Quality of Stored Grain

    Institute of Scientific and Technical Information of China (English)

    SHANG Zhi-gen; LOU Wei; ZHOU Wei-min

    2006-01-01

    The quality of grain changes continually during its storage,including the change of its physical characteristics and physiological characteristics. This paper presents an approach to predict the change of the quality of stored grain with data mining technology. Logistic Regression, Decision Tree and Multilayer Perceptron are applied to predict the change of the grains' quality control index and to obtain the grains' quality change probability. The grain sampling with higher probability can be processed earlier.

  6. The Strength-Grain Size Relationship in Ultrafine-Grained Metals

    Science.gov (United States)

    Balasubramanian, N.; Langdon, Terence G.

    2016-04-01

    Metals processed by severe plastic deformation (SPD) techniques, such as equal-channel angular pressing (ECAP) and high-pressure torsion (HPT), generally have submicrometer grain sizes. Consequently, they exhibit high strength as expected on the basis of the Hall-Petch (H-P) relationship. Examples of this behavior are discussed using experimental data for Ti, Al, and Ni. These materials typically have grain sizes greater than ~50 nm where softening is not expected. An increase in strength is usually accompanied by a decrease in ductility. However, both high strength and high ductility may be achieved simultaneously by imposing high strain to obtain ultrafine-grain sizes and high fractions of high-angle grain boundaries. This facilitates grain boundary sliding, and an example is presented for a cast Al-7 pct Si alloy processed by HPT. In some materials, SPD may result in a weakening even with a very fine grain size, and this is due to microstructural changes during processing. Examples are presented for an Al-7034 alloy processed by ECAP and a Zn-22 pct Al alloy processed by HPT. In some SPD-processed materials, it is possible that grain boundary segregation and other features are present leading to higher strengths than predicted by the H-P relationship.

  7. Simulation of grain size effects in nanocrystalline shape memory alloys

    Science.gov (United States)

    Ahluwalia, Rajeev; Quek, Siu Sin; Wu, David T.

    2015-06-01

    Recently, it has been demonstrated that martensitic transformation in nanocrystalline shape memory alloys can be suppressed for small grain sizes. Motivated by these results, we study the grain size dependence of martensitic transformations and stress-strain response of nanocrystalline shape memory alloys within the framework of the Ginzburg-Landau (GL) theory. A GL model for a square to rectangle transformation in polycrystals is extended to account for grain boundary effects. We propose that an inhibition of the transformation in grain boundary regions can occur, if the grain boundary energy of the martensite is higher than that of the austenite phase. We show that this inhibition of transformation in grain boundary regions has a strong influence on domain patterns inside grains. Although the transformation is inhibited only at the grain boundaries, it leads to a suppression of the transformation even inside the grains as grain size is decreased. In fact, below a critical grain size, the transformation can be completely suppressed. We explain these results in terms of the extra strain gradient cost associated with grain boundaries, when the transformation is inhibited at grain boundaries. On the other hand, no significant size effects are observed when transformation is not inhibited at grain boundaries. We also study the grain size dependence of the stress strain curve. It is found that when the transformation is inhibited at grain boundaries, a significant reduction in the hysteresis associated with stress-strain curves during the loading-unloading cycles is observed. The hysteresis for this situation reduces even further as the grain size is reduced, which is consistent with recent experiments. The simulations also demonstrate that the mechanical behavior is influenced by inter-granular interactions and the local microstructural neighbourhood of a grain has a stronger influence than the orientation of the grain itself.

  8. The influence of grain boundary structure on the penetration of gallium into aluminum grain boundaries

    Science.gov (United States)

    Hugo, Richard Charles

    1998-12-01

    Liquid Metal Embrittlement is a form of environmental embrittlement that dramatically reduces the fracture toughness of many metals and alloys. It occurs when surfaces of certain solid metals are wet by certain liquid metals. The Al-Ga system provides a remarkable example of intergranular attack. The Al-Ga equilibrium phase diagram reveals no intermetallic compounds and very limited mutual solubilities, which implies that interactions between Al and Ga should be minimal. Yet when liquid Ga wets the surface of an unstressed Al specimen, the Ga will penetrate the Al grain boundaries, replacing each boundary with a liquid layer. The driving force is generally considered to be the reduction in energy when a grain boundary is replaced by two Ga-Al interfaces. Once an Al sample has been penetrated by Ga, it fails at almost no load. In this dissertation, in-situ Transmission Electron Microscope (TEM) studies are presented that elucidate the physical nature of the Ga penetration front. Although many of the TEM specimens were bicrystals, all but one of the grain boundaries studied were "general" boundaries; that is, they were low symmetry boundaries with high-index rotation axes, and no low-index planes common to both grains. Since the atomic structure of these grain boundaries cannot be resolved experimentally, atomistic computer models were constructed to assist in interpreting TEM results. TEM observations indicated that the penetration front is a line defect, possessing a stress field that interacts with lattice dislocations. The penetration front was also observed to interact with structural variations within the grain boundary. Interactions with lattice dislocations were used to estimate the penetration front thickness. Penetration speeds were not found to be determined by grain boundary energy or grain boundary excess volume. Penetration speeds were, however, found to depend qualitatively on the presence of penetration barriers in the grain boundary.

  9. US Feed Grains Mycotoxin Conference Report

    Science.gov (United States)

    Mycotoxins are toxic compounds produce by fungi (molds). Mycotoxins are a major problem throughout the world. Grains and foods can become infected with these fungi which produce mycotoxins and when these commodities are fed to animals or consumed by humans pose a significant threat to both animal ...

  10. Against the Grain: Teaching Historical Complexity

    Science.gov (United States)

    Neumann, Dave

    2013-01-01

    Many teachers and scholars have written about the importance of inquiry in effective history instruction. At its core, inquiry involves student investigation of a significant historical problem. Experienced teachers, however, often reveal their skill in purposely teaching against the grain. Skilled teachers help students appreciate historical…

  11. [Amino acid composition of rice grain proteins].

    Science.gov (United States)

    Peruanskiĭ, Iu V; Savich, I M

    1976-01-01

    The composition of the major reserve proteins of rice grain--globulins, prolamines and glutelins--was examined in four rice varieties (Dubovsky 129, Kuban 3, Alakul, Ushtobinsky). Globulins proved to be most heterogeneous whereas glutelins appeared to be least heterogeneous. In regards to the ratio of components globulins showed high variability and glutelins displayed high stability. PMID:1005365

  12. Dynamic Abnormal Grain Growth in Refractory Metals

    Science.gov (United States)

    Noell, Philip J.; Taleff, Eric M.

    2015-11-01

    High-temperature plastic deformation of the body-centered cubic (BCC) refractory metals Mo and Ta can initiate and propagate abnormal grains at significantly lower temperatures and faster rates than is possible by static annealing alone. This discovery reveals a new and potentially important aspect of abnormal grain growth (AGG) phenomena. The process of AGG during plastic deformation at elevated temperatures, termed dynamic abnormal grain growth (DAGG), was observed at homologous temperatures between 0.52 and 0.72 in both Mo and Ta sheet materials; these temperatures are much lower than those for previous observations of AGG in these materials during static annealing. DAGG was used to repeatedly grow single crystals several centimeters in length. Investigations to date have produced a basic understanding of the conditions that lead to DAGG and how DAGG is affected by microstructure in BCC refractory metals. The current state of understanding for DAGG is reviewed in this paper. Attention is given to the roles of temperature, plastic strain, boundary mobility and preexisting microstructure. DAGG is considered for its potential useful applications in solid-state crystal growth and its possibly detrimental role in creating undesired abnormal grains during thermomechanical processing.

  13. Diffuse Galactic Emission from Spinning Dust Grains

    OpenAIRE

    Draine, B. T.; Lazarian, A.

    1997-01-01

    Spinning interstellar dust grains produce detectable rotational emission in the 10-100 GHz frequency range. We calculate the emission spectrum, and show that this emission can account for the ``anomalous'' Galactic background component which correlates with 100um thermal emission from dust. Implications for cosmic background studies are discussed.

  14. Ignition Delay Studies on Hypergolic Fuel Grains

    Directory of Open Access Journals (Sweden)

    S. R. Jain

    1988-07-01

    Full Text Available The ignition delays of several solid hypergolic fuel compositions, casted using various polymeric binders, or as melts, have been determined with fuming nitric acid as oxidizer. The ignition delays of various hypergolic fuel compositions increase drasticaliy on casting with binders like. carboxyl or hydroxyl termninated polybutadiene. Fuel grains cast using some newly syhthesised epoxy  resins with other ingrcdients, such as curing agent, magnesium powder and fuel, have short ignition delays of the order of 200 ms, and also good mechanical strength. Increasing the amount of binder in the composition retards the hypergolicity of the rain. Similar studies have been made on melt-cast systems using low melting hypergolic fuels for casting fuel powders. The ignition delays of the melt-cast grains, are longer than those determined taking the composition in the powder form. The effect of highly hypergolic additives, and metal powders, on the ignition delay of the cast compositions has been determined. Grains having good mechanical strength and short ignition delays have been obtained by optimising the fuel grain composition.

  15. Interactions between Dislocations and Grain Boundaries

    NARCIS (Netherlands)

    Soer, Wouter Anthon

    2006-01-01

    Dislocations (line defects) and grain boundaries (planar defects) are two types of lattice defects that are crucial to the deformation behavior of metals. Permanent deformation of a crystalline material is microscopically associated with the nucleation and propagation of dislocations, and extensive

  16. Induced mutants for cereal grain protein improvement

    International Nuclear Information System (INIS)

    Out of 17 papers and one summary presented, six dealing with the genetic improvement of seed protein using ionizing radiations fall within the INIS subject scope. Other topics discussed were non-radiation induced mutants used for cereal grain protein improvement

  17. Cereal grains for nutrition and health benefits

    DEFF Research Database (Denmark)

    Björck, Inger; Östman, Elin; Kristensen, Mette;

    2012-01-01

    Epidemiological studies have linked whole grain intake to the prevention of the metabolic syndrome, obesity and associated chronic diseases such as CVD and T2D. The Nutrition module within the HEALTHGRAIN project, included 10 partners and undertook in vitro, animal and human in vivo studies...

  18. IMPACT OF OZONE ON GRAIN SORGHUM YIELD

    Science.gov (United States)

    Grain sorghum(sorghum vulgare Pers.) is an important animal feed crop, and it is sometimes planted as a substitute for field corn. Although sorghum is grown in areas of the central and southern U.S. where potentially damaging concentrations of 03 exist, no data are available rega...

  19. Assessment of MARMOT Grain Growth Model

    Energy Technology Data Exchange (ETDEWEB)

    Fromm, B. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Fuel Modeling and Simulation Dept.; Zhang, Y. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Fuel Modeling and Simulation Dept.; Schwen, D. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Fuel Modeling and Simulation Dept.; Brown, D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pokharel, R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-12-01

    This report assesses the MARMOT grain growth model by comparing modeling predictions with experimental results from thermal annealing. The purpose here is threefold: (1) to demonstrate the validation approach of using thermal annealing experiments with non-destructive characterization, (2) to test the reconstruction capability and computation efficiency in MOOSE, and (3) to validate the grain growth model and the associated parameters that are implemented in MARMOT for UO2. To assure a rigorous comparison, the 2D and 3D initial experimental microstructures of UO2 samples were characterized using non-destructive Synchrotron x-ray. The same samples were then annealed at 2273K for grain growth, and their initial microstructures were used as initial conditions for simulated annealing at the same temperature using MARMOT. After annealing, the final experimental microstructures were characterized again to compare with the results from simulations. So far, comparison between modeling and experiments has been done for 2D microstructures, and 3D comparison is underway. The preliminary results demonstrated the usefulness of the non-destructive characterization method for MARMOT grain growth model validation. A detailed analysis of the 3D microstructures is in progress to fully validate the current model in MARMOT.

  20. Women in Grains Research Project--Extract.

    Science.gov (United States)

    Berrisford, Nickie

    Research aimed at recognizing, encouraging, enhancing, and harnessing the skills and contributions of women in the Australian grains industry involved a number of women in Victoria in focus groups, telephone interviews, and questionnaire surveys. Results indicate that women perceived themselves as providing guidance, operational assistance,…

  1. Large grain cavities from pure niobium ingot

    Science.gov (United States)

    Myneni, Ganapati Rao; Kneisel, Peter; Cameiro, Tadeu

    2012-03-06

    Niobium cavities are fabricated by the drawing and ironing of as cast niobium ingot slices rather than from cold rolled niobium sheet. This method results in the production of niobium cavities having a minimum of grain boundaries at a significantly reduced cost as compared to the production of such structures from cold rolled sheet.

  2. Molecular hydrogen formation on grain surfaces

    CERN Document Server

    Cazaux, S; Tielens, A G G M; Le Bourlot, J; Walmsley, M C

    2005-01-01

    We reconsider H2 formation on grain surfaces. We develop a rate equation model which takes into account the presence of both physisorbed and chemisorbed sites on the surface, including quantum mechanical tunnelling and thermal diffusion. In this study, we took into consideration the uncertainties on the characteristics of graphitic surfaces. We calculate the H2 formation efficiency with the Langmuir Hinshelwood and Eley Rideal mechanisms, and discuss the importance of these mechanisms for a wide range of grain and gas temperatures. We also develop a Monte Carlo simulation to calculate the H2 formation efficiency and compare the results to our rate equation models. Our results are the following: (1) Depending on the barrier against chemisorption, we predict the efficiency of H2 formation for a wide range of grain and gas temperatures. (2) The Eley-Rideal mechanism has an impact on the H2 formation efficiency at high grain and gas temperatures. (3) The fact that we consider chemisorption in our model makes the ...

  3. Whole Grain Intake Reduces Pancreatic Cancer Risk

    Science.gov (United States)

    Lei, Qiucheng; Zheng, Huazhen; Bi, Jingcheng; Wang, Xinying; Jiang, Tingting; Gao, Xuejin; Tian, Feng; Xu, Min; Wu, Chao; Zhang, Li; Li, Ning; Li, Jieshou

    2016-01-01

    Abstract Mounting evidence from epidemiology studies suggests that whole grain intake may reduce pancreatic cancer risk, but convincing evidence is scarce. We conducted a meta-analysis to assess the association between whole grain intake and pancreatic cancer risk. Relevant observational studies were identified by searching PubMed, Embase, Scopus, and Cochrane library databases for the period from January 1980 to July 2015, with no restrictions. We calculated the summary odds ratios (ORs) for pancreatic cancer using random-effects model meta-analysis. Between-study heterogeneity was analyzed using the I2 statistic. A total of 8 studies regarding whole grain intake were included in the meta-analysis. The pooled OR of pancreatic cancer for those with high versus low whole grain intake was 0.76 (95% confidence interval [CI], 0.64–0.91; P = 0.002). There was no significant heterogeneity across these studies (I2 = 11.7%; Pheterogeneity = 0.339). In the subgroup analysis by geographic area, the summary ORs of developing pancreatic cancer were 0.64 (95% CI, 0.53–0.79; P < 0.001; I2 = 0%; Pheterogeneity = 0.482) in the United States (n = 4) and 0.95 (95% CI, 0.63–1.43; P = 0.803; I2 = 45.6%; Pheterogeneity = 0.175) in Europe (n = 2). In the subgroup analysis by type of whole grain, the summary ORs were 0.72 (95% CI, 0.60–0.87; P = .001; I2 = 0; Pheterogeneity = 0.876) for grains (n = 4) and 0.74 (95% CI, 0.27–2.02; P = 0.554; I2 = 86.3%; Pheterogeneity = 0.007) for wheat (n = 2). A high intake of whole grains was associated with a reduced risk of pancreatic cancer. Because of the absent of more cohort studies, further prospective studies need to be conducted to ensure conclusions that are more robust. PMID:26945361

  4. Analysis of Grain Boundary Character in a Fine-Grained Nickel-Based Superalloy 718

    Science.gov (United States)

    Araujo, L. S.; dos Santos, D. S.; Godet, S.; Dille, J.; Pinto, A. L.; de Almeida, L. H.

    2014-11-01

    In the current work, sheets of superalloy 718 were processed via thermomechanical route by hot and cold rolling, followed by annealing below the δ phase solvus temperature and precipitation hardening to optimum strength. Grain boundary character distribution throughout the processing was mapped via EBSD and its evolution discussed. The results show that it is possible to process the alloy to a fine grain size obtaining concomitantly a considerably high proportion of special boundaries Σ3, Σ9, and Σ27. The precipitation of δ phase presented a strong grain refining role, without significantly impairing the twinning mechanism and, consequently, the Σ3, Σ9, and Σ27 boundary formations.

  5. Deformation bands in ⟨120⟩ grains in coarse-grained aluminium

    DEFF Research Database (Denmark)

    Bilde-Sørensen, Jørgen

    1986-01-01

    Coarse-grained aluminium, deformed in tension to a strain of 0.05, was examined in a scanning electron microscope by channelling contrast. Pronounced bands with a width typically of the order of 200 μm were found in some grains with an orientation close to [120]. When observed on surfaces close to...... [001], the boundaries between the bands were parallel to [010] and the neighbouring bands were rotated around [100] with respect to one another. Two slip systems in a critical relationship are equally stressed with a Schmid factor of 0.49 in grains with a [120] orientation, namely (a/2)[011](111) and...

  6. Paleowattmeters: A scaling relation for dynamically recrystallized grain size

    Science.gov (United States)

    Austin, Nicholas J.; Evans, Brian

    2007-04-01

    During dislocation creep, mineral grains often evolve to a stable size, dictated by the deformation conditions. We suggest that grain-size evolution during deformation is determined by the rate of mechanical work. Provided that other elements of microstructure have achieved steady state and that the dissipation rate is roughly constant, then changes in internal energy will be proportional to changes in grain-boundary area. If normal grain-growth and dynamic grain-size reduction occur simultaneously, then the steady-state grain size is determined by the balance of those rates. A scaling model using these assumptions and published grain-growth and mechanical relations matches stress grain-size relations for quartz and olivine rocks with no fitting. For marbles, the model also explains scatter not rationalized by assuming that recrystallized grain size is a function of stress alone. When extrapolated to conditions typical for natural mylonites, the model is consistent with field constraints on stresses and strain rates.

  7. Impact of Industrialization on Grain Consumption and Countermeasures

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    This paper analyzes the impact of industrialization on grain consumption from growth of residents’ income and change of diet structure,expansion of size of population,and development of new biomass energy industry.The economic growth in the course of industrialization promotes growth of residents’ income,changes residents’ diet structure;industrialization leads to rural urbanization and rise of urban residents;industrial development brings about grain demand of biomass energy.All of these greatly increase demand of grain consumption.On the basis of these situations,it presents following countermeasures to guarantee grain consumption demand in the course of industrialization:heighten awareness to fully realize the significance of rapid development of industrialization to grain security;control population growth and improve grain conversion ratio;strengthen grain-saving construction and advocate moderate consumption;develop non-grain biomass energy in many channels to guarantee grain security.

  8. Analytical model for intergrain expansion and cleavage: random grain boundaries

    International Nuclear Information System (INIS)

    A description of rigid-body grain boundary relaxation and cleavage in tungsten is performed using a pair-wise Morse interatomic potential in real and reciprocal spaces. Cleavage energies and grain boundary dilatation of random grain boundaries were formulated and computed using atomic layer interaction energies. These values were determined using a model for a relaxed random grain boundary that consists of rigid grains on either side of the boundary plane that are allowed to float to reach the equilibrium position. Expressions are given that describe in real space the energy of interatomic interaction on random grain boundaries with twist orientation. It was shown that grain-boundary expansion and cleavage energies of the most widespread random grain boundaries are mainly determined by grain boundary atomic density

  9. 4-D XRD for strain in many grains using triangulation

    Energy Technology Data Exchange (ETDEWEB)

    Bale, Hrishikesh A.; Hanan, Jay C.; Tamura, Nobumichi

    2006-12-31

    Determination of the strains in a polycrystalline materialusing 4-D XRD reveals sub-grain and grain-to-grain behavior as a functionof stress. Here 4-D XRD involves an experimental procedure usingpolychromatic micro-beam X-radiation (micro-Laue) to characterizepolycrystalline materials in spatial location as well as with increasingstress. The in-situ tensile loading experiment measured strain in a modelaluminum-sapphire metal matrix composite using the Advanced Light Source,Beam-line 7.3.3. Micro-Laue resolves individual grains in thepolycrystalline matrix. Results obtained from a list of grains sorted bycrystallographic orientation depict the strain states within and amongindividual grains. Locating the grain positions in the planeperpendicular to the incident beam is trivial. However, determining theexact location of grains within a 3-D space is challenging. Determiningthe depth of the grains within the matrix (along the beam direction)involved a triangulation method tracing individual rays that producespots on the CCD back to the point of origin. Triangulation wasexperimentally implemented by simulating a 3-D detector capturingmultiple diffraction images while increasing the camera to sampledistance. Hence by observing the intersection of rays from multiple spotsbelonging to the corresponding grain, depth is calculated. Depthresolution is a function of the number of images collected, grain to beamsize ratio, and the pixel resolution of the CCD. The 4DXRD methodprovides grain morphologies, strain behavior of each grain, andinteractions of the matrix grains with each other and the centrallylocated single crystal fiber.

  10. The accumulation and trapping of grains at planet gaps: effects of grain growth and fragmentation

    CERN Document Server

    Gonzalez, J -F; Maddison, S T; Pinte, C; Ménard, F

    2015-01-01

    We model the dust evolution in protoplanetary disks with full 3D, Smoothed Particle Hydrodynamics (SPH), two-phase (gas+dust) hydrodynamical simulations. The gas+dust dynamics, where aerodynamic drag leads to the vertical settling and radial migration of grains, is consistently treated. In a previous work, we characterized the spatial distribution of non-growing dust grains of different sizes in a disk containing a gap-opening planet and investigated the gap's detectability with the Atacama Large Millimeter/submillimeter Array (ALMA). Here we take into account the effects of grain growth and fragmentation and study their impact on the distribution of solids in the disk. We show that rapid grain growth in the two accumulation zones around planet gaps is strongly affected by fragmentation. We discuss the consequences for ALMA observations.

