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1

MAIZE FINE STREAK VIRUS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The report outlines the salient features of maize fine streak virus (MFSV) including a general description of the causal virus species, virion properties, genome description, the relationship of the virus to other taxa, biological properties of the disease and agronomic aspects of the disease. Maize...

2

Wheat streak mosaic virus lacking HC-Pro is competent to produce disease synergism in mixed infections with Maize chlorotic mottle virus  

Technology Transfer Automated Retrieval System (TEKTRAN)

Single infections of maize plants with the tritimovirus Wheat streak mosaic virus (WSMV) or the machlomovirus Maize chlorotic mottle virus (MCMV) are characterized by systemic chlorosis but not necrosis. Co-infection of maize with both viruses results in disease synergism and induction of corn leth...

3

Inhibition of maize streak virus (MSV) replication by transient and transgenic expression of MSV replication-associated protein mutants  

Microsoft Academic Search

Maize streak disease is a severe agricultural problem in Africa and the development of maize genotypes resistant to the causal agent, Maize streak virus (MSV), is a priority. A transgenic approach to engineering MSV-resistant maize was developed and tested in this study. A pathogen- derived resistance strategy was adopted by using targeted deletions and nucleotide-substitution mutants of the multifunctional MSV

Dionne N. Shepherd; Tichaona Mangwende; Darren P. Martin; Marion Bezuidenhout; Jennifer A. Thomson; Edward P. Rybicki

2007-01-01

4

A high degree of African streak virus diversity within Nigerian maize fields includes a new mastrevirus from Axonopus compressus.  

PubMed

The A-strain of maize streak virus (MSV-A; genus Mastrevirus, family Geminiviridae), the causal agent of maize streak disease, places a major constraint on maize production throughout sub-Saharan Africa. In West-African countries such as Nigeria, where maize is not cultivated year-round, this MSV strain is forced to overwinter in non-maize hosts. In order to both identify uncultivated grasses that might harbour MSV-A during the winter season and further characterise the diversity of related maize-associated streak viruses, we collected maize and grass samples displaying streak symptoms in a number of Nigerian maize fields. From these we isolated and cloned 18 full mastrevirus genomes (seven from maize and 11 from various wild grass species). Although only MSV-A isolates were obtained from maize, both MSV-A and MSV-F isolates were obtained from Digitaria ciliaris. Four non-MSV African streak viruses were also sampled, including sugarcane streak Reunion virus and Urochloa streak virus (USV) from Eleusine coacana, USV from Urochloa sp., maize streak Reunion virus (MSRV) from both Setaria barbata and Rottboellia sp., and a novel highly divergent mastrevirus from Axonopus compressus, which we have tentatively named Axonopus compressus streak virus (ACSV). Besides the discovery of this new mastrevirus species and expanding the known geographical and host ranges of MSRV, we have added D. ciliaris to the list of uncultivated species within which Nigerian MSV-A isolates are possibly able to overwinter. PMID:24796552

Oluwafemi, Sunday; Kraberger, Simona; Shepherd, Dionne N; Martin, Darren P; Varsani, Arvind

2014-10-01

5

Comparative analysis of Panicum streak virus and Maize streak virus diversity, recombination patterns and phylogeography  

PubMed Central

Background Panicum streak virus (PanSV; Family Geminiviridae; Genus Mastrevirus) is a close relative of Maize streak virus (MSV), the most serious viral threat to maize production in Africa. PanSV and MSV have the same leafhopper vector species, largely overlapping natural host ranges and similar geographical distributions across Africa and its associated Indian Ocean Islands. Unlike MSV, however, PanSV has no known economic relevance. Results Here we report on 16 new PanSV full genome sequences sampled throughout Africa and use these together with others in public databases to reveal that PanSV and MSV populations in general share very similar patterns of genetic exchange and geographically structured diversity. A potentially important difference between the species, however, is that the movement of MSV strains throughout Africa is apparently less constrained than that of PanSV strains. Interestingly the MSV-A strain which causes maize streak disease is apparently the most mobile of all the PanSV and MSV strains investigated. Conclusion We therefore hypothesize that the generally increased mobility of MSV relative to other closely related species such as PanSV, may have been an important evolutionary step in the eventual emergence of MSV-A as a serious agricultural pathogen. The GenBank accession numbers for the sequences reported in this paper are GQ415386-GQ415401 PMID:19903330

2009-01-01

6

Biological and Genomic Sequence Characterization of Maize streak virus Isolates from Wheat.  

PubMed

ABSTRACT Maize streak virus (MSV) is best known as the causal agent of maize streak disease. However, only a genetically uniform subset of the viruses within this diverse species is actually capable of producing severe symptoms in maize. Whereas these "maize-type" viruses all share greater than 95% sequence identity, MSV strains isolated from grasses may share as little as 79% sequence identity with the maize-type viruses. Here, we present the complete genome sequences and biological characterization of two MSV isolates from wheat that share approximately 89% sequence identity with the maize-type viruses. Clonal populations of these two isolates, named MSV-Tas and MSV-VW, were leafhopper-transmitted to Digitaria sanguinalis and a range of maize, wheat, and barley genotypes. Whereas the two viruses showed some differences in their pathogenicity in maize, they were both equally pathogenic in D. sanguinalis and the various wheat and barley genotypes tested. Phylogenetic analyses involving the genome sequences of MSV-Tas and MSV-VW, a new maize-type virus also fully sequenced in this study (MSV-VM), and all other available African streak virus sequences, indicated that MSV-Tas and MSV-VW are close relatives that together represent a distinct MSV strain. Sequence analyses revealed that MSV-VM has a recombinant genome containing MSV-Tas/VW-like sequences within its movement protein gene. PMID:18944143

Willment, J A; Martin, D P; Van der Walt, E; Rybicki, E P

2002-01-01

7

Mapping the distribution of maize streak virus genotypes across the forest and transition zones of Ghana.  

PubMed

Throughout sub-Saharan Africa, maize streak virus strain A (MSV-A), the causal agent of maize streak disease (MSD), is an important biological constraint on maize production. In November/December 2010, an MSD survey was carried out in the forest and transition zones of Ghana in order to obtain MSV-A virulence sources for the development of MSD-resistant maize genotypes with agronomic properties suitable for these regions. In 79 well-distributed maize fields, the mean MSD incidence was 18.544 % and the symptom severity score was 2.956 (1 = no symptoms and 5 = extremely severe). We detected no correlation between these two variables. Phylogenetic analysis of cloned MSV-A isolates that were fully sequenced from samples collected in 51 of these fields, together with those sampled from various other parts of Africa, indicated that all of the Ghanaian isolates occurred within a broader cluster of West African isolates, all belonging to the highly virulent MSV-A1 subtype. Besides being the first report of a systematic MSV survey in Ghana, this study is the first to characterize the full-genome sequences of Ghanaian MSV isolates. The 51 genome sequences determined here will additionally be a valuable resource for the rational selection of representative MSV-A variant panels for MSD resistance screening. PMID:25344899

Oppong, Allen; Offei, Samuel K; Ofori, Kwadwo; Adu-Dapaah, Hans; Lamptey, Joseph N L; Kurenbach, Brigitta; Walters, Matthew; Shepherd, Dionne N; Martin, Darren P; Varsani, Arvind

2015-02-01

8

Maize streak virus-resistant transgenic maize: a first for Africa.  

PubMed

In this article, we report transgene-derived resistance in maize to the severe pathogen maize streak virus (MSV). The mutated MSV replication-associated protein gene that was used to transform maize showed stable expression to the fourth generation. Transgenic T2 and T3 plants displayed a significant delay in symptom development, a decrease in symptom severity and higher survival rates than non-transgenic plants after MSV challenge, as did a transgenic hybrid made by crossing T2 Hi-II with the widely grown, commercial, highly MSV-susceptible, white maize genotype WM3. To the best of our knowledge, this is the first maize to be developed with transgenic MSV resistance and the first all-African-produced genetically modified crop plant. PMID:17924935

Shepherd, Dionne N; Mangwende, Tichaona; Martin, Darren P; Bezuidenhout, Marion; Kloppers, Frederik J; Carolissen, Charlene H; Monjane, Adérito L; Rybicki, Edward P; Thomson, Jennifer A

2007-11-01

9

Serotyping and strain identification of maize streak virus isolates.  

PubMed

Four strains of maize streak virus, namely the Panicum maximum, Digitaria setigera and sugarcane strains, have been identified from 19 isolates by ELISA using polyclonal antisera cross-absorbed with particles of the maize strain. The results suggest there is an epitope of the maize strain which is not dependent on the capsid being intact and which is common to all the members of the group; other strain-specific epitopes are probably conformation-dependent. A specific epitope (probably internal) occurs on the coat protein of a maize strain isolate, D(R)D, grown in D. velutina, that is also present on the coat protein of the D. setigera (previously reported as D. sanguinalis) strain. Specific internal epitopes also occur in the coat proteins of sugarcane and P. maximum strains. The use of indirect ELISA was necessary for accurate serotyping. The serological reactivities of particles of all the members of each type were identical irrespective of the host from which they were extracted. Sap extracts proved to be more reliable sources of antigen than virus preparations, which could vary in their serological reactivity. Nevertheless, serological differentiation index values determined in tests using either type of antigen proved reliable and consistent. PMID:1697327

Pinner, M S; Markham, P G

1990-08-01

10

Quantification of Maize Fine Streak Virus Genomic and Positive-sense RNAs in Infected Maize Reveals High Level Accumulation of ORF 3 and 4 MFSV Transcripts  

Technology Transfer Automated Retrieval System (TEKTRAN)

Quantification of Maize fine streak virus genomic and positive-sense RNAs in infected maize reveals high level accumulation of ORF 3 and 4 MFSV transcripts. We improved methods to analyze RNA produced by Maize fine streak virus (MVSF) within infected maize tissue using real-time RT-qPCR. We designe...

11

Plant host range and leafhopper transmission of Maize fine streak virus  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize fine streak virus (MFSV), an emerging rhabdovirus species in the genus Nucleorhabdovirus, is persistently transmitted by the black-faced leafhopper, Graminella nigrifrons (Forbes). MFSV was transmitted to maize, wheat, oats, rye, barley, foxtail, annual ryegrass and quackgrass by G. nigrifron...

12

Inhibition of maize streak virus (MSV) replication by transient and transgenic expression of MSV replication-associated protein mutants.  

PubMed

Maize streak disease is a severe agricultural problem in Africa and the development of maize genotypes resistant to the causal agent, Maize streak virus (MSV), is a priority. A transgenic approach to engineering MSV-resistant maize was developed and tested in this study. A pathogen-derived resistance strategy was adopted by using targeted deletions and nucleotide-substitution mutants of the multifunctional MSV replication-associated protein gene (rep). Various rep gene constructs were tested for their efficacy in limiting replication of wild-type MSV by co-bombardment of maize suspension cells together with an infectious genomic clone of MSV and assaying replicative forms of DNA by quantitative PCR. Digitaria sanguinalis, an MSV-sensitive grass species used as a model monocot, was then transformed with constructs that had inhibited virus replication in the transient-expression system. Challenge experiments using leafhopper-transmitted MSV indicated significant MSV resistance--from highly resistant to immune--in regenerated transgenic D. sanguinalis lines. Whereas regenerated lines containing a mutated full-length rep gene displayed developmental and growth defects, those containing a truncated rep gene both were fertile and displayed no growth defects, making the truncated gene a suitable candidate for the development of transgenic MSV-resistant maize. PMID:17170465

Shepherd, Dionne N; Mangwende, Tichaona; Martin, Darren P; Bezuidenhout, Marion; Thomson, Jennifer A; Rybicki, Edward P

2007-01-01

13

Black leaf streak and viral leaf streak: New banana diseases in East Africa  

Microsoft Academic Search

Black leaf streak, caused by Mycosphaerella fijiensis a virulent pathogen of bananas and plantains, is recorded from Zanzibar. This is the first record of this important pathogen from East Africa. Viral leaf streak of bananas is also identified from Zanzibar. The presence of panama disease and high infestations of root nematode are also noted.

A. J. Dabek; J. M. Waller

1990-01-01

14

MAIZE NECROTIC STREAK VIRUS IS MOST CLOSELY RELATED TO THE GENUS TOMBUSVIRIDAE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Initial reports indicated that Maize necrotic streak virus (MNeSV) is most closely related to viruses in the family Tombusviridae (Louie et al., 2000, Plant Dis. 84:1133-1139). The first two open reading frames (ORFs) encode a 33 kDa protein and a 92 kDa readthrough protein which are similar in siz...

15

Nuclear import of Maize fine streak virus proteins in Drosophila S2 cells  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize fine streak virus (MFSV) is a member of the genus Nucleorhabdovirus, family Rhabdoviridae and is transmitted by the leafhopper Graminella nigrifons. The virus replicates in both its plant host and in its insect vector. Nucleorhabdoviruses replicate in the nucleus and assemble at the inner nu...

16

PHYSICAL CHARACTERIZATION, INSECT VECTOR IDENTIFICATION AND GENOME SEQUENCE ANALYSIS OF MAIZE FINE STREAK RHABDOVIRUS (MFSV): A RECENTLY DISCOVERED PATHOGEN OF MAIZE  

Technology Transfer Automated Retrieval System (TEKTRAN)

We have identified a new rhabdovirus in maize plants (Zea mays L.) collected from fields of Syngenta sweet corn near Bainbridge in Decatur County, Georgia in the fall of 1999. The virus is serologically distinct from other maize-infecting rhabdoviruses and was named Maize fine streak virus (MFSV). ...

17

Recombination, decreased host specificity and increased mobility may have driven the emergence of maize streak virus as an agricultural pathogen  

PubMed Central

Maize streak virus (MSV; family Geminiviridae, genus Mastrevirus), the causal agent of maize streak disease, ranks amongst the most serious biological threats to food security in subSaharan Africa. Although five distinct MSV strains have been currently described, only one of these – MSV-A – causes severe disease in maize. Due primarily to their not being an obvious threat to agriculture, very little is known about the ‘grass-adapted’ MSV strains, MSV-B, -C, -D and -E. Since comparing the genetic diversities, geographical distributions and natural host ranges of MSV-A with the other MSV strains could provide valuable information on the epidemiology, evolution and emergence of MSV-A, we carried out a phylogeographical analysis of MSVs found in uncultivated indigenous African grasses. Amongst the 83 new MSV genomes presented here, we report the discovery of six new MSV strains (MSV-F to -K). The non-random recombination breakpoint distributions detectable with these and other available mastrevirus sequences partially mirror those seen in begomoviruses, implying that the forces shaping these breakpoint patterns have been largely conserved since the earliest geminivirus ancestors. We present evidence that the ancestor of all MSV-A variants was the recombinant progeny of ancestral MSV-B and MSV-G/-F variants. While it remains unknown whether recombination influenced the emergence of MSV-A in maize, our discovery that MSV-A variants may both move between and become established in different regions of Africa with greater ease, and infect more grass species than other MSV strains, goes some way towards explaining why MSV-A is such a successful maize pathogen. PMID:18753214

Varsani, Arvind; Shepherd, Dionne N.; Monjane, Adérito L.; Owor, Betty E.; Erdmann, Julia B.; Rybicki, Edward P.; Peterschmitt, Michel; Briddon, Rob W.; Markham, Peter G.; Oluwafemi, Sunday; Windram, Oliver P.; Lefeuvre, Pierre; Lett, Jean-Michel; Martin, Darren P.

2008-01-01

18

Maize Disease Resistance  

Technology Transfer Automated Retrieval System (TEKTRAN)

Worldwide losses in maize due to disease (not including animals or viruses) were estimated to be about 9% in 2001-3 . This varied significantly by region with estimates of 4% in northern Europe and 14% in West Africa and South Asia (http://www.cabicompendium.org/cpc/economic.asp). Losses have tende...

19

Complete Genome Sequence and In Planta Subcellular Localization of Maize Fine Streak Virus Proteins  

Microsoft Academic Search

The genome of the nucleorhabdovirus maize fine streak virus (MFSV) consists of 13,782 nucleotides of nonsegmented, negative-sense, single-stranded RNA. The antigenomic strand consisted of seven open reading frames (ORFs), and transcripts of all ORFs were detected in infected plants. ORF1, ORF6, and ORF7 had significant similarities to the nucleocapsid protein (N), glycoprotein (G), and polymerase (L) genes of other rhabdoviruses,

Chi-Wei Tsai; Margaret G. Redinbaugh; Kristen J. Willie; Sharon Reed; Michael Goodin; Saskia A. Hogenhout

2005-01-01

20

Structure of the Maize Streak Virus Geminate Particle Wei Zhang,* Norman H. Olson,* Timothy S. Baker,* Lee Faulkner,,  

E-print Network

; maize streak virus; ssDNA virus; three-dimen- sional image reconstruction. INTRODUCTION At the beginning-stranded DNA (ssDNA) genomes. The characteristic twinned or "gemi- nate" particles, which consist of two joined-dimensional image reconstruction methods. The particle, of dimensions 220 380 Å, has an overall 52-point- group

Baker, Timothy S.