  11. Analysis of Theoretical Basis of Direct Subsidies for Grain Production

    Institute of Scientific and Technical Information of China (English)

    Shengping; SHI; Xiaorong; LUO; Hongjing; LI

    2014-01-01

    Financial distribution to compensate grain production reflects governmental macro-control on grain production and supply. With the reference of agricultural basic theory,agricultural multi-function theory,economic externality theory,public finance and other theories,this article points out that direct subsidies for grain production is reasonable and necessary with six main theoretical basis,namely fundamentality,multi-function,positive externality of grain production,particularity of grain supply and demand,grain safety being closely linked with national security and basic function of service-oriented government.

  12. Effect of grain boundary sliding on the toughness of ultrafine grain structure steel: A molecular dynamics simulation study

    Institute of Scientific and Technical Information of China (English)

    Xie Hong-Xian; Liu Bo; Yin Fu-Xing; Yu Tao

    2013-01-01

    Molecular dynamics simulations are carried out to investigate the mechanisms of low-temperature impact toughness of the ultrafine grain structure steel.The simulation results suggest that the sliding of the {001}/{ 11 0} type and { 110}/{ 111 } type grain boundary can improve the impact toughness.Then,the mechanism of grain boundary sliding is studied and it is found that the motion of dislocations along the grain boundary is the underlying cause of the grain boundary sliding.Finally,the sliding of the grain boundary is analyzed from the standpoint of the energy.We conclude that the measures which can increase the quantity of the {001}/{110} type and {110}/{111} type grain boundary and elongate the free gliding distance of dislocations along these grain boundaries will improve the low-temperature impact toughness of the ultrafine grain structure steel.

  13. ESTIMATING THE INTENSITY OF GERM-GRAIN MODELS WITH OVERLAPPING GRAINS

    Directory of Open Access Journals (Sweden)

    Hamid Ghorbani

    2011-05-01

    Full Text Available Formulas are derived for the spherical contact distribution of a planar germ-grain model Z with circular grains where the germs formeither a 'segment cluster' process or a 'line-based' Poisson point process. They are used in order to estimate the intensityl of the germprocess by means of the spherical contact distribution function. As an application the number of dislocations on a silicon wafer is estimated.

  14. The effect of grain source and grain processing on performance of feedlot cattle: a review.

    Science.gov (United States)

    Owens, F N; Secrist, D S; Hill, W J; Gill, D R

    1997-03-01

    Effects of grain species and grain processing method on DMI, rate and efficiency of gain, and feeding value for cattle fed high concentrate diets were appraised by statistically compiling results from 605 comparisons from feeding trials published in North American journals and experiment station bulletins since 1974. Metabolizable energy (ME) values for each grain and processing method were calculated by quadratic procedures from DMI and animal performance. Averaged across processing methods, ME values for corn, milo, and wheat grain (3.40, 3.22, and 3.46 Mcal/kg DM) fell within 9% of ME estimates from NRC (1996) for beef cattle. In contrast, ME values for barley and oats grain (3.55 and 3.46 Mcal/kg DM) were 24% and 17% greater than NRC (1996) estimates. Compared with the dry rolled forms, high moisture corn and milo resulted in lower ADG and DMI. Compared with dry rolling, either steam rolling or flaking of corn, milo, and wheat decreased DMI without decreasing ADG and improved feed efficiency by 10, 15, and 10%, respectively. Compared with dry rolled grain, steam flaking increased (P barley and oats. Higher moisture content of high-moisture corn decreased dry matter intake without depressing ADG and improved efficiency and increased ME of the grain. Compared with steam flakes of moderate thinness, processing milo or barley to a very thin flake tended to reduce ADG and failed to improve feed efficiency. The ideal roughage source and roughage moisture content for maximum ME and ADG varied with grain processing method. Feeding corn silage rather than alfalfa and wet rather than dry roughage depressed (P flaked corn or wheat. PMID:9078507

  15. Development of two-stage grain grinder

    Directory of Open Access Journals (Sweden)

    V. N. Trubnikov

    2016-01-01

    Full Text Available The most important task in the development of the diet of farm animals feeding is a selection of the most balanced in its composition and most nutritious feeds, which are safe and meet all the necessary requirements at the same time. To evaluate the productive value of feeds and their effectiveness the rate of food productive action η was proposed. This ratio reflects the productive part of the total value of the exchange energy of the daily feed ration and is an essential criterion of the feed quality indicators. In the feed rations of animals the most expensive, but energy-rich feed is a mixed fodder, a mixture of grinded seeds of agricultural crops and protein, mineral and vitamin additives. In the diet for its nutritional value, this feed product is for cattle – 50, pigs – 60… 100 and birds – 100%. The basic operation in the production of mixed fodder is seeds grinding, i.e. their destruction under the influence of external forces, exceeding the forces of molecular adhesion of the grains particles. To grind the grain different ways are used: chopping, grinding, impact «in flight», crushing, etc. In the production of mixed fodder on the existing production equipment, there is the problem of getting the grain mixed fodder the necessary degree of grinding and uniform in its particle size distribution at the same time. When receiving too coarse grinding there is a problem of difficult digestibility of mixed fodder by farm animals. Moreover grinding process is accompanied by a high energy consumption. Grain grinder, the principle of which is based on the implementation of two ways of grinding grain: splitting and impact «in flight» is proposed. The proposed constructive solutions allow to obtain a high-performance technical means for crushing seeds of crops, as well as reduce energy costs that arise during the course of the process of obtaining of mixed fodder. The methodology justification of degree of grain grinding by

  16. The effects of grain size and grain boundary characteristics on the thermal conductivity of nanocrystalline diamond

    Science.gov (United States)

    Spiteri, David; Anaya, Julian; Kuball, Martin

    2016-02-01

    Molecular dynamics simulation was used to study the effects of each grain dimension and of grain boundary characteristics on the inter-grain thermal boundary resistance (TBR) and intragrain thermal conductivity of nanocrystalline diamond. The effect of the grain boundaries perpendicular to the heat flow was studied using a multiple slab configuration, which greatly reduced the artifacts associated with the heat source/sink. The TBR between the slabs was found to be more sensitive to the atomic arrangement at the boundary than to the tilt angle between the slabs. When the atomic arrangement at the interface was altered from the minimum energy configuration, the TBR increased by a factor of three, suggesting that a sub-optimal interface quality between the grains could play a large role in reducing the thermal conductivity of nanocrystalline diamond. The thermal conductivity between the boundaries was found to be similar to the bulk value, even when the boundaries were only 25 nm apart. The effect of grain boundaries parallel to the heat flow was found to have a large dependence on the microstructural details. Parallel boundaries which were 2 nm apart reduced the thermal conductivity of defect-free diamond by between one third and a factor of ten.

  17. Grain-boundary structures in hexagonal materials: Coincident and near coincident grain boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Farkas, D. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Materials Science and Engineering)

    1994-07-01

    Embedded atom method (EAM) simulations of the structure of grain boundaries in hexagonal metal, are presented. The simulations use recently developed interatomic potentials for Ti and Co. Structures were calculated for various symmetrical tilt boundaries with the [1,100] tilt axis. The structures obtained for both metals are very similar. The energies for the Co boundaries are higher than those for Ti by a factor of 2. The structural unit model was applied to the computed grain-boundary structures in these hexagonal materials. As in cubic materials, the structural unit model can describe a series of symmetrical tilt coincident boundaries. In addition, when the coincidence ratio in the grain-boundary plane varies with the c/a ratio, a structural unit-type model can describe the variation of grain-boundary structure with c/a ratio. This model is adequate for describing series of symmetrical tilt boundaries with the grain-boundary plane oriented perpendicular to a fixed crystallographic direction and varying c/a ratios. For the structures of the so-called near coincident boundaries that appear in these materials, it was concluded that near coincident boundaries behave similarly to exact coincidence boundaries if there is a coincident periodic structure in the grain-boundary plane. This may occur even without a three-dimensional (3-D) coincident site lattice.

  18. Genetic dissection of grain size and grain number trade-offs in CIMMYT wheat germplasm.

    Directory of Open Access Journals (Sweden)

    Simon Griffiths

    Full Text Available Grain weight (GW and number per unit area of land (GN are the primary components of grain yield in wheat. In segregating populations both yield components often show a negative correlation among themselves. Here we use a recombinant doubled haploid population of 105 individuals developed from the CIMMYT varieties Weebill and Bacanora to understand the relative contribution of these components to grain yield and their interaction with each other. Weebill was chosen for its high GW and Bacanora for high GN. The population was phenotyped in Mexico, Argentina, Chile and the UK. Two loci influencing grain yield were indicated on 1B and 7B after QTL analysis. Weebill contributed the increasing alleles. The 1B effect, which is probably caused by to the 1BL.1RS rye introgression in Bacanora, was a result of increased GN, whereas, the 7B QTL controls GW. We concluded that increased in GW from Weebill 7B allele is not accompanied by a significant reduction in grain number. The extent of the GW and GN trade-off is reduced. This makes this locus an attractive target for marker assisted selection to develop high yielding bold grain varieties like Weebill. AMMI analysis was used to show that the 7B Weebill allele appears to contribute to yield stability.

  19. CHP plant reduces grain whisky costs

    Energy Technology Data Exchange (ETDEWEB)

    Forrester, R.

    1989-04-01

    Scottish Grain Distillers Limited operate one of the largest grain whisky spirit production units in Scotland at Port Dundas Distillery, Glasgow. In 1972, a treatment plant for the distillery residues was installed. This was a major user of steam and fuelled by oil. In 1983, prompted by spiralling oil price rises, changes in the plant were initiated resulting in a significant move away from steam to electricity as the main source of energy and replacing oil by gas as the boiler fuel. To further improve the economics, an on-site gas turbine combined heat and power (CHP) system has been installed, any excess power being exported to the national grid. Estimated savings achieved by the CHP system point to a payback of 5.2 years on the gross investment capital. (U.K.).

  20. Combining ability of white grain popcorn populations

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Scapim

    2006-01-01

    Full Text Available The objectives of this study were to indicate the best improvement strategy and select parents to begin animprovement program of white grain popcorn based on the combining ability and heterosis of eight populations selected inexperiments in the northwestern region of Paraná. The traits plant and ear height, grain yield and popping expansion wereevaluated. The base populations, the F1 and five controls were evaluated in Maringá, state of Paraná, over the course of twoyears. Heterosis for popping expansion was very low and the best improvement strategy is to raise the values of poppingexpansion up to commercial levels through intrapopulation improvement of the populations BRS Angela and SC 002. Intenseselection must be applied to reduce plant and ear height; interpopulation selection must not be initiated at this moment.

  1. Economic efficiency of the maize grain

    Directory of Open Access Journals (Sweden)

    Ana Mariana Dincu

    2014-11-01

    Full Text Available In this work, was calculated and the level of profitability for several levels of production for grain maize cultivation. We chose corn because it is one of the most important forage crops, we could say even the largest, occupying third place among cultivated plants worldwide. Along with wheat and barley, the food is the biggest part of the population in the world, directly or converted to animal products. Maize can be used in animal feed in various forms. The most used is corn grain, which is characterized by a very high nutritional value, this product is properly regarded as a feed concentrate. Culture of maize have been designed two levels of production: 4000 kg / ha and 6000 kg / ha.

  2. Breakdown of Superconductivity in Small Metallic Grains

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhi-Qian; ZHENG Ren-Rong

    2000-01-01

    Superconductivity in small metallic grains is carefully checked as their size is decreased to a few nm when the average level spacing d could be compared with the bulk gap Δ. Using random matrix theory to the mean field, we find that the average theoretical values of the critical level spacing for both odd and even numbers of electrons and the transition temperature Tc in three Gauss ensembles are quite different for those from the model of uniformly spaced levels. For Sz = 1/2, as grain size is reduced, the transition temperature or the granular gap decreases monotonously, and the relation 2△(0)/kB Tc ≤ 3.53 always exists.

  3. STUDY ON GRAIN MARKET IN THE WORLD

    Directory of Open Access Journals (Sweden)

    Elena COFAS

    2013-01-01

    Full Text Available In the global economy, the market occupies a representative place because the grain is grown on a large area and it is important both to ensure food security and safety, but also for animal feed. In order to accomplish this study we have used certain indicators, of which the most representative are: acreage, production obtained, yield per hectare, food consumption, imports, exports and last but not least the price. World market of cereals has increased in the past decade due to increased consumption of cereals, especially in less developed countries economically. World grain market evolution in the analyzed period was disrupted on one side by the global economic crisis and on the other side by bad weather changes that occur on a global scale and have had a negative impact on acreage, production achieved, prices etc. According to forecasts the global market for cereals is expected to increase trade with cerereale, while diminishing stocks.

  4. Coarse-grained Modeling of DNA Curvature

    CERN Document Server

    Freeman, Gordon S; Lequieu, Joshua P; Whitmer, Jonathan K; de Pablo, Juan J

    2014-01-01

    Modeling of DNA-protein interactions is a complex process involving many important time and length scales. This can be facilitated through the use of coarse-grained models which reduce the number of degrees of freedom and allow efficient exploration of binding configurations. It is known that the local structure of DNA can significantly affect its protein-binding properties (i.e. intrinsic curvature in DNA-histone complexes). In a step towards comprehensive DNA-protein modeling, we expand the 3SPN.2 coarse-grained model to include intrinsic shape, and validate the refined model against experimental data including melting temperature, local flexibility, persistence length, and minor groove width profile.

  5. Genetic engineering for high methionine grain legumes.

    Science.gov (United States)

    Müntz, K; Christov, V; Saalbach, G; Saalbach, I; Waddell, D; Pickardt, T; Schieder, O; Wüstenhagen, T

    1998-08-01

    Methionine (Met) is the primary limiting essential amino acid in grain legumes. The imbalance in amino acid composition restricts their biological value (BV) to 55 to 75% of that of animal protein. So far improvement of the BV could not be achieved by conventional breeding. Therefore, genetic engineering was employed by several laboratories to resolve the problem. Three strategies have been followed. A) Engineering for increased free Met levels; B) engineering of endogenous storage proteins with increased numbers of Met residues; C) transfer of foreign genes encoding Met-rich proteins, e.g. the Brazil nut 2S albumin (BNA) and its homologue from sunflower, into grain legumes. The latter strategy turned out to be most promising. In all cases the gene was put under the control of a developmentally regulated seed specific promoter and transferred into grain legumes using the bacterial Agrobacterium tumefaciens-system. Integration into and copy numbers in the plant genome as well as Mendelian inheritance and gene dosage effects were verified. After correct precursor processing the mature 2S albumin was intracellularly deposited in protein bodies which are part of the vacuolar compartment. The foreign protein amounted to 5 to 10% of the total seed protein in the best transgenic lines of narbon bean (Vicia narbonensis L., used in the authors' laboratories), lupins (Lupinus angustifolius L., used in CSIRO, Australia), and soybean (Glycine max (L.) Merr., used by Pioneer Hi-Bred, Inc., USA). In the narbon bean the increase of Met was directly related to the amount of 2S albumin in the transgenic seeds, but in soybean it remained below the theoretically expected value. Nevertheless, trangenic soybean reached 100%, whereas narbon bean and lupins reached approximately 80% of the FAO-standard for nutritionally balanced food proteins. These results document that the Met problem of grain legumes can be resolved by genetic engineering.

  6. Soaring Grain Prices Raise Global Concerns

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ rain prices often dominate all other product prices, and an increase in their price is usually considered as a prelude to inflation. The three fairly serious inflations, in 1985, 1988-1989, and 1993-1995respectively, were all preceded by grain price hikes. Furthermore, the money supply surged in the preceding year or during the same year in which these inflations occurred. This year has witnessed the same symptoms.

  7. Combining abilities of silage maize grain yield

    Directory of Open Access Journals (Sweden)

    Živanović Tomislav

    2005-01-01

    Full Text Available The aim of the present study was to evaluate the following parameters of maize grain yield: variability of inbred lines and their diallel hybrids superior-parent heterosis and general and special combining abilities. According to obtained results of the two-year study, it can be concluded that variability of this trait is significantly affected by a genotype, year and their interaction. As expected, hybrids had higher average grain yields than inbreds due to the depression of this trait that occurs in inbreds during inbreeding. The highest average value of heterosis for gain yield was detected in the hybrid ZPLB405 x ZPLB406 (123.0% and 178.1% in 1997 and 1998, respectively. The estimation of combining abilities was done on the basis of diallel hybrids after the method established by Griffing, 1956 (method II, mathematical model I. The analysis of variance of combining ability for grain yield indicated highly significant values of GCA and SCA for the observed trait in both study years. Grain yield inheritance was more affected by non-additive genes (dominance and epistasis as indicated by the GCA to SCA ratio that was smaller than unity. The inbreds ZPLB401 and ZPLB406 had high GCA effects, while the hybrid combinations ZPLB40Î x ZPLB402, ZPLB401 x ZPLB403, ZPLB401 x ZPLB405, ZPLB402 x ZPLB406, ZPLB403 x ZPLB406, ZPLB404 x ZPLB406, ZPLB405 x ZPLB406 had high SCA effects in both study years. These hybrid combinations include one parent with high GCA effects and other with low GCA effects. Furthermore, there are combinations ZPLB402 x ZPLB405, ZPLB403 x ZPLB405 and ZPLB404 x ZPLB405 with significant SCA effects that include parents with low GCA effects. This is probably the result of the additive type (additive x additive of interaction between parents.

  8. Insect pests of stored grain products

    International Nuclear Information System (INIS)

    The presence of insects in stored products is a worldwide recognized problem. In this report chemical and physical methods to control insect infestations in stored products are discussed. Special attention is given to the use of ionizing radiation to control insect pests in stored grains. The radiosensitivity of the most common insect pests at their different developmental stages is presented and discussed. The conclusions of this review are compiled in an executive summary. 62 refs

  9. Statistic Ensemble Theory of Small Superconducting Grains

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhi-Qian; ZHENG Ren-Rong

    2001-01-01

    We apply the random matrix theory to small metallic grains in different spin states of S = 0, 1/2, 1, 3/2, 2, 5/2, .., and find that there exist theoretical critical level spacings de at which the superconductivity would breakdown. We also find that the higher the spin state, the smaller the critical level spacing, and for the state of S = 0superconducting enhancement actually exists.

  10. Nutritive quality of Finnish grown grain legumes

    OpenAIRE

    Lizarazo, Clara; Santanen, Arja; Stoddard, Fred

    2010-01-01

    Grain legumes have excellent nutritional quality that makes them a staple ingredient for feeding ruminants, pigs and poultry. Legumes are known for their high protein content, and although they are low in the sulphur-containing amino acids and tryptophan, they have a high content of lysine; thus they are an ideal supplement to cereal-based diets and food products (Duranti & Cius 1997). Legumes have many beneficial effects in human diet. There is potential and sufficient far...

  11. Quantification of phytic acid in grains

    OpenAIRE

    Reason, D.A.; M. J. Watts; Devez, A.

    2015-01-01

    This report describes the validation of a cost effective method for quantifying phytic acid in grains, namely, rice and wheat, using UV/Vis spectroscopy. Background information describing phytic acid and its impact on human biological systems and hence the importance of its analysis is included in this report. The validation method involved a range of tests to determine accuracy, precision and reproducibility of the method. Multiple sample matrices were used including standards...

  12. Prebiotic molecules and interstellar grain clumps

    International Nuclear Information System (INIS)

    It is stated that interstellar molecules detected by radioastronomical techniques in galactic clouds cover a wide range of types and complexities. Amongst the heaviest recently discovered is cyanodiacetylene. There have also been earlier detections of precursors to the simplest amino-acid, glycine and probably detections of polyoxymethylene polymers and co-polymers. A possible identification of organic molecules of even greater complexity is here discussed, together with implications for the commencement of biological activity. The large departures from thermodynamic equilibrium in the interstellar medium and the co-existence of solid grains, molecules, radicals, ions, and uv photons provide conditions that are ideal for production of 'exotic' molecular species. The effect of clumping of dust grains is discussed. The possible spectral identification of highly complex organic species in the interstellar medium is also discussed and reference is made to a property common to a wide class of such molecules, that is, an absorption band centered at 2,200 A. It is tempting to identify this feature with the well-known 2,200 A band of the interstellar extinction curve. It is thought that it may be tentatively concluded that the data so far obtained could be interpreted as independent new chemical evidence of the existence of composite grain clumps in the interstellar medium and in carbonaceous chondrites, and that these grain clumps probably include a significant mass fraction of highly complex organic pre-biotic molecules that could have led to the start and dispersal of biological activity on the Earth and elsewhere in the Galaxy. Processes of natural selection probably also played an important part, particularly in the production of self-replicable peptide chains. The problem of protection of pre-biotic material against external disruptive agencies, such as u/v light, is also discussed. (U.K.)

  13. Regulation of aleurone development in cereal grains.

    Science.gov (United States)

    Becraft, Philip W; Yi, Gibum

    2011-03-01

    The aleurone layer of cereal grains is important biologically as well as nutritionally and economically. Here, current knowledge on the regulation of aleurone development is reviewed. Recent reports suggest that the control of aleurone development is more complex than earlier models portrayed. Multiple levels of genetic regulation control aleurone cell fate, differentiation, and organization. The hormones auxin and cytokinin can also influence aleurone development. New technical advances promise to facilitate future progress.

  14. Grain boundary and triple junction diffusion in nanocrystalline copper

    Energy Technology Data Exchange (ETDEWEB)

    Wegner, M., E-mail: m.wegner@uni-muenster.de; Leuthold, J.; Peterlechner, M.; Divinski, S. V., E-mail: divin@uni-muenster.de [Institut für Materialphysik, Universität Münster, Wilhelm-Klemm-Straße 10, D-48149, Münster (Germany); Song, X., E-mail: xysong@bjut.edu.cn [College of Materials Science and Engineering, Beijing University of Technology, 100124 Beijing (China); Wilde, G. [Institut für Materialphysik, Universität Münster, Wilhelm-Klemm-Straße 10, D-48149, Münster (Germany); Institute of Nanochemistry and Nanobiology, School of Environmental and Chemical Engineering, Shanghai University, 200444 Shanghai (China)

    2014-09-07

    Grain boundary and triple junction diffusion in nanocrystalline Cu samples with grain sizes, 〈d〉, of ∼35 and ∼44 nm produced by spark plasma sintering were investigated by the radiotracer method using the {sup 63}Ni isotope. The measured diffusivities, D{sub eff}, are comparable with those determined previously for Ni grain boundary diffusion in well-annealed, high purity, coarse grained, polycrystalline copper, substantiating the absence of a grain size effect on the kinetic properties of grain boundaries in a nanocrystalline material at grain sizes d ≥ 35 nm. Simultaneously, the analysis predicts that if triple junction diffusion of Ni in Cu is enhanced with respect to the corresponding grain boundary diffusion rate, it is still less than 500⋅D{sub gb} within the temperature interval from 420 K to 470 K.

  15. Grain Refinement of Permanent Mold Cast Copper Base Alloys

    Energy Technology Data Exchange (ETDEWEB)

    M.Sadayappan; J.P.Thomson; M.Elboujdaini; G.Ping Gu; M. Sahoo

    2005-04-01

    Grain refinement is a well established process for many cast and wrought alloys. The mechanical properties of various alloys could be enhanced by reducing the grain size. Refinement is also known to improve casting characteristics such as fluidity and hot tearing. Grain refinement of copper-base alloys is not widely used, especially in sand casting process. However, in permanent mold casting of copper alloys it is now common to use grain refinement to counteract the problem of severe hot tearing which also improves the pressure tightness of plumbing components. The mechanism of grain refinement in copper-base alloys is not well understood. The issues to be studied include the effect of minor alloy additions on the microstructure, their interaction with the grain refiner, effect of cooling rate, and loss of grain refinement (fading). In this investigation, efforts were made to explore and understand grain refinement of copper alloys, especially in permanent mold casting conditions.

  16. Longitudinal Decline in Lung Function Measurements among Saskatchewan Grain Workers

    Directory of Open Access Journals (Sweden)

    Punam Pahwa

    2003-01-01

    Full Text Available OBJECTIVE: To evaluate the relationship between the long term effects of grain dust and decline in lung function among grain elevator workers in Saskatchewan, studied over a 15-year period.

  17. Impact Property of Ultra Fine Grain Copper

    Directory of Open Access Journals (Sweden)

    Fahad Al-Mufadi

    2014-06-01

    Full Text Available Ultrafine Grained (UFG and Nano-Structured (NS materials have experienced a rapid development during the last decade and made profound impact on every field of materials science and engineering. The present study has been undertaken to develop ultrafine grained pure copper by severe plastic deformation method and to examine the impact property by different characterizing tools. For this aim, equal channel angular pressing die with the channel angle, outer corner angle and channel diameter of 90°, 17° and 20 mm, respectively had been designed and manufactured. Commercial pure copper billets were ECAPed up to four passes by route BC at the ambient temperature. The results indicated that there is a great improvement at the hardness measurement, yield strength and ultimate tensile strength after ECAP process. It is found that the magnitudes of HV reach 136 from 52 HV after the final pass. Also, about 285 and 125% enhancement at the YS and UTS values have been obtained after the fourth pass as compared to the as-received conditions, respectively. On the other hand, the elongation to failure and impact energy have been reduced by imposing ECAP process and pass numbers. It is needed to say that about 56% reductions in the impact energy have been attained for the samples as contrasted to annealed specimens. Furthermore, the grain size of the final pass is 800 nm for Cu sample. Finally, fracture surfaces of billets after impact test have been investigated using Scanning Electron Microscope (SEM.

  18. Communication Optimizations for Fine-Grained UPCApplications

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wei-Yu; Iancu, Costin; Yelick, Katherine

    2005-07-08

    Global address space languages like UPC exhibit high performance and portability on a broad class of shared and distributed memory parallel architectures. The most scalable applications use bulk memory copies rather than individual reads and writes to the shared space, but finer-grained sharing can be useful for scenarios such as dynamic load balancing, event signaling, and distributed hash tables. In this paper we present three optimization techniques for global address space programs with fine-grained communication: redundancy elimination, use of split-phase communication, and communication coalescing. Parallel UPC programs are analyzed using static single assignment form and a data flow graph, which are extended to handle the various shared and private pointer types that are available in UPC. The optimizations also take advantage of UPC's relaxed memory consistency model, which reduces the need for cross thread analysis. We demonstrate the effectiveness of the analysis and optimizations using several benchmarks, which were chosen to reflect the kinds of fine-grained, communication-intensive phases that exist in some larger applications. The optimizations show speedups of up to 70 percent on three parallel systems, which represent three different types of cluster network technologies.

  19. Dust grains from the heart of supernovae

    CERN Document Server

    Bocchio, M; Schneider, R; Bianchi, S; Limongi, M; Chieffi, A

    2016-01-01

    Dust grains are classically thought to form in the winds of AGB stars. However, nowadays there is increasing evidence for dust formation in SNe. In order to establish the relative importance of these two classes of stellar sources of dust it is important to know what is the fraction of freshly formed dust in SN ejecta that is able to survive the passage of the reverse shock and be injected in the interstellar medium. With this aim, we have developed a new code, GRASH_Rev, that allows to follow the dynamics of dust grains in the shocked SN ejecta and to compute the time evolution of the mass, composition and size distribution of the grains. We consider four well studied SNe in the Milky Way and LMC: SN 1987a, Cas A, the Crab Nebula, and N49. For all the simulated models, we find good agreement with observations. Our study suggests that SN 1987A is too young for the reverse shock to have affected the dust mass. Conversely, in the other three SNe, the reverse shock has already destroyed between 10 and 40% of the...

  20. Therapeutic Effect of Cereal Grains: A Review.

    Science.gov (United States)

    Singhal, Poonam; Kaushik, Geetanjali

    2016-04-01

    Over the last few decades, life style changes have resulted in drastic increase in the incidence of diabetes all over the world, especially in the developing countries. Oral hypoglycemic agents and insulin form the main stay in controlling diabetes but they have prominent side effects and fail to significantly alter the course of diabetic complications. Appropriate diet and exercise programs that form a part of lifestyle modifications have proven to be greatly effective in the management of this disease. Dietary therapy is showing a bright future in the prevention and treatment of diabetes. Cereal grains which form the staple diet for humans in most of the countries are increasingly being used to treat diabetes and other associated disorders in view of their anti-diabetic and anti-lipidemic potential. Given this background, this paper reviews the possible mechanisms of lowering blood sugar and cholesterol levels possessed by various commonly consumed cereal grains. It is concluded that cereal grains are not only the potential sources of energy but also possess the therapeutic role in preventing metabolic disorders and decreasing the risk factors for cardiovascular and renal diseases. PMID:25746052

  1. Radiation Disinfestation of Grain and Seeds

    International Nuclear Information System (INIS)

    Current interest in radiation treatment of grain and seeds mainly revolves about its efficacy for control of insect infestations in these products. The recent literature on this subject is reviewed and gaps still existing in the fundamental and practical knowledge of radiation disinfestation.are pointed out. Research programmes in the United States Department of Agriculture that are under way, or planned for the immediate future, are discussed in detail. Current studies are being directed toward establishing minimum effective doses for sexual sterilization and mortality, influence of environmental factors on dose requirements, and potential for the development of biological resistance. In May 1966 the scope of the work expanded as a new grain products irradiator became operative and applied studies were initiated. An integral part of this, research is a study of the effect of irradiation on the quality of food and feed grains and on cereal products, at the doses for both insect control and fungal disinfection. This paper examines critically the results of research in this area and estimates future research, needs. (author)

  2. Multiple age components in individual molybdenite grains

    Science.gov (United States)

    Aleinikoff, John N.; Creaser, Robert A.; Lowers, Heather; Magee, Charles W.; Grauch, Richard I.

    2012-01-01

    Re–Os geochronology of fractions composed of unsized, coarse, and fine molybdenite from a pod of unusual monazite–xenotime gneiss within a granulite facies paragneiss, Hudson Highlands, NY, yielded dates of 950.5 ± 2.5, 953.8 ± 2.6, and 941.2 ± 2.6 Ma, respectively. These dates are not recorded by co-existing zircon, monazite, or xenotime. SEM–BSE imagery of thin sections and separated grains reveals that most molybdenite grains are composed of core and rim plates that are approximately perpendicular. Rim material invaded cores, forming irregular contacts, probably reflecting dissolution/reprecipitation. EPMA and LA-ICP-MS analyses show that cores and rims have different trace element concentrations (for example, cores are relatively enriched in W). On the basis of inclusions of zircon with metamorphic overgrowths, we conclude that molybdenite cores and rims formed after high-grade regional metamorphism. The discovery of cores and rims in individual molybdenite grains is analogous to multi-component U-Pb geochronometers such as zircon, monazite, and titanite; thus, molybdenite should be carefully examined before dating to ensure that the requirement of age homogeneity is fulfilled.

  3. ELECTROSTATICALLY SUPPORTED MIXING OF FINE GRAINED PARTICLES

    Institute of Scientific and Technical Information of China (English)

    K.-E.; Wirth; M.; Linsenbühler

    2005-01-01

    The processing of fine-grained particles with diameters between 1 and 10 microns is difficult due to strong van-der-Waals attraction forces. In order to improve the handling properties, the fine-grained particles, i.e. host-particles,are coated with various nanoparticles, i.e. guest-particles. The mixing of fine-grained powders is influenced by particle-particle interactions. If these forces are distinctively used, both interactive and ordered mixtures can be produced.These particle mixtures consist of composite-particles that have new physical properties. These modified properties d epend strongly on the coating process, the diameter- and mass-relationship of the guest- and the host-particles. The properties of the composite-particles can systematically be adjusted to the requirements of industrial applications. For example, a laboratory bubbling fluidized bed can be used to describe the conveying behavior of the functionalized host-particles. Applications for the functionalized particles are in the pharmaceutical and the powder coating industries,e.g. enhanced dry powder inhalers and thin lacquer films. The present research compares three different mixing/coating processes. The composite-particles are characterized by TEM, SEM and with their fluidization characteristics. The coating process itself is monitored by the electrostatic charge of the particles.

  4. Responses of ethylene and ACC in rice grains to soil moisture and their relations to grain filling

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The objectives of this study were to-investigate ethylene and 1-aminocylopropane-1-carboxylic acid (ACC) in rice grains and root bleeding sap during the grain filling period and their relationship to the grain filling rate.Two high lodging-resistant rice (Oryza sativa L.) cultivars were grown in pots or tanks.Three treatments,including well watered (WW),moderate soil-drying (MD) and severe soil-drying (SD),were conducted from 9 days of post-anthesis until maturity.The effects of chemical regulators on the concentrations of ethylene and ACC in the grains were also studied.The results show that MD significantly increased the grainfilling rate and grain weight,whereas SD significantly reduced the grain-filling rate and grain weight.Concentrations of ethylene and ACC in the grains were very high at the early grain filling stage and then sharply decreased during the linear period of grain growth.MD reduced the ACC concentrations and ethylene evolution rate,whereas SD remarkably increased the ACC concentrations and ethylene evolution rate.Both the ethylene evolution rate in rice grains and the ACC concentrations in the root-bleeding sap were significantly and positively correlated with the ACC concentrations in rice grains.The ethylene evolution rate was significantly and negatively correlated with the grain-filling rate.The application of amino-ethoxyvinylglycine (AVG),an inhibitor of ethylene synthesis,at 9-13 days of postanthesis significantly reduced the ACC concentrations and ethylene evolution rate of grains,but significantly enhanced the activities of sucrose synthase,ADP glucose pyrophosphorylase and soluble starch synthase.The results were reversed when ethephon,an ethylenereleasing agent,was applied.The results suggest that moderate soil drying during the grain-filling period in rice could inhibit the production of ethylene and ACC and therefore accelerate grain filling and increase grain weight.

  5. Grain Size Dependence of Exchange-Coupling Interaction between Magnetically Soft-Hard Grains and Effective Anisotropy

    Institute of Scientific and Technical Information of China (English)

    韩广兵; 高汝伟; 傅爽; 刘汉强; 冯维存; 陈伟

    2004-01-01

    Taking α-Fe and Nd2Fe14B grains as example, the grain size dependence of the exchange-coupling interaction and effective anisotropy and also their variations depending on the ratio of magnetically soft and hard grain sizes, Ds∶ Dh, were investigated. When grain size D>Lex, the grain's anisotropy is the statistic value of the coupled and uncoupled part. The anisotropy constant of uncoupled part is the common value K1 and that of coupled part varies with the distance to the grain surface. The effective anisotropy constant between magnetically soft and hard grains, Keff, can be expressed as the sum of the products of volume fractions for soft and hard grains, respectively, and the corresponding mean anisotropy constants. The calculation results indicate that the exchange-coupling interaction is enhanced with the reduction of grain size, and the effective anisotropy decreases with reducing grain size and increasing ratio of Ds∶ Dh. In order to get high effective anisotropy constant, Keff, in composite magnetically soft-hard grains, the hard grain size should be larger than 30 nm and the soft grain size should be about 10 nm.

  6. PRESENT STATE AND PROBLEMS OF FORMING AN EFFECTIVE GRAIN MARKET

    OpenAIRE

    Tsvyrko, A.

    2012-01-01

    The article deals with current issues of forming a highly grain market. Statistical data reflecting the current state of the problem. Based on studies of the current state of the grain market highlighted the main target indicators defined the conditions for achieving the projected performance of the grain market and its products and recommendations for further development and growth of grain production capacity in Russia.

  7. Molecular functions of genes related to grain shape in rice

    OpenAIRE

    Zheng, Jia; Zhang, Yadong; Wang, Cailin

    2015-01-01

    Because grain shape is an important component of rice grain yield, the discovery of genes related to rice grain shape has attracted much attention of rice breeding programs. In recent years, some of these genes have been cloned and studied. They have been found not only regulate grain shape by changing the shape of the spikelet hull, but also regulate endosperm development through control of cell division using different molecular mechanisms. In this paper, we review the recent research on ge...

  8. Economic Potential for Nutritional Improvement in Feed Grains

    OpenAIRE

    Brennan, John P.; Singh, Rajinder Pal; Bialowas, Adam

    2000-01-01

    Feed grains researchers have abundant technical opportunities to select various options for improvement of nutritional characteristics of feed grains. Choosing between those opportunities is a difficult issue for research funding organisations. In this paper, efforts to address the relative economic benefits from the different options for feed grains nutritional improvement are reported. The economic benefits arising from nutritional improvements in various feed grains are examined and compar...

  9. Model Predictive Control of the Grain Drying Process

    OpenAIRE

    Feng Han; Chuncheng Zuo; Wenfu Wu; Junxing Li; Zhe Liu

    2012-01-01

    Drying plays an important role in the postharvesting process of grain. To ensure the quality of the dried grain and improve the intelligent level in drying process, a digital simulation of corn drying machine system based on a virtual instrument was established for 5HSZ dryer, automatically control the air temperature, and predict the discharging speed of grain and so forth. Finally, an online measurement and automated control software of grain parameters were developed to provide the changes...

  10. Annealing-induced Grain Refinement in a Nanostructured Ferritic Steel

    Institute of Scientific and Technical Information of China (English)

    Limin Wang; Zhenbo Wangt; Sheng Guo; Ke Lu

    2012-01-01

    A nanostructured surface layer with a mean ferrite grain size of -8 nm was produced on a Fe-gCr steel by means of surface mechanical attrition treatment. Upon annealing, ferrite grains coarsen with increasing temperature and their sizes increase to -40 nm at 973 K. Further increasing annealing temperature leads to an obvious reduction of ferrite grain sizes, to -14 nm at 1173 K. The annealing-induced grain refinement is analyzed in terms of phase transformations in the nanostructured steel.

  11. Foreign Grain Security Mechanisms and Implications for China

    OpenAIRE

    Cao, Shuhua; Nie, Lei; Ma, Weipeng

    2014-01-01

    With constant growth of China’s population and increasingly serious situation of farmland protection, the grain security has become a hot issue of China. This study firstly elaborated grain security measures in grain exporters, such as the United States, Australia, and EU, and grain importers such as Japan, South Korea and India. In line with these security measures, it analyzed implementation background of these policies. Finally, combining social and economic development situations and na...

  12. Longitudinal Decline in Lung Function Measurements among Saskatchewan Grain Workers

    OpenAIRE

    Punam Pahwa; Ambikaipakan Senthilselvan; McDuffie, Helen H; Dosman, James A

    2003-01-01

    OBJECTIVE: To evaluate the relationship between the long term effects of grain dust and decline in lung function among grain elevator workers in Saskatchewan, studied over a 15-year period.METHODS: The Grain Dust Medical Surveillance Program was started by Labour Canada in 1978 and longitudinally studied the respiratory health of Canadian grain elevator workers over a 15-year period (1978 to 1993). Data on respiratory symptoms and pulmonary function tests (forced expiratory volume in 1 s [FEV...

  13. Does whole grain consumption alter gut microbiota and satiety?

    Science.gov (United States)

    This review summarizes recent studies examining whole grain consumption and its effect on gut microbiota and satiety in healthy humans. Both individual whole grain cereals and interventions with combined whole grain cereals were considered. Possible links between the fermentation of non-digestible c...

  14. Major Grain Growers in Jiaojiang District,Taizhou City

    Institute of Scientific and Technical Information of China (English)

    Zuda; BAO; Yangdong; DING; Xiaping; DAI; Lang; XU

    2013-01-01

    Based on the survey data of major grain growers in Jiaojiang District,we make a thorough inquiry into the current situation and various problems concerning major grain growers in this district,explore the factors that affect major grain growers’ operation behavior,and set forth corresponding countermeasures for solving these problems and promoting further development.

  15. Ancient Whole Grain Gluten-free Egg-free Pasta

    Science.gov (United States)

    The USDA food guide recommends that at least ½ of all the grains eaten should be whole grains. The FDA allows food Health Claim labels for food containing 51% whole gains and 11 g of dietary fiber per serving. This is the only report demonstrating innovative ancient whole grain, gluten-free, egg-fre...

  16. Ancient whole grain gluten-free egg-free Pasta

    Science.gov (United States)

    The USDA food guide recommends that at least ½ of all the grains eaten should be whole grains. The FDA allows food Health Claim labels for food containing 51% whole gains and 11 g of dietary fiber per serving. This is the only report demonstrating innovative ancient whole grain, gluten-free, egg-fre...

  17. Causality Between Market Liquidity and Depth for Energy and Grains

    NARCIS (Netherlands)

    R. Sari (Ramazan); S.M. Hammoudeh (Shawkat); C-L. Chang (Chia-Lin); M.J. McAleer (Michael)

    2011-01-01

    textabstractThis paper examines the roles of futures prices of crude oil, gasoline, ethanol, corn, soybeans and sugar in the energy-grain nexus. It also investigates the own- and cross-market impacts for lagged grain trading volume and open interest in the energy and grain markets. According to the

  18. Whole grain foods and health – a Scandinavian perspective

    Science.gov (United States)

    Frølich, Wenche; Åman, Per; Tetens, Inge

    2013-01-01

    The food-based dietary guidelines in the Scandinavian countries that recommend an intake of minimum 75 g whole grain per 10 MJ (2,388 kcal) per day are mainly derived from prospective cohort studies where quantitative but little qualitative details are available on whole grain products. The objective of the current paper is to clarify possible differences in nutritional and health effects of the types of whole grain grown and consumed in the Scandinavian countries. A further objective is to substantiate how processing may influence the nutritional value and potential health effects of different whole grains and whole grain foods. The most commonly consumed whole grain cereals in the Scandinavian countries are wheat, rye, and oats with a considerable inter-country variation in the consumption patterns and with barley constituting only a minor role. The chemical composition of these different whole grains and thus the whole grain products consumed vary considerably with regard to the content of macro- and micronutrients and bioactive components. A considerable amount of scientific substantiation shows that processing methods of the whole grains are important for the physiological and health effects of the final whole grain products. Future research should consider the specific properties of each cereal and its processing methods to further identify the uniqueness and health potentials of whole grain products. This would enable the authorities to provide more specific food-based dietary guidelines in relation to whole grain to the benefit of both the food industry and the consumer. PMID:23411562

  19. Ammonia disinfection of corn grains intended for ethanol fermentation

    Directory of Open Access Journals (Sweden)

    Magdalena Broda

    2009-12-01

    Full Text Available Background. Bacterial contamination is an ongoing problem for commercial bioethanol plants. It concerns factories using grain and also other raw materials for ethanol fermentation. Bacteria compete with precious yeasts for sugar substrates and micronutrients, secrete lactic and acetic acids, which are toxic for yeast and this competition leads to significant decrease of bioethanol productivity. For this study, bacterial contamination of corn grain was examined. Then the grain was treated by ammonia solution to reduce microbial pollution and after that the microbiological purity of grain was tested one more time. Disinfected and non-disinfected corn grains were ground and fermentation process was performed. Microbiological purity of this process and ethanol yield was checked out. Material and methods. The grain was disinfected by ammonia solution for two weeks. Then the grain was milled and used as a raw material for the ethanol fermentation. The fermentation process was carried out in 500-ml Erlenmeyer flasks. Samples were withdrawn for analysis at 0, 24, 48, 72 hrs. The number of total viable bacteria, lactic acid bacteria, acetic acid bacteria, anaerobic bacteria and the quantity of yeasts and moulds were signified by plate method. Results. Ammonia solution effectively reduces bacterial contamination of corn grain. Mash from grain disinfected by ammonia contains less undesirable microorganisms than mash from crude grain. Moreover, ethanol yield from disinfected grain is at the highest level. Conclusions. The ammonia solution proved to be a good disinfection agent for grain used as a raw material for bioethanol fermentation process.