21

Reconstructing the History of Maize Streak Virus Strain A Dispersal To Reveal Diversification Hot Spots and Its Origin in Southern Africa ? †  

PubMed Central

Maize streak virus strain A (MSV-A), the causal agent of maize streak disease, is today one of the most serious biotic threats to African food security. Determining where MSV-A originated and how it spread transcontinentally could yield valuable insights into its historical emergence as a crop pathogen. Similarly, determining where the major extant MSV-A lineages arose could identify geographical hot spots of MSV evolution. Here, we use model-based phylogeographic analyses of 353 fully sequenced MSV-A isolates to reconstruct a plausible history of MSV-A movements over the past 150 years. We show that since the probable emergence of MSV-A in southern Africa around 1863, the virus spread transcontinentally at an average rate of 32.5 km/year (95% highest probability density interval, 15.6 to 51.6 km/year). Using distinctive patterns of nucleotide variation caused by 20 unique intra-MSV-A recombination events, we tentatively classified the MSV-A isolates into 24 easily discernible lineages. Despite many of these lineages displaying distinct geographical distributions, it is apparent that almost all have emerged within the past 4 decades from either southern or east-central Africa. Collectively, our results suggest that regular analysis of MSV-A genomes within these diversification hot spots could be used to monitor the emergence of future MSV-A lineages that could affect maize cultivation in Africa. PMID:21715477

Monjane, Adérito L.; Harkins, Gordon W.; Martin, Darren P.; Lemey, Philippe; Lefeuvre, Pierre; Shepherd, Dionne N.; Oluwafemi, Sunday; Simuyandi, Michelo; Zinga, Innocent; Komba, Ephrem K.; Lakoutene, Didier P.; Mandakombo, Noella; Mboukoulida, Joseph; Semballa, Silla; Tagne, Appolinaire; Tiendrébéogo, Fidèle; Erdmann, Julia B.; van Antwerpen, Tania; Owor, Betty E.; Flett, Bradley; Ramusi, Moses; Windram, Oliver P.; Syed, Rizwan; Lett, Jean-Michel; Briddon, Rob W.; Markham, Peter G.; Rybicki, Edward P.; Varsani, Arvind

2011-01-01

22

Computer analysis identifies sequence homologies between potential gene products of Maize Streak Virus and those of Cassava Latent Virus and Tomato Golden Mosaic Virus  

Microsoft Academic Search

The amino acid sequences of the putative polypeptides of maize streak virus (MSV) have been systematically compared with those of cassava latent virus (CLV) and tomato golden mosaic virus (TGMV) using the programme DIAGON (8).

P. M. Mullineaux; J. Donson; M. I. Boulton; B. A. M. Morris-Krsinich; P. G. Markham; J. W. Davies

1985-01-01

23

Strand-specific real-time RT-PCR quantitation of Maize fine streak virus genomic and positive-sense RNAs using high temperature reverse transcription  

Technology Transfer Automated Retrieval System (TEKTRAN)

Efforts to analyze the replicative RNA produced by Maize fine streak virus (MVSF) within maize tissue was complicated by the lack of specificity during cDNA generation using standard reverse transcriptase protocols. Real-time qRT-PCR using cDNA generated by priming with random hexamers does not dist...

24

Strand-specific real-time RT-PCR quantitation of Maize fine streak virus genomic and positive-sense RNAs using high temperature reverse transcription  

Technology Transfer Automated Retrieval System (TEKTRAN)

Efforts to analyze the replicative RNA produced by Maize fine streak virus (MFSV) within maize tissue was complicated by the lack of specificity during cDNA generation using standard reverse transcriptase protocols. Real-time qRT-PCR using cDNA generated by priming with random hexamers does not dist...

25

Genetic Insights into Graminella nigrifrons Competence for Maize fine streak virus Infection and Transmission  

PubMed Central

Background Most plant-infecting rhabdoviruses are transmitted by one or a few closely related insect species. Additionally, intraspecific differences in transmission efficacy often exist among races/biotypes within vector species and among strains within a virus species. The black-faced leafhopper, Graminella nigrifrons, is the only known vector of the persistent propagative rhabdovirus Maize fine streak virus (MFSV). Only a small percentage of leafhoppers are capable of transmitting the virus, although the mechanisms underlying vector competence are not well understood. Methodology RNA-Seq was carried out to explore transcript expression changes and sequence variation in G. nigrifrons and MFSV that may be associated with the ability of the vector to acquire and transmit the virus. RT-qPCR assays were used to validate differential transcript accumulation. Results/Significance Feeding on MFSV-infected maize elicited a considerable transcriptional response in G. nigrifrons, with increased expression of cytoskeleton organization and immunity transcripts in infected leafhoppers. Differences between leafhoppers capable of transmitting MFSV, relative to non-transmitting but infected leafhoppers were more limited, which may reflect difficulties discerning between the two groups and/or the likelihood that the transmitter phenotype results from one or a few genetic differences. The ability of infected leafhoppers to transmit MFSV did not appear associated with virus transcript accumulation in the infected leafhoppers or sequence polymorphisms in the viral genome. However, the non-structural MFSV 3 gene was expressed at unexpectedly high levels in infected leafhoppers, suggesting it plays an active role in the infection of the insect host. The results of this study begin to define the functional roles of specific G. nigrifrons and MFSV genes in the viral transmission process. PMID:25420026

Michel, Andrew P.; Stewart, Lucy R.; Redinbaugh, Margaret G.

2014-01-01

26

Transcriptome of the Plant Virus Vector Graminella nigrifrons, and the Molecular Interactions of Maize fine streak rhabdovirus Transmission  

PubMed Central

Background Leafhoppers (Hemiptera: Cicadellidae) are plant-phloem feeders that are known for their ability to vector plant pathogens. The black-faced leafhopper (Graminella nigrifrons) has been identified as the only known vector for the Maize fine streak virus (MFSV), an emerging plant pathogen in the Rhabdoviridae. Within G. nigrifrons populations, individuals can be experimentally separated into three classes based on their capacity for viral transmission: transmitters, acquirers and non-acquirers. Understanding the molecular interactions between vector and virus can reveal important insights in virus immune defense and vector transmission. Results RNA sequencing (RNA-Seq) was performed to characterize the transcriptome of G. nigrifrons. A total of 38,240 ESTs of a minimum 100 bp were generated from two separate cDNA libraries consisting of virus transmitters and acquirers. More than 60% of known D. melanogaster, A. gambiae, T. castaneum immune response genes mapped to our G. nigrifrons EST database. Real time quantitative PCR (RT-qPCR) showed significant down-regulation of three genes for peptidoglycan recognition proteins (PGRP – SB1, SD, and LC) in G. nigrifrons transmitters versus control leafhoppers. Conclusions Our study is the first to characterize the transcriptome of a leafhopper vector species. Significant sequence similarity in immune defense genes existed between G. nigrifrons and other well characterized insects. The down-regulation of PGRPs in MFSV transmitters suggested a possible role in rhabdovirus transmission. The results provide a framework for future studies aimed at elucidating the molecular mechanisms of plant virus vector competence. PMID:22808205

Chen, Yuting; Cassone, Bryan J.; Bai, Xiaodong; Redinbaugh, Margaret G.; Michel, Andrew P.

2012-01-01

27

Molecular characterization of segments S7 to S10 of a southern rice black-streaked dwarf virus isolate from maize in northern China.  

PubMed

Southern rice black-streaked dwarf virus (SRBSDV) is a novel Fijivirus prevalent in rice in southern and central China, and northern Vietnam. Its genome has 10 segments of double-stranded RNA named S1 to S10 according to their size. An isolate of SRBSDV, JNi4, was obtained from naturally infected maize plants from Ji'ning, Shandong province, in the 2008 maize season. Segments S7 to S10 of JNi4 share nucleotide identities of 72.6%-73.1%, 72.3%-73%, 73.9%-74.5% and 77.3%-79%, respectively, with corresponding segments of Rice black-streaked dwarf virus isolates, and identities of 99.7%, 99.1%-99.7%, 98.9%-99.5%, and 98.6%-99.2% with those of SRBSDV isolates HN and GD. JNi4 forms a separate branch with GD and HN in the phylogenetic trees constructed with genomic sequences of S7 to S10. These results confirm the proposed taxonomic status of SRBSDV as a distinct species of the genus Fijivirus and indicate that JNi4 is an isolate of SRBSDV. Shandong is so far the northernmost region where SRBSDV is found in China. PMID:21331890

Yin, Xiao; Xu, Fei-fei; Zheng, Fang-qiang; Li, Xiang-dong; Liu, Bao-shen; Zhang, Chun-qing

2011-02-01

28

Phylogenetic and recombination analysis of rice black-streaked dwarf virus segment 9 in China.  

PubMed

Rice black-streaked dwarf virus (RBSDV) is an economically important virus that causes maize rough dwarf disease and rice black-streaked dwarf disease in East Asia. To study RBSDV variation and recombination, we examined the segment 9 (S9) sequences of 49 RBSDV isolates from maize and rice in China. Three S9 recombinants were detected in Baoding, Jinan, and Jining, China. Phylogenetic analysis showed that Chinese RBSDV isolates could be classified into two groups based on their S9 sequences, regardless of host or geographical origin. Further analysis suggested that S9 has undergone negative and purifying selection. PMID:25633210

Zhou, Yu; Weng, Jian-Feng; Chen, Yan-Ping; Liu, Chang-Lin; Han, Xiao-Hua; Hao, Zhuan-Fang; Li, Ming-Shun; Yong, Hong-Jun; Zhang, De-Gui; Zhang, Shi-Huang; Li, Xin-Hai

2015-04-01

29

Molecular interactions and immune responses between Maize fine streak virus and the leafhopper vector Graminella nigrifrons through differential expression and RNA interference.  

PubMed

Graminella nigrifrons is the only known vector for Maize fine streak virus (MFSV). In this study, we used real-time quantitative PCR to compare the expression profiles of transcripts that putatively function in the insect immune response: four peptidoglycan recognition proteins (PGRP-SB1, -SD, -LC and LB), Toll, spaetzle, defensin, Dicer-2 (Dcr-2), Argonaut-2 (Ago-2) and Arsenic resistance protein 2 (Ars-2). Except for PGRP-LB and defensin, transcripts involved in humoral pathways were significantly suppressed in G. nigrifrons fed on MFSV-infected maize. The abundance of three RNA interference (RNAi) pathway transcripts (Dcr-2, Ago-2, Ars-2) was significantly lower in nontransmitting relative to transmitting G. nigrifrons. Injection with double-stranded RNA (dsRNA) encoding segments of the PGRP-LC and Dcr-2 transcripts effectively reduced transcript levels by 90 and 75% over 14 and 22 days, respectively. MFSV acquisition and transmission were not significantly affected by injection of either dsRNA. Knock-down of PGRP-LC resulted in significant mortality (greater than 90%) at 27 days postinjection, and resulted in more abnormal moults relative to those injected with Dcr-2 or control dsRNA. The use of RNAi to silence G. nigrifrons transcripts will facilitate the study of gene function and pathogen transmission, and may provide approaches for developing novel targets of RNAi-based pest control. PMID:25693649

Chen, Y; Redinbaugh, M G; Michel, A P

2015-06-01

30

Loop-mediated isothermal amplification for rapid detection of the causal agents of cassava brown streak disease.  

PubMed

The causal agents of cassava brown streak disease have recently been identified as Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV). Primers have been developed for rapid detection of these viruses by reverse transcription loop-mediated isothermal amplification (RT-LAMP). Performance of the RT-LAMP assays compared favourably with published RT-PCR and real-time RT-PCR methods. Furthermore, amplification by RT-LAMP is completed in 40 min and does not require thermal cycling equipment. Modification of the RT-LAMP reactions to use labelled primers allowed rapid detection of amplification products using lateral flow devices containing antibodies specific to the incorporated labels, avoiding the need for fluorescence detection or gel electrophoresis. PMID:22820076

Tomlinson, J A; Ostoja-Starzewska, S; Adams, I P; Miano, D W; Abidrabo, P; Kinyua, Z; Alicai, T; Dickinson, M J; Peters, D; Boonham, N; Smith, J

2013-08-01

31

Research of Maize Leaf Disease Identifying Models Based Image Recognition  

Microsoft Academic Search

\\u000a The methods of recognition and diagnosis of main maize leaf diseases using machine vision were studied in the paper. Threshold\\u000a method was adopted to do image segmentation, and area-marking method was used calculating the num of disease as well as wiping\\u000a off redundancy dots. And then Freeman link code was used to calculate form feature. Finally diseases were deduced according

Yu-Xia Zhao; Ke-Ru Wang; Zhong-Ying Bai; Shao-Kun Li; Rui-Zhi Xie; Shi-Ju Gao

32

The Genetic Basis of Disease Resistance in Maize  

Technology Transfer Automated Retrieval System (TEKTRAN)

The advent of high throughput genomics has accelerated progress in understanding the genetic basis of disease resistance in maize, much as it enhanced discovery in other fields. Here we summarize progress made in recent years using resources such as association mapping and nested association mapping...

33

EVALUATION OF RESISTANCE TO WHEAT SPINDLE STREAK MOSAIC VIRUS BY ANALYSIS OF DISEASE INCIDENCE DATA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Once Wheat spindle streak mosaic virus (WSSMV) becomes established in a field, the only available control tactic is the planting of resistant genotypes. In this study we assessed 113 genotypes of autumn-sown wheat, rye, triticale, and barley for resistance to WSSMV in a three-year trial in a field t...

34

Transcriptional Response of Virus-Infected Cassava and Identification of Putative Sources of Resistance for Cassava Brown Streak Disease  

PubMed Central

Cassava (Manihot esculenta) is a major food staple in sub-Saharan Africa, which is severely affected by cassava brown streak disease (CBSD). The aim of this study was to identify resistance for CBSD as well as to understand the mechanism of putative resistance for providing effective control for the disease. Three cassava varieties; Kaleso, Kiroba and Albert were inoculated with cassava brown streak viruses by grafting and also using the natural insect vector the whitefly, Bemisia tabaci. Kaleso expressed mild or no disease symptoms and supported low concentrations of viruses, which is a characteristic of resistant plants. In comparison, Kiroba expressed severe leaf but milder root symptoms, while Albert was susceptible with severe symptoms both on leaves and roots. Real-time PCR was used to estimate virus concentrations in cassava varieties. Virus quantities were higher in Kiroba and Albert compared to Kaleso. The Illumina RNA-sequencing was used to further understand the genetic basis of resistance. More than 700 genes were uniquely overexpressed in Kaleso in response to virus infection compared to Albert. Surprisingly, none of them were similar to known resistant gene orthologs. Some of the overexpressed genes, however, belonged to the hormone signalling pathways and secondary metabolites, both of which are linked to plant resistance. These genes should be further characterised before confirming their role in resistance to CBSD. PMID:24846209

Maruthi, M. N.; Bouvaine, Sophie; Tufan, Hale A.; Mohammed, Ibrahim U.; Hillocks, Rory J.

2014-01-01

35

Wheat Streak Mosaic Virus  

E-print Network

Figure 1. Leaves infected with Wheat Streak Mosaic Virus. Picture from KSU Department of Plant Pathology web-site. Figure 2. Wheat plant infected with Wheat Streak Mosaic Virus and High Plains Virus. Picture was provided by Dr. Charlie Rush, Plant....edu/Agriculture/Entomology/entfacts/fldcrops/ef117. htm ? Compendium of Wheat Diseases, Wiese. American Phy- topathological Society. 1987. Produced by AgriLife Communications and Marketing, Texas A&M System Extension publications can be found on the Web at: http://AgriLifebookstore.org Visit...

Morgan, Gaylon

2005-01-26

36

Identification and fine-mapping of a QTL, qMrdd1, that confers recessive resistance to maize rough dwarf disease  

PubMed Central

Background Maize rough dwarf disease (MRDD) is a devastating viral disease that results in considerable yield losses worldwide. Three major strains of virus cause MRDD, including maize rough dwarf virus in Europe, Mal de Río Cuarto virus in South America, and rice black-streaked dwarf virus in East Asia. These viral pathogens belong to the genus fijivirus in the family Reoviridae. Resistance against MRDD is a complex trait that involves a number of quantitative trait loci (QTL). The primary approach used to minimize yield losses from these viruses is to breed and deploy resistant maize hybrids. Results Of the 50 heterogeneous inbred families (HIFs), 24 showed consistent responses to MRDD across different years and locations, in which 9 were resistant and 15 were susceptible. We performed trait-marker association analysis on the 24 HIFs and found six chromosomal regions which were putatively associated with MRDD resistance. We then conducted QTL analysis and detected a major resistance QTL, qMrdd1, on chromosome 8. By applying recombinant-derived progeny testing to self-pollinated backcrossed families, we fine-mapped the qMrdd1 locus into a 1.2-Mb region flanked by markers M103-4 and M105-3. The qMrdd1 locus acted in a recessive manner to reduce the disease-severity index (DSI) by 24.2–39.3%. The genetic effect of qMrdd1 was validated using another F6 recombinant inbred line (RIL) population in which MRDD resistance was segregating and two genotypes at the qMrdd1 locus differed significantly in DSI values. Conclusions The qMrdd1 locus is a major resistance QTL, acting in a recessive manner to increase maize resistance to MRDD. We mapped qMrdd1 to a 1.2-Mb region, which will enable the introgression of qMrdd1-based resistance into elite maize hybrids and reduce MRDD-related crop losses. PMID:24079304

2013-01-01

37

Stolbur phytoplasma transmission to maize by Reptalus panzeri and the disease cycle of maize redness in Serbia.  

PubMed

Maize redness (MR), induced by stolbur phytoplasma ('Candidatus Phytoplasma solani', subgroup 16SrXII-A), is characterized by midrib, leaf, and stalk reddening and abnormal ear development. MR has been reported from Serbia, Romania, and Bulgaria for 50 years, and recent epiphytotics reduced yields by 40 to 90% in South Banat District, Serbia. Potential vectors including leafhoppers and planthoppers in the order Hemiptera, suborder Auchenorrhyncha, were surveyed in MR-affected and low-MR-incidence fields, and 33 different species were identified. Only Reptalus panzeri populations displayed characteristics of a major MR vector. More R. panzeri individuals were present in MR-affected versus low-MR fields, higher populations were observed in maize plots than in field border areas, and peak population levels preceded the appearance of MR in late July. Stolbur phytoplasma was detected in 17% of R. panzeri adults using nested polymerase chain reaction but not in any other insects tested. Higher populations of R. panzeri nymphs were found on maize, Johnsongrass (Sorghum halepense), and wheat (Triticum aestivum) roots. Stolbur phytoplasma was detected in roots of these three plant species, as well as in R. panzeri L(3) and L(5) nymphs. When stolbur phytoplasma-infected R. panzeri L(3) nymphs were introduced into insect-free mesh cages containing healthy maize and wheat plants, 89 and 7%, respectively, became infected. These results suggest that the MR disease cycle in South Banat involves mid-July transmission of stolbur phytoplasma to maize by infected adult R. panzeri. The adult R. panzeri lay eggs on infected maize roots, and nymphs living on these roots acquire the phytoplasma from infected maize. The nymphs overwinter on the roots of wheat planted into maize fields in the autumn, allowing emergence of phytoplasma-infected vectors the following July. PMID:19671007

Jovi?, J; Cvrkovi?, T; Mitrovi?, M; Krnjaji?, S; Petrovi?, A; Redinbaugh, M G; Pratt, R C; Hogenhout, S A; Tosevski, I

2009-09-01

38

Variable number of tandem repeat markers in the genome sequence of Mycosphaerella fijiensis, the causal agent of black leaf streak disease of banana (Musa spp)  

Microsoft Academic Search

Abstract: We searched the genome of Mycosphaerella fijiensis for molecular markers that would allow population genetics analysis of this plant pathogen. M. fijiensis, the causal agent of banana leaf streak disease, also known as black Sigatoka, is the most devastating pathogen attacking bananas (Musa spp). Recently, the entire genome sequence of M. fijiensis became available. We screened this database for

S. A. L. Garcia; Lee van der T. A. J; C. F. Ferreira; Lintel Hekkert te B; M. F. Zapater; S. B. Goodwin; M. Guzmán; G. H. J. Kema; M. T. Souza

2010-01-01

39

Development of VNTR Markers to Assess Genetic Diversity of Mycosphaerella Fijiensis, the Causal Agent of Black Leaf Streak Disease in Bananas (Musa spp.)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Mycosphaerella fijiensis is the causal agent of black leaf streak (BLS) disease in bananas. This pathogen threatens global banana production as the main export cultivars are highly susceptible. As a consequence, commercial banana plantations must be protected chemically with fungicides; up to 40 app...

40

Expression of the Newcastle disease virus fusion protein in transgenic maize and immunological studies  

Microsoft Academic Search

Transgenic plants have been employed successfully as a low-cost system for the production of therapeutically valuable proteins,\\u000a including antibodies, antigens and hormones. Here, we report the expression of the fusion (F) gene of the Newcastle disease\\u000a virus (NDV) in transgenic maize plants. The expression of the transgene, driven by the maize ubiquitin promoter, caused accumulation\\u000a of the F protein in

Octavio Guerrero-Andrade; Elizabeth Loza-Rubio; Teresa Olivera-Flores; Tamás Fehérvári-Bone; Miguel Angel Gómez-Lim

2006-01-01

41

Primitive Streak (dorsal view)  

NSDL National Science Digital Library

This FlashTM animation is the first of a seven part series that presents the primitive streak from different angles. This installment displays the dorsal view, which provides an overview of elongation and regression. Epiblast is seen migrating medially, towards and into the streak. The appearance of the neural tube and somites demonstrates that morphogenesis commences before the streak recedes away.

PhD Jack D Thatcher (West Virginia School of Osteopathic Medicine Structural Biology)

2011-06-23

42

Targeted discovery of quantitative trait loci for resistance to northern leaf blight and other diseases of maize  

Technology Transfer Automated Retrieval System (TEKTRAN)

To capture diverse alleles at a set of loci associated with disease resistance in maize, heterogeneous inbred family (HIF) analysis was applied for targeted QTL mapping and near-isogenic line (NIL) development. Tropical maize lines CML52 and DK888 were chosen as donors of alleles based on their know...

43

Plant-Plant-Microbe Mechanisms Involved in Soil-Borne Disease Suppression on a Maize and Pepper Intercropping System  

PubMed Central

Background Intercropping systems could increase crop diversity and avoid vulnerability to biotic stresses. Most studies have shown that intercropping can provide relief to crops against wind-dispersed pathogens. However, there was limited data on how the practice of intercropping help crops against soil-borne Phytophthora disease. Principal Findings Compared to pepper monoculture, a large scale intercropping study of maize grown between pepper rows reduced disease levels of the soil-borne pepper Phytophthora blight. These reduced disease levels of Phytophthora in the intercropping system were correlated with the ability of maize plants to form a “root wall” that restricted the movement of Phytophthora capsici across rows. Experimentally, it was found that maize roots attracted the zoospores of P. capsici and then inhibited their growth. When maize plants were grown in close proximity to each other, the roots produced and secreted larger quantities of 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA) and 6-methoxy-2-benzoxazolinone (MBOA). Furthermore, MBOA, benzothiazole (BZO), and 2-(methylthio)-benzothiazole (MBZO) were identified in root exudates of maize and showed antimicrobial activity against P. capsici. Conclusions Maize could form a “root wall” to restrict the spread of P. capsici across rows in maize and pepper intercropping systems. Antimicrobe compounds secreted by maize root were one of the factors that resulted in the inhibition of P. capsici. These results provide new insights into plant-plant-microbe mechanisms involved in intercropping systems. PMID:25551554

Mei, Xinyue; Liao, Jingjing; Ding, Xupo; Deng, Weiping; Fan, Limin; He, Xiahong; Vivanco, Jorge M.; Li, Chengyun; Zhu, Youyong; Zhu, Shusheng

2014-01-01

44

Interactive Separating Streak Surfaces  

Microsoft Academic Search

Streak surfaces are among the most important features to support 3D unsteady flow exploration, but they are also among the computationally most demanding. Furthermore, to enable a feature driven analysis of the flow, one is mainly interested in streak surfaces that show separation profiles and thus detect unstable manifolds in the flow. The computation of such separation surfaces requires to

Florian Ferstl; Kai Bürger; Holger Theisel; Rüdiger Westermann

2010-01-01

45

Microchannel plate streak camera  

DOEpatents

An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras is disclosed. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1,000 KeV x-rays. 3 figs.

Wang, C.L.

1989-03-21

46

Microchannel plate streak camera  

DOEpatents

An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 KeV x-rays.

Wang, Ching L. (Livermore, CA)

1989-01-01

47

Microchannel plate streak camera  

DOEpatents

An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (uv to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 keV x-rays.

Wang, C.L.

1984-09-28

48

Visible Embryo: Primitive Streak  

NSDL National Science Digital Library

the page on early placentation and primitive streak formation from a comprehensive resource of information on human development from conception to birth, designed for both medical student and interested lay people.

Carmen Arbona (Mouseworks)

2006-09-08

49

Interactive separating streak surfaces.  

PubMed

Streak surfaces are among the most important features to support 3D unsteady flow exploration, but they are also among the computationally most demanding. Furthermore, to enable a feature driven analysis of the flow, one is mainly interested in streak surfaces that show separation profiles and thus detect unstable manifolds in the flow. The computation of such separation surfaces requires to place seeding structures at the separation locations and to let the structures move correspondingly to these locations in the unsteady flow. Since only little knowledge exists about the time evolution of separating streak surfaces, at this time, an automated exploration of 3D unsteady flows using such surfaces is not feasible. Therefore, in this paper we present an interactive approach for the visual analysis of separating streak surfaces. Our method draws upon recent work on the extraction of Lagrangian coherent structures (LCS) and the real-time visualization of streak surfaces on the GPU. We propose an interactive technique for computing ridges in the finite time Lyapunov exponent (FTLE) field at each time step, and we use these ridges as seeding structures to track streak surfaces in the time-varying flow. By showing separation surfaces in combination with particle trajectories, and by letting the user interactively change seeding parameters such as particle density and position, visually guided exploration of separation profiles in 3D is provided. To the best of our knowledge, this is the first time that the reconstruction and display of semantic separable surfaces in 3D unsteady flows can be performed interactively, giving rise to new possibilities for gaining insight into complex flow phenomena. PMID:20975199

Ferstl, Florian; Bürger, Kai; Theisel, Holger; Westermann, Rüdiger

2010-01-01

50

Streak camera receiver definition study  

NASA Technical Reports Server (NTRS)

Detailed streak camera definition studies were made as a first step toward full flight qualification of a dual channel picosecond resolution streak camera receiver for the Geoscience Laser Altimeter and Ranging System (GLRS). The streak camera receiver requirements are discussed as they pertain specifically to the GLRS system, and estimates of the characteristics of the streak camera are given, based upon existing and near-term technological capabilities. Important problem areas are highlighted, and possible corresponding solutions are discussed.

Johnson, C. B.; Hunkler, L. T., Sr.; Letzring, S. A.; Jaanimagi, P.

1990-01-01

51

Mapping QTL conferring resistance in maize to gray leaf spot disease caused by Cercospora zeina  

PubMed Central

Background Gray leaf spot (GLS) is a globally important foliar disease of maize. Cercospora zeina, one of the two fungal species that cause the disease, is prevalent in southern Africa, China, Brazil and the eastern corn belt of the USA. Identification of QTL for GLS resistance in subtropical germplasm is important to support breeding programmes in developing countries where C.?zeina limits production of this staple food crop. Results A maize RIL population (F7:S6) from a cross between CML444 and SC Malawi was field-tested under GLS disease pressure at five field sites over three seasons in KwaZulu-Natal, South Africa. Thirty QTL identified from eleven field trials (environments) were consolidated to seven QTL for GLS resistance based on their expression in at least two environments and location in the same core maize bins. Four GLS resistance alleles were derived from the more resistant parent CML444 (bin 1.10, 4.08, 9.04/9.05, 10.06/10.07), whereas the remainder were from SC Malawi (bin 6.06/6.07, 7.02/7.03, 9.06). QTLs in bin 4.08 and bin 6.06/6.07 were also detected as joint QTLs, each explained more than 11% of the phenotypic variation, and were identified in four and seven environments, respectively. Common markers were used to allocate GLS QTL from eleven previous studies to bins on the IBM2005 map, and GLS QTL “hotspots” were noted. Bin 4.08 and 7.02/7.03 GLS QTL from this study overlapped with hotspots, whereas the bin 6.06/6.07 and bin 9.06 QTLs appeared to be unique. QTL for flowering time (bin 1.07, 4.09) in this population did not correspond to QTL for GLS resistance. Conclusions QTL mapping of a RIL population from the subtropical maize parents CML444 and SC Malawi identified seven QTL for resistance to gray leaf spot disease caused by C.?zeina. These QTL together with QTL from eleven studies were allocated to bins on the IBM2005 map to provide a basis for comparison. Hotspots of GLS QTL were identified on chromosomes one, two, four, five and seven, with QTL in the current study overlapping with two of these. Two QTL from this study did not overlap with previously reported QTL. PMID:24885661

2014-01-01

52

Jet Streak Circulations  

NSDL National Science Digital Library

This Webcast is based on a presentation given by Dr. James T. Moore of Saint Louis University at the 5th Annual MSC/COMET Winter Weather Workshop on 30 November 2004 in Boulder, Colorado. Dr. Moore reviews many aspects of jet streak dynamics including convergence/divergence, ageostrophic winds, propagation, and coupled jets.

2014-09-14

53

Meta-analysis of constitutive QTLs for disease resistance in maize and its synteny conservation in the rice genome.  

PubMed

We collected data regarding 340 disease resistance quantitative trait loci (QTLs) from the maize genomic database (MaizeGDB). We constructed an integrated linkage map and analyzed this map by using the BioMercator 2.1 software with IBM2 2008 Neighbors genetic linkage map as a reference. We used a meta-analysis method to identify five "consensus" synthetic resistance QTLs located on maize chromosomes 1, 3, 6, and 10, with map intervals of 5.14, 9.00, 28.50, 1.73, and 33.34 cM, respectively. The gene and marker sequences within the five "consensus" QTLs were downloaded from the MaizeGDB website. We identified eight resistance gene analogs (RGAs), through comparison of these sequences with the resistance genes of other members of Poaceae by using the online BLASTx software. On the basis of comparative mapping between the maize genetic map and the rice physical map, 54 rice and 44 maize resistance genes were projected onto the maize IBM2 2008 Neighbors genetic linkage map by using a synteny conservation approach. Additionally, 15 resistance genes in the "consensus" QTL regions were found in two "consensus" QTLs on chromosomes 3 and 6; these resistance genes included rp3, scmv2, wsm2, RG3, RG16, RG36, RG51, RG53, scmv1, mdm1, RG5, RG8, RG10, RG14, and RG29. Our results provide valuable information for fine-mapping QTL, gene cloning, and molecular breeding for resistance in maize. PMID:25730034

Zhao, L; Liu, H J; Zhang, C X; Wang, Q Y; Li, X H

2015-01-01

54

Stolbur Phytoplasma Transmission to Maize by Reptalus panzeri and the Disease Cycle of Maize Redness in Serbia  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize redness (MR), induced by stolbur phytoplasma (Candidatus Phytoplasma solani, subgroup 16SrXII-A), is characterized by midrib, leaf and stalk reddening and abnormal ear development. MR has been reported from Serbia, Romania and Bulgaria for 50 years, and recent epiphytotics reduced yields by 4...

55

USING QTL ANALYSIS TO STUDY THE EFFECT OF GENETIC BACKGROUND ON A DISEASE LESION MIMIC IN MAIZE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize plants are subjected to many stresses in the field during growth. How they respond to such stresses can affect yield. If plants can be altered to have greater tolerance to stresses, such as common field diseases, yields would be improved. The goal of this research is to identify quantitativ...

56

Primitive Streak, Oblique Overview  

NSDL National Science Digital Library

This FlashTM animation is the seventh and last of a series that presents the primitive streak from different angles. This installment displays the streak from an oblique angle, which provides an overview of simultaneous processes. Cells that ingress through the steak early insert into the underlying hypoblast and differentiate into endodermal cells. The notochordal process emerges from HensenÂ?s node. Mesenchyme dissociates from the streak and spreads throughout the germ disc. The distal end of the notochordal process fuses with the endoderm and flattens into the notochordal plate. The plate dissociates form the endoderm to form the solid notochord. Eventually the streak completely regresses, leaving the three germ layers; ectoderm, mesoderm, endoderm, with the notochord buried in the paraxial mesoderm. To open the animation using Internet Explorer follow these steps. (1.) Click the link for the animation. (2.) A dialog box may pop up that begins with the statement "Windows cannot open this file:" If this box does not appear proceed to step four. If it does choose "Select the program from a list," then click OK. (3.) Another dialog box will pop up that lists different programs. Make sure "Internet Explorer" is selected, then click OK. (4.) Internet Explorer will pop up. Beneath the toolbars at the top of the window a yellow bar will appear that reads "To help protect your security, Internet Explorer has restricted this webpage from running scripts or Active X controls that could access your computer. Click here for options..." Pass the cursor over this yellow bar and click the right mouse button. (5.) A dialog box will pop up. Left click the option "Allow Blocked Content." (6.) Another dialog box will appear labeled "Security Warning" asking you to confirm that you want to run the content. Click "Yes." (7.) The Flash animation will appear in the Internet Explorer Window. (8.) Instructions for navigating the lesson are provided by the first frame of the animation.

PhD Jack D Thatcher (West Virginia School of Osteopathic Medicine Structural Biology)

2011-06-23

57

Disruption of ceramide biosynthesis and accumulation of sphingoid bases and sphingoid base 1-phosphates: A mechanism for Fusarium verticillioides effects in maize-seedling disease.  

Technology Transfer Automated Retrieval System (TEKTRAN)

In sweet corn at the seedling and seed maturation stages, Fusarium can be a serious field problem. The fungus Fusarium verticillioides infects maize and produces fumonisins, inhibitors of ceramide synthase. To determine the role of fumonisins in maize seedling disease, seeds were inoculated with fu...

58

Influence of Maize Root Colonization by the Rhizosphere Actinomycetes and Yeast Fungi on Plant Growth and on the Biological Control of Late Wilt Disease  

Microsoft Academic Search

Isolates of 85 actinomycetes and 40 yeast fungi were obtained from the rhizosphere of maize plant (Zea mays L.) and were screened for in vitro antagonism to Cephalosporium maydis, a causal agent of late wilt disease of maize. Of these, six actinomycetes and five yeast fungi isolates were found to be strongly antagonistic to the pathogen in vitro. The isolates

ADEL A. EL-MEHALAWY; NAZIHA M. HASSANEIN; HEND M. KHATER; EL-ZAHRAA A. KARAM EL-DIN; YOUSSEF A. YOUSSEF

59

Triton's streaks as windblown dust  

NASA Technical Reports Server (NTRS)

Explanations for the surface streaks observed by Voyager 2 on Triton's southern hemisphere are discussed. It is shown that, despite Triton's tenuous atmosphere, low-cohesion dust trains with diameters of about 5 micron or less may be carried into suspension by aeolian surface shear stress, given expected geostrophic wind speeds of about 10 m/s. For geyser-like erupting dust plumes, it is shown that dust-settling time scales and expected wind velocities can produce streaks with length scales in good agreement with those of the streaks. Thus, both geyserlike eruptions or direct lifting by surface winds appear to be viable mechanisms for the origin of the streaks.

Sagan, Carl; Chyba, Christopher

1990-01-01

60

Streaking into Middle School Science: The Dell Streak Pilot Project  

ERIC Educational Resources Information Center

A case study is conducted implementing the Dell Streak seven-inch android device into eighth grade science classes of one teacher in a rural middle school in the Piedmont region of North Carolina. The purpose of the study is to determine if the use of the Dell Streaks would increase student achievement on standardized subject testing, if the…

Austin, Susan Eudy

2012-01-01

61

BARLEY YELLOW STREAK MOSAIC VIRUS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Barley yellow streak mosaic virus (BaYSMV) was discovered in barley from Montana, U.S.A. in 1982, and later reported in several western states, Alaska, and Alberta, Canada. Barley plants show chlorotic streaks, stripes, and dashes parallel to the leaf veins and varying degrees of stunting; increased...