  20. Whole grain foods and health – a Scandinavian perspective

    Directory of Open Access Journals (Sweden)

    Wenche Frølich

    2013-02-01

    Full Text Available The food-based dietary guidelines in the Scandinavian countries that recommend an intake of minimum 75 g whole grain per 10 MJ (2,388 kcal per day are mainly derived from prospective cohort studies where quantitative but little qualitative details are available on whole grain products. The objective of the current paper is to clarify possible differences in nutritional and health effects of the types of whole grain grown and consumed in the Scandinavian countries. A further objective is to substantiate how processing may influence the nutritional value and potential health effects of different whole grains and whole grain foods. The most commonly consumed whole grain cereals in the Scandinavian countries are wheat, rye, and oats with a considerable inter-country variation in the consumption patterns and with barley constituting only a minor role. The chemical composition of these different whole grains and thus the whole grain products consumed vary considerably with regard to the content of macro- and micronutrients and bioactive components. A considerable amount of scientific substantiation shows that processing methods of the whole grains are important for the physiological and health effects of the final whole grain products. Future research should consider the specific properties of each cereal and its processing methods to further identify the uniqueness and health potentials of whole grain products. This would enable the authorities to provide more specific food-based dietary guidelines in relation to whole grain to the benefit of both the food industry and the consumer.

  1. 7 CFR 800.98 - Weighing grain in combined lots.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Weighing grain in combined lots. 800.98 Section 800.98... Provisions and Procedures § 800.98 Weighing grain in combined lots. (a) General. The weighing of bulk or sacked grain loaded aboard, or being loaded aboard, or unloaded from two or more carriers as a...

  2. Association of Phytate Formation with Grain Filling in Rice

    Institute of Scientific and Technical Information of China (English)

    WANG Ruo-zhong; XIAO Lang-tao; DING Jun-hui; YAN Qin-quan

    2003-01-01

    The grain-filling characteristics of six rice varieties (combinations) and the relationships between their relative biochemistry composition during phytate synthesizing and grain plumpness were studied. Regarding results for ISHR1,ISHR2, R198 and JW21, with good grain plumpness, the two-step-filling in superior spikelets and inferior spikelets was not clear, while for ISHR3 and 559, with poor grain plumpness, it was very clear. From booting stage to flowering stage, the contents of phytate and inositol in varieties with good grain plumpness was obviously higher than those in varieties with poor grain plumpness. While at grain filling stage, the content of inorganic phosphorus in varieties with poor grain plumpness was obviously higher than that in varieties with good grain plumpness. The contents of phytate and inositol from booting stage to flowering stage was highly significantly correlated with the initial filling power (RO), the mean filling rate (RM) and grain filling percentage (PGF), and the content of inorganic phosphorus at grain filling stage was negatively significantly correlated with R0, FM and PGF. Furthermore, effective approach to improving grain filling was put forward.

  3. Grain-to-Grain Compositional Variations and Phase Segregation in Copper-Zinc-Tin-Sulfide Films.

    Science.gov (United States)

    Alvarez Barragan, Alejandro; Malekpour, Hoda; Exarhos, Stephen; Balandin, Alexander A; Mangolini, Lorenzo

    2016-09-01

    We have performed a rigorous investigation of the structure and composition of individual grains in copper-zinc-tin-sulfide (CZTS) films realized by sulfurization of a sputtered metal stack. Although on average close to the ideal CZTS stoichiometry, elemental analysis shows significant grain-to-grain variations in composition. High-resolution Raman spectroscopy indicates that this is accompanied by grain-to-grain structural variations as well. The intensity from the 337 cm(-1) Raman peak, generally assigned to the kesterite phase of CZTS, remains constant over a large area of the sample. On the other hand, signals from secondary phases at 376 cm(-1) (copper-tin-sulfide) and 351 cm(-1) (zinc-sulfide) show significant variation over the same area. These results confirm the great complexity inherent to this material system. Moreover, structural and compositional variations are recognized in the literature as a factor limiting the efficiency of CZTS photovoltaic devices. This study demonstrates how a seemingly homogeneous CZTS thin film can actually have considerable structural and compositional variations at the microscale, and highlights the need for routine microscale characterization in this material system. PMID:27538122

  4. H2 recombination on interstellar grains. [due to hydrogen atom chemisorption on graphite grains

    Science.gov (United States)

    Barlow, M. J.; Silk, J.

    1976-01-01

    From a consideration of relevant theoretical and experimental data it is concluded that H atoms (but not H2 molecules) will be chemisorbed on interstellar graphite grains, with H2 formation proceeding efficiently for graphite grain temperatures less than 70 K. It is argued that graphite grains will act as the principal sites for H2 formation, with a formation rate of about 4 to the minus 17th cu cm per sec. Heating by H2 molecules formed by surface recombination is analyzed in the context of the available experimental data, and a heating rate is derived and compared with other suggested cloud heating mechanisms. It is concluded that H2 recombination will provide the largest heat source in diffuse clouds if the albedo of interstellar dust in the 912-1200 A region is high (about 0.9), whereas if the albedo in this wavelength region is lower (about 0.5), photoelectron ejection from grains will tend to predominate, and can explain observed cloud temperatures with a carbon depletion factor of approximately 2, a factor attributable to a normal interstellar abundance of graphite grains.

  5. Supplying materials needed for grain growth characterizations of nano-grained UO2

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Kun [Argonne National Lab. (ANL), Argonne, IL (United States); Miao, Yinbin [Argonne National Lab. (ANL), Argonne, IL (United States); Yun, Di [Argonne National Lab. (ANL), Argonne, IL (United States); Jamison, Laura M. [Argonne National Lab. (ANL), Argonne, IL (United States); Lian, Jie [Rensselaer Polytechnic Inst., Troy, NY (United States); Yao, Tiankei [Rensselaer Polytechnic Inst., Troy, NY (United States)

    2015-09-30

    This activity is supported by the US Nuclear Energy Advanced Modeling and Simulation (NEAMS) Fuels Product Line (FPL) and aims at providing experimental data for the validation of the mesoscale simulation code MARMOT. MARMOT is a mesoscale multiphysics code that predicts the coevolution of microstructure and properties within reactor fuel during its lifetime in the reactor. It is an important component of the Moose-Bison-Marmot (MBM) code suite that has been developed by Idaho National Laboratory (INL) to enable next generation fuel performance modeling capability as part of the NEAMS Program FPL. In order to ensure the accuracy of the microstructure based materials models being developed within the MARMOT code, extensive validation efforts must be carried out. In this report, we summarize our preliminary synchrotron radiation experiments at APS to determine the grain size of nanograin UO2. The methodology and experimental setup developed in this experiment can directly apply to the proposed in-situ grain growth measurements. The investigation of the grain growth kinetics was conducted based on isothermal annealing and grain growth characterization as functions of duration and temperature. The kinetic parameters such as activation energy for grain growth for UO2 with different stoichiometry are obtained and compared with molecular dynamics (MD) simulations.

  6. A new model of grain growth kinetics in UO{sub 2} fuel pellets. Part 1: Grain growth kinetics controlled by grain face bubble migration

    Energy Technology Data Exchange (ETDEWEB)

    Veshchunov, M.S. [Russian Academy of Sciences, Nuclear Safety Institute (IBRAE), 52, B. Tulskaya, Moscow 115191 (Russian Federation)]. E-mail: vms@ibrae.ac.ru

    2005-11-15

    A new mechanism of the lenticular grain face bubble migration which controls the bubble mobility and determines the drag force exerted on the grain boundary, is developed. It is shown that besides a more complicated (so called 'lenticular') shape of grain face bubbles, the migration mechanism of these bubbles might be essentially different from the intragranular bubbles, owing to their specific location on and interaction with a grain boundary. The model is validated against tests on grain growth kinetics during steady irradiation exposure and during post-irradiation annealing of UO{sub 2} fuel samples, and allows explanation of a strong retarding effect of irradiation on the grain growth observed in these tests.

  7. Micromechanical testing of stress corrosion cracking of individual grain boundaries

    International Nuclear Information System (INIS)

    Grain boundaries of different misorientation and chemistry have differing susceptibilities to stress corrosion cracking but carrying out mechanical tests on individual grain boundaries of known character has until now been very difficult. We present a method for manufacturing specimens containing a single grain boundary (in 304 stainless steel) using focused ion beam machining. A nanoindenter/atomic force microscope was used to drive controlled grain boundary crack growth under load in an active solution. Scanning electron microscopy examination confirmed the growth of the crack along the grain boundary.

  8. Recrystallization from a Three-Grain Crystalline Iron

    Directory of Open Access Journals (Sweden)

    Bo Zhao

    2015-01-01

    Full Text Available The solid state recrystallization and grain boundary migrations in an iron nanoparticle Fe2616 with three grains were studied by a molecular dynamics simulation. It was found that nucleation rates could be determined as the smaller grains were consumed by the larger ones. Moreover, the grain disorder was more important than the misorientation angle in governing the rates. Suggestions about the critical nuclei for the recrystallization are proposed. No obvious interaction between the grain boundaries was observed in the example studied in this report.

  9. Grain Boundary Traction Signatures: Quantitative Predictors of Dislocation Emission

    Science.gov (United States)

    Li, Ruizhi; Chew, Huck Beng

    2016-08-01

    We introduce the notion of continuum-equivalent traction fields as local quantitative descriptors of the grain boundary interface. These traction-based descriptors are capable of predicting the critical stresses to trigger dislocation emissions from ductile ⟨110 ⟩ symmetrical-tilt nickel grain boundaries. We show that Shockley partials are emitted when the grain boundary tractions, in combination with external tensile loading, generate a resolved shear stress to cause dislocation slip. The relationship between the local grain boundary tractions and the grain boundary energy is established.

  10. Proteomics of Rice Grain under High Temperature Stress

    Directory of Open Access Journals (Sweden)

    Toshiaki eMitsui

    2013-03-01

    Full Text Available Recent proteomic analyses revealed dynamic changes of metabolisms during rice grain development. Interestingly, proteins involved in glycolysis, citric acid cycle, lipid metabolism, and proteolysis were accumulated at higher levels in mature grain than those of developing stages. High temperature stress in rice ripening period causes damaged (chalky grains which have loosely packed round shape starch granules. The high temperature stress response on protein expression is complicated, and the molecular mechanism of the chalking of grain is obscure yet. Here, the current state on the proteomics research of rice grain grown under high temperature stress is briefly overviewed.

  11. Whole grain foods and health - A Scandinavian perspective

    DEFF Research Database (Denmark)

    Frølich, Wenche; Aman, Per; Tetens, Inge

    2013-01-01

    of different whole grains and whole grain foods. The most commonly consumed whole grain cereals in the Scandinavian countries are wheat, rye, and oats with a considerable inter-country variation in the consumption patterns and with barley constituting only a minor role. The chemical composition...... and health effects of the final whole grain products. Future research should consider the specific properties of each cereal and its processing methods to further identify the uniqueness and health potentials of whole grain products. This would enable the authorities to provide more specific food...

  12. Foreign Grain Security Mechanisms and Implications for China

    Institute of Scientific and Technical Information of China (English)

    Shuhua; CAO; Lei; NIE; Weipeng; MA

    2014-01-01

    With constant growth of China’s population and increasingly serious situation of farmland protection,the grain security has become a hot issue of China.This study firstly elaborated grain security measures in grain exporters,such as the United States,Australia,and EU,and grain importers such as Japan,South Korea and India.In line with these security measures,it analyzed implementation background of these policies.Finally,combining social and economic development situations and natural resource endowment of China,it revealed the implications of these measures for China and came up with policy recommendations for China’s grain security.

  13. Strategic Analysis on Objectives of National Grain Security

    Institute of Scientific and Technical Information of China (English)

    Hong; YANG

    2015-01-01

    Price of global agricultural products rises with great fluctuation. China’s food price also increases constantly. This leads to high concern of both at home and abroad for food and grain security. On the basis of making an overall analysis on current situation of grain security and making judgment on future grain security in China,this paper analyzed objectives,strategies and policies of national grain security in the new period. Finally,it came up with strategies and policy recommendations for improving agricultural production and guaranteeing national grain security.

  14. NUMERICAL SIMULATION FOR DEFORMATION OF NANO-GRAINED METALS

    Institute of Scientific and Technical Information of China (English)

    杨卫; 洪伟

    2002-01-01

    Electro-deposition technique is capable of producing nano-grainedbulk copper specimens that exhibit superplastic extensibility at room temperature.Metals of such small grain sizes deform by grains sliding, with little distortion occur-ring in the grain cores. Accommodation mechanisms such as grain boundary diffusion,sliding and grain rotation control the kinetics of the process. Actual deformation min-imizes the plastic dissipation and stored strain energy for representative steps of grainneighbor switching. Numerical simulations based on these principles are discussed inthis paper.

  15. Grain Growth Behavior in Sintered Nd-Fe-B Magnets

    Institute of Scientific and Technical Information of China (English)

    Liu Xianglian; Zhou Shouzeng

    2007-01-01

    The Nd2Fe14B grain growth behavior in sintered Nd-Fe-B magnets was quantitatively described. The effects of sintering temperature and time, and alloy powder size and its distribution on grain growth process were analyzed. Hence, possible grain growth mechanisms in these magnets were qualitatively discussed. The Nd2Fe14B grain growth proceeded at quite a high rate in the initial 0~1 h of sintering and from then onwards the grain growth rate decreased. A large average particle size or a wide particle size distribution of initial alloy powders was found to remarkably accelerate the grain growth process and even result in the occurrence of abnormal grain growth. On the basis of experimental results, two grain growth mechanisms were considered to operate during sintering of Nd-Fe-B magnets, that is, dissolution and re-precipitation of Nd2Fe14B particles, and Nd2Fe14B particle growth by coalescence. It was believed that Nd2Fe14B particle growth by coalescence not only produced a large average grain size and a wide grain size distribution, but also was the fundamental reason for the formation of abnormally large grains in the microstructure of sintered Nd-Fe-B magnets.

  16. Kinetic Modeling of Sunflower Grain Filling and Fatty Acid Biosynthesis.

    Science.gov (United States)

    Durruty, Ignacio; Aguirrezábal, Luis A N; Echarte, María M

    2016-01-01

    Grain growth and oil biosynthesis are complex processes that involve various enzymes placed in different sub-cellular compartments of the grain. In order to understand the mechanisms controlling grain weight and composition, we need mathematical models capable of simulating the dynamic behavior of the main components of the grain during the grain filling stage. In this paper, we present a non-structured mechanistic kinetic model developed for sunflower grains. The model was first calibrated for sunflower hybrid ACA855. The calibrated model was able to predict the theoretical amount of carbohydrate equivalents allocated to the grain, grain growth and the dynamics of the oil and non-oil fraction, while considering maintenance requirements and leaf senescence. Incorporating into the model the serial-parallel nature of fatty acid biosynthesis permitted a good representation of the kinetics of palmitic, stearic, oleic, and linoleic acids production. A sensitivity analysis showed that the relative influence of input parameters changed along grain development. Grain growth was mostly affected by the specific growth parameter (μ') while fatty acid composition strongly depended on their own maximum specific rate parameters. The model was successfully applied to two additional hybrids (MG2 and DK3820). The proposed model can be the first building block toward the development of a more sophisticated model, capable of predicting the effects of environmental conditions on grain weight and composition, in a comprehensive and quantitative way. PMID:27242809

  17. Kinetic Modeling of Sunflower Grain Filling and Fatty Acid Biosynthesis

    Science.gov (United States)

    Durruty, Ignacio; Aguirrezábal, Luis A. N.; Echarte, María M.

    2016-01-01

    Grain growth and oil biosynthesis are complex processes that involve various enzymes placed in different sub-cellular compartments of the grain. In order to understand the mechanisms controlling grain weight and composition, we need mathematical models capable of simulating the dynamic behavior of the main components of the grain during the grain filling stage. In this paper, we present a non-structured mechanistic kinetic model developed for sunflower grains. The model was first calibrated for sunflower hybrid ACA855. The calibrated model was able to predict the theoretical amount of carbohydrate equivalents allocated to the grain, grain growth and the dynamics of the oil and non-oil fraction, while considering maintenance requirements and leaf senescence. Incorporating into the model the serial-parallel nature of fatty acid biosynthesis permitted a good representation of the kinetics of palmitic, stearic, oleic, and linoleic acids production. A sensitivity analysis showed that the relative influence of input parameters changed along grain development. Grain growth was mostly affected by the specific growth parameter (μ′) while fatty acid composition strongly depended on their own maximum specific rate parameters. The model was successfully applied to two additional hybrids (MG2 and DK3820). The proposed model can be the first building block toward the development of a more sophisticated model, capable of predicting the effects of environmental conditions on grain weight and composition, in a comprehensive and quantitative way. PMID:27242809

  18. Landau-Lifhsitz-Bloch equation for exchange coupled grains

    CERN Document Server

    Vogler, Christoph; Bruckner, Florian; Suess, Dieter

    2014-01-01

    Heat assisted recording is a promising technique to further increase the storage density in hard disks. Multilayer recording grains with graded Curie temperature is discussed to further assist the write process. Describing the correct magnetization dynamics of these grains, from room temperature to far above the Curie point, during a write process is required for the calculation of bit error rates. We present a coarse grained approach based on the Landau-Lifshitz-Bloch (LLB) equation to model exchange coupled grains with low computational effort. The required temperature dependent material properties such as the zero-field equilibrium magnetization as well as the parallel and normal susceptibilities are obtained by atomistic Landau-Lifshitz-Gilbert (LLB) simulations. Each grain is described with one magnetization vector. In order to mimic the atomistic exchange interaction between the grains a special treatment of the exchange field in the coarse grained approach is presented.

  19. Grain growth in nanocrystalline Ni-20%Fe alloy

    Energy Technology Data Exchange (ETDEWEB)

    Park, Y.B.; Park, J.; Kim, S.S. [Dept. of Materials Science and Metallurgical Engineering, Sunchon National Univ., Sunchon (Korea); Yim, T.H. [Materials Process Technology R and D Center, Korea Inst. of Industrial Technology, Chonan (Korea)

    2001-07-01

    Grain growth was investigated in a nanocrystalline Ni-20wt-%Fe alloy fabricated by an electrodeposition method, and its effect on the texture evolution was examined. The as-deposited specimens revealed a strong {l_brace}100{r_brace} and a weak {l_brace}111{r_brace} fibre-type textures. Grain growth in the material occurred on annealing beyond 370 C and resulted in the texture change that the {l_brace}111{r_brace} fibre strongly developed at the expense of the {l_brace}100{r_brace} fibre. It was observed using orientation imaging microscopy (OIM) that the {l_brace}111{r_brace} grains are much coarser than other oriented grains in the early stages of grain growth. The relationship between the texture evolution and the microstructural change accompanied by grain growth is interpreted and discussed in terms of the orientation dependency of grain growth. (orig.)

  20. Textures and grain growth in nanocrystalline Fe-Ni alloys

    Energy Technology Data Exchange (ETDEWEB)

    Seo, J.H.; Kim, J.K.; Park, Y.B. [Dept. of Materials Science and Metallurgical Engineering, Nanomaterials Research Center, Sunchon National Univ. (Korea); Yim, T.H. [Production Technology Center, Korea Inst. of Industrial Technology, Chonan (Korea)

    2005-07-01

    The texture evolution due to grain growth that takes place during annealing was investigated in nanocrystalline Fe-Ni alloys fabricated by using a continuous electroforming method. In the current materials, grain growth occurred during annealing at much lower temperatures than in conventional coarse-grained counterparts. With regard to the macrotextures, the as-deposited textures were of fibre-type characterized by strong <100>//ND and weak <111>//ND components, and the occurrence of grain growth resulted in the strong development of the <111>//ND fibre texture with the minor <100>//ND components. It was clarified using orientation imaging microscopy that abnormal growth of the <111>//ND grains in the early stages of grain growth plays an important role on the texture evolution. The origin of the abnormal grain growth has been discussed in terms of the orientation dependence of energy density. (orig.)

  1. Cycloid motions of grains in unmagnetized dust plasma

    CERN Document Server

    He, Ya-feng; Zhang, Yong-liang; Liu, Fu-cheng

    2014-01-01

    Hypocycloid and epicycloid motions of irregular grain (pine pollen) are observed for the first time in unmagnetized dust plasma in 2D horizontal plane. Hypocycloid motions occur both inside and outside the glass ring which confines the grain. Epicycloid motion only appears outside the glass ring. Cuspate cycloid motions, circle motion, and stationary grain are also observed. All these motions are related with both the initial conditions of dropped grain and the discharge parameters. The Magnus force originated from the spin of the irregular grain is confirmed by comparison experiments with regular microspheres, and it plays important role on these (cuspate) cycloid motions. The observed complex motions are explained in term of force analysis and numerical simulations. Periodical change of the cyclotron radius as the grain travelling results in the (cuspate) cycloid motions. Our results show that the (cuspate) cycloid motions are distinctive features of irregular grain immersed in plasma.

  2. Influence of Grain Boundary on Melting

    Institute of Scientific and Technical Information of China (English)

    王暾; 周富信; 刘曰武

    2001-01-01

    The temperature behaviour of an Al bicrystal with surfaces consisting of (110) and (111) crystals is simulated using molecular dynamics. The result shows that the (110) crystal losses its crystalline order at 820K, whereas the disorder does not propagate through the (111) crystal at this temperature. Instead, some disordered atoms are recrystallized into the (111) crystal and the initial grain boundary changes into a stable order-disorder interface. Thus, it was discovered that at a temperature near its melting point, the (111) crystal grew and obstructed the propagation of disorder. Such an obstruction is helpfulfor understanding melting.

  3. The gravitational description of coarse grained microstates

    Energy Technology Data Exchange (ETDEWEB)

    Alday, Luis F. [Institute for Theoretical Physics and Spinoza Institute, Utrecht University, 3508 TD Utrecht (Netherlands); Boer, Jan de [Instituut voor Theoretische Fysica, Valckenierstraat 65, 1018XE Amsterdam (Netherlands); Messamah, Ilies [Instituut voor Theoretische Fysica, Valckenierstraat 65, 1018XE Amsterdam (Netherlands)

    2006-12-15

    In this paper we construct a detailed map from pure and mixed half-BPS states of the D1-D5 system to half-BPS solutions of type IIB supergravity. Using this map, we can see how gravity arises through coarse graining microstates, and we can explicitly confirm the microscopic description of conical defect metrics, the M = 0 BTZ black hole and of small black rings. We find that the entropy associated to the natural geometric stretched horizon typically exceeds that of the mixed state from which the geometry was obtained.