62

Root Interactions in a Maize/Soybean Intercropping System Control Soybean Soil-Borne Disease, Red Crown Rot  

PubMed Central

Background Within-field multiple crop species intercropping is well documented and used for disease control, but the underlying mechanisms are still unclear. As roots are the primary organ for perceiving signals in the soil from neighboring plants, root behavior may play an important role in soil-borne disease control. Principal Findings In two years of field experiments, maize/soybean intercropping suppressed the occurrence of soybean red crown rot, a severe soil-borne disease caused by Cylindrocladium parasiticum (C. parasiticum). The suppressive effects decreased with increasing distance between intercropped plants under both low P and high P supply, suggesting that root interactions play a significant role independent of nutrient status. Further detailed quantitative studies revealed that the diversity and intensity of root interactions altered the expression of important soybean PR genes, as well as, the activity of corresponding enzymes in both P treatments. Furthermore, 5 phenolic acids were detected in root exudates of maize/soybean intercropped plants. Among these phenolic acids, cinnamic acid was released in significantly greater concentrations when intercropped maize with soybean compared to either crop grown in monoculture, and this spike in cinnamic acid was found dramatically constrain C. parasiticum growth in vitro. Conclusions To the best of our knowledge, this study is the first report to demonstrate that intercropping with maize can promote resistance in soybean to red crown rot in a root-dependent manner. This supports the point that intercropping may be an efficient ecological strategy to control soil-borne plant disease and should be incorporated in sustainable agricultural management practices. PMID:24810161

Gao, Xiang; Wu, Man; Xu, Ruineng; Wang, Xiurong; Pan, Ruqian; Kim, Hye-Ji; Liao, Hong

2014-01-01

63

Cerberus Wind Streaks  

NASA Technical Reports Server (NTRS)

(Released 6 May 2002) The Science Cerberus is a dark region on Mars that has shrunk down from a continuous length of about 1000 km to roughly three discontinuous spots a few 100 kms in length in less than 20 years. There are two competing processes at work in the Cerberus region that produce the bright and dark features seen in this THEMIS image. Bright dust settles out of the atmosphere, especially after global dust storms, depositing a layer just thick enough to brighten the dark surfaces. Deposition occurs preferentially in the low wind 'shadow zones' within craters and downwind of crater rims, producing the bright streaks. The direction of the streaks clearly indicates that the dominant winds come from the northeast. Dust deposition would completely blot out the dark areas if it were not for the action of wind-blown sand grains scouring the surface and lifting the dust back into the atmosphere. Again, the shadow zones are protected from the blowing sand, preserving the bright layer of dust. Also visible in this image are lava flow features extending from the flanks of the huge Elysium volcanoes to the northwest. Two shallow channels and a raised flow lobe are just barely discernable. The lava channel in the middle of the image crosses the boundary of the bright and dark surfaces without any obvious change in its morphology. This demonstrates that the bright dust layer is very thin in this location, perhaps as little as a few millimeters. The Story Mars is an ever-changing land of spectacular contrasts. This THEMIS image shows the Cerberus region of Mars, a dark area located near the Elysium volcanoes and fittingly named after the three-headed, dragon-tailed dog who guards the door of the underworld. Two opposing processes are at work here: a thin layer of dust falling from the atmosphere and/or dust storms creating brighter surface areas (e.g. the top left portion of this image) and dust being scoured away by the action of the Martian wind disturbing the sand grains and freeing the lighter dust to fly away once more (the darker portions of this image). There are, however, some darker areas that are somewhat shielded and protected from the wind that have yielded bright, dusty crater floors and wind streaks that trail out behind the craters. These wind streaks tell a story all their own as to the prevailing wind direction coming from the northeast. This, added to the fact that this dark region was once 1000 km in length and has dwindled to just a few isolated dark splotches of 100 kilometers in the past 20 years, help us to see that the Martian environment is still quite dynamic and capable of changing. Finally, this being a volcanic region, a lobe of a lava flow from the immense Elysium volcanoes to the northwest is visible stretching across the bottom one-quarter of the image.

2002-01-01

64

Eragrostis minor streak virus: an Asian streak virus in Africa  

Microsoft Academic Search

The genus Mastrevirus of the single-stranded DNA virus family Geminiviridae consists of four distinct virus lineages that have been sampled in different parts of the Old World. These include the Panicoideae-infecting African streak viruses (ten described species including the geographical outlier, Digitaria streak virus [DSV] from Vanuatu) and Australian striate mosaic viruses (three described species), the dicotyledonous-plant-infecting mastreviruses (seven described

Darren P. Martin; Daphne Linderme; Pierre Lefeuvre; Dionne N. Shepherd; Arvind Varsani

2011-01-01

65

Genetically Modified, Insect Resistant Maize: Implications for Management of Ear and Stalk Diseases  

NSDL National Science Digital Library

This article summarizes six years of research that indicate that Bt transformation of maize hybrids enhances the safety of grain for livestock and human food products by reducing the plants' vulnerability to mycotoxin-producing Fusarium fungi.

G. P. Munkvold (Iowa State University; )

2000-09-12

66

Promoters for pregenomic RNA of banana streak badnavirus are active for transgene expression in monocot and dicot plants  

Microsoft Academic Search

Two putative promoters from Australian banana streak badnavirus (BSV) isolates were analysed for activity in different plant species. In transient expression systems the My (2105 bp) and Cv (1322 bp) fragments were both shown to have promoter activity in a wide range of plant species including monocots (maize, barley, banana, millet, wheat, sorghum), dicots (tobacco, canola, sunflower, Nicotiana benthamiana, tipu

Peer M. Schenk; Tony Remans; László Sági; Adrian R. Elliott; Ralf G. Dietzgen; Rony Swennen; Paul R. Ebert; Christopher P. L. Grof; John M. Manners

2001-01-01

67

Immunofluorescence localization and ultrastructure of Stewart’s wilt disease bacterium Pantoea stewartii in maize leaves and in its flea beetle vector Chaetocnema pulicaria (Coleoptera: Chrysomelidae)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Pantoea stewartii is the causal agent of Stewart's wilt of sweet corn, the most serious bacterial disease of sweet corn and maize in the North-Central and Eastern USA. P. stewartii is transmitted mainly by the corn flea beetle Chaetocnema pulicaria (Coleoptera: Chrysomelidae) and this bacterium is a...

68

Fumonisin production is necessary for development of the full spectrum of symptoms indicative of Fusarium verticillioides maize-seedling disease and evidence for disruption of sphingolipid metabolism as the proximate cause.  

Technology Transfer Automated Retrieval System (TEKTRAN)

The fungus Fusarium verticillioides infects maize and produces fumonisins, inhibitors of ceramide synthase. To determine the role of fumonisins in maize seedling disease, seeds were inoculated with fumonisin producing or non-producing strains of F. verticillioides. Seedlings grown from seeds inocul...

69

Southern rice black-streaked dwarf virus: a white-backed planthopper-transmitted fijivirus threatening rice production in Asia.  

PubMed

Southern rice black-streaked dwarf virus (SRBSDV), a non-enveloped icosahedral virus with a genome of 10 double-stranded RNA segments, is a novel species in the genus Fijivirus (family Reoviridae) first recognized in 2008. Rice plants infected with this virus exhibit symptoms similar to those caused by Rice black-streaked dwarf virus. Since 2009, the virus has rapidly spread and caused serious rice losses in East and Southeast Asia. Significant progress has been made in recent years in understanding this disease, especially about the functions of the viral genes, rice-virus-insect interactions, and epidemiology and control measures. The virus can be efficiently transmitted by the white-backed planthopper (WBPH, Sogatella furcifera) in a persistent circulative propagative manner but cannot be transmitted by the brown planthopper (Nilaparvata lugens) and small brown planthopper (Laodelphax striatellus). Rice, maize, Chinese sorghum (Coix lacryma-jobi) and other grass weeds can be infected via WBPH. However, only rice plays a major role in the virus infection cycle because of the vector's preference. In Southeast Asia, WBPH is a long-distance migratory rice pest. The disease cycle can be described as follows: SRBSDV and its WBPH vector overwinter in warm tropical or sub-tropical areas; viruliferous WBPH adults carry the virus from south to north via long-distance migration in early spring, transmit the virus to rice seedlings in the newly colonized areas, and lay eggs on the infected seedlings; the next generation of WBPHs propagate on infected seedlings, become viruliferous, disperse, and cause new disease outbreaks. Several molecular and serological methods have been developed to detect SRBSDV in plant tissues and individual insects. Control measures based on protection from WBPH, including seedbed coverage, chemical seed treatments, and chemical spraying of seedlings, have proven effective in China. PMID:24058362

Zhou, Guohui; Xu, Donglin; Xu, Dagao; Zhang, Maoxin

2013-01-01

70

Analysis of quantitative disease resistance to southern leaf blight and of multiple disease resistance in maize, using near-isogenic lines.  

PubMed

Maize inbred lines NC292 and NC330 were derived by repeated backcrossing of an elite source of southern leaf blight (SLB) resistance (NC250P) to the SLB-susceptible line B73, with selection for SLB resistance among and within backcross families at each generation. Consequently, while B73 is very SLB susceptible, its sister lines NC292 and NC330 are both SLB resistant. Previously, we identified the 12 introgressions from NC250P that differentiate NC292 and NC330 from B73. The goals of this study were to determine the effects of each introgression on resistance to SLB and to two other foliar fungal diseases of maize, northern leaf blight and gray leaf spot. This was achieved by generating and testing a set of near isogenic lines carry single or combinations of just two or three introgressions in a B73 background. Introgressions 3B, 6A, and 9B (bins 3.03-3.04, 6.01, and 9.02-9.03) all conferred significant levels of SLB resistance in the field. Introgression 6A was the only introgression that had a significant effect on juvenile plant resistance to SLB. Introgressions 6A and 9B conferred resistance to multiple diseases. PMID:21997760

Belcher, Araby R; Zwonitzer, John C; Santa Cruz, Jose; Krakowsky, Mathew D; Chung, Chia-Lin; Nelson, Rebecca; Arellano, Consuelo; Balint-Kurti, Peter J

2012-02-01

71

Maize databases  

Technology Transfer Automated Retrieval System (TEKTRAN)

This chapter is a succinct overview of maize data held in the species-specific database MaizeGDB (the Maize Genomics and Genetics Database), and selected multi-species data repositories, such as Gramene/Ensembl Plants, Phytozome, UniProt and the National Center for Biotechnology Information (NCBI), ...

72

Overexpression of rice black-streaked dwarf virus p7-1 in Arabidopsis results in male sterility due to non-dehiscent anthers.  

PubMed

Rice black-streaked dwarf virus (RBSDV), a member of the genus Fijivirus in the family Reoviridae, is propagatively transmitted by the small brown planthopper (Laodelphax striatellus Fallén). RBSDV causes rice black-streaked dwarf and maize rough dwarf diseases, which lead to severe yield losses in crops in China. Although several RBSDV proteins have been studied in detail, the functions of the nonstructural protein P7-1 are still largely unknown. To investigate the role of the P7-1 protein in virus pathogenicity, transgenic Arabidopsis thaliana plants were generated in which the P7-1 gene was expressed under the control of the 35S promoter. The RBSDV P7-1-transgenic Arabidopsis plants (named P7-1-OE) were male sterility. Flowers and pollen from P7-1-transgenic plants were of normal size and shape, and anthers developed to the normal size but failed to dehisce. The non-dehiscent anthers observed in P7-1-OE were attributed to decreased lignin content in the anthers. Furthermore, the reactive oxygen species levels were quite low in the transgenic plants compared with the wild type. These results indicate that ectopic expression of the RBSDV P7-1 protein in A. thaliana causes male sterility, possibly through the disruption of the lignin biosynthesis and H2O2-dependent polymerization pathways. PMID:24260239

Sun, Feng; Yuan, Xia; Xu, Qiufang; Zhou, Tong; Fan, Yongjian; Zhou, Yijun

2013-01-01

73

Time-resolved photoemission using attosecond streaking  

NASA Astrophysics Data System (ADS)

We theoretically study time-resolved photoemission in atoms as probed by attosecond streaking. We review recent advances in the study of the photoelectric efect in the time domain and show that the experimentally accessible time shifts can be decomposed into distinct contributions that stem from the feld-free photoionization process itself and from probe-field induced corrections. We perform accurate quantum-mechanical as well as classical simulations of attosecond streaking for efective one-electron systems and determine all relevant contributions to the time delay with attosecond precision. In particular, we investigate the properties and limitations of attosecond streaking for the transition from short-ranged potentials (photodetachment) to long-ranged Coulomb potentials (photoionization). As an example for a more complex system, we study time-resolved photoionization for endohedral fullerenes A@C60 and discuss how streaking time shifts are modifed due to the interaction of the C60 cage with the probing infrared streaking field.

Nagele, S.; Pazourek, R.; Wais, M.; Wachter, G.; Burgdörfer, J.

2014-04-01

74

Purification and some properties of reovirus-like particles from leafhoppers and their possible involvement in wallaby ear disease of maize.  

PubMed

Reovirus-like particles, occurring in association with viroplasms, crystalline arrays and tubules, in the cytoplasm of Cicadulina bimaculata capable of inducing wallaby ear disease in maize, were purified from the insects by differential centrifugation, treatment with the nonionic detergent, Nonidet P-40, and sucrose density gradient centrifugation. The purified particles have a double-shelled icosahedral structure about 70 nm in diameter with external projections (A spikes) about 10 nm long located at the 12 vertices. These intact particles (IPs) are morphologically similar to those of Fiji disease virus (FDV), but are more stable. Cores were produced by enzymatic digestion of IPs with alpha-chymotrypsin. The cores are icosahedra about 57 nm in diameter with projections (B spikes) located at the 12 vertices, resembling those of FDV and cytoplasmic polyhedrosis virus. Immunization of a rabbit with purified IPs resulted in the production of antibodies specific to IPs, cores, and dsRNA. Immunoelectron microscopic investigations revealed that there is no relationship between this virus and FDV, maize rough dwarf, oat sterile dwarf, pangola stunt, and rice ragged stunt viruses, all members of the genus Fijivirus in the family Reoviridae. The nucleic acid extracted from partially purified virus was resolved into 10 segments by polyacrylamide gel electrophoresis. Reovirus-like particles or viroplasms could not be detected in thin sections of maize seedlings colonized by C. bimaculata showing wallaby ear symptoms. In the light of these data the possible etiology of wallaby ear disease is discussed. PMID:18631635

Boccardo, G; Hatta, T; Francki, R I; Grivell, C J

1980-01-30

75

Electro-optic Phase Grating Streak Spectrometer  

SciTech Connect

The electro-optic phase grating streak spectrometer (EOPGSS) generates a time-resolved spectra equivalent to that obtained with a conventional spectrometer/streak camera combination, but without using a streak camera (by far the more expensive and problematic component of the conventional system). The EOPGSS is based on a phase, rather than an amplitude grating. Further, this grating is fabricated of electro-optic material such as, for example, KD*P, by either etching grooves into an E-O slab, or by depositing lines of the E-O material onto an optical flat. An electric field normal to the grating alters the material’s index of refraction and thus affects a shift (in angle) of the output spectrum. Ramping the voltage streaks the spectrum correspondingly. The streak and dispersion directions are the same, so a second (static, conventional) grating disperses the spectrum in the orthogonal direction to prevent different wavelengths from “overwriting” each other. Because the streaking is done by the grating, the streaked output spectrum is recorded with a time-integrating device, such as a CCD. System model, typical design, and performance expectations will be presented.

Goldin, F. J.

2012-08-02

76

Photorealistic Rendering of Rain Streaks Kshitiz Garg Shree K. Nayar  

E-print Network

Photorealistic Rendering of Rain Streaks Kshitiz Garg Shree K. Nayar Columbia University qview 30 10 RealImages ofRainStreaks Rendered RainStreaks o o o o o o o o o o o o o o o o o o o o o o o o o o oo o o Figure 1: Appearance of actual rain streaks and rendered rain streaks. The top row shows

Nayar, Shree K.

77

Wheat Curl Mite and Wheat Streak Mosaic Virus Spread from Volunteer Wheat Figure 2. Spectral profiles at three points identified in Figure  

E-print Network

Wheat Curl Mite and Wheat Streak Mosaic Virus Spread from Volunteer Wheat Figure 2. Spectral Management Information Technologies (CALMIT) (apeters@calmit.unl.edu) Background: Wheat streak mosaic (WSM) is the most severe disease of winter wheat in the Great Plains. Estimates indicate WSM causes an average loss

Nebraska-Lincoln, University of

78

The Primitive Streak, Cross Section  

NSDL National Science Digital Library

This FlashTM animation is the third of a seven part series that presents the primitive streak from different angles. This installment displays the cross section, which is conducive to observing invagination. Epiblast cells ingress through the middle of the germ disc, to differentiate into either endoderm or mesenchymal mesoderm. The endoderm proliferates to drive the hypoblast into the extraembryonic endoderm of the yolk sac. The mesenchyme spreads between the epiblast and endoderm. Although not drawn to scale, the progressive thickening from lateral to paraxial mesoderm is depicted. To open the animation using Internet Explorer follow these steps. (1.) Click the link for the animation. (2.) A dialog box may pop up that begins with the statement "Windows cannot open this file:" If this box does not appear proceed to step four. If it does choose "Select the program from a list," then click OK. (3.) Another dialog box will pop up that lists different programs. Make sure "Internet Explorer" is selected, then click OK. (4.) Internet Explorer will pop up. Beneath the toolbars at the top of the window a yellow bar will appear that reads "To help protect your security, Internet Explorer has restricted this webpage from running scripts or Active X controls that could access your computer. Click here for options..." Pass the cursor over this yellow bar and click the right mouse button. (5.) A dialog box will pop up. Left click the option "Allow Blocked Content." (6.) Another dialog box will appear labeled "Security Warning" asking you to confirm that you want to run the content. Click "Yes." (7.) The Flash animation will appear in the Internet Explorer Window. (8.) Instructions for navigating the lesson are provided by the first frame of the animation.

PhD Jack D Thatcher (West Virginia School of Osteopathic Medicine Structural Biology)

2011-06-23

79

Mapping QTL Contributing to SCMV Resistance in Tropical Maize  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sugarcane mosaic virus (SCMV) has been increasing in importance as a maize disease in Brazil. In this study, were mapped and characterized quantitative trait loci (QTL) associated to resistance to SCMV in a maize population consisting of 150 F2:3 families from the cross between two tropical maize i...

80

Southern leaf blight disease severity is correlated with decreased maize leaf epiphytic bacterial species richness and the phyllosphere bacterial diversity decline is enhanced by nitrogen fertilization  

PubMed Central

Plant leaves are inhabited by a diverse group of microorganisms that are important contributors to optimal growth. Biotic and abiotic effects on plant growth are usually studied in controlled settings examining response to variation in single factors and in field settings with large numbers of variables. Multi-factor experiments with combinations of stresses bridge this gap, increasing our understanding of the genotype-environment-phenotype functional map for the host plant and the affiliated epiphytic community. The maize inbred B73 was exposed to single and combination abiotic and the biotic stress treatments: low nitrogen fertilizer and high levels of infection with southern leaf blight (causal agent Cochliobolus heterostrophus). Microbial epiphyte samples were collected at the vegetative early-season phase and species composition was determined using 16S ribosomal intergenic spacer analysis. Plant traits and level of southern leaf blight disease were measured late-season. Bacterial diversity was different among stress treatment groups (P < 0.001). Lower species richness—alpha diversity—was correlated with increased severity of southern leaf blight disease when disease pressure was high. Nitrogen fertilization intensified the decline in bacterial alpha diversity. While no single bacterial ribotype was consistently associated with disease severity, small sets of ribotypes were good predictors of disease levels. Difference in leaf bacterial-epiphyte diversity early in the season were correlated with plant disease severity, supporting further tests of microbial epiphyte-disease correlations for use in predicting disease progression. PMID:25177328

Manching, Heather C.; Balint-Kurti, Peter J.; Stapleton, Ann E.

2014-01-01

81

Large photocathode area picosecond streak tube  

NASA Astrophysics Data System (ADS)

The paper reports on the development of a new streak image tube with accelerating mesh and large (18 mm) photocathode work area. The tube's temporal resolution is close to one picosecond. To govern photoelectronic images the tube possesses shutter and deflector plates. Its geometric design allows uniform spatial resolution (more than 25 lp/mm) along the entire photocathode work area at 1.3 electron-optical magnification and negligibly small distortion. Being a continuation of the well-known PV and PIF - type streak image tubes developed in due time in GPI, the tube represents a promising tool for taking pictures of ultrafast processes in wide radiation spectrum range.

Andreev, S. V.; Belolipetski, V. S.; Ivanova, S. R.; Kulechenkova, T. P.; Levina, G. P.; Makushina, V. A.; Monastyrskiy, M. A.; Polykarkina, N. D.; Schelev, M. Ya.; Semichastnova, Z. M.; Sokolov, V. E.

2008-11-01

82

Reinventing MaizeGDB  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Maize Database (MaizeDB) to the Maize Genetics and Genomics Database (MaizeGDB) turns 20 this year, and such a significant milestone must be celebrated! With the release of the B73 reference sequence and more sequenced genomes on the way, the maize community needs to address various opportunitie...

83

Chromatin Structure of Wheat Breeding Lines Resistant to Wheat Streak Mosaic Virus.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Wheat Streak Mosaic Virus (WSMV) is an important disease limiting wheat production, however no WSMV resistance effective above 18°C is present within the primary genetic pool of wheat (Triticum aestivum L.). In contrast, the wild relative Thinopyrum intermedium (2n=6x=42) shows good resistance to WS...

84

The first satellite laser echoes recorded on the streak camera  

NASA Technical Reports Server (NTRS)

The application of the streak camera with the circular sweep for the satellite laser ranging is described. The Modular Streak Camera system employing the circular sweep option was integrated into the conventional Satellite Laser System. The experimental satellite tracking and ranging has been performed. The first satellite laser echo streak camera records are presented.

Hamal, Karel; Prochazka, Ivan; Kirchner, Georg; Koidl, F.

1993-01-01

85

Pantoea stewartii subsp. stewartii exhibits surface motility, which is a critical aspect of Stewart's wilt disease development on maize.  

PubMed

Pantoea stewartii subsp. stewartii is a plant-pathogenic bacterium that causes Stewart's vascular wilt in maize. The organism is taxonomically described as aflagellated and nonmotile. We recently showed that P. stewartii colonizes the xylem of maize as sessile, cell-wall-adherent biofilms. Biofilm formation is a developmental process that generally involves some form of surface motility. For that reason, we reexamined the motility properties of P. stewartii DC283 based on the assumption that the organism requires some form of surface motility for biofilm development. Here, we show that the organism is highly motile on agar surfaces. This motility is flagella dependent, shown by the fact that a fliC mutant, impaired in flagellin subunit synthesis, is nonmotile. Motility also requires the production of stewartan exopolysaccharide. Moreover, surface motility plays a significant role in the colonization of the plant host. PMID:18785831

Herrera, Carmen M; Koutsoudis, Maria D; Wang, Xiaolei; von Bodman, Susanne B

2008-10-01

86

Wind Streaks on Venus: Clues to Atmospheric Circulation  

NASA Technical Reports Server (NTRS)

Magellan images reveal surface features on Venus attributed to wind processes. Sand dunes, wind-sculpted hills, and more than 5830 wind streaks have been identified. The streaks serve as local "wind vanes," representing wind direction at the time of streak formation and allowing the first global mapping of near-surface wind patterns on Venus. Wind streaks are oriented both toward the equator and toward the west. When streaks associated with local transient events, such as impact cratering, are deleted, the westward component is mostly lost but the equatorward component remains. This pattern is consistent with a Hadley circulation of the lower atmosphere.

Greeley, Ronald; Schubert, Gerald; Limonadi, Daniel; Bender, Kelly C.; Newman, William I.; Thomas, Peggy E.; Weitz, Catherine M.; Wall, Stephen D.

1994-01-01

87

Plant growth hormones suppress the development of Harpophora maydis, the cause of late wilt in maize  

Microsoft Academic Search

Late wilt, a severe vascular disease of maize caused by the fungus Harpophora maydis, is characterized by rapid wilting of maize plants before tasseling and until shortly before maturity. The pathogen is currently controlled by resistant maize cultivars, but the disease is constantly spreading to new areas. The plant’s late phenological stage at which the disease appears suggests that plant

Ofir Degani; Ran Drori; Yuval Goldblat

2015-01-01

88

Analysis of quantitative disease resistance to southern leaf blight and of multiple disease resistance in maize, using near-isogenic lines  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize inbred lines NC292 and NC330 were derived by repeated backcrossing of an elite source of southern leaf blight (SLB) resistance (NC250P) to the SLB-susceptible line B73, with selection for SLB resistance among and within backcross families at each generation. Consequently, while B73 is very SLB...

89

Structure-based computational study of two disease resistance gene homologues (Hm1 and Hm2) in maize (Zea mays L.) with implications in plant-pathogen interactions.  

PubMed

The NADPH-dependent HC-toxin reductases (HCTR1 and 2) encoded by enzymatic class of disease resistance homologous genes (Hm1 and Hm2) protect maize by detoxifying a cyclic tetrapeptide, HC-toxin, secreted by the fungus Cochliobolus carbonum race 1(CCR1). Unlike the other classes' resistance (R) genes, HCTR-mediated disease resistance is an inimitable mechanism where the avirulence (Avr) component from CCR1 is not involved in toxin degradation. In this study, we attempted to decipher cofactor (NADPH) recognition and mode of HC-toxin binding to HCTRs through molecular docking, molecular dynamics (MD) simulations and binding free energy calculation methods. The rationality and the stability of docked complexes were validated by 30-ns MD simulation. The binding free energy decomposition of enzyme-cofactor complex was calculated to find the driving force behind cofactor recognition. The overall binding free energies of HCTR1-NADPH and HCTR2-NADPH were found to be -616.989 and -16.9749 kJ mol-1 respectively. The binding free energy decomposition revealed that the binding of NADPH to the HCTR1 is mainly governed by van der Waals and nonpolar interactions, whereas electrostatic terms play dominant role in stabilizing the binding mode between HCTR2 and NADPH. Further, docking analysis of HC-toxin with HCTR-NADPH complexes showed a distinct mode of binding and the complexes were stabilized by a strong network of hydrogen bond and hydrophobic interactions. This study is the first in silico attempt to unravel the biophysical and biochemical basis of cofactor recognition in enzymatic class of R genes in cereal crop maize. PMID:24847713

Dehury, Budheswar; Patra, Mahesh Chandra; Maharana, Jitendra; Sahu, Jagajjit; Sen, Priyabrata; Modi, Mahendra Kumar; Choudhury, Manabendra Dutta; Barooah, Madhumita

2014-01-01

90

Photonic streaking of attosecond pulse trains  

NASA Astrophysics Data System (ADS)

High harmonic radiation, produced when intense laser pulses interact with matter, is composed of a train of attosecond pulses. Individual pulses in this train carry information on ultrafast dynamics that vary from one half-optical-cycle to the next. Here, we demonstrate an all-optical photonic streaking measurement that provides direct experimental access to each attosecond pulse by mapping emission time onto propagation angle. This is achieved by inducing an ultrafast rotation of the instantaneous laser wavefront at the focus. We thus time-resolve attosecond pulse train generation, and hence the dynamics in the nonlinear medium itself. We apply photonic streaking to harmonic generation in gases and directly observe, for the first time, the influence of non-adiabatic electron dynamics and plasma formation on the generated attosecond pulse train. These experimental and numerical results also provide the first evidence of the generation of attosecond lighthouses in gases, which constitute ideal sources for attosecond pump-probe spectroscopy.

Kim, Kyung Taec; Zhang, Chunmei; Ruchon, Thierry; Hergott, Jean-François; Auguste, Thierry; Villeneuve, D. M.; Corkum, P. B.; Quéré, F.

2013-08-01

91

Understanding baseball team standings and streaks  

Microsoft Academic Search

Can one understand the statistics of wins and losses of baseball teams? Are their consecutive-game winning and losing streaks\\u000a self-reinforcing or can they be described statistically? We apply the Bradley-Terry model, which incorporates the heterogeneity\\u000a of team strengths in a minimalist way, to answer these questions. Excellent agreement is found between the predictions of\\u000a the Bradley-Terry model and the rank

C. Sire; S. Redner

2009-01-01

92

The New Streak Image Tube PIF-01  

NASA Astrophysics Data System (ADS)

A new, small-size image-converter tube type PIF-01 has been developed for recording of various high speed phenomena with subpicosecond time resolution. The designing goal of the new image-converter tube having four electrodes geometry (photocathode, acceleration mesh, focusing electrode, anode diaphragm) and incorporating with a modern deflection system, was to simultaneously improve temporal resolution and dynamic range.Preliminary experimental results confirm the efficiency of the software developed for picofemtosecond streak tube computation and optimization.

Degtyareva, V. P.; Kulikov, Yu V.; Monastyrski, M. A.; Platonov, V. N.; Postovalov, V. E.; Prokhorov, A. M.; Ulasyuk, V. N.; Ushakov, V. K.; Schelev, M. Y.

1985-02-01

93

Vascular Streak Dieback of cacao in Southeast Asia and Melanesia: in planta detection of the pathogen and a new taxonomy  

Microsoft Academic Search

Vascular Streak Dieback (VSD) disease of cacao (Theobroma cacao) in Southeast Asia and Melanesia is caused by a basidiomycete (Ceratobasidiales) fungus Oncobasidium theobromae (syn. =Thanatephorus theobromae). The most characteristic symptoms of the disease are green-spotted leaf chlorosis or, commonly since about 2004, necrotic blotches, followed by senescence of leaves beginning on the second or third flush behind the shoot apex,

Gary J. Samuels; Adnan Ismaiel; Ade Rosmana; Muhammad Junaid; David Guest; Peter Mcmahon; Philip Keane; Agus Purwantara; Smilja Lambert; Marianela Rodriguez-Carres; Marc A. Cubeta

94

Fumonisin Disruption of Ceramide Biosynthesis in Maize Roots and the Effects on Plant Development and Fusarium verticillioides-Induced Seedling Disease  

Technology Transfer Automated Retrieval System (TEKTRAN)

The fungus Fusarium verticillioides infects maize (Zea mays) and produces fumonisins, inhibitors of acyl coenzyme A dependent ceramide synthase. To determine the role of fumonisins on maize root development, seeds were inoculated with pathogenic or non- pathogenic strains of F. verticillioides. Ro...

95

Design of microcontroller based system for automation of streak camera  

Microsoft Academic Search

A microcontroller based system has been developed for automation of the S-20 optical streak camera, which is used as a diagnostic tool to measure ultrafast light phenomenon. An 8 bit MCS family microcontroller is employed to generate all control signals for the streak camera. All biasing voltages required for various electrodes of the tubes are generated using dc-to-dc converters. A

M. J. Joshi; J. Upadhyay; P. P. Deshpande; M. L. Sharma; C. P. Navathe

2010-01-01

96

A compensating wheat-Thinopyrum intermedium Robertsonian translocation conferring resistance to wheat streak mosaic virus and Triticum mosaic virus  

Technology Transfer Automated Retrieval System (TEKTRAN)

Wheat streak mosaic virus (WSMV), is a potentially devastating disease of common wheat in the Great Plains of North America. So far, two genes conferring resistance to WSMV have been named and used in cultivar improvement. Here we report a new source of resistance that was derived from a wheat-Th. i...

97

Maize aluminum tolerance  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize is one of the most economically important food crops grown on acid soils, where aluminum (Al) toxicity greatly limits crop yields. Considerable variation for Al tolerance exists in maize, and this variation has been exploited for many years by plant breeders to enhance maize Al tolerance. Curr...

98

MaizeCyc: Metabolic networks in maize  

Technology Transfer Automated Retrieval System (TEKTRAN)

MaizeCyc is a catalog of known and predicted metabolic and transport pathways that enables plant researchers to graphically represent the metabolome of maize (Zea mays), thereby supporting integrated systems-biology analysis. Supported analyses include molecular and genetic/phenotypic profiling (e.g...

99

Responses of Maize (Zea mays L.) near isogenic lines carrying Wsm1, Wsm2 and Wsm3 to three viruses in the Potyviridae  

Technology Transfer Automated Retrieval System (TEKTRAN)

Three independent genes controlling resistance to Wheat streak mosaic virus (WSMV; family Potyviridae; genus Tritimovirus) were previously identified on chromosomes six (Wsm1), three (Wsm2) and ten (Wsm3) in the resistant maize (Zea mays L.) inbred line Pa405. Near isogenic lines (NIL) carrying eac...

100

Breeding for Improved Resistance to Fumonisin Contamination in Maize  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize grain infected by Fusarium verticillioides may contain the mycotoxin fumonisin, which is associated with livestock and human diseases. To reduce levels of fumonisin in grain, efforts are underway to identify sources of maize with increased resistance to fungal infection and fumonisin contamin...

101

High performance imaging streak camera for the National Ignition Facility.  

PubMed

An x-ray streak camera platform has been characterized and implemented for use at the National Ignition Facility. The camera has been modified to meet the experiment requirements of the National Ignition Campaign and to perform reliably in conditions that produce high electromagnetic interference. A train of temporal ultra-violet timing markers has been added to the diagnostic in order to calibrate the temporal axis of the instrument and the detector efficiency of the streak camera was improved by using a CsI photocathode. The performance of the streak camera has been characterized and is summarized in this paper. The detector efficiency and cathode measurements are also presented. PMID:23278024

Opachich, Y P; Kalantar, D H; MacPhee, A G; Holder, J P; Kimbrough, J R; Bell, P M; Bradley, D K; Hatch, B; Brienza-Larsen, G; Brown, C; Brown, C G; Browning, D; Charest, M; Dewald, E L; Griffin, M; Guidry, B; Haugh, M J; Hicks, D G; Homoelle, D; Lee, J J; Mackinnon, A J; Mead, A; Palmer, N; Perfect, B H; Ross, J S; Silbernagel, C; Landen, O

2012-12-01

102

Multivariate analysis of maize disease resistances suggests a pleiotropic genetic basis and implicates a glutathione S-transferase gene  

Technology Transfer Automated Retrieval System (TEKTRAN)

Plants are attacked by pathogens representing diverse taxonomic groups, such that genes providing multiple disease resistance (MDR) would likely be under positive selection pressure. We examined the novel proposition that naturally occurring allelic variants may confer MDR. To do so, we applied a ...

103

Streak image denoising and segmentation using adaptive Gaussian guided filter.  

PubMed

In streak tube imaging lidar (STIL), streak images are obtained using a CCD camera. However, noise in the captured streak images can greatly affect the quality of reconstructed 3D contrast and range images. The greatest challenge for streak image denoising is reducing the noise while preserving details. In this paper, we propose an adaptive Gaussian guided filter (AGGF) for noise removal and detail enhancement of streak images. The proposed algorithm is based on a guided filter (GF) and part of an adaptive bilateral filter (ABF). In the AGGF, the details are enhanced by optimizing the offset parameter. AGGF-denoised streak images are significantly sharper than those denoised by the GF. Moreover, the AGGF is a fast linear time algorithm achieved by recursively implementing a Gaussian filter kernel. Experimentally, AGGF demonstrates its capacity to preserve edges and thin structures and outperforms the existing bilateral filter and domain transform filter in terms of both visual quality and peak signal-to-noise ratio performance. PMID:25321679

Jiang, Zhuocheng; Guo, Baoping

2014-09-10

104

Vascular Streak Dieback of cacao in Southeast Asia detection and Melanesia: in planta detection of the pathogen and a new taxonomy  

Technology Transfer Automated Retrieval System (TEKTRAN)

Vascular Streak Dieback (VSD) disease of cacao (Theobroma cacao) in Southeast Asia and Melanesia is caused by a basidiomycete (Ceratobasidiales) fungus described in a monotypic genus as Oncobasidium theobromae (syn. =Thanatephorus theobromae). The symptoms of the disease include green-spotted chloro...