  4. Fine-grained control of user attributes

    DEFF Research Database (Denmark)

    Olesen, Henning; Khajuria, Samant

    2014-01-01

    Private users, enterprises and other stakeholders have a strong need to protect their resources when interacting with each other. For the users it is a matter of protecting vital personal information and assets (privacy protection), and for enterprises the main concern is to protect...... their intellectual property and confidential data, documents, etc. In this paper we focus on the employee-enterprise interaction and discuss how recent technological progress, in particular the framework of User Managed Access (UMA), can enable fine-grained control of resources and new roles of interaction. The work...

  5. An algebraic approach to coarse graining

    CERN Document Server

    Markopoulou, F

    2000-01-01

    We propose that Kreimer's method of Feynman diagram renormalization via a Hopf algebra of rooted trees can be fruitfully employed in the analysis of block spin renormalization or coarse graining of inhomogeneous statistical systems. Examples of such systems include spin foam formulations of non-perturbative quantum gravity as well as lattice gauge and spin systems on irregular lattices and/or with spatially varying couplings. We study three examples which are Z_2 lattice gauge theory on irregular 2-dimensional lattices, Ising/Potts models with varying bond strengths and (1+1)-dimensional spin foam models.

  6. Cereal grains and coronary heart disease.

    Science.gov (United States)

    Truswell, A S

    2002-01-01

    Cereal grains and their products provide around 30% of total energy intake in British adults, (much more than any of the other major food groups). Coronary heart disease (CHD) is the largest single cause of death in Britain and many other Western countries. This review examines the question whether there is a relation between cereal consumption and CHD. Several of the nutrients in cereals have known potential for reducing risk factors for CHD: the linoleic acid, fibre, vitamin E, selenium and folate. Cereals also contain phytoestrogens of the lignan family and several phenolic acids with antioxidant properties. Processing generally reduces the content of these nutrients and bioprotective substances. Although cereals at the farm gate are very low in salt, processed cereal foods, eg bread and some breakfast cereals, are high-salt foods and thus could contribute to raising blood pressure. Human experiments have clearly shown that oat fibre tends to lower plasma total and LDL cholesterol but wheat fibre does not. Rice bran and barley may also lower cholesterol but most people do not eat enough barley to have an effect. Cereal foods with low glycaemic index such as pasta and oats are beneficial for people with diabetes and might lower plasma lipids. Between 1996 and 2001 an accumulation of five very large cohort studies in the USA, Finland and Norway have all reported that subjects consuming relatively large amounts of whole grain cereals have significantly lower rates of CHD. This confirms an earlier report from a small British cohort. The protective effect does not seem to be due to cholesterol-lowering. While cohort studies have shown this consistent protective effect of whole grain cereals, there has been (only one) randomised controlled secondary prevention trial of advice to eat more cereal fibre. In this there was no reduction of the rate of reinfarction. The trial had some weaknesses, eg there were eight different diets, compliance was not checked objectively

  7. Fine grain tungsten produced with nanoscale powder

    Institute of Scientific and Technical Information of China (English)

    Tao Lin; Fang Zhao; Liying Zhang; Chengyi Wu; Zhimeng Guo

    2005-01-01

    Nanoscale tungsten powder was prepared by reducing nanoscale tungsten trioxide in hydrogen to WO2.90 and further to W powder. After compacted with a rubber die, the nanoscale tungsten powder was sintered in a high-temperature dilatometer to investigate its shrinkage process. The results show that the compact of the nanoscale tungsten powder starts to shrink at 1050℃ and ends at 1500℃. The shrinkage rate reaches the maximum value at 1210℃. The relative density of sintered samples is 96.4%, and its grain size is about 5.8 μm.

  8. Influence of anisotropic grain boundary properties on the evolution of grain boundary character distribution during grain growth—a 2D level set study

    International Nuclear Information System (INIS)

    The present study elaborates on a 2D level set model of polycrystal microstructures that was recently established by adding the influence of anisotropic grain boundary energy and mobility on microstructure evolution. The new model is used to trace the evolution of grain boundary character distribution during grain growth. The employed level set formulation conveniently allows the grain boundary characteristics to be quantified in terms of coincidence site lattice (CSL) type per unit of grain boundary length, providing a measure of the distribution of such boundaries. In the model, both the mobility and energy of the grain boundaries are allowed to vary with misorientation. In addition, the influence of initial polycrystal texture is studied by comparing results obtained from a polycrystal with random initial texture against results from a polycrystal that initially has a cube texture. It is shown that the proposed level set formulation can readily incorporate anisotropic grain boundary properties and the simulation results further show that anisotropic grain boundary properties only have a minor influence on the evolution of CSL boundary distribution during grain growth. As anisotropic boundary properties are considered, the most prominent changes in the CSL distributions are an increase of general low-angle Σ1 boundaries as well as a more stable presence of Σ3 boundaries. The observations also hold for the case of an initially cube-textured polycrystal. The presence of this kind of texture has little influence over the evolution of the CSL distribution. Taking into consideration the anisotropy of grain boundary properties, grain growth alone does not seem to be sufficient to promote any significantly increased overall presence of CSL boundaries. (paper)

  9. Grain boundary and grain interior conduction in {gamma}'-Bi{sub 2}MoO{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Vera, C.M.C. [Laboratorio de Peliculas Delgadas, Facultad de Ingenieria, Universidad de Buenos Aires, Paseo Colon 850, 1063 Buenos Aires (Argentina)]. E-mail: cvera@fi.uba.ar; Aragon, R. [Laboratorio de Peliculas Delgadas, Facultad de Ingenieria, Universidad de Buenos Aires, Paseo Colon 850, 1063 Buenos Aires (Argentina); CINSO, CONICET, CITEFA, Lasalle 4397, Villa Martelli, Buenos Aires (Argentina)

    2005-07-25

    Impedance spectroscopy of fine grained (<10 {mu}m) {gamma}'-Bi{sub 2}MoO{sub 6} samples, in the frequency range of 0.1 Hz-250 kHz, relevant to sensor applications, up to 800 deg. C, has been used to characterize grain boundary and grain interior contributions to conduction. Above 500 deg. C, the grain boundary contribution is no longer rate limiting and conduction is dominated by the grain interior component. The corresponding activation energies are 0.98 eV for grain boundary and 0.73 eV for grain interior components. The weak dependence of conductivity on oxygen partial pressure below 500 deg. C can be attributed to electrode-electrolyte interface phenomena, whereas the robust response to ethanol is commensurate with changes in intrinsic ionic conductivity.

  10. A coarse-grained spectral signature generator

    Science.gov (United States)

    Lam, K. P.; Austin, J. C.; Day, C. R.

    2007-01-01

    This paper investigates the method for object fingerprinting in the context of element specific x-ray imaging. In particular, the use of spectral descriptors that are illumination invariant and viewpoint independent for pattern identification was examined in some detail. To improve generating the relevant "signature", the spectral descriptor constructed is enhanced with a differentiator which has built-in noise filtration capability and good localisation properties, thus facilitating the extraction of element specific features at a coarse-grained level. In addition to the demonstrable efficacy in identifying significant image intensity transitions that are associated with the underlying physical process of interest, the method has the distinct advantage of being conceptually simple and computationally efficient. These latter properties allow the descriptor to be further utilised by an intelligent system capable of performing a fine-grained analysis of the extracted pattern signatures. The performance of the spectral descriptor has been studied in terms of the quality of the signature vectors that it generated, quantitatively based on the established framework of Spectral Information Measure (SIM). Early results suggested that such a multiscale approach of image sequence analysis offers a considerable potential for real-time applications.

  11. Coarse graining flow of spin foam intertwiners

    CERN Document Server

    Dittrich, Bianca; Seth, Cameron J; Steinhaus, Sebastian

    2016-01-01

    Simplicity constraints play a crucial role in the construction of spin foam models, yet their effective behaviour on larger scales is scarcely explored. In this article we introduce intertwiner and spin net models for the quantum group $\\text{SU}(2)_k \\times \\text{SU}(2)_k$, which implement the simplicity constraints analogous to 4D Euclidean spin foam models, namely the Barrett-Crane (BC) and the Engle-Pereira-Rovelli-Livine/Freidel-Krasnov (EPRL/FK) model. These models are numerically coarse grained via tensor network renormalization, allowing us to trace the flow of simplicity constraints to larger scales. In order to perform these simulations we have substantially adapted tensor network algorithms, which we discuss in detail. The BC and the EPRL/FK model behave very differently under coarse graining: While the unique BC intertwiner model is a fixed point and therefore constitutes a 2D topological phase, BC spin net models flow away from the initial simplicity constraints and converge to several different ...

  12. Deuterium enrichment of the interstellar grain mantle

    Science.gov (United States)

    Das, Ankan; Sahu, Dipen; Majumdar, Liton; Chakrabarti, Sandip K.

    2016-01-01

    We carry out Monte Carlo simulation to study deuterium enrichments of interstellar grain mantles under various physical conditions. Based on the physical properties, various types of clouds are considered. We find that in diffuse cloud regions, very strong radiation fields persists and hardly a few layers of surface species are formed. In translucent cloud regions with a moderate radiation field, significant number of layers would be produced and surface coverage is mainly dominated by photo-dissociation products such as, C, CH3, CH2D, OH and OD. In the intermediate dense cloud regions (having number density of total hydrogen nuclei in all forms ˜2 × 104 cm-3), water and methanol along with their deuterated derivatives are efficiently formed. For much higher density regions (˜106 cm-3), water and methanol productions are suppressed but surface coverages of CO, CO2, O2 and O3 are dramatically increased. We find a very high degree of fractionation of water and methanol. Observational results support a high fractionation of methanol but surprisingly water fractionation is found to be low. This is in contradiction with our model results indicating alternative routes for de-fractionation of water. Effects of various types of energy barriers are also studied. Moreover, we allow grain mantles to interact with various charged particles (such as H+, Fe+, S+ and C+) to study the stopping power and projected range of these charged particles on various target ices.

  13. Grain product of 34 soya mutant lines

    International Nuclear Information System (INIS)

    This work was development with the objective of obtaining information of the agronomic behavior of 34 soya mutant lines (R4M18) for human consumption and this way to select the 2 better lines. The genetic materials were obtained starting from the variety ISAAEG-B M2 by means of the application of recurrent radiation with Co60 gammas, to a dose of 350 Gray for the first two generations and both later to 200 Gray and selection during 17 cycles, being obtained the 34 better lines mutants with agronomic characteristic wanted and good flavor. The obtained results were that the mutant lines L25 and L32 produced the major quantity in branches/plant number with 7.5 and 7.25, pods/plant number with 171.25 and 167, grains/plant number with 350.89 and 333.07 and grain product (ton/ha) to 15% of humidity 5.15 and 4.68 ton/ha, respectively. (Author)

  14. Coarse-Grain Modeling of Energetic Materials

    Science.gov (United States)

    Brennan, John

    2015-06-01

    Mechanical and thermal loading of energetic materials can incite responses over a wide range of spatial and temporal scales due to inherent nano- and microscale features. Many energy transfer processes within these materials are atomistically governed, yet the material response is manifested at the micro- and mesoscale. The existing state-of-the-art computational methods include continuum level approaches that rely on idealized field-based formulations that are empirically based. Our goal is to bridge the spatial and temporal modeling regimes while ensuring multiscale consistency. However, significant technical challenges exist, including that the multiscale methods linking the atomistic and microscales for molecular crystals are immature or nonexistent. To begin addressing these challenges, we have implemented a bottom-up approach for deriving microscale coarse-grain models directly from quantum mechanics-derived atomistic models. In this talk, a suite of computational tools is described for particle-based microscale simulations of the nonequilibrium response of energetic solids. Our approach builds upon recent advances both in generating coarse-grain models under high strains and in developing a variant of dissipative particle dynamics that includes chemical reactions.

  15. Equilibrium behavior of coarse-grained chaos

    Science.gov (United States)

    Egolf, David A.; Ballard, Christopher C.; Esty, C. Clark

    2015-03-01

    A wide variety of systems exhibiting spatiotemporal chaos have been shown to be extensive, in that their fractal dimensions grow linearly with volume. Ruelle argued that this extensivity is evidence that these systems can be viewed as a gas of weakly-interacting regions. We have tested this idea by performing large-scale computational studies of spatiotemporal chaos in the 1D complex Ginzburg-Landau equation, and we have found that aspects of the coarse-grained system are well-described not only as a gas, but as an equilibrium gas -- in particular, a Tonks gas (and variants) in the grand canonical ensemble. Furthermore, for small system sizes, the average number of particles in the corresponding Tonks gas exhibits oscillatory, decaying deviations from extensivity in agreement with deviations in the fractal dimension found by Fishman and Egolf. This result not only supports Ruelle's picture but also suggests that the coarse-grained behavior of this far-from-equilibrium system might be understood using equilibrium statistical mechanics.

  16. Transmission Electron Microscopy of Itokawa Regolith Grains

    Science.gov (United States)

    Keller, Lindsay P.; Berger, E. L.

    2013-01-01

    Introduction: In a remarkable engineering achievement, the JAXA space agency successfully recovered the Hayabusa space-craft in June 2010, following a non-optimal encounter and sur-face sampling mission to asteroid 25143 Itokawa. These are the first direct samples ever obtained and returned from the surface of an asteroid. The Hayabusa samples thus present a special op-portunity to directly investigate the evolution of asteroidal sur-faces, from the development of the regolith to the study of the effects of space weathering. Here we report on our preliminary TEM measurements on two Itokawa samples. Methods: We were allocated particles RA-QD02-0125 and RA-QD02-0211. Both particles were embedded in low viscosity epoxy and thin sections were prepared using ultramicrotomy. High resolution images and electron diffraction data were ob-tained using a JEOL 2500SE 200 kV field-emission scanning-transmission electron microscope. Quantitative maps and anal-yses were obtained using a Thermo thin-window energy-dispersive x-ray (EDX) spectrometer. Results: Both particles are olivine-rich (Fo70) with µm-sized inclusions of FeS and have microstructurally complex rims. Par-ticle RA-QD02-0125 is rounded and has numerous sub-µm grains attached to its surface including FeS, albite, olivine, and rare melt droplets. Solar flare tracks have not been observed, but the particle is surrounded by a continuous 50 nm thick, stuctur-ally disordered rim that is compositionally similar to the core of the grain. One of the surface adhering grains is pyrrhotite show-ing a S-depleted rim (8-10 nm thick) with nanophase Fe metal grains (<5 nm) decorating the outermost surface. The pyrrhotite displays a complex superstructure in its core that is absent in the S-depleted rim. Particle RA-QD02-0211 contains solar flare particle tracks (2x109 cm-2) and shows a structurally disordered rim 100 nm thick. The track density corresponds to a surface exposure of 103-104 years based on the track production rate

  17. Shocks in dense clouds. IV. Effects of grain-grain processing on molecular line emission

    CERN Document Server

    Anderl, S; Forêts, G Pineau des; Flower, D R

    2014-01-01

    Grain-grain processing has been shown to be an indispensable ingredient of shock modelling in high density environments. For densities higher than \\sim10^5 cm-3, shattering becomes a self-enhanced process that imposes severe chemical and dynamical consequences on the shock characteristics. Shattering is accompanied by the vaporization of grains, which can directly release SiO to the gas phase. Given that SiO rotational line radiation is used as a major tracer of shocks in dense clouds, it is crucial to understand the influence of vaporization on SiO line emission. We have developed a recipe for implementing the effects of shattering and vaporization into a 2-fluid shock model, resulting in a reduction of computation time by a factor \\sim100 compared to a multi-fluid modelling approach. This implementation was combined with an LVG-based modelling of molecular line radiation transport. Using this model we calculated grids of shock models to explore the consequences of different dust-processing scenarios. Grain-...

  18. Grain boundary diffusion of Fe in ultrafine-grained nanocluster-strengthened ferritic steel

    International Nuclear Information System (INIS)

    Grain boundary diffusion of Fe in nanocluster-strengthened ferritic steel (Fe-14Cr-3W-0.4Ti-0.25Y2O3 in wt.%) has been investigated. The steel was produced by mechanical alloying followed by hot extrusion. The final grain size was ∼200 nm. The diffusivity of Fe was measured within the temperature range 423-820 K. The grain boundary penetration at lower temperatures revealed a specific time dependence, which indicates a residual interconnected porosity in the ferritic steel. In order to quantify the percolating porosity, conventional radiotracer (59Fe) diffusion measurements were combined with a study of room temperature penetration of liquid 110mAg solution to distinguish between solid-state diffusion along boundaries and penetration along the surface of interconnected cavities. The presence of porosity affected the diffusion process, introducing a hierarchy of internal interfaces. The grain boundary diffusion coefficient and the diffusivity along internal surfaces were determined in the so-called type C-C, C-B and B-B kinetic regimes of interface diffusion in a hierarchical microstructure. Using the residual activity method and a 65Zn tracer, the volume fraction of the percolating porosity was estimated to be 0.6%.

  19. Choosing Whole-Grain Foods: 10 Tips for Purchasing and Storing Whole-Grain Foods

    Science.gov (United States)

    ... Eat Fruits Food Gallery Vegetables All About the Vegetable Group Nutrients and Health Benefits Tips to Help You Eat Vegetables Beans ... Updated: Jul 6, 2016 RESOURCES FOR NUTRITION AND HEALTH MYPLATE What Is MyPlate? Fruits Vegetables Grains Protein Foods Dairy Oils ONLINE TOOLS SuperTracker ...

  20. COMPETITIVE ADVANTAGES OF TRANSPORT LOGISTICS OF THE REGIONAL GRAIN MARKET

    Directory of Open Access Journals (Sweden)

    Smirnov V. V.

    2015-06-01

    Full Text Available The article deals with the place of transport logistics in the system of specialization of the region, territorial labor division and the grain business export potential. It examines the competitive advantages in relation to territorial and environmental factors, production, business, and grain market, the role of these factors in raising the economic efficiency of grain business, taking into account rapidly changing conditions in domestic and global markets. It gives details of the competitive advantages of the port transit segment of the Krasnodar region on the grain major sea carriers example. Effective use of the strong sides of land and sea components of the grain transit will help to further successful integration of the region grain business into the global economics system, it will increase the regional grain production competitiveness. The grain transit schemes improving process should be built taking into account optimization of the delivery channels, excluding parasitic mediators, motivate all participants on the final result according to the criterion of profit which is received not due to the increase in tariff rates, but by providing diverse services, enhancing productivity, introducing of specialization and specific transport costs reducing. It is also proposed to reduce transport costs during the grain transit to domestic and foreign markets due to the capabilities of specialized logistical centers, to organize transport corridors for the grain delivery on their base

  1. Marketing whole grain breads in Canada via food labels.

    Science.gov (United States)

    Sumanac, Dunja; Mendelson, Rena; Tarasuk, Valerie

    2013-03-01

    A recommendation for increased whole grain consumption was released in Canada in 2007 to promote adequate intakes of fibre and magnesium. Since then, a proliferation of 'whole grain' claims on food packaging has been observed, but whole grain labelling is voluntary and unregulated in Canada. Through a detailed survey of bread sold in three supermarkets, this study examined how the presence of front-of-package reference to whole grain relates to (i) the presence and nature of whole grain ingredients, (ii) nutrient content, and (iii) price of the product. Twenty-one percent of breads bore a reference to whole grain on the front-of-package and the front-of-package reference to whole grain was a better predictor of fibre content than any information that could be gleaned from the ingredient list. On average, breads with a whole grain reference were higher in fibre and magnesium and lower in sodium. Mean price did not differ by presence of a whole grain reference, but breads with whole grain labelling were less likely to be low in price. Voluntary nutrition labelling may be targeting a discrete market of health-conscious consumers who are willing to pay premium prices for more healthful options. PMID:23178749

  2. China’s grain production: status and prospects

    Institute of Scientific and Technical Information of China (English)

    姜长云; 张晓敏; 张艳平

    2009-01-01

    In this paper, we first look back at China’s grain production since reform and opening up and review the main factors of grain production at different stages. Secondly we find that the improvement of the per unit yield has become a major factor in the increase of grain production, and that corn has become a major grain production support variety; compared with the other varieties, paddy rice is most vulnerable in production; grain production has increasingly become dependant on scientific and technological progress and the role of infrastructure. Thirdly, the transformation of low-yielding fields in the future, the development of reserve land resources and acceleration of scientific and technological progress – these factors together promote China’s great potential for grain production; but through adjusting variety structure to promote grain production is nearly impossible. Finally, the main constraints of China’s future grain production are as follows: reduction of arable land and water shortages is becoming increasingly constrained; agricultural comparative advantage is low; opportunity cost is high and accelerating at the same time; and the uncertainties of (1) whether the agricultural inputs by government at all levels of can significantly increase the intensity; (2) whether support of the reform of grain production and systems can achieve breakthrough; and (3) whether the risk of the development of grain production can be effectively prevented. On this basis, we draw the relevant conclusions and policy recommendations.

  3. Grain size distribution of the matrix in the Allende chondrite

    Science.gov (United States)

    Toriumi, M.

    1989-03-01

    Results are presented from analytical TEM, high-resolution TEM, and SEM studies of the Allende chondrite, showing that the matrix consists of very fine-grained Fe-rich olivine, Ca-poor and Fe-rich clinopyroxene, Fe-rich spinel, and Ni-bearing troilite. Slightly sintered and non-sintered very fine-grained aggregates are observed. The results suggest that the coarse-grained olivine aggregates experienced a heating event, whereas the ultrafine-grained aggregates did not. The size and frequency distributions of matrix grains are measured. The frequency distribution displays a long-term tail with power law and a log-normal pattern with a peak at 5 nm in the range from 1 to 10 nm. This suggests that the fine-grained matrix was probably formed at conditions far from equilibrium in the protosolar cloud.

  4. Design of modular control system for grain dryers

    Science.gov (United States)

    He, Gaoqing; Liu, Yanhua; Zu, Yuan

    In order to effectively control the temperature of grain drying bin, grain ,air outlet as well as the grain moisture, it designed the control system of 5HCY-35 which is based on MCU to adapt to all grains drying conditions, high drying efficiency, long life usage and less manually. The system includes: the control module of the constant temperature and the temperature difference control in drying bin, the constant temperature control of heating furnace, on-line testing of moisture, variety of grain-circulation speed control and human-computer interaction interface. Spatial curve simulation, which takes moisture as control objectives, controls the constant temperature and the temperature difference in drying bin according to preset parameter by the user or a list to reduce the grains explosive to ensure the seed germination percentage. The system can realize the intelligent control of high efficiency and various drying, the good scalability and the high quality.

  5. The bio refinery; producing feed and fuel from grain.

    Science.gov (United States)

    Scholey, D V; Burton, E J; Williams, P E V

    2016-04-15

    It is both possible and practicable to produce feed and fuel from grain. Using the value of grain to produce renewable energy for transport, while using the remaining protein content of the grain as a valuable protein source for livestock and for fish, can be seen as a complimentary and optimal use of all the grain constituents. Consideration must be given to maximise the value of the yeast components, as substantial yeast is generated during the fermentation of the grain starch to produce ethanol. Yeast is a nutritionally rich feed ingredient, with potential for use both as feed protein and as a feed supplement with possible immunity and gut health enhancing properties. Bioprocessing, with the consequent economies of scale, is a process whereby the value of grain can be optimised in a way that is traditional, natural and sustainable for primarily producing protein and oil for feed with a co-product ethanol as a renewable fuel. PMID:26617037

  6. Activation energies of grain growth mechanisms in aluminum coatings

    Energy Technology Data Exchange (ETDEWEB)

    Jankowski, Alan [Lawrence Livermore National Laboratory, Chemistry and Materials Science, CA (United States)]. E-mail: jankowski1@11nl.gov; Ferreira, James [Lawrence Livermore National Laboratory, Chemistry and Materials Science, CA (United States); Hayes, Jeffrey [Lawrence Livermore National Laboratory, Mechanical Engineering, Livermore, CA 94551-9900 (United States)

    2005-11-22

    To produce a specific grain size in metallic coatings requires precise control of the time at temperature during the deposition process. Aluminum coatings are deposited using electron-beam evaporation onto heated substrate surfaces of both mica and lithium flouride. The grain size of the coating is determined upon examination of the microstructure in plan view and cross-section. Ideal grain growth is observed over the entire experimental range of temperature examined from 413 to 843 K. A transition in the activation energy for grain growth from 0.87 to 2.04 eV atom{sup -1} is observed as the temperature increases from < 526 K to > 588 K. The transition is indicative of the dominant mechanism for grain growth shifting with increasing temperature from grain boundary to lattice diffusion.

  7. Effects and mechanisms of grain refinement in aluminium alloys

    Indian Academy of Sciences (India)

    K T Kashyap; T Chandrashekar

    2001-08-01

    Grain refinement plays a crucial role in improving characteristics and properties of cast and wrought aluminium alloys. Generally Al–Ti and Al–Ti–B master alloys are added to the aluminium alloys to grain refine the solidified product. The mechanism of grain refinement is of considerable controversy in the scientific literature. The nucleant effects i.e. which particle and its characteristics nucleate -Al, has been the subject of intensive research. Lately the solute effect i.e. the effect of dissolved titanium on grain refinement, has come into forefront of grain refinement research. The present paper attempts to review the literature on the nucleant effects and solute effects on grain refinement and addresses the importance of dissolved titanium in promoting nucleation of -Al on nucleant particles.

  8. Kinetic constants of abnormal grain growth in nanocrystalline nickel

    Science.gov (United States)

    Aleshin, A. N.

    2016-02-01

    The grain growth in nanocrystalline nickel with a purity of 99.5 at % during non-isothermal annealing was experimentally investigated using differential scanning calorimetry and transmission electron microscopy. Nanocrystalline nickel was prepared by electrodeposition and had an average grain size of approximately 20 nm. It was shown that, at a temperature corresponding to the calorimetric signal peak, abnormal grain growth occurs with the formation of a bimodal grain microstructure. Calorimeters signals were processed within the Johnson-Mehl-Avrami formalism. This made it possible to determine the exponent of the corresponding equation, the frequency factor, and the activation energy of the grain growth, which was found to be equal to the activation energy of the vacancy migration. The reasons for the abnormal grain growth in nanocrystalline nickel were discussed.

  9. Segregation ratios of colored grains in F1 hybrid wheat

    Directory of Open Access Journals (Sweden)

    Zifeng Guo

    2012-01-01

    Full Text Available Nutritious and functional foods from wheat have received great attention in recent years. Colored-grain wheat contains a large number of nutrients such as anthocyanins and hence the breeding is interesting. In this work, colored-grained wheat lines of mixed pollination of einkorn wheat (Triticum boeoticum, AA and French rye (French Secale cereale, RR were used as male parents and wheat line Y1642 (derived from common wheat and Agropyron elongatum, AABBDD was used as the female parent. These colored wheat were used for diallel cross to study the segregation ratios of F1 colored grains. Results show that the color inheritance of purple-grained wheat follows a maternal inheritance pattern and that the blue-grained wheat expresses xenia in most cases. In some circumstances, the grains with different color shades appear in the same spike.

  10. Atomically ordered solute segregation behaviour in an oxide grain boundary

    Science.gov (United States)

    Feng, Bin; Yokoi, Tatsuya; Kumamoto, Akihito; Yoshiya, Masato; Ikuhara, Yuichi; Shibata, Naoya

    2016-01-01

    Grain boundary segregation is a critical issue in materials science because it determines the properties of individual grain boundaries and thus governs the macroscopic properties of materials. Recent progress in electron microscopy has greatly improved our understanding of grain boundary segregation phenomena down to atomistic dimensions, but solute segregation is still extremely challenging to experimentally identify at the atomic scale. Here, we report direct observations of atomic-scale yttrium solute segregation behaviours in an yttria-stabilized-zirconia grain boundary using atomic-resolution energy-dispersive X-ray spectroscopy analysis. We found that yttrium solute atoms preferentially segregate to specific atomic sites at the core of the grain boundary, forming a unique chemically-ordered structure across the grain boundary. PMID:27004614

  11. Modification of computer simulation of normal grain growth

    Institute of Scientific and Technical Information of China (English)

    李剑; 李世晨; 郑子樵; 刘祖耀; 陈大钦

    2004-01-01

    A set of principles on transition probability was supplied for the physical process of grain growth. In accord with these principles, a modified transition probability considering the influence of temperature was put forward to simulate the normal grain growth relying on temperature and second phase particles. The modified transition probability correctly reflects the dependence of grain growth on the temperature. The effect of different shapes of second phase particles on the grain growth process was taken into account using the modified transition probability.The relationship between the area fraction of second phase particles and the limit of grain size of the matrix was given. The microstructural evolution patterns employed to 2-D were given. The results agree well with the real grain growth process. All these suggest that the modified transition probability is better than the conventional one.

  12. Austenite grain growth calculation of 0.028% Nb steel

    Directory of Open Access Journals (Sweden)

    Priadi D.

    2011-01-01

    Full Text Available Modeling of microstructural evolution has become a powerful tool for materials and process design by providing quantitative relationships for microstructure, composition and processing. Insufficient attention has been paid to predicting the austenite grain growth of microalloyed steel and the effect of undissolved microalloys. In this research, we attempted to calculate a mathematical model for austenite grain growth of 0.028% Nb steel, which can account for abnormal grain growth. The quantitative calculation of austenite grain growth generated from this model fit well with the experimental grain growth data obtained during reheating of niobium steels. The results of this study showed that increasing the temperature increases the austenite grain size, with a sharp gradient observed at higher temperatures.

  13. Microstructural stability of ultrafine grained cold sprayed 6061 aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Rokni, M.R., E-mail: mohammadreza.rokni@mines.sdsmt.edu [Department of Materials and Metallurgical Engineering, Advanced Materials Processing Center, South Dakota School of Mines and Technology (SDSM and T), SD (United States); Widener, C.A. [Department of Materials and Metallurgical Engineering, Advanced Materials Processing Center, South Dakota School of Mines and Technology (SDSM and T), SD (United States); Champagne, V.R. [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, Aberdeen Proving Ground, MD (United States)

    2014-01-30

    The microstructural stability of ultrafine grained (UFG) cold spray 6061 aluminum deposits produced by high pressure cold spray were investigated by in situ heating to a fully annealed state via a hot-stage transmission electron microscope (TEM). It was possible to observe the precise locations and temperatures of different microstructural changes, like dislocation movement and other restoration processes. Even after heating up to the annealing temperature for this alloy, the deposited layer in the perpendicular direction was found to preserve the UFG structures, which were the result of different recrystallization mechanisms caused by the high strains present during cold spraying. Extensive solute segregation at the grain boundaries acted as an obstruction for grain boundary migration in this direction, thereby preventing grain growth. However, in the direction parallel to the deposited surface, the UFGs were not resistant to grain coursing like the other direction, since the grain boundaries had much less solute segregation.

  14. Coarse graining in spin foam models

    Energy Technology Data Exchange (ETDEWEB)

    Markopoulou, Fotini

    2003-03-07

    We formulate the problem of finding the low-energy limit of spin foam models as a coarse-graining problem in the sense of statistical physics. This suggests that renormalization group methods may be used to find that limit. However, since spin foams are models of spacetime at the Planck scale, novel issues arise: these microscopic models are sums over irregular, background-independent lattices. We show that all of these issues can be addressed by the recent application of the Kreimer Hopf algebra for quantum field theory renormalization to non-perturbative statistical physics. The main difference from the standard renormalization group is that the Hopf algebra executes block transformations in parts of the lattice only but in a controlled manner so that the end result is a fully block-transformed lattice.

  15. Toxigenicity of fungi from grain sorghum.

    Science.gov (United States)

    Diener, U L; Morgan-Jones, G; Wagener, R E; Davis, N D

    1981-07-10

    The mycoflora of nine varieties of grain sorghum was determined by plating serial dilutions of ground samples on rose bengal-streptomycin agar. Seventeen species of fungi representing 10 genera were identified. Curvularia, Penicillium, Mucor, and Aspergillus were dominant genera. Extracts of P. herquei were highly toxic to brine shrimp, while those of C. clavata, C. lunata, and Mucor mucedo showed low to moderate toxicity. Extracts of C. clavata, C. lunata, and M. mucedo were highly toxic to chicken embryos; those of six other species showed low to moderate toxicity. Extracts of C. clavata, C. lunata, M. mucedo, Fusarium moniliforme, Alternaria tenuissima. P. herquei, and P. steckii showed varying degrees of toxicity to day-old cockerels.

  16. From Grains to Planetesimals: Les Houches Lecture

    CERN Document Server

    Youdin, Andrew

    2008-01-01

    This pedagogical review covers an unsolved problem in the theory of protoplanetary disks: the growth of dust grains into planetesimals, solids at least a kilometer in size. I summarize timescale constraints imposed on planetesimal formation by circumstellar disk observations, analysis of meteorites, and aerodynamic radial migration. The infall of ~meter-sized solids in a hundred years is the most stringent constraint. I review proposed mechanisms for planetesimal formation. Collisional coagulation models are informed by laboratory studies of microgravity collisions. The gravitational collapse (or Safronov-Goldreich-Ward) hypothesis involves detailed study of the interaction between solid particles and turbulent gas. I cover the basics of aerodynamic drag in protoplanetary disks, including radial drift and vertical sedimentation. I describe various mechanisms for particle concentration in gas disks -- including turbulent pressure maxima, drag instabilities and long-lived anticylonic vortices. I derive a genera...

  17. Randomized Grain Boundary Liquid Crystal Phase

    Science.gov (United States)

    Chen, D.; Wang, H.; Li, M.; Glaser, M.; Maclennan, J.; Clark, N.

    2012-02-01

    The formation of macroscopic, chiral domains, in the B4 and dark conglomerate phases, for example, is a feature of bent-core liquid crystals resulting from the interplay of chirality, molecular bend and molecular tilt. We report a new, chiral phase observed in a hockey stick-like liquid crystal molecule. This phase appears below a smectic A phase and cools to a crystal phase. TEM images of the free surface of the chiral phase show hundreds of randomly oriented smectic blocks several hundred nanometers in size, similar to those seen in the twist grain boundary (TGB) phase. However, in contrast to the TGB phase, these blocks are randomly oriented. The characteristic defects in this phase are revealed by freeze-fracture TEM images. We will show how these defects mediate the randomized orientation and discuss the intrinsic mechanism driving the formation of this phase. This work is supported by NSF MRSEC Grant DMR0820579 and NSF Grant DMR0606528.

  18. Ceres Revealed in a Grain of Salt

    Science.gov (United States)

    Zolensky, M. E.; Bodnar, R. J.; Chan, Q. H.-S.; Hagiya, K.; Komatsu, M.; Steele, A.; Fries, M.; Kebukawa, Y.; Mikouchi, T.; Ohsumi, K.

    2016-01-01

    Introduction: Zag and Monahans (1998) are H chondrite regolith breccias containing 4.5 giga-year-old halite crystals which contain abundant inclusions of aqueous fluids, solids and organics. These all originated on a cryo-volcanically-active C class asteroid, probably 1 Ceres; the halite was transported to the regolith of the H chondrite parent asteroid, potentially 6 Hebe. Detailed analysis of these solids will thus potentially reveal the mineralogy of Ceres. Mineralogy of solids in the Monahans Halite Solid grains are present in the halites, which were entrained within the mother brines during eruption, including material from the interior and surface of the erupting body. The solids include abundant, widely variable organics that could not have been significantly heated (which would have resulted in the loss of fluids from the halite). Our analyses by Raman microprobe, SEM/EDX, synchrotron X-ray diffraction, UPLC-FD/QToF-MS, C-XANES and TEM reveal that these trapped grains include macromolecular carbon (MMC) similar in structure to CV3 chondrite matrix carbon, aliphatic carbon compounds, olivine (Fo99-59), high- and low-Ca pyroxene, feldspars, phyllosilicates, magnetite, sulfides, metal, lepidocrocite, carbonates, diamond, apatite and zeolites. Conclusions: The halite in Monahans and Zag derive from a water and carbon-rich object that was cryo-volcanically active in the early solar system, probably Ceres. The Dawn spacecraft found that Ceres includes C chondrite materials. Our samples include both protolith and aqueously-altered samples of the body, permitting understanding of alteration conditions. Whatever the halite parent body, it was rich in a wide variety of organics and warm, liquid water at the solar system's dawn.

  19. The disinfestation of grains and stored products through ionizing radiations

    International Nuclear Information System (INIS)

    Disinfestation of stored products and grains through ionizing radiation is reviewed. A promising technique, the one of irradiation to achieve sterilization and increasing mortality of stored grain insects, which are commonly destructive to the main crops in Brazil is explained. Methodology to determine the sterilizing dose and lethality; the wholesomeness of irradiated grains and searches realized in Brazil with Sitophilus, Sototroga, Zabrotes and Acanthocelides are also presented

  20. Radon emanation rate as a function of monazite grain size

    International Nuclear Information System (INIS)

    In this study, a sample of monazite from local mining area was divided to 7 parts according to size (μm) and each sample was analysed using silicon surface barrier detector and multichannel analyser. From this study it has found that small grain monazite produced more radon that big grain monazite and radium is distributed on or near the surface of the monazite grain

  1. Organic Grain Amaranth Production in Kamuli District, Uganda

    OpenAIRE

    Graham, M W; Delate, K.; Burras, C.L.; Mazur, R.E.; Brenner, D.M.; M. M. Tenywa; Nakimbugwe, D.N.; Kabahuma, M.; Abili, A.

    2011-01-01

    Metadata only record Grain amaranths (Amaranthus spp.) are high protein content and protein quality pseudo-cereal crops whose favorable nutritional profile belies their potential to alleviate nutrition and food insecurity in developing countries. Grain amaranth was introduced as a nutrient dense food into the Kamuli District, eastern Uganda, in 2006. However, initial analysis of protein content of amaranth grain pooled from farms in the Kamuli District indicated that protein levels ranged ...

  2. Strong Electron Tunneling through a Small Metallic Grain

    OpenAIRE

    Golubev, D. S.; Zaikin, A. D.

    1996-01-01

    Electron tunneling through mesoscopic metallic grains can be treated perturbatively only provided the tunnel junction conductances are sufficiently small. If it is not the case, fluctuations of the grain charge become strong. As a result (i) contributions of all -- including high energy -- charge states become important and (ii) excited charge states become broadened and essentially overlap. At the same time the grain charge remains discrete and the system conductance $e$-periodically depends...

  3. Grain Transportation Policy and Transformation in Western Canadian Agriculture

    OpenAIRE

    Doan, Darcie; Paddock, Brian; Dyer, Jan

    2003-01-01

    This paper provides an overview of grain transportation policy in Canada over the last 100 years, including the inception of the Crow Rate, the replacement of the Crow Rate with the Western Grain Transportation Act(WGTA), and finally, the repeal of the WGTA. Particular emphasis is placed on the structural change to the western agricultural economy that occurred following repeal of the WGTA in 1995. When grain transportation subsidies were removed, industry responded quickly to market signals ...

  4. Electronic Structure of a Disordered Grain Boundary in Graphene

    Science.gov (United States)

    Lambin, Ph.; Vancso, P.; Nemes-Incze, P.; Mark, G.; Biró, L. P.

    2013-05-01

    Grain boundaries are constitutional elements of graphene grown on a solid metallic surface by CVD. The electronic properties of computer models of grain boundaries in graphene have been investigated by tight-binding calculations and compared with available ab initio data and with recent experimental scanning tunneling spectroscopic measurements. It is shown that twofold coordinated atoms and non-hexagonal rings, both present in grain boundaries, give rise to specific features in the local density of states.

  5. Ammonia disinfection of corn grains intended for ethanol fermentation

    OpenAIRE

    Magdalena Broda; Włodzimierz Grajek

    2009-01-01

    Background. Bacterial contamination is an ongoing problem for commercial bioethanol plants. It concerns factories using grain and also other raw materials for ethanol fermentation. Bacteria compete with precious yeasts for sugar substrates and micronutrients, secrete lactic and acetic acids, which are toxic for yeast and this competition leads to significant decrease of bioethanol productivity. For this study, bacterial contamination of corn grain was examined. Then the grain was treated by a...

  6. LOGISTICS AND SUPPLY CHAIN STRATEGIES IN GRAIN EXPORTING

    OpenAIRE

    Wilson, William W.; Carlson, Donald C.E.; Bruce L. DAHL

    2001-01-01

    During the past decade, the grain shipping industry has become highly competitive and technologically advanced. These changes, along with the introduction of innovative shipping mechanisms, have made logistics management an important source of opportunity and risk for grain shippers. In this study, a stochastic simulation model was developed to evaluate the tradeoffs and effects of key variables on logistical performance in managing the grain supply chain. Average demurrage cost for the suppl...

  7. Characteristic of grain contamination with weeds in some cereal varieties

    OpenAIRE

    Franciszek Pawłowski; Marian Wesołowski

    2013-01-01

    Grain contamination with weeds in winter wheat, winter rye, spring barley and seeding oats harvested with combines was examined. A different number of seeds and weed species was found to be present in 1 kg of grain of the cereal varieties compared. Certain similarities were noticed in the botanical composition and in the frequency of occurrence of weed seeds in the examined samples of cereal grains.

  8. Characteristic of grain contamination with weeds in some cereal varieties

    Directory of Open Access Journals (Sweden)

    Franciszek Pawłowski

    2013-12-01

    Full Text Available Grain contamination with weeds in winter wheat, winter rye, spring barley and seeding oats harvested with combines was examined. A different number of seeds and weed species was found to be present in 1 kg of grain of the cereal varieties compared. Certain similarities were noticed in the botanical composition and in the frequency of occurrence of weed seeds in the examined samples of cereal grains.

  9. Adaptive Coarse Graining, Environment, Strong Decoherence, and Quasiclassical Realms

    CERN Document Server

    Gell-Mann, Murray

    2013-01-01

    Three ideas are introduced that when brought together characterize the realistic quasiclassical realms of our quantum universe as particular kinds of sets of alternative coarse-grained histories defined by quasiclassical variables: (1) Branch dependent adaptive coarse grainings that can be close to maximally refined and can simplify calculation. (2) Narrative coarse grainings that describe how features of the universe change over time and allow the construction of an environment. (3) A notion of strong decoherence that characterizes realistic mechanisms of decoherence.

  10. Interlinking backscatter, grain size and benthic community structure

    Science.gov (United States)

    McGonigle, Chris; Collier, Jenny S.

    2014-06-01

    The relationship between acoustic backscatter, sediment grain size and benthic community structure is examined using three different quantitative methods, covering image- and angular response-based approaches. Multibeam time-series backscatter (300 kHz) data acquired in 2008 off the coast of East Anglia (UK) are compared with grain size properties, macrofaunal abundance and biomass from 130 Hamon and 16 Clamshell grab samples. Three predictive methods are used: 1) image-based (mean backscatter intensity); 2) angular response-based (predicted mean grain size), and 3) image-based (1st principal component and classification) from Quester Tangent Corporation Multiview software. Relationships between grain size and backscatter are explored using linear regression. Differences in grain size and benthic community structure between acoustically defined groups are examined using ANOVA and PERMANOVA+. Results for the Hamon grab stations indicate significant correlations between measured mean grain size and mean backscatter intensity, angular response predicted mean grain size, and 1st principal component of QTC analysis (all p response predicted mean grain size (r2 = 0.692; p response predicted grain size (p < 0.001), and QTC class (p = 0.009). Mean grain size (Clamshell) shows a significant difference between groups for mean backscatter (p = 0.001); other methods were not significant. PERMANOVA for the Hamon abundance shows benthic community structure was significantly different between acoustic groups for all methods (p ≤ 0.001). Overall these results show considerable promise in that more than 60% of the variance in the mean grain size of the Clamshell grab samples can be explained by mean backscatter or acoustically-predicted grain size. These results show that there is significant predictive capacity for sediment characteristics from multibeam backscatter and that these acoustic classifications can have ecological validity.