105

Semiclassical model for attosecond angular streaking.  

PubMed

Attosecond angular streaking is a new technique to achieve unsurpassed time accuracy of only a few attoseconds. Recently this has been successfully used to set an upper limit on the electron tunneling delay time in strong laser field ionization. The measurement technique can be modeled with either the time-dependent Schrödinger equation (TDSE) or a more simple semiclassical approach that describes the process in two steps in analogy to the three-step model in high harmonic generation (HHG): step one is the tunnel ionization and step two is the classical motion in the strong laser field. Here we describe in detail a semiclassical model which is based on the ADK theory for the tunneling step, with subsequent classical propagation of the electron in the laser field. We take into account different ellipticities of the laser field and a possible wavelength-dependent ellipticity that is typically observed for pulses in the two-optical-cycle regime. This semiclassical model shows excellent agreement with the experimental result. PMID:20721150

Smolarski, M; Eckle, P; Keller, U; Dörner, R

2010-08-16

106

Dynamics of low-speed streak evolution and interaction in laminar boundary layer  

NASA Astrophysics Data System (ADS)

The present paper presents an experimental effort on the regeneration process of two low-speed laminar streaks in a zero-pressure-gradient laminar boundary layer. Two vertical thin wires separated by a spanwise distance of 30mm are used to introduce disturbances of two rolls of transitional Kármán vortex street to the downstream boundary layer. Both hydrogen bubble visualization and particle image velocimetry (PIV) measurement show that two low-speed streaks are induced through leading-edge receptivity process. As these streaks develop in the downstream, two additional low-speed streaks begin to appear outboard of the flank of the original two, together with complex dynamics of streak splitting and merging. A flow pattern of four streaks aligned along the spanwise direction occurs finally in the far downstream. It is found that besides the mechanisms of streak breakdown, the streak interaction is also an important factor characterizing the instability of low speed streaks and their regeneration process.

Deng, Si-Chao; Pan, Chong; Wang, Jin-Jun

2014-10-01

107

MaizeGDB, the maize model organism database  

Technology Transfer Automated Retrieval System (TEKTRAN)

MaizeGDB is the maize research community's database for maize genetic and genomic information. In this seminar I will outline our current endeavors including a full website redesign, the status of maize genome assembly and annotation projects, and work toward genome functional annotation. Mechanis...

108

Promoters for pregenomic RNA of banana streak badnavirus are active for transgene expression in monocot and dicot plants.  

PubMed

Two putative promoters from Australian banana streak badnavirus (BSV) isolates were analysed for activity in different plant species. In transient expression systems the My (2105 bp) and Cv (1322 bp) fragments were both shown to have promoter activity in a wide range of plant species including monocots (maize, barley, banana, millet, wheat, sorghum), dicots (tobacco, canola, sunflower, Nicotiana benthamiana, tipu tree), gymnosperm (Pinus radiata) and fern (Nephrolepis cordifolia). Evaluation of the My and Cv promoters in transgenic sugarcane, banana and tobacco plants demonstrated that these promoters could drive high-level expression of either the green fluorescent protein (GFP) or the beta-glucuronidase (GUS) reporter gene (uidA) in vegetative plant cells. In transgenic sugarcane plants harbouring the Cv promoter, GFP expression levels were comparable or higher (up to 1.06% of total soluble leaf protein as GFP) than those of plants containing the maize ubiquitin promoter (up to 0.34% of total soluble leaf protein). GUS activities in transgenic in vitro-grown banana plants containing the My promoter were up to seven-fold stronger in leaf tissue and up to four-fold stronger in root and corm tissue than in plants harbouring the maize ubiquitin promoter. The Cv promoter showed activities that were similar to the maize ubiquitin promoter in in vitro-grown banana plants, but was significantly reduced in larger glasshouse-grown plants. In transgenic in vitro-grown tobacco plants, the My promoter reached activities close to those of the 35S promoter of cauliflower mosaic virus (CaMV), while the Cv promoter was about half as active as the CaMV 35S promoter. The BSV promoters for pregenomic RNA represent useful tools for the high-level expression of foreign genes in transgenic monocots. PMID:11587511

Schenk, P M; Remans, T; Sági, L; Elliott, A R; Dietzgen, R G; Swennen, R; Ebert, P R; Grof, C P; Manners, J M

2001-10-01

109

Widespread occurrence and diversity of Cassava brown streak virus (Potyviridae: Ipomovirus) in Tanzania.  

PubMed

Cassava brown streak disease (CBSD) has been a problem in Tanzania since 1936. Existing literature indicated limited distribution of the disease to low altitudes, usually <100 m above sea level, but the current geographical distribution of the disease was not known. Whether a single or many strains for the virus exist in Tanzania had not been reported to date. In this study, CBSD was recorded from sea level to ?1,800 m above sea level. In total, 2,730 cassava plants were assessed for CBSD leaf symptoms in 91 fields and root symptoms were assessed at 81 sites. A sample was taken from each site for laboratory screening for Cassava brown streak virus (CBSV). CBSD mean foliar and root incidences were 38 and 36%, respectively. Reverse-transcription polymerase chain reaction of a partial 3'-terminal coat protein (CP) region of CBSV indicated the presence of CBSV in 67 of the 91 (73%) samples. Forty-three amplicons were sequenced, and phylogenetic comparisons with nucleotide sequences from GenBank (National Center for Biotechnology Information database) suggested that one major clade of CBSV primarily exists in Tanzania. However, there was nucleotide sequence divergence of up to 19% among the 42 isolates. In all, 42 of the 43 sequences had 80 to 100% nucleotide identity with 6 previously reported CP-CBSV sequences (from Mozambique and Tanzania). In total, 13 of 42 isolates had <80% nucleotide identities with three previously reported Ugandan CBSV sequences. One isolate, FJ687177, shared <78% sequence identity with the other Tanzanian sequences but was closely related (93%) to Ugandan isolates. It is likely that isolate FJ687177 may belong to a less widely distributed recently described species (clade 2) of CBSV, named Ugandan cassava brown streak virus (UCBSV). PMID:21916624

Rwegasira, G M; Momanyi, G; Rey, M E C; Kahwa, G; Legg, J P

2011-10-01

110

IBM MAIZE COMMUNITY RESOURCES  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Maize Mapping Project is funded to develop a physical map of maize that will be anchored to the genetic map by molecular and trait markers, to develop data management resources allowing for analysis and curation, and to provide accessibility to the public of all of the resources developed throug...

111

Maize Genetic Resources  

Technology Transfer Automated Retrieval System (TEKTRAN)

This chapter describes the resources held at the Maize Genetics Cooperation • Stock Center in detail and also provides some information about the North Central Regional Plant Introduction Station (NCRPIS) in Ames, IA, Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT) in Mexico, and the N...

112

Hitting Is Contagious in Baseball: Evidence from Long Hitting Streaks  

PubMed Central

Data analysis is used to test the hypothesis that “hitting is contagious”. A statistical model is described to study the effect of a hot hitter upon his teammates’ batting during a consecutive game hitting streak. Box score data for entire seasons comprising streaks of length games, including a total observations were compiled. Treatment and control sample groups () were constructed from core lineups of players on the streaking batter’s team. The percentile method bootstrap was used to calculate confidence intervals for statistics representing differences in the mean distributions of two batting statistics between groups. Batters in the treatment group (hot streak active) showed statistically significant improvements in hitting performance, as compared against the control. Mean for the treatment group was found to be to percentage points higher during hot streaks (mean difference increased points), while the batting heat index introduced here was observed to increase by points. For each performance statistic, the null hypothesis was rejected at the significance level. We conclude that the evidence suggests the potential existence of a “statistical contagion effect”. Psychological mechanisms essential to the empirical results are suggested, as several studies from the scientific literature lend credence to contagious phenomena in sports. Causal inference from these results is difficult, but we suggest and discuss several latent variables that may contribute to the observed results, and offer possible directions for future research. PMID:23251507

Bock, Joel R.; Maewal, Akhilesh; Gough, David A.

2012-01-01

113

Time delays for attosecond streaking in photoionization of neon  

NASA Astrophysics Data System (ADS)

We revisit the time-resolved photoemission in neon atoms as probed by attosecond streaking. We calculate streaking time shifts for the emission of 2p and 2s electrons and compare the relative delay as measured in a recent experiment by Schultze et al. [Science 328, 1658 (2010), 10.1126/science.1189401]. The B-spline R-matrix method is employed to calculate accurate Eisenbud-Wigner-Smith time delays from multielectron dipole transition matrix elements for photoionization. The additional laser field-induced time shifts in the exit channel are obtained from separate, time-dependent simulations of a full streaking process by solving the time-dependent Schrödinger equation on the single-active-electron level. The resulting accurate total relative streaking time shifts between 2s and 2p emission lie well below the experimental data. We identify the presence of unresolved shake-up satellites in the experiment as a potential source of error in the determination of streaking time shifts.

Feist, Johannes; Zatsarinny, Oleg; Nagele, Stefan; Pazourek, Renate; Burgdörfer, Joachim; Guan, Xiaoxu; Bartschat, Klaus; Schneider, Barry I.

2014-03-01

114

Response of maize (Zea mays L.) lines carrying Wsm1, Wsm2 and Wsm3 to the potyviruses Johnsongrass mosaic virus and Sorghum mosaic virus  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize dwarf mosaic disease is one of the most important viral diseases of maize throughout the world. It is caused by a set of related viruses in the family Potyviridae, genus Potyvirus, including Maize dwarf mosaic virus (MDMV), Sugarcane mosaic virus (SCMV), Johnsongrass mosaic virus (JGMV), and S...

115

A time-resolved image sensor for tubeless streak cameras  

NASA Astrophysics Data System (ADS)

This paper presents a time-resolved CMOS image sensor with draining-only modulation (DOM) pixels for tube-less streak cameras. Although the conventional streak camera has high time resolution, the device requires high voltage and bulky system due to the structure with a vacuum tube. The proposed time-resolved imager with a simple optics realize a streak camera without any vacuum tubes. The proposed image sensor has DOM pixels, a delay-based pulse generator, and a readout circuitry. The delay-based pulse generator in combination with an in-pixel logic allows us to create and to provide a short gating clock to the pixel array. A prototype time-resolved CMOS image sensor with the proposed pixel is designed and implemented using 0.11um CMOS image sensor technology. The image array has 30(Vertical) x 128(Memory length) pixels with the pixel pitch of 22.4um. .

Yasutomi, Keita; Han, SangMan; Seo, Min-Woong; Takasawa, Taishi; Kagawa, Keiichiro; Kawahito, Shoji

2014-03-01

116

Experimental observations of rapid Maize streak virus evolution reveal a strand-specific nucleotide substitution bias  

Microsoft Academic Search

BACKGROUND: Recent reports have indicated that single-stranded DNA (ssDNA) viruses in the taxonomic families Geminiviridae, Parvoviridae and Anellovirus may be evolving at rates of ~10-4 substitutions per site per year (subs\\/site\\/year). These evolution rates are similar to those of RNA viruses and are surprisingly high given that ssDNA virus replication involves host DNA polymerases with fidelities approximately 10 000 times

Eric van der Walt; Darren P Martin; Arvind Varsani; Jane E Polston; Edward P Rybicki

2008-01-01

117

A Geminivirus, Serologically Related to Maize Streak Virus, from Digitaria sanguinalis from Vanuatu  

Microsoft Academic Search

SUMMARY Electron microscopy of purified particles of a virus found in Dig#aria sanguinalis from Vanuatu (formerly New Hebrides) indicated that it is a geminivirus. Preparations of virus particles contained one coat protein of tool. wt. about 27 500 and circular and linear single-stranded DNA about 2350 nucleotides in length. In thin sections of infected cells, geminate particles were found in

MICHEL DOLLET; GIAN PAOLO ACCOTTO; VITTORIA LISA; JOSIANE MENISSIER; GUIDO BOCCARDO

1986-01-01

118

Transformation of Digitaria sanguinalis: A model system for testing maize streak virus resistance in Poaceae  

Microsoft Academic Search

Digitaria sanguinalis, an African grass, was micropropagated from immature inflorescences and callus was transformed by particle\\u000a gun bombardment. Integration and expression of the bar and uidA genes was shown in the T0 generation. Transformants were shown to be fertile by the production of viable seeds. The time taken from bombardment to\\u000a the setting of seed was approximately four months. D.

Wusi Chen; Sandra J. Lennox; Kenneth E. Palmer; Jennifer A. Thomson

1998-01-01

119

Wheat streak mosaic virus-Structural parameters for a Potyvirus  

SciTech Connect

Wheat streak mosaic virus is a Tritimovirus, a member of the Potyviridae family, which includes the very large Potyvirus genus. We have examined wheat streak mosaic virus by electron microscopy and fiber diffraction from partially oriented sols, and analyzed the results to estimate the symmetry and structural parameters of the viral helix. The virions have an apparent radius of 63 {+-} 5 A. The viral helix has a pitch of 33.4 A {+-} 0.6 A. There appear to be 6.9 subunits per turn of the helix, although we cannot completely eliminate values of 5.9 or 7.9 for this parameter.

Parker, Lauren [Center for Structural Biology, Vanderbilt University, Nashville, TN 37232 (United States); Kendall, Amy [Center for Structural Biology, Vanderbilt University, Nashville, TN 37232 (United States); Berger, P.H. [Department of Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339 (United States); Shiel, P.J. [Department of Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339 (United States); Stubbs, Gerald [Center for Structural Biology, Vanderbilt University, Nashville, TN 37232 (United States)]. E-mail: gerald.stubbs@vanderbilt.edu

2005-09-15

120

Comparative characteristics of various phosphor screens in streak tubes  

NASA Astrophysics Data System (ADS)

Effectiveness decrease of the phosphor screens of the P11 and P20 types for streak tubes in the picosecond region is shown. It is shown that the complete amplification of the circuit 'streak tube + image intensifier + CCD' in the picosecond region is the same as one of the circuit 'streak tube + etched CCD instead of the screen in a whole volume,' though the static amplification in the first case is by two orders higher. A special streak tube of the PV series has been manufactured. The screen of this tube consists of 4 various phosphor screens prepared on the same fiber-optical disk in the form of closely placed strips of 5 mm width: K-71 (blue), K-78 (green), 'cadmium' (green), IL-3P (red). A streak tube with the phosphor screen KL3-2 (green) has also been investigated. Principal scheme of the experiment is shown in Figure 1. In these experiments, the voltage between the tube's photocathode and screen was of 14 KeV, photocathode current density approximately 100 (mu) A/mm2, and duration of the pulse initiating the photocathode -- of 10-7 s. The shape of the phosphor screen irradiation response is presented in Figure 2 as an oscillogram. For each phosphor screen type the oscillogram is normalized to unit. In Table 1, the time intervals are presented during which the phosphor screen is lighting up being excited by current pulses of 10-7 s. With the use of the phosphor screen decaying curves it is possible to determine the duration of time during which the image amplifier (usually with MCP) should remain open being placed in the electron-optical camera between the streak tube and readout system. The time interval, during which about 70% of the lightsum for phosphor screens of three types are lighting up, is presented in Table 2. Taking into account that high noise level is inherent to the image intensifiers with MCP, it is advisable to use in streak tubes the phosphor screens with minor lighting-up time duration, and to turn on the MCP for a minimal required time. In the Russian streak camera 'Agat' this time is equal to (6 - 8) (DOT) 10-4 s, which significantly exceeds the required time.

Ageeva, N. I.; Brykhnevich, G. I.; Gorbenko, B. Z.; Ivanova, S. P.; Kulichenkova, T. P.; Semichastnova, Zoya M.; Skiballanovich, T. A.; Schelev, Mikhail Y.

1999-06-01

121

Mars - Wind streak production as related to obstacle type and size  

NASA Technical Reports Server (NTRS)

The characteristics of wind streaks associated with Martian craters and hills in the size range of 100 m to 80 km (corresponding to obstacle heights of a few to several hundred meters) have been analyzed from Viking Orbiter images. Both dark erosional and bright depositional streaks form over the entire obstacle size range, but there are preferred obstacle sizes for producing streaks. Bright streaks form more readily in association with relatively smaller obstacles than do dark streaks. Small obstacles produce both types of streaks more effectively than do large ones. Hills produce streaks as effectively as do craters of comparable height. Alternative explanations of bright streak formation are evaluated in terms of their ability to account for these observations. The most satisfactory models invoke blocking of atmospheric flow downwind of an obstacle and consequent deposition of dust within the sheltered zone.

Lee, S. W.

1984-01-01

122

Localization of cells of the prospective neural plate, heart and somites within the primitive streak and epiblast of avian embryos at intermediate primitive-streak stages.  

PubMed

By constructing avian transplantation chimeras using fluorescently-labeled grafts and antibodies specific for grafted cells, we have generated a prospective fate map of the primitive streak and epiblast of the avian blastoderm at intermediate primitive-streak stages (stages 3a/3b). This high-resolution map confirms our previous study on the origin of the cardiovascular system from the primitive streak at these stages and provides new information on the epiblast origin of the neural plate, heart and somites. In addition, the origin of the rostral endoderm is now documented in more detail. The map shows that the prospective neural plate arises from the epiblast in close association with the rostral end of the primitive streak and lies within an area extending 250 microm rostral to the streak, 250 microm lateral to the streak and 125 microm caudal to the rostral border of the streak. The future floor plate of the neural tube arises within the midline just rostral to the streak, confirming our earlier study, but unlike at the late-primitive streak stages when both Hensen's node and the midline area rostral to Hensen's node contribute to the floor plate, only the area rostral to the primitive streak contributes to the floor plate at intermediate primitive-streak stages. Instead of contributing to the floor plate of the neural tube, the rostral end of the primitive streak at intermediate primitive-streak stages forms the notochord as well as the rostromedial endoderm, which lies beneath the prechordal plate mesoderm and extends caudolaterally on each side toward the cardiogenic areas. The epiblast lateral to the primitive streak and caudal to the neural plate contributes to the heart and it does so in rostrocaudal sequence (i.e., rostral grafts contribute to rostral levels of the straight heart tube, whereas progressively more caudal grafts contribute to progressively more caudal levels of the straight heart tube), and individual epiblast grafts contribute cells to both the myocardium and endocardium. The prospective somites (i.e., paraxial mesoderm) lie within the epiblast just lateral to the prospective heart mesoderm. Comparing this map with that constructed at late primitive-streak stages reveals that by the late primitive-streak stages, prospective heart mesoderm has moved from the epiblast through the primitive streak and into the mesodermal mantle, and that some of the prospective somitic mesoderm has entered the primitive streak and is undergoing ingression. PMID:11490112

Lopez-Sanchez, C; Garcia-Martinez, V; Schoenwolf, G C

2001-01-01

123

DISSECTION OF QUANTITATIVE TRAIT LOCI (QTL) ASSOCIATED WITH GRAY LEAF SPOT RESISTANCE AND MATURITY IN MAIZE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Abstract Gray Leaf Spot (GLS) is recognized as one of the most significant yield-limiting diseases of maize worldwide and has the potential to threaten maize production. Breeding for resistance provides the best preventive measure against the disease. However, associations between GLS and maturity c...

124

Hot streaks and phantom cooling in a turbine rotor passage. I - Separate effects  

NASA Technical Reports Server (NTRS)

Experimental documentation and analytical correlations demonstrating the effects of hot streak accumulation and phantom cooling on turbine rotor airfoil surface temperature. Test results are shown for a range of controlling variables to identify where streak accumulation and phantom cooling are most likely to be strongest. These variables include streak injection location, streak-to-free stream density ratio and coolant-to-free stream density and velocity ratios.

Roback, Richard J.; Dring, Robert P.

1992-01-01

125

Global maize trade and food security: implications from a social network model.  

PubMed

In this study, we developed a social network model of the global trade of maize: one of the most important food, feed, and industrial crops worldwide, and critical to food security. We used this model to analyze patterns of maize trade among nations, and to determine where vulnerabilities in food security might arise if maize availability was decreased due to factors such as diversion to nonfood uses, climatic factors, or plant diseases. Using data on imports and exports from the U.N. Commodity Trade Statistics Database for each year from 2000 to 2009 inclusive, we summarized statistics on volumes of maize trade between pairs of nations for 217 nations. There is evidence of market segregation among clusters of nations; with three prominent clusters representing Europe, Brazil and Argentina, and the United States. The United States is by far the largest exporter of maize worldwide, whereas Japan and the Republic of Korea are the largest maize importers. In particular, the star-shaped cluster of the network that represents U.S. maize trade to other nations indicates the potential for food security risks because of the lack of trade these other nations conduct with other maize exporters. If a scenario arose in which U.S. maize could not be exported in as large quantities, maize supplies in many nations could be jeopardized. We discuss this in the context of recent maize ethanol production and its attendant impacts on food prices elsewhere worldwide. PMID:23656551

Wu, Felicia; Guclu, Hasan

2013-12-01

126

Global Maize Trade and Food Security: Implications from a Social Network Model  

PubMed Central

In this study, we developed a social network model of the global trade of maize: one of the most important food, feed, and industrial crops worldwide, and critical to food security. We used this model to analyze patterns of maize trade among nations, and to determine where vulnerabilities in food security might arise if maize availability were decreased due to factors such as diversion to non-food uses, climatic factors, or plant diseases. Using data on imports and exports from the United Nations Commodity Trade Statistics Database for each year from 2000 to 2009 inclusive, we summarized statistics on volumes of maize trade between pairs of nations for 217 nations. There is evidence of market segregation among clusters of nations; with three prominent clusters representing Europe, Brazil and Argentina, and the United States. The United States is by far the largest exporter of maize worldwide, while Japan and the Republic of Korea are the largest maize importers. In particular, the star-shaped cluster of the network that represents US maize trade to other nations indicates the potential for food security risks because of the lack of trade these other nations conduct with other maize exporters. If a scenario arose in which US maize could not be exported in as large quantities, maize supplies in many nations could be jeopardized. We discuss this in the context of recent maize ethanol production and its attendant impacts on food prices elsewhere worldwide. PMID:23656551

Wu, Felicia; Guclu, Hasan

2013-01-01

127

The effect of Aloe vera leaf gel on fatty streak formation in hypercholesterolemic rabbits  

PubMed Central

Background: Atherosclerosis is a complex disease that is associated with a variety of etiologic factors such as hyperlipidemia and inflammation. Aloe vera (Liliaceae family) has been used traditionally as an anti-inflammatory drug. The aims of this survey were to define the beneficial effects of Aloe vera leaf gel on some of the atherosclerosis risk factors, and also fatty streak formation in hypercholesterolemic rabbits. Materials ans Methods: 32 white male rabbits were randomly divided into four experimental groups (n = 8, each). During the study, the animals had a standard diet (control group), high cholesterol diet (HC group), high cholesterol diet with Aloe vera leaf gel (3.2%v/v) (HC+ Aloe group) and Aloe vera leaf gel (Aloe group) for 30 days. Fasting blood samples were collected from all animals at the beginning and end of the study. Then total cholesterol (TC), fasting blood sugar (FBS), triglyceride (TG) and CRP were measured before and after experimental periods. By the end of the study, the aortas were removed and investigated for atherosclerosis plaque formation. Results: Significant differences were observed in TC and CRP levels of the high-cholesterol diet with Aloe vera and the high-cholesterol diet alone (p < 0.05). The formation of fatty streaks in the aorta was also significantly lower in the same animals under the influence of dietary Aloe vera(p < 0.05). The control and Aloe group did not show any evidence of atherosclerosis. No significant difference was found between the groups in TG and FBS. Conclusions: The data suggests that Aloe vera has beneficial effects on the prevention of fatty streak development; it may reduce the development of atherosclerosis through modification of risk factors. However, further studies are needed to understand the mechanisms whereby this plant exerts its anti-atherosclerotic effects. PMID:23626607

Dana, Nasim; Javanmard, Shaghayegh Haghjooy; Asgary, Sedigheh; Asnaashari, Hossein; Abdian, Narges

2012-01-01

128

Reliable and repeatable characterization of optical streak cameras.  

PubMed

Optical streak cameras are used as primary diagnostics for a wide range of physics and laser experiments at facilities such as the National Ignition Facility. To meet the strict accuracy requirements needed for these experiments, the systematic nonlinearities of the streak cameras (attributed to nonlinearities in the optical and electrical components that make up the streak camera system) must be characterized. In some cases the characterization information is used as a guide to help determine how experiment data should be taken. In other cases, the characterization data are applied to the raw data images to correct for the nonlinearities. In order to characterize an optical streak camera, a specific set of data is collected, where the response to defined inputs are recorded. A set of analysis software routines has been developed to extract information such as spatial resolution, dynamic range, and temporal resolution from this data set. The routines are highly automated, requiring very little user input and thus provide very reliable and repeatable results that are not subject to interpretation. An emphasis on quality control has been placed on these routines due to the high importance of the camera characterization information. PMID:19044688

Charest, Michael R; Torres, Peter; Silbernagel, Christopher T; Kalantar, Daniel H

2008-10-01

129

Reliable and Repeatable Characterization of Optical Streak Cameras  

SciTech Connect

Optical streak cameras are used as primary diagnostics for a wide range of physics and laser experiments at facilities such as the National Ignition Facility (NIF). To meet the strict accuracy requirements needed for these experiments, the systematic nonlinearities of the streak cameras (attributed to nonlinearities in the optical and electrical components that make up the streak camera system) must be characterized. In some cases the characterization information is used as a guide to help determine how experiment data should be taken. In other cases, the characterization data are applied to the raw data images to correct for the nonlinearities. In order to characterize an optical streak camera, a specific set of data is collected, where the response to defined inputs are recorded. A set of analysis software routines has been developed to extract information such as spatial resolution, dynamic range, and temporal resolution from this data set. The routines are highly automated, requiring very little user input and thus provide very reliable and repeatable results that are not subject to interpretation. An emphasis on quality control has been placed on these routines due to the high importance of the camera characterization information.

Michael Charest Jr., Peter Torres III, Christopher Silbernagel, and Daniel Kalantar

2008-10-31

130

Soft x-ray streak camera for laser fusion applications  

SciTech Connect

This thesis reviews the development and significance of the soft x-ray streak camera (SXRSC) in the context of inertial confinement fusion energy development. A brief introduction of laser fusion and laser fusion diagnostics is presented. The need for a soft x-ray streak camera as a laser fusion diagnostic is shown. Basic x-ray streak camera characteristics, design, and operation are reviewed. The SXRSC design criteria, the requirement for a subkilovolt x-ray transmitting window, and the resulting camera design are explained. Theory and design of reflector-filter pair combinations for three subkilovolt channels centered at 220 eV, 460 eV, and 620 eV are also presented. Calibration experiments are explained and data showing a dynamic range of 1000 and a sweep speed of 134 psec/mm are presented. Sensitivity modifications to the soft x-ray streak camera for a high-power target shot are described. A preliminary investigation, using a stepped cathode, of the thickness dependence of the gold photocathode response is discussed. Data from a typical Argus laser gold-disk target experiment are shown.

Stradling, G.L.

1981-04-01

131

Constructing streak surfaces for 3D unsteady vector fields  

Microsoft Academic Search

Visualization of 3D, unsteady flow (4D) is very difficult due to both perceptual challenges and the large size of 4D vector field data. One approach to this challenge is to use integral surfaces to visualize the 4D properties of the field. However the construction of streak surfaces has remained elusive due to problems stemming from expensive computation and complex meshing

Tony McLoughlin; Robert S. Laramee; Eugene Zhang

2010-01-01

132

Maize (Zea mays L.).  

PubMed

Agrobacterium tumefaciens-mediated transformation is an effective method for introducing genes into maize. In this chapter, we describe a detailed protocol for genetic transformation of the maize genotype Hi II. Our starting plant material is immature embryos cocultivated with an Agrobacterium strain carrying a standard binary vector. In addition to step-by-step laboratory transformation procedures, we include extensive details in growing donor plants and caring for transgenic plants in the greenhouse. PMID:25300834

Frame, Bronwyn; Warnberg, Katey; Main, Marcy; Wang, Kan

2015-01-01

133

Ipomoviruses: Squash vein yellowing virus, Cucumber vein yellowing virus, Cassava brown streak virus, and Ugandan cassava brown streak virus  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ipomoviruses including Squash vein yellowing virus, Cucumber vein yellowing virus and Cassava brown streak virus are currently causing significant economic impact on crop production in several regions of the world. Only recently have results of detailed characterization of their whitefly transmissi...

134

MAIZE GDB: THE MAIZE GENETICS AND GENOMICS DATABASE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Three exercises are presented to familiarize workshop participants with how to use the MaizeGDB website. The first exercise guides the student through the online MaizeGDB Tutorial and asks questions that can only be answered by having completed the exercise. The second exercise uses the MaizeGDB w...

135

Maize Photoperiod Control: Part II  

Technology Transfer Automated Retrieval System (TEKTRAN)

During the 2007 and 2008 seasons, the staff of the Germplasm Enhancement of Maize Project and the Maize Curatorial Project staff of the North Central Regional Plant Introduction Station experimented with various types of structures to ensure that field plantings of tropical maize germplasm were expo...

136

Chapter 11 Insect transmitted virus and mollicute disease  

Technology Transfer Automated Retrieval System (TEKTRAN)

Insect-transmitted diseases of maize are found throughout the maize growing regions of the world. These diseases are caused by viruses, phytoplasmas and spiroplasmas. The pathogens, vectors and plant hosts for the major insect-transmitted diseases of maize world-wide are reviewed. Factors leading to...

137

Megahertz streak-mode Fourier domain optical coherence tomography  

NASA Astrophysics Data System (ADS)

Here we present an ultrahigh-speed Fourier-domain optical coherence tomography (OCT) that records the OCT spectrum in streak mode with a high-speed area scan camera, which allows higher OCT imaging speed than can be achieved with a line-scan camera. Unlike parallel OCT techniques that also use area scan cameras, the conventional single-mode fiber-based point-scanning mechanism is retained to provide a confocal gate that rejects multiply scattered photons from the sample. When using a 1000 Hz resonant scanner as the streak scanner, 1,016,000 A-scans have been obtained in 1 s. This method's effectiveness has been demonstrated by recording in vivo OCT-image sequences of embryonic chick hearts at 1000 frames/s. In addition, 2-megahertz OCT data have been obtained with another high speed camera.

Wang, Rui; Yun, Julie X.; Yuan, Xiaocong; Goodwin, Richard; Markwald, Roger R.; Gao, Bruce Z.

2011-06-01

138

9. VIEW OF 'BLUE STREAK' HAMMER MILL (Prater Pulverizer Co., ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. VIEW OF 'BLUE STREAK' HAMMER MILL (Prater Pulverizer Co., Chicago, Illinois), LOCATED IN THE SOUTHEAST CORNER OF THE BASEMENT, WAS ADDED IN THE EARLY 1930s. THIS WAS THE MILL'S FIRST ELECTRIC-POWERED MACHINERY. THE HAMMER MILL WAS USED TO PULVERIZE OATS, ALFALFA MEAL, AND CORN. Photographer: Louise Taft Cawood, July 1986 - Alexander's Grist Mill, Lock 37 on Ohio & Erie Canal, South of Cleveland, Valley View, Cuyahoga County, OH

139

Genome-wide association study (GWAS) of resistance to head smut in maize.  

PubMed

Head smut, caused by the fungus Sphacelotheca reiliana (Kühn) Clint, is a devastating global disease in maize, leading to severe quality and yield loss each year. The present study is the first to conduct a genome-wide association study (GWAS) of head smut resistance using the Illumina MaizeSNP50 array. Out of 45,868 single nucleotide polymorphisms in a panel of 144 inbred lines, 18 novel candidate genes were associated with head smut resistance in maize. These candidate genes were classified into three groups, namely, resistance genes, disease response genes, and other genes with possible plant disease resistance functions. The data suggested a complicated molecular mechanism of maize resistance against S. reiliana. This study also suggested that GWAS is a useful approach for identifying causal genetic factors for head smut resistance in maize. PMID:23017907

Wang, Ming; Yan, Jianbing; Zhao, Jiuran; Song, Wei; Zhang, Xiaobo; Xiao, Yannong; Zheng, Yonglian

2012-11-01

140

Reliable and Repeatable Characterization of Optical Streak Cameras  

SciTech Connect

Optical streak cameras are used as primary diagnostics for a wide range of physics and laser performance verification experiments at the National Ignition Facility (NIF). To meet the strict accuracy requirements needed for these experiments, the systematic nonlinearities of the streak cameras (attributed to nonlinearities in the optical and electronic components that make up the streak camera system) must be characterized. In some cases the characterization information is used as a guide to help determine how experiment data should be taken. In other cases the characterization data is used to “correct” data images, to remove some of the nonlinearities. In order to obtain these camera characterizations, a specific data set is collected where the response to specific known inputs is recorded. A set of analysis software routines has been developed to extract information such as spatial resolution, dynamic range, temporal resolution, etc., from this data set. The routines are highly automated, requiring very little user input and thus provide very reliable and repeatable results that are not subject to interpretation. An emphasis on quality control has been placed on these routines due to the high importance of the camera characterization information.

Michael R. Charest, Peter Torres III, Christopher Silbernagel

2008-03-01

141

Design of microcontroller based system for automation of streak camera  

NASA Astrophysics Data System (ADS)

A microcontroller based system has been developed for automation of the S-20 optical streak camera, which is used as a diagnostic tool to measure ultrafast light phenomenon. An 8 bit MCS family microcontroller is employed to generate all control signals for the streak camera. All biasing voltages required for various electrodes of the tubes are generated using dc-to-dc converters. A high voltage ramp signal is generated through a step generator unit followed by an integrator circuit and is applied to the camera's deflecting plates. The slope of the ramp can be changed by varying values of the capacitor and inductor. A programmable digital delay generator has been developed for synchronization of ramp signal with the optical signal. An independent hardwired interlock circuit has been developed for machine safety. A LABVIEW based graphical user interface has been developed which enables the user to program the settings of the camera and capture the image. The image is displayed with intensity profiles along horizontal and vertical axes. The streak camera was calibrated using nanosecond and femtosecond lasers.

Joshi, M. J.; Upadhyay, J.; Deshpande, P. P.; Sharma, M. L.; Navathe, C. P.

2010-08-01

142

Stabilization of boundary layer streaks by plasma actuators  

NASA Astrophysics Data System (ADS)

A flow's transition from laminar to turbulent leads to increased levels of skin friction. In recent years, dielectric barrier discharge actuators have been shown to be able to delay the onset of turbulence in boundary layers. While the laminar to turbulent transition process can be initiated by several different instability mechanisms, so far, only stabilization of the Tollmien-Schlichting path to transition has received significant attention, leaving the stabilization of other transition paths using these actuators less explored. To fill that void, a bi-global stability analysis is used here to examine the stabilization of boundary layer streaks in a laminar boundary layer. These streaks, which are important to both transient and by-pass instability mechanisms, are damped by the addition of a flow-wise oriented plasma body force to the boundary layer. Depending on the magnitude of the plasma actuation, this damping can be up to 25% of the perturbation's kinetic energy. The damping mechanism appears to be due to highly localized effects in the immediate vicinity of the body force, and when examined using a linearized Reynolds-averaged Navier-Stokes energy balance, indicate negative production of the perturbation's kinetic energy. Parametric studies of the stabilization have also been performed, varying the magnitude of the plasma actuator's body force and the spanwise wavenumber of the actuation. Based on these parametric studies, the damping of the boundary layer streaks appears to be linear with respect to the total amount of body force applied to the flow.

Riherd, Mark; Roy, Subrata

2014-03-01

143

Nitric oxide detoxification by Fusarium verticillioides flavohemoglobin and role in pathogenicity of maize  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fusarium verticillioides is a non-obligate plant pathogen of maize causing a number of specific diseases, including root rot, kernel rot, seed rot, stalk rot, and seedling blight. The saprophytic nature of this fungus, its production of the mycotoxin fumonisin, and complex relationship maize puts t...