  11. Radiation pressure on fluffy submicron-sized grains

    CERN Document Server

    Silsbee, Kedron

    2015-01-01

    We investigate the claim that the ratio {\\beta} of radiation pressure force to gravitational force on a dust grain in our solar system can substantially exceed unity for some grain sizes, provided that grain porosity is high enough. For model grains consisting of random aggregates of silicate spherules, we find that the maximum value of {\\beta} is almost independent of grain porosity, but for small (<0.3 {\\mu}m) grains, {\\beta} actually decreases with increasing porosity. These results affect the interpretation of the grain trajectories estimated from the Stardust mission, which were modeled assuming {\\beta} values exceeding one. We find that radiation pressure effects are not large enough for particles Orion and Hylabrook captured by Stardust to be of interstellar origin given their reported impact velocities. We also investigate the effect of metallic iron inclusions in the dust grains, and find that metallic iron will increase {\\beta}, but at least half the grain (by mass) must be iron in order to raise...

  12. Simulation of Ceramic Grain Growth in Three Dimensions

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Microstructural evolutions of ceramic grain growth at atomistic scale were modeled. The simulation was preceded with Monte-Carlo method, using Visual C++ and OpenGL languages. Realistic images in series were monitored both in two d imensions and three dimensions. Simulated image of grain growth in this series i s presented in left figure with N 0=25, r=0.40 nm, α=0.1, T=1 300 ℃, and P 0=50 %. It was seen that the average grain size increases wit h the time of grain growth. It is in good agreement with t...

  13. Grain and Oilseed Shipment Sizes and Distance Hauled by Rail

    OpenAIRE

    Prater, Marvin; Sparger, Adam

    2013-01-01

    Grain and railroads have an interdependent relationship. Grain is one of the most important commodities for railroads. It is the primary agricultural commodity moved by rail, comprising 7.9 percent by tons of all commodities, 94 percent by tons of all farm commodities, and 8.4 percent of total rail revenue in 2009. In turn, railroads represent a vital component of the grain network, hauling 33 percent of all grain transported in the United States in 2007. As domestic and export markets have e...

  14. Production and Recoil Loss of Cosmogenic Nuclides in Presolar Grains

    Science.gov (United States)

    Trappitsch, Reto; Leya, Ingo

    2016-05-01

    Presolar grains are small particles that condensed in the vicinity of dying stars. Some of these grains survived the voyage through the interstellar medium (ISM) and were incorporated into meteorite parent bodies at the formation of the Solar System. An important question is when these stellar processes happened, i.e., how long presolar grains were drifting through the ISM. While conventional radiometric dating of such small grains is very difficult, presolar grains are irradiated with galactic cosmic rays (GCRs) in the ISM, which induce the production of cosmogenic nuclides. This opens the possibility to determine cosmic-ray exposure (CRE) ages, i.e., how long presolar grains were irradiated in the ISM. Here, we present a new model for the production and loss of cosmogenic 3He, 6,7Li, and 21,22Ne in presolar SiC grains. The cosmogenic production rates are calculated using a state-of-the-art nuclear cross-section database and a GCR spectrum in the ISM consistent with recent Voyager data. Our findings are that previously measured 3He and 21Ne CRE ages agree within the (sometimes large) 2σ uncertainties and that the CRE ages for most presolar grains are smaller than the predicted survival times. The obtained results are relatively robust since interferences from implanted low-energy GCRs into the presolar SiC grains and/or from cosmogenic production within the meteoroid can be neglected.

  15. Barium concentration in grain of Aegilops and Triticum species

    Directory of Open Access Journals (Sweden)

    Denčić Srbislav S.

    2015-01-01

    Full Text Available The aim of this study was to evaluate the concentration of barium in grain of various Aegilops and Triticum species with different genomes. The studied species differed significantly with respect to the concentration of barium. The grain of wild diploid Aegilops speltoides, the donor of B genome, contained significantly higher Ba concentration than all other analyzed genotypes. Wild and cultivated tetraploid wheats (Triticum diciccoides, Triticum dicoccon, Triticum turgidum and Triticum durum had the lowest Ba concentration in grain. The modern cultivated hexaploid varieties presented substantial variation in grain concentration of barium. The highest Ba concentration (3.42 mg/kg occurred in Serbian winter wheat variety Panonnia.

  16. New Process for Grain Refinement of Aluminum. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Joseph A. Megy

    2000-09-22

    A new method of grain refining aluminum involving in-situ formation of boride nuclei in molten aluminum just prior to casting has been developed in the subject DOE program over the last thirty months by a team consisting of JDC, Inc., Alcoa Technical Center, GRAS, Inc., Touchstone Labs, and GKS Engineering Services. The Manufacturing process to make boron trichloride for grain refining is much simpler than preparing conventional grain refiners, with attendant environmental, capital, and energy savings. The manufacture of boride grain refining nuclei using the fy-Gem process avoids clusters, salt and oxide inclusions that cause quality problems in aluminum today.

  17. Design of zirconia grain boundaries——An exploration of the design of oxide ceramic grain boundaries

    Institute of Scientific and Technical Information of China (English)

    郭新; 袁润章

    1996-01-01

    The grain-boundary resistance of ZrO2 mainly consists of the contribution from the space-charge layers Rsc and that from the grain-boundary phase Rgbp The reduction of Rsc can be realized by the segregations of solutes with positive effective charge in the space-charge layers,while the reduction of Rgbp can be achieved by decreasing the amount of the grain-boundary phase,changing the morphology of the phase and forming grain-boundary phase with high conductivity.The best grain-boundary design effect can only be achieved by the joint design of the space-charge layers and the grain-boundary phase.

  18. Causes of Poor Grain Plumpness of Two-Line Hybrids and Their Relationships to the Contents of Hormones in the Rice Grain

    Institute of Scientific and Technical Information of China (English)

    ZHAO Bu-hong; LIU Kai; ZHANG Hong-xi; ZHU Qing-sen; YANG Jian-chang

    2007-01-01

    This study was designed to elucidate the grain filling characteristics and the causes of poor grain plumpness of some two-line hybrid rice combinations and their hormonal mechanism. Six varieties, including three two-line hybrid rice combinations,that show differences in seed-setting and grain filling, were used. And the contents of starch, sucrose, zeatin (Z) + zeatin riboside (ZR), indole-3-acetic acid (IAA), and abscisic acid (ABA), the ethylene evolution rate, activities of sucrose synthase (SuSase) and starch synthase (StSase) in grains, the seed-setting and grain filling rate were investigated. The correlations amongst these were analyzed. The results showed that the poor grain filling of two-line hybrids was mainly attributed to the higher unfilled grain rate and the lower filling degree of inferior grains. During the early and mid grain filling periods, the sucrose content in inferior grains was greater than that in superior grains for the combinations with poor grain filling, indicating that the substrate concentration was not the principal factor for their slow grain filling and poor grain plumpness of the inferior grains of two-line hybrids. Z + ZR, IAA, and ABA in superior grains were obviously greater than those in inferior grains at early grain filling stage. The maximum and mean contents of Z + ZR, IAA, and ABA were positively very significantly correlated with the maximum and mean grain-filling rate, filling degree, and gram weight.The evolution rate of ethylene was greater in inferior grains than in superior grains and greater for the combinations with poor grain plumpness than those with good grain plumpness at the early or mid filling stages. The evolution rate of ethylene was negatively and significantly correlated with the grain filling rate, the grain filling degree, and the grain weight.Spraying ethephon (ethylene-releasing agent) at the early grain filling stage increased the evolution rate of ethylene,reduced the ABA content and activities

  19. Computation of parent austenite grain orientation from product grain orientations upon displacive phase transformations

    International Nuclear Information System (INIS)

    A reverse computation procedure is proposed for calculating parent austenite orientations, which are experimentally challenging to obtain, based on the final texture after austenite-to-bainite and austenite-to-martensite phase transformations. Specifically, post-transformation electron backscatter diffraction scans of bainite and martensite were carried out in order to identify the product crystal orientations within a single former austenite grain. Subsequently, the Kurdjumov–Sachs relationship was utilized to compute the parent austenite crystal orientation based on these data. The proposed method provided a unique solution for the initial austenite grain orientation in most of the cases. Overall, the proposed computational procedure constitutes a means of understanding the factors influencing microstructural evolution in displacive phase transformations. (paper)

  20. Method of aeration disinfecting and drying grain in bulk and pretreating seeds and a transverse blow silo grain dryer therefor

    Science.gov (United States)

    Danchenko, Vitaliy G.; Noyes, Ronald T.; Potapovych, Larysa P.

    2012-02-28

    Aeration drying and disinfecting grain crops in bulk and pretreating seeds includes passing through a bulk of grain crops and seeds disinfecting and drying agents including an ozone and air mixture and surrounding air, subdividing the disinfecting and drying agents into a plurality of streams spaced from one another in a vertical direction, and passing the streams at different heights through levels located at corresponding heights of the bulk of grain crops and seeds transversely in a substantially horizontal direction.

  1. High night temperatures during grain number determination reduce wheat and barley grain yield: a field study.

    Science.gov (United States)

    García, Guillermo A; Dreccer, M Fernanda; Miralles, Daniel J; Serrago, Román A

    2015-11-01

    Warm nights are a widespread predicted feature of climate change. This study investigated the impact of high night temperatures during the critical period for grain yield determination in wheat and barley crops under field conditions, assessing the effects on development, growth and partitioning crop-level processes driving grain number per unit area (GN). Experiments combined: (i) two contrasting radiation and temperature environments: late sowing in 2011 and early sowing in 2013, (ii) two well-adapted crops with similar phenology: bread wheat and two-row malting barley and (iii) two temperature regimes: ambient and high night temperatures. The night temperature increase (ca. 3.9 °C in both crops and growing seasons) was achieved using purpose-built heating chambers placed on the crop at 19:000 hours and removed at 7:00 hours every day from the third detectable stem node to 10 days post-flowering. Across growing seasons and crops, the average minimum temperature during the critical period ranged from 11.2 to 17.2 °C. Wheat and barley grain yield were similarly reduced under warm nights (ca. 7% °C(-1) ), due to GN reductions (ca. 6% °C(-1) ) linked to a lower number of spikes per m(2) . An accelerated development under high night temperatures led to a shorter critical period duration, reducing solar radiation capture with negative consequences for biomass production, GN and therefore, grain yield. The information generated could be used as a starting point to design management and/or breeding strategies to improve crop adaptation facing climate change.

  2. High night temperatures during grain number determination reduce wheat and barley grain yield: a field study.

    Science.gov (United States)

    García, Guillermo A; Dreccer, M Fernanda; Miralles, Daniel J; Serrago, Román A

    2015-11-01

    Warm nights are a widespread predicted feature of climate change. This study investigated the impact of high night temperatures during the critical period for grain yield determination in wheat and barley crops under field conditions, assessing the effects on development, growth and partitioning crop-level processes driving grain number per unit area (GN). Experiments combined: (i) two contrasting radiation and temperature environments: late sowing in 2011 and early sowing in 2013, (ii) two well-adapted crops with similar phenology: bread wheat and two-row malting barley and (iii) two temperature regimes: ambient and high night temperatures. The night temperature increase (ca. 3.9 °C in both crops and growing seasons) was achieved using purpose-built heating chambers placed on the crop at 19:000 hours and removed at 7:00 hours every day from the third detectable stem node to 10 days post-flowering. Across growing seasons and crops, the average minimum temperature during the critical period ranged from 11.2 to 17.2 °C. Wheat and barley grain yield were similarly reduced under warm nights (ca. 7% °C(-1) ), due to GN reductions (ca. 6% °C(-1) ) linked to a lower number of spikes per m(2) . An accelerated development under high night temperatures led to a shorter critical period duration, reducing solar radiation capture with negative consequences for biomass production, GN and therefore, grain yield. The information generated could be used as a starting point to design management and/or breeding strategies to improve crop adaptation facing climate change. PMID:26111197

  3. 3D reconstruction of grains in polycrystalline materials using a tessellation model with curved grain boundaries

    Science.gov (United States)

    Šedivý, Ondřej; Brereton, Tim; Westhoff, Daniel; Polívka, Leoš; Beneš, Viktor; Schmidt, Volker; Jäger, Aleš

    2016-06-01

    A compact and tractable representation of the grain structure of a material is an extremely valuable tool when carrying out an empirical analysis of the material's microstructure. Tessellations have proven to be very good choices for such representations. Most widely used tessellation models have convex cells with planar boundaries. Recently, however, a new tessellation model - called the generalised balanced power diagram (GBPD) - has been developed that is very flexible and can incorporate features such as curved boundaries and non-convexity of cells. In order to use a GBPD to describe the grain structure observed in empirical image data, the parameters of the model must be chosen appropriately. This typically involves solving a difficult optimisation problem. In this paper, we describe a method for fitting GBPDs to tomographic image data. This method uses simulated annealing to solve a suitably chosen optimisation problem. We then apply this method to both artificial data and experimental 3D electron backscatter diffraction (3D EBSD) data obtained in order to study the properties of fine-grained materials with superplastic behaviour. The 3D EBSD data required new alignment and segmentation procedures, which we also briefly describe. Our numerical experiments demonstrate the effectiveness of the simulated annealing approach (compared to heuristic fitting methods) and show that GBPDs are able to describe the structures of polycrystalline materials very well.

  4. Grain size distribution and topology in 3D grain growth simulation with large-scale Monte Carlo method

    Institute of Scientific and Technical Information of China (English)

    Hao Wang; Guo-quan Liu; Xiang-ge Qin

    2009-01-01

    Three-dimensional normal grain growth was appropriately simulated using a Potts model Monte Carlo algorithm.The quasi-stationary grain size distribution obtained from simulation agreed well with the experimental result of pure iron.The Weibull function with a parameter β=2.77 and the Yu-Liu function with a parameter v =2.71 fit the quasi-stationary grain size distribution well.The grain volume distribution is a function that decreased exponentially with increasing grain volume.The distribution of boundary area of grains has a peak at S/=0.5,where S is the boundary area of a grain and is the mean boundary area of all grains in the system.The lognormal function fits the face number distribution well and the peak of the face number distribution is f=10.The mean radius of f=faced grains is not proportional to the face number,but appears to be related by a curve convex upward.In the 2D cross-section,both the perimeter law and the Aboav-Weaire law are observed to hold.

  5. Grain-damage hysteresis and plate tectonic states

    Science.gov (United States)

    Bercovici, David; Ricard, Yanick

    2016-04-01

    Shear localization in the lithosphere is an essential ingredient for understanding how and why plate tectonics is generated from mantle convection on terrestrial planets. The theoretical model for grain-damage and pinning in two-phase polycrystalline rocks provides a frame-work for understanding lithospheric shear weakening and plate-generation, and is consistent with laboratory and field observations of mylonites. Grain size evolves through the competition between coarsening, which drives grain-growth, and damage, which drives grain reduction. The interface between crystalline phases controls Zener pinning, which impedes grain growth. Damage to the interface enhances the Zener pinning effect, which then reduces grain-size, forcing the rheology into the grain-size-dependent diffusion creep regime. This process thus allows damage and rheological weakening to co-exist, providing a necessary positive self-weakening feedback. Moreover, because pinning inhibits grain-growth it promotes shear-zone longevity and plate-boundary inheritance. However, the suppression of interface damage at low interface curvature (wherein inter-grain mixing is inefficient and other energy sinks of deformational work are potentially more facile) causes a hysteresis effect, in which three possible equilibrium grain-sizes for a given stress coexist: (1) a stable, large-grain, weakly-deforming state, (2) a stable, small-grain, rapidly-deforming state analogous to ultramylonites, and (3) an unstable, intermediate grain-size state perhaps comparable to protomylonites. A comparison of the model to field data suggests that shear-localized zones of small-grain mylonites and ultra-mylonites exist at a lower stress than the co-existing large-grain porphyroclasts, rather than, as predicted by paleopiezometers or paleowattmeters, at a much higher stress; this interpretation of field data thus allows localization to relieve instead of accumulate stress. The model also predicts that a lithosphere that

  6. Grain shrinkage driven by surface and grain boundary energy in Ba{sub 5}Nb{sub 4}O{sub 15} powder

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Hidehiko [Nano Ceramics Center, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)]. E-mail: tanaka.hidehiko@nims.go.jp; Nakano, Hiromi [Electron Microscope Laboratory, Faculty of Science and Technology, Ryukoku University, 1-5 Yokotani Seta-Ooe, Otsu, Shiga 520-2194 (Japan); Suyama, Y. [Division for Research Science and Engineering, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504 (Japan)

    2007-04-15

    The shrinkage and disappearance of small Ba{sub 5}Nb{sub 4}O{sub 15} grains in a large grain matrix at 1133 K observed by transmission electron microscopy (TEM), included grain volume and boundary shrinkage. Rate equations for these processes were formulated based on the concept that total excess free energy directly stimulates material transport in volume, surface, or grain boundary diffusion. Based on these equations, grain vanishing was simulated and it was found that volume diffusion combined with boundary diffusion occurred, and high grain boundary energy and low grain boundary diffusivity made grains vanish while maintaining a truncated spherical shape.

  7. Laboratory Studies Of Circumstellar Carbonaceous Grain Formation

    Science.gov (United States)

    Contreras, Cesar; Sciamma-O'Brien, Ella; Salama, Farid

    2014-06-01

    The study of the formation processes of dust is essential to understand the budget of extraterrestrial organic molecules. Although dust with all its components plays an important role in the evolution of interstellar (IS) chemistry and in the formation of organic molecules, little is known on the formation processes of carbonaceous dust. We report the progress that was recently achieved in this domain using NASA Ames’ COSmIC facility (Contreras & Salama 2013, ApJS, 208, 6). PAHs are important chemical building blocks of IS dust. They are detected in IDPs and in meteoritic samples. Additionally, observational, laboratory, and theoretical studies have shown that PAHs are an important, ubiquitous component of the ISM. The formation of PAHs from smaller molecules has not been extensively studied. Therefore, we have performed laboratory experiments to study the dynamic processes of carbon grain formation, starting from the smallest hydrocarbon molecules into the formation of larger PAH and further into nanograins. Studies of IS dust analogs formed from a variety of PAH and hydrocarbon precursors as well as species that include the atoms O, N, and S, have recently been performed in our laboratory using the COSmIC facility to provide conditions that simulate IS and circumstellar environments. The species formed in the COSmiC chamber through a pulsed discharge nozzle plasma source are detected and characterized with a cavity ringdown spectrometer coupled to a time-of-flight mass spectrometer, thus providing both spectroscopic and ion mass information in-situ. Analysis of solid soot particles was also conducted using scanning electron microscopy at the UCSC/NASA Ames’ MACS facility. The SEM analysis of the deposition of soot from methane and acetylene precursors seeded in argon plasmas provide examples on the types of nanoparticles and micrograins that are produced in these gas mixtures under our experimental conditions. From these measurements, we derive information on

  8. Size modification of recent pollen grains under different treatments

    NARCIS (Netherlands)

    Reitsma, Tj.

    1969-01-01

    The effect of various chemicals on the size of recent pollen grains of Corylus avellana L. and Quercus robur L. was studied. The size of acetolysed grains was affected by the treatment prior to acetolysis and moreover by the duration of acetolysis. Preparation methods, which produce comparable sizes

  9. Determining Grain-scale Vorticity Axes from Crystallographic Orientation Data

    Science.gov (United States)

    Michels, Z. D.; Kruckenberg, S. C.; Davis, J. R.; Tikoff, B.

    2015-12-01

    Aggregates deformed by crystal plastic mechanisms often contain grains that exhibit crystallographic distortion (e.g., kinking, undulose extinction, subgrain development). In such grains, crystallographic orientations are typically dispersed along small circles on lower hemisphere equal-area plots. Thus, we consider that an intragranular dispersion axis represents a grain-scale axis of material rotation, and its position coincides with that of a highly localized vorticity axis. We present a new method for determining the position of a grain-scale vorticity axis from intragranular crystallographic orientation data. This method leverages a method of rotational statistics known as principal geodesic analysis to identify a single best-fit rotational axis that matches the rotational dispersion of crystallographic orientations in a deformed grain. We further demonstrate that populations of such grain-scale vorticity axes can be used to infer a preferred vorticity axis for volumes of deformed aggregates. As an example of this type of application, we calculate intragranular vorticity axes from a sample-scale selection of grains (i.e., all the grains mapped in an EBSD orientation map) and use kernel density estimation to identify a preferred, sample-scale vorticity axis. The results of our bulk analysis match the vorticity axis inferred in previous studies of rocks deformed in the same shear zones.

  10. Failure behavior of single sand grains: theory versus experiment

    NARCIS (Netherlands)

    Brzesowsky, R.H.; Spiers, C.J.; Peach, C.J.; Hangx, S.J.T.

    2011-01-01

    Grain‐scale brittle fracture and grain rearrangement play an important role in controlling the compaction behavior of reservoir rocks during the early stages of burial. Therefore, the understanding of single‐grain failure is important. We performed constant displacement rate crushing tests carried o

  11. Annealing Twinning and the Nucleation of Recrystallization at Grain Boundaries

    DEFF Research Database (Denmark)

    Jones, A R.

    1981-01-01

    Experimental evidence is presented which shows that, in three different low stacking fault energy materials, annealing twins form at grain boundaries during the very early stages of recovery following deformation. These observations provide the basis for the suggestion that twinning at grain...

  12. Grain Growth in Samples of Aluminum Containing Alumina Particles

    DEFF Research Database (Denmark)

    Tweed, C. J.; Hansen, Niels; Ralph, B.