144

Quality Protein Maize for Africa: Closing the Protein Inadequacy Gap in Vulnerable Populations12  

PubMed Central

Africa shares a unique relationship with maize (Zea mays). After its introduction from New World explorers, maize was quickly adopted as the cornerstone of local cuisine, especially in sub-Saharan countries. Although maize provides macro- and micronutrients required for humans, it lacks adequate amounts of the essential amino acids lysine and tryptophan. For those consuming >50% of their daily energy from maize, pandemic protein malnutrition may exist. Severe protein and energy malnutrition increases susceptibility to life-threatening diseases such as tuberculosis and gastroenteritis. A nutritionally superior maize cultivar named quality protein maize (QPM) represents nearly one-half century of research dedicated to malnutrition eradication. Compared with traditional maize types, QPM has twice the amount of lysine and tryptophan, as well as protein bioavailability that rivals milk casein. Animal and human studies suggest that substituting QPM for common maize results in improved health. However, QPM’s practical contribution to maize-subsisting populations remains unresolved. Herein, total protein and essential amino acid requirements recommended by the WHO and the Institute of Medicine were applied to estimate QPM target intake levels for young children and adults, and these were compared with mean daily maize intakes by African country. The comparisons revealed that ?100 g QPM is required for children to maintain adequacy of lysine, the most limiting amino acid, and nearly 500 g is required for adults. This represents a 40% reduction in maize intake relative to common maize to meet protein requirements. The importance of maize in Africa underlines the potential for QPM to assist in closing the protein inadequacy gap. PMID:22332054

Nuss, Emily T.; Tanumihardjo, Sherry A.

2011-01-01

145

MaizeGDB - Past, present, and future  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Maize Genetics and Genomics Database (MaizeGDB) turns 20 this year. This editorial outlines MaizeGDB's history and connection to the Maize Genetics Cooperation, describes key components of how the MaizeGDB interface will be completely redesigned over the course of the next two years to meet cur...

146

MaizeGDB Community Curation Tools  

Technology Transfer Automated Retrieval System (TEKTRAN)

MaizeGDB (http://www.maizegdb.org) is the community database for maize genetics and genomics. The success of the MaizeGDB project largely can be attributed to the involvement of the community of maize geneticists. Members of the community have (1) made their data available by contributing to MaizeGD...

147

Bioinformatics The Maize Genetics and Genomics Database.  

E-print Network

Bioinformatics The Maize Genetics and Genomics Database. The Community Resource for Access to Diverse Maize Data1 Carolyn J. Lawrence, Trent E. Seigfried, and Volker Brendel* Department of Genetics 50011­3260 (T.E.S.) The Maize Genetics and Genomics Database (MaizeGDB) serves the maize (Zea mays

Brendel, Volker

148

Identification of multiple ear-colonizing insect and disease resistance in CIMMYT maize inbred lines with varying levels of silk maysin.  

PubMed

Ninety four corn inbred lines selected from International Center for the Improvement of Maize and Wheat (CIMMYT) in Mexico were evaluated for levels of silk maysin in 2001 and 2002. Damage by major ear-feeding insects [i.e., corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae); maize weevil, Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae); brown stink bug, Euschistus servus (Say); southern green stink bugs, Nezara viridula (L.) (Heteroptera: Pentatomidae)], and common smut [Ustilago maydis DC (Corda)] infection on these inbred lines were evaluated in 2005 and 2006 under subtropical conditions at Tifton, GA. Ten inbred lines possessing good agronomic traits were also resistant to the corn earworm. The correlation between ear-feeding insect damage or smut infection and three phenotypic traits (silk maysin level, husk extension, and husk tightness of corn ears) was also examined. Corn earworm and stink bug damage was negatively correlated to husk extension, but not to either silk maysin levels or husk tightness. In combination with the best agronomic trait ratings that show the least corn earworm and stink bug damage, lowest smut infection rate, and good insect-resistant phenotypic traits (i.e., high maysin and good husk coverage and husk tightness), 10 best inbred lines (CML90, CML92, CML94, CML99, CML104, CML108, CML114, CML128, CML137, and CML373) were identified from the 94 lines examined. These selected inbred lines will be used for further examination of their resistance mechanisms and development of new corn germplasm that confers multiple ear-colonizing pest resistance. PMID:18767760

Ni, Xinzhi; Krakowsky, Matthew D; Buntin, G David; Rector, Brian G; Guo, Baozhu; Snook, Maurice E

2008-08-01

149

Streak camera based SLR receiver for two color atmospheric measurements  

NASA Technical Reports Server (NTRS)

To realize accurate two-color differential measurements, an image digitizing system with variable spatial resolution was designed, built, and integrated to a photon-counting picosecond streak camera, yielding a temporal scan resolution better than 300 femtosecond/pixel. The streak camera is configured to operate with 3 spatial channels; two of these support green (532 nm) and uv (355 nm) while the third accommodates reference pulses (764 nm) for real-time calibration. Critical parameters affecting differential timing accuracy such as pulse width and shape, number of received photons, streak camera/imaging system nonlinearities, dynamic range, and noise characteristics were investigated to optimize the system for accurate differential delay measurements. The streak camera output image consists of three image fields, each field is 1024 pixels along the time axis and 16 pixels across the spatial axis. Each of the image fields may be independently positioned across the spatial axis. Two of the image fields are used for the two wavelengths used in the experiment; the third window measures the temporal separation of a pair of diode laser pulses which verify the streak camera sweep speed for each data frame. The sum of the 16 pixel intensities across each of the 1024 temporal positions for the three data windows is used to extract the three waveforms. The waveform data is processed using an iterative three-point running average filter (10 to 30 iterations are used) to remove high-frequency structure. The pulse pair separations are determined using the half-max and centroid type analysis. Rigorous experimental verification has demonstrated that this simplified process provides the best measurement accuracy. To calibrate the receiver system sweep, two laser pulses with precisely known temporal separation are scanned along the full length of the sweep axis. The experimental measurements are then modeled using polynomial regression to obtain a best fit to the data. Data aggregation using normal point approach has provided accurate data fitting techniques and is found to be much more convenient than using the full rate single shot data. The systematic errors from this model have been found to be less than 3 ps for normal points.

Varghese, Thomas K.; Clarke, Christopher; Oldham, Thomas; Selden, Michael

1993-01-01

150

Cell streak imaging cytometry for rare cell detection.  

PubMed

Detection of rare cells, such as circulating tumor cells, have many clinical applications. To measure rare cells with increased sensitivity and improved data managements, we developed an imaging flow cytometer with a streak imaging mode capability. The new streak mode imaging mode utilizes low speed video to capture moving fluorescently labeled cells in a flow cell. Each moving cell is imaged on multiple pixels on each frame, where the cell path is marked as a streak line proportional to the length of the exposure. Finding rare cells (e.g., <1 cell/mL) requires measuring larger sample volumes to achieve higher sensitivity, therefore we combined streak mode imaging with a "wide" high throughput flow cell (e.g. flow rates set to 10 mL/min) in contrast to the conventional "narrow" hydrodynamic focusing cells typically used in cytometry that are inherently limited to low flow rates. The new flow cell is capable of analyzing 20 mL/min of fluorescently labeled cells. To further increase sensitivity, the signal to noise ratio of the images was also enhanced by combining three imaging methods: (1) background subtraction, (2) pixel binning, and (3) CMOS color channel selection. The streaking mode cytometer has been used for the analysis of SYTO-9 labeled THP-1 human monocytes in buffer and in blood. Samples of cells at 1 cell/mL and 0.1 cell/mL were analyzed in 30 mL with flow rates set to 10 mL/min and frame rates of 4 fps (frame per second). For the target of 1 cell/mL, an average concentration of 0.91 cell/mL was measured by cytometry, with a standard error of 0.03 (C(95) = 0.85-0.97). For the target of 0.1 cell/mL, an average concentration of 0.083 cell/mL was measured, with a standard error of 0.01 (C(95) = 0.065-0.102). Whole blood was also spiked with SYTO-9 labeled cells to a concentration of 10 cell/mL, and the average flow cytometry measurement was 8.7 cells/mL (i.e. 0.87 cells/mL in diluted blood) with a 95% CL of 8.1-9.2 cells/mL. This demonstrated the ability to detect rare cells in blood with high accuracy. Such detection approaches for rare cells have many potential clinical applications. Furthermore, the simplicity and low cost of this device may enable expansion of cell-based clinical diagnostics, especially in resource-poor settings. PMID:25212069

Balsam, Joshua; Bruck, Hugh Alan; Rasooly, Avraham

2015-02-15

151

Hot streaks and phantom cooling in a turbine rotor passage. II - Combined effects and analytical modelling  

NASA Technical Reports Server (NTRS)

Experimental documentation and analytical correlations demonstrating the effects of hot streak accumulation and phantom cooling on turbine rotor airfoil surface temperature are presented. Results are shown which quantify the impact of a nonuniform temperature profile at the entrance of a turbine due to combustor-generated hot and cold streaks, and cooling air discharged from the trailing edge of the upstream stator. Experimental results are shown for a range of controlling variables to identify where streak accumulation and phantom cooling were most likely to be strongest. These variables include streak-to-free stream density ratio, streak injection location, and coolant-to-free stream density and velocity ratios. Experimental results are shown for the combined effects of hot streak and stator coolant on the adiabatic recovery temperature of the rotor.

Roback, Richard J.; Dring, Robert P.

1992-01-01

152

Hot streaks and phantom cooling in a turbine rotor passage. II - Combined effects and analytical modelling  

NASA Astrophysics Data System (ADS)

Experimental documentation and analytical correlations demonstrating the effects of hot streak accumulation and phantom cooling on turbine rotor airfoil surface temperature are presented. Results are shown which quantify the impact of a nonuniform temperature profile at the entrance of a turbine due to combustor-generated hot and cold streaks, and cooling air discharged from the trailing edge of the upstream stator. Experimental results are shown for a range of controlling variables to identify where streak accumulation and phantom cooling were most likely to be strongest. These variables include streak-to-free stream density ratio, streak injection location, and coolant-to-free stream density and velocity ratios. Experimental results are shown for the combined effects of hot streak and stator coolant on the adiabatic recovery temperature of the rotor.

Roback, Richard J.; Dring, Robert P.

1992-06-01

153

Evidence of recombination and genetic diversity in southern rice black-streaked dwarf virus.  

PubMed

Southern rice black-streaked dwarf virus (SRBSDV) causes one of the most serious viral diseases of rice in China and Vietnam. Sequence identities of S10, encoding the major capsid protein, were 98.0 %-100 % and 98.3 %-100 % at the nucleotide and amino acid level, respectively. Our results suggest that the codon at position 550 of S10 is under positive selection, while most of the other codons are under neutral evolution. Putative recombination events were identified in genomic RNA segments S1, 2, 4, 5, 6 and 10, which are rare in plant-infecting dsRNA viruses. This study reveals the current state of SRBSDV evolution. PMID:23605668

Li, Yongqiang; Xia, Zihao; Peng, Jun; Zhou, Tao; Fan, Zaifeng

2013-10-01

154

Paramutation in maize  

Microsoft Academic Search

Paramutation is a heritable change in gene expression induced by allele interactions. This review summarizes key experiments on three maize loci, which undergo paramutation. Similarities and differences between the phenomenology at the three loci are described. In spite of many differences with respect to the stability of the reduced expression states at each locus or whether paramutation correlates with DNA

Vicki L. Chandler; William B. Eggleston; Jane E. Dorweiler

2000-01-01

155

Use of an advanced intercross line population for mapping of quantitative trait loci for northern leaf blight resistance in maize and for the investigation of multiple disease resistance  

Technology Transfer Automated Retrieval System (TEKTRAN)

In this paper we identify regions of the genome conferring resistance to the corn disease, northern corn leaf blight. We also report evidence for the existence of genes conferring resistance to multiple diseases....

156

A-maize-ing Diversity  

NSDL National Science Digital Library

Maize (Zea mays)â??cornâ??is a staple food source in much of the world, as well as a source of cooking oil, grain alcohol, livestock feed, and biofuel. There is enormous quantitative variation among maize strains for traits of agronomic importance. Buckler and colleagues describe the genetic properties of a new resource for mapping maize quantitative traits, and discuss the genetic architecture of a key traitâ??flowering timeâ??derived from it.

Trudy Mackay (North Carolina State University; Department of Genetics)

2009-08-07

157

Agrobacterium-mediated infectivity of cloned digitaria streak virus DNA.  

PubMed

A monomeric clone of double-stranded DNA synthesized in vitro DNA of the geminivirus Digitaria streak (DSV) was subcloned as a tandem dimeric unit into a binary vector of Agrobacterium tumefaciens, creating a plasmid pDS2. Inoculation of digitaria sanguinalis with A. tumefaciens carrying pDS2 resulted in viral infection. The symptoms, virus particles, and DNA forms obtained were indistinguishable from those of a natural DSV infection of D. sanguinalis. Inoculations have also induced infections in Zea mays and Avena sativa. The sequence of the Agrobacterium-mediated infectious clone of DSV has been determined. PMID:3341112

Donson, J; Gunn, H V; Woolston, C J; Pinner, M S; Boulton, M I; Mullineaux, P M; Davies, J W

1988-01-01

158

Attosecond streaking of core lines of copper dihalides  

E-print Network

In the attosecond (as) streaking of Cu 3s core-level photoemission of copper dihalides, we predict theoretically that the satellite ($3d^9$) is emitted later than the main line ($3d^{10}L^{-1}$; $L$: ligand). The emission time delay is originated from the electron correlation between the core level and 3d shell, which leads to the difference in core-hole screening between satellite and main lines. Further, we find that the time delay corresponds to a quantification of the extrinsic loss of photoemission.

J. D. Lee

2011-09-26

159

Parametric frequency upconversion, optical fiber transmission, and streak camera recording  

SciTech Connect

The use of optical fiber for the transmission of information over relatively long distances is being recognized as the only viable solution to many data transmission problems, particularly those requiring high information density and faithful temporal content. This necessary reliance upon the optical carrier has meant that the image-tube based optical streak camera is often the instrument of choice for recording single-shot multi-parameter events with high temporal resolution. However, current photocathode technology is incompatible with the trend of the optical fiber industry toward the use of the 1300 to 1600 nm wavelength regime. To retain the advantages of optical streak-camera recording and optical fiber transmission, a way must be found to ''upconvert'' the optical carrier to higher energy. This report describes the use of an intense lazer pump beam coincident with the IR signal into a non-linear crystal (LiIO/sub 3/) to increase the signal's frequency. A beam splitter is used to separate the signal from the pump beam at the detector. The physical theory underlying this process is described. (JDH)

Lowry, M.E.; Rotter, M.D.

1987-01-30

160

Microprocessor-controlled, wide-range streak camera  

SciTech Connect

Bechtel Nevada/NSTec recently announced deployment of their fifth generation streak camera. This camera incorporates many advanced features beyond those currently available for streak cameras. The arc-resistant driver includes a trigger lockout mechanism, actively monitors input trigger levels, and incorporates a high-voltage fault interrupter for user safety and tube protection. The camera is completely modular and may deflect over a variable full-sweep time of 15 nanoseconds to 500 microseconds. The camera design is compatible with both large- and small-format commercial tubes from several vendors. The embedded microprocessor offers Ethernet connectivity, and XML [extensible markup language]-based configuration management with non-volatile parameter storage using flash-based storage media. The camera’s user interface is platform-independent (Microsoft Windows, Unix, Linux, Macintosh OSX) and is accessible using an AJAX [asynchronous Javascript and XML]-equipped modem browser, such as Internet Explorer 6, Firefox, or Safari. User interface operation requires no installation of client software or browser plug-in technology. Automation software can also access the camera configuration and control using HTTP [hypertext transfer protocol]. The software architecture supports multiple-simultaneous clients, multiple cameras, and multiple module access with a standard browser. The entire user interface can be customized.

Amy E. Lewis, Craig Hollabaugh

2006-09-01

161

A possible role for chemotaxis in primitive streak formation  

NASA Astrophysics Data System (ADS)

One of the fundamental problems in modern biology is to understand the transformation of a fertilized egg to an adult organism. A key stage of this developmental process is gastrulation, in which cell germ layers are defined, and the basic three-dimensional body plan of the organism is established. Presented here is a model used to investigate the collective cell movement which is observed at the onset of gastrulation in the Chick embryo. In the avian embryo, gastrulation is initiated by a cadre of cells moving coherently, bisecting the embryo, thereby forming a structure known as the primitive streak. The mechanisms underlying primitive streak formation are the subject of recent experimental controversy. One hypothesis is that coherent cell motion is driven by chemotactic response to long-range signaling gradients. We will present results from large-scale computer simulations testing this hypothesis. In particular, we perform simulations using the Subcellular Element Model (SEM). Within the model framework, a single cell is represented by a collection of visco-elastically interacting elements. Dynamic interactions of elements are motivated, as coarse-grained representations, of the actively remodeling cell cytoskeleton. We have found that, in addition to chemotaxis, active cell migration is crucial for ``fluidizing" the tissue thereby allowing large-scale coherent cell movement.

Sandersius, Sebastian A.; Weijer, Cornelis J.; Newman, Timothy J.

2010-03-01

162

Simplified picosecond streak image tube for designing inexpensive commercial cameras  

NASA Astrophysics Data System (ADS)

The current demand for inexpensive streak camera manufacturing leads to the necessity in development of a variety of relatively simple and low cost image-converter tubes. One such tube, known as PIF-C, designed and manufactured in the Photoelectronics Department of the General Physics Institute (GPI), is now commercially available. Its experimentally measured time resolution in streak mode has approached one picosecond, and 3 ps in synchroscan mode at 82 MHz operation frequency. In single frame mode at 100 ns exposure time, the spatial resolution over 6 mm input area is within 15 lp/mm. Electron optical