    1983-01-01

    A study of the two-dimensional and three-dimensional grain size distributions before and after grain growth treatments has been made in samples having a range of oxide contents. In order to collect statistically useful amounts of data, an automatic image analyzer was used and the resulting data w...

  13. DISRUPTION OF CHARGED DUST GRAINS IN COMETARY PLASMA ENVIRONMENTS

    Institute of Scientific and Technical Information of China (English)

    Shi Zhidong; Li Zhongyuan; Chen Yao

    2000-01-01

    The equilibrium potential and dust fragmentation criterion of fluffy dust grains in plasma are calculated for comet P/Halley . It is found that the dust grain acquires its largest negative potential and disruptive probability about 50,000km from the comet where the dust mass spectrum measured by the spacecraft took a great change.

  14. A Madurella mycetomatis Grain Model in Galleria mellonella Larvae.

    Directory of Open Access Journals (Sweden)

    Wendy Kloezen

    Full Text Available Eumycetoma is a chronic granulomatous subcutaneous infectious disease, endemic in tropical and subtropical regions and most commonly caused by the fungus Madurella mycetomatis. Interestingly, although grain formation is key in mycetoma, its formation process and its susceptibility towards antifungal agents are not well understood. This is because grain formation cannot be induced in vitro; a mammalian host is necessary to induce its formation. Until now, invertebrate hosts were never used to study grain formation in M. mycetomatis. In this study we determined if larvae of the greater wax moth Galleria mellonella could be used to induce grain formation when infected with M. mycetomatis. Three different M. mycetomatis strains were selected and three different inocula for each strain were used to infect G. mellonella larvae, ranging from 0.04 mg/larvae to 4 mg/larvae. Larvae were monitored for 10 days. It appeared that most larvae survived the lowest inoculum, but at the highest inoculum all larvae died within the 10 day observation period. At all inocula tested, grains were formed within 4 hours after infection. The grains produced in the larvae resembled those formed in human and in mammalian hosts. In conclusion, the M. mycetomatis grain model in G. mellonella larvae described here could serve as a useful model to study the grain formation and therapeutic responses towards antifungal agents in the future.

  15. Ecology and IPM of Insects at Grain Elevators

    Science.gov (United States)

    Cost-effectiveness of insect pest management depends upon its integration with other elevator operations. Successful integration may require consideration of insect ecology. Field infestation has not been observed for grain received at elevators. Grain may be infested during harvest by residual inse...

  16. Does Whole Grain Consumption Alter Gut Microbiota and Satiety?

    Directory of Open Access Journals (Sweden)

    Danielle N. Cooper

    2015-05-01

    Full Text Available This review summarizes recent studies examining whole grain consumption and its effect on gut microbiota and satiety in healthy humans. Studies comparing whole grains to their refined grain counterparts were considered, as were studies comparing different grain types. Possible mechanisms linking microbial metabolism and satiety are described. Clinical trials show that whole grain wheat, maize, and barley alter the human gut microbiota, but these findings are based on a few studies that do not include satiety components, so no functional claims between microbiota and satiety can be made. Ten satiety trials were evaluated and provide evidence that whole oats, barley, and rye can increase satiety, whereas the evidence for whole wheat and maize is not compelling. There are many gaps in the literature; no one clinical trial has examined the effects of whole grains on satiety and gut microbiota together. Once understanding the impact of whole grains on satiety and microbiota is more developed, then particular grains might be used for better appetite control. With this information at hand, healthcare professionals could make individual dietary recommendations that promote satiety and contribute to weight control.

  17. Measuring the elastic strain of individual grains in polycrystalline materials

    DEFF Research Database (Denmark)

    3DXRD is not only an excellent tool when it comes to non-destructively determining the positions and orientations of individual grains within the bulk of a polycrystalline material, the experiment can also provide grain resolved elastic strain tensors. To extract this information the program Fit...

  18. Computing wheat nitrogen requirements from grain yield and protein maps

    Science.gov (United States)

    Optical protein sensors and mass-flow yield monitors provide the opportunity to continuously measure grain quality and quantity during harvesting. This chapter illustrates how yield monitor and grain protein measurements may provide useful postharvest information for evaluating water or nitrogen (N)...

  19. Exploring the Use of Whole Grain Pasta in School Lunches

    Science.gov (United States)

    Rosen, Renee A.; Hauge, Denise A.; Arndt, Elizabeth A.; Veal, Mike; Marquart, Len

    2011-01-01

    Pasta is a popular grain food served as an entree or side dish in both home and away-from-home settings. In schools, pasta is served less frequently than other entrees. Pasta, especially whole-grain pasta, offers an opportunity to incorporate less expensive, nutritious, and versatile dishes into school meals. A need exists to develop whole-grain…

  20. Polyphenols and antioxidant capacity: Rice versus other common cereal grains

    Science.gov (United States)

    The consumption of whole cereal grains has been strongly recommended by many governmental and non-profit health organizations based on epidemiological studies associating whole-grain consumption with reduced incidences of chronic diseases. Bioactive phytochemicals, such as polyphenolic compounds, ri...

  1. Antioxidant activity of phytochemicals from dried distillers grain oil

    Science.gov (United States)

    A distillate was obtained by molecular distillation of oil extracted from distiller’s dried grains (DDG). The dried distiller’s grains distillate (DDGD) contained phytosterols, steryl ferulates, tocopherols, tocotrienols, and carotenoids. DDGD was tested for its impact on the oxidative stability in...

  2. 76 FR 59186 - Renewal of National Grain Car Council

    Science.gov (United States)

    2011-09-23

    ... Board intends to renew the charter of the National Grain Car Council (NGCC). ADDRESSES: A copy of the charter is available at the Library of the Surface Transportation Board, 395 E Street, SW., Washington, DC... Surface Transportation Board Renewal of National Grain Car Council AGENCY: Surface Transportation...

  3. 78 FR 58383 - Renewal of National Grain Car Council

    Science.gov (United States)

    2013-09-23

    ... Board intends to renew the charter of the National Grain Car Council (NGCC). ADDRESSES: A copy of the charter is available at the Library of the Surface Transportation Board, 395 E Street SW., Washington, DC... Surface Transportation Board Renewal of National Grain Car Council AGENCY: Surface Transportation...

  4. Observational tests for grain chemistry: posterior isotopic labelling

    NARCIS (Netherlands)

    S.B. Charnley; P. Ehrenfreund; T.J. Millar; A.C.A. Boogert; A.J. Markwick; H.M. Butner; R. Ruiterkamp; S.D. Rodgers

    2004-01-01

    We propose a series of detailed observations that should allow current ideas concerning the important catalytic pathways to interstellar molecules on interstellar dust grains to be tested. The atoms and molecules that accrete on cold grains and take part in surface reactions will be selectively frac

  5. Modelling grain growth in the framework of Rational Extended Thermodynamics

    Science.gov (United States)

    Kertsch, Lukas; Helm, Dirk

    2016-05-01

    Grain growth is a significant phenomenon for the thermomechanical processing of metals. Since the mobility of the grain boundaries is thermally activated and energy stored in the grain boundaries is released during their motion, a mutual interaction with the process conditions occurs. To model such phenomena, a thermodynamic framework for the representation of thermomechanical coupling phenomena in metals including a microstructure description is required. For this purpose, Rational Extended Thermodynamics appears to be a useful tool. We apply an entropy principle to derive a thermodynamically consistent model for grain coarsening due to the growth and shrinkage of individual grains. Despite the rather different approaches applied, we obtain a grain growth model which is similar to existing ones and can be regarded as a thermodynamic extension of that by Hillert (1965) to more general systems. To demonstrate the applicability of the model, we compare our simulation results to grain growth experiments in pure copper by different authors, which we are able to reproduce very accurately. Finally, we study the implications of the energy release due to grain growth on the energy balance. The present unified approach combining a microstructure description and continuum mechanics is ready to be further used to develop more elaborate material models for complex thermo-chemo-mechanical coupling phenomena.

  6. Cavitation-aided grain refinement in aluminium alloys

    NARCIS (Netherlands)

    Atamanenko, T.V.

    2010-01-01

    This thesis deals with grain refinement under the influence of ultrasonic-driven cavitation in aluminium casting processes. Three major goals of this research were: (1) to identify the mechanism of the cavitation-aided grain refinement at different stages of solidification; (2) to reveal the conditi

  7. Dynamic recrystallization and grain growth in olivine rocks

    NARCIS (Netherlands)

    Kellermann Slotemaker, A.

    2006-01-01

    A mechanism based description of the rheology of olivine is essential for modeling of upper mantle geodynamics. Previously, mantle flow has been investigated using flow laws for grain size insensitive (GSI) dislocation creep and/or grain size sensitive (GSS) diffusion creep of olivine. Generally, fl

  8. Grain-boundary melting: A Monte Carlo study

    DEFF Research Database (Denmark)

    Besold, Gerhard; Mouritsen, Ole G.

    1994-01-01

    Grain-boundary melting in a lattice-gas model of a bicrystal is studied by Monte Carlo simulation using the grand canonical ensemble. Well below the bulk melting temperature T(m), a disordered liquidlike layer gradually emerges at the grain boundary. Complete interfacial wetting can be observed...

  9. Application of 198Au grains for carcinoma of oral cavity

    International Nuclear Information System (INIS)

    The purpose of this study is to analyze the results of the treatment using gold grain implants over the past 9 years and to evaluate the usefulness of this treatment method. From January 1985 through April 1993, a total of 45 patients with squamous cell carcinomas of the oral cavity and the oropharynx were treated with 198Au grain (gold grain) at the Department of Radiology, Osaka University Medical School. The initial activity of the grains supplied weekly by the Japan Radioisotope Association was usually 5 mCi (185 MBq), and single implants were usual. In case of combined external irradiation, telecobalt γ-rays or 4 MV X-rays were used for treatment before implant. The local control rate for patients with T1 stages was 80% (20/25) and with T2 stages, 59% (10/17). The local control rate was 71% (10/14) for gold grain alone and 72% (13/18) for external irradiation combined with gold grain implants (combined therapy). In combined therapy, the median of the interval between external irradiation and gold grain implants was 21 days. The treatment interval or patients with recurrent diseases was 22 days, 22, 27, 39 and 46, respectively. The progression rate showed a tendency to increase in the patients with longer interval (more than 21 days), and with partial regression after external irradiation and gold grain implantation is an important factor in combined therapy. Therefore, we emphasize that the time interval should be shorter than 3 weeks. (orig.)

  10. Computing wheat nitrogen requirements from grain yield and protein maps

    Science.gov (United States)

    Optical protein sensors and mass-flow yield monitors provide the opportunity to continuously measure grain quality and quantity during harvesting. This chapter illustrates how yield monitor and grain protein measurements may provide useful post-harvest information for evaluating water or nitrogen (...

  11. DESI-MS Analysis of Mycotoxins from Grain Matrices

    Science.gov (United States)

    Introduction – Determination of mycotoxins in grain matrices is a frequent need of growers and processors of cereal grains. Sample preparation for mycotoxin analysis is often laborious and time consuming. Here we demonstrate the application of desorption electrospray ionization – mass spectrometry...

  12. Segregation of solute elements at grain boundaries in an ultrafine grained Al-Zn-Mg-Cu alloy

    International Nuclear Information System (INIS)

    The solute segregation at grain boundaries (GBs) of an ultrafine grained (UFG) Al-Zn-Mg-Cu alloy processed by equal-channel angular pressing (ECAP) at 200 oC was characterised using three-dimensional atom probe. Mg and Cu segregate strongly to the grain boundaries. In contrast, Zn does not always show clear segregation and may even show depletion near the grain boundaries. Trace element Si selectively segregates at some GBs. An increase in the number of ECAP passes leads to a decrease in the grain size but an increase in solute segregation at the boundaries. The significant segregation of alloying elements at the boundaries of ultrafine-grained alloys implies that less solutes will be available in the matrix for precipitation with a decrease in the average grain size. -- Research Highlights: → Atom probe tomography has been employed successfully to reveal unique segregation of solutes at ultrafine grained material. → Mg and Cu elements segregated strongly at the grain boundary of an ultrafine grained Al-Zn-Mg-Cu alloy processed by 4-pass and 8-pass ECAP at 200 oC. Zn frequently depleted at GBs with a Zn depletion region of 7-15 nm in width on one or both sides of the GBs. Only a small fraction (3/13) of GBs were observed with a low level of Zn segregation where the combined Mg and Cu excess is over 3.1 atom/nm2. Si appeared selectively segregated at some of the GBs. → The increase in number of ECAP passes from 4 to 8 correlated with the increase in mean level segregation of Mg and Cu for both solute excess and peak concentration. → The change of plane normal of a grain boundary within 30o only leads to a slight change in the solute segregation level.

  13. Dust grains from the heart of supernovae

    CERN Document Server

    Bocchio, M; Schneider, R; Bianchi, S; Limongi, M; Chieffi, A

    2016-01-01

    Dust grains are classically thought to form in the winds of asymptotic giant branch (AGB) stars. However, there is increasing evidence today for dust formation in supernovae (SNe). To establish the relative importance of these two classes of stellar sources of dust, it is important to know the fraction of freshly formed dust in SN ejecta that is able to survive the passage of the reverse shock and be injected in the interstellar medium. We have developed a new code (GRASH\\_Rev) which follows the newly-formed dust evolution throughout the supernova explosion until the merging of the forward shock with the circumstellar ISM. We have considered four well studied SNe in the Milky Way and Large Magellanic Cloud: SN1987A, CasA, the Crab Nebula, and N49. For all the simulated models, we find good agreement with observations and estimate that between 1 and 8$\\%$ of the observed mass will survive, leading to a SN dust production rate of $(3.9 \\pm 3.7) \\times 10^{-4}$ M$_{\\odot}$yr$^{-1}$ in the Milky Way. This value i...

  14. Producing more grain with lower environmental costs.

    Science.gov (United States)

    Chen, Xinping; Cui, Zhenling; Fan, Mingsheng; Vitousek, Peter; Zhao, Ming; Ma, Wenqi; Wang, Zhenlin; Zhang, Weijian; Yan, Xiaoyuan; Yang, Jianchang; Deng, Xiping; Gao, Qiang; Zhang, Qiang; Guo, Shiwei; Ren, Jun; Li, Shiqing; Ye, Youliang; Wang, Zhaohui; Huang, Jianliang; Tang, Qiyuan; Sun, Yixiang; Peng, Xianlong; Zhang, Jiwang; He, Mingrong; Zhu, Yunji; Xue, Jiquan; Wang, Guiliang; Wu, Liang; An, Ning; Wu, Liangquan; Ma, Lin; Zhang, Weifeng; Zhang, Fusuo

    2014-10-23

    Agriculture faces great challenges to ensure global food security by increasing yields while reducing environmental costs. Here we address this challenge by conducting a total of 153 site-year field experiments covering the main agro-ecological areas for rice, wheat and maize production in China. A set of integrated soil-crop system management practices based on a modern understanding of crop ecophysiology and soil biogeochemistry increases average yields for rice, wheat and maize from 7.2 million grams per hectare (Mg ha(-1)), 7.2 Mg ha(-1) and 10.5 Mg ha(-1) to 8.5 Mg ha(-1), 8.9 Mg ha(-1) and 14.2 Mg ha(-1), respectively, without any increase in nitrogen fertilizer. Model simulation and life-cycle assessment show that reactive nitrogen losses and greenhouse gas emissions are reduced substantially by integrated soil-crop system management. If farmers in China could achieve average grain yields equivalent to 80% of this treatment by 2030, over the same planting area as in 2012, total production of rice, wheat and maize in China would be more than enough to meet the demand for direct human consumption and a substantially increased demand for animal feed, while decreasing the environmental costs of intensive agriculture. PMID:25186728

  15. Computer simulation of dust grain evolution

    International Nuclear Information System (INIS)

    The latest results are reported from a Monte Carlo code that is being developed at NASA Ames. The goal of this program, is to derive from the observed and presumed properties of the interstellar medium (ISM) the following information: (1) the size spectrum of interstellar dust; (2) the chemical structure of interstellar dust; (3) interstellar abundances; and (4) the lifetime of a dust grain in the ISM. Presently this study is restricted to refractory interstellar material, i.e., the formation and destruction of ices are not included in the program. The program is embedded in an analytic solution for the bulk chemical evolution of a two-phase interstellar medium in which stars are born in molecular clouds, but new nucleosynthesis products and stellar return are entered into a complementary intercloud medium. The well-mixed matter of each interstellar phase is repeatedly cycled stochastically through the complementary phase and back. Refractory dust is created by thermal condensation as stellar matter flows away from sites of nucleosynthesis such as novae and supernovae and/or from the matter returned from evolved intermediate stars. The history of each particle is traced by standard Monte Carlo techniques as it is sputtered and fragmented by supernova shock waves in the intercloud medium. It also accretes an amorphous mantle of gaseous refractory atoms when its local medium joins with the molecular cloud medium. Finally it encounters the possibility of astration (destruction by star formation) within the molecular clouds

  16. Deuterium enrichment of the interstellar grain mantle

    CERN Document Server

    Das, Ankan; Chakrabarti, Sandip K

    2015-01-01

    We carry out Monte-Carlo simulation to study deuterium enrichment of interstellar grain mantles under various physical conditions. Based on the physical properties, various types of clouds are considered. We find that in diffuse cloud regions, very strong radiation fields persists and hardly a few layers of surface species are formed. In translucent cloud regions with a moderate radiation field, significant number of layers would be produced and surface coverage is mainly dominated by photo-dissociation products such as, C,CH_3,CH_2D,OH and OD. In the intermediate dense cloud regions (having number density of total hydrogen nuclei in all forms ~ 2 x 10^4 cm^-3), water and methanol along with their deuterated derivatives are efficiently formed. For much higher density regions (~ 10^6 cm^-3), water and methanol productions are suppressed but surface coverage of CO,CO_2,O_2,O_3 are dramatically increased. We find a very high degree of fractionation of water and methanol. Observational results support a high frac...

  17. Lipid composition of grains from wild grasses

    Directory of Open Access Journals (Sweden)

    Zydgalo, J. A.

    1995-02-01

    Full Text Available Physicochemical characteristics, fatty acid and sterol composition were studied in grains of Agropyron elongatum, Bromus catharticus, Festuca arundinacea, Stipa hyaline and Panicum maximum. The highest protein level was found in A. elongatum. Linoleic and palmitic acids were the predominant fatty acids in all species, β-sitosterol was by far the most prominent sterol component in all samples, while Δ7-stigmasterol was detected in only trace amounts.

    Se estudió las características físico-químicas, la composición de ácidos grasos y esteroles de Agropyron elongatum, Bromus catharticus, Festuca arundinacea, Stipa hialina y Panicum maximum. Los niveles más altos de proteínas fueron encontrados en A. elongatum. Dentro de los ácidos grasos el linoleico y el palmítico fueron los predominantes. En todas las muestras el β-sitosterol fue el esterol que se presentó en mayor cantidad, mientras que el Δ7-estigmasterol fue detectado en cantidades trazas.

  18. Fusariotoxins in Wheat Grain in Serbia

    Directory of Open Access Journals (Sweden)

    Ana Stepanić

    2011-01-01

    Full Text Available Samples of wheat grain (41, collected during the 2010 harvest from seven localities inSerbia, were analysed for the presence of zearalenone (ZEA, T-2 toxin, deoxynivalenol (DONand fumonisine B1 (FB1. Results of Enzyme-Linked Immunosorbent Assay (ELISA showedthat all analysed samples were positive for the presence of at least one of four observedfusariotoxins. The most distributed mycotoxins were ZEA (90.2%, with the average concentrationof 442.6μg kg–1 and T-2 (90.2%, with the average concentration of 24.2 μg kg–1.DON (73.2% and FB1 (84.4% were detected in a somewhat smaller number of samples, buttheir average concentrations were higher (1988.1 μg DON kg–1 and 882.7 μg FB1 kg–1. Theestablished correlations between concentrations of DON and FB1 (r = 0.32 or DON and ZEA(r = 0.22 were not statistically significant. A negative correlation was established betweenconcentrations of T-2 and FB1 (r= -0.24, as well as, between T-2 and DON (r = -0.36. Detectedconcentrations of ZEA and T-2 were bellow the level prescribed by the World Health Organisation(WHO, while concentrations of FB1 and DON detected in five that is, 17 samples,respectively, were above the permissible limit for human consumption

  19. Cyclitols in maturing grains of wheat, triticale and barley

    Directory of Open Access Journals (Sweden)

    Lesław B. Lahuta

    2011-04-01

    Full Text Available In the present study, the feeding of stem-flag leaf-ear explants of wheat, triticale and barley with d-chiro-inositol and d-pinitol was used for modification of the composition of soluble carbohydrates in grains without genetic transformation of plants. Maturing grains indicated ability to uptake exogenously applied cyclitols, not occurring naturally in cereal plants, and synthesized their a-d-galactosides. The pattern of changes in soluble carbohydrates during grain maturation and germination was not disturbed by the uptake and accumulation of cyclitols. Both, d-chiro-inositol and d-pinitol as well as their a-d-galactosides can be an additional pool of soluble carbohydrates accumulated by maturing grains, without decreasing seeds viability. This is the first report indicating the possibility of introduction of cyclitols with potentially human health benefits properties into cereal grains.

  20. Temperature Dependence of the Particle Diffusion Coefficient in Dust Grains

    Science.gov (United States)

    Pechal, Radim; Richterova, Ivana; Pavlu, Jiri; Safrankova, Jana; Nemecek, Zdenek

    2014-05-01

    During the interaction of ions/neutrals with dust grains, some of the particles are implanted into the grain and, as a consequence, the density gradient induces their diffusion toward the grain surface. Their release can cause a transport of these particles over large distances in space. In our laboratory experiment, measurements of the diffusion coefficient of the particles implanted into the dust grain are carried out in an electrodynamic quadrupole trap. Although experimental setup does not allow an assessment of the dust grain temperature, it can be modified (e.g., by changing thermal radiation from the surrounding walls, laser irradiation, etc.). We present an upgraded laboratory set-up and the resulting temperature dependence of diffusion coefficient estimations and discuss implications for the space dust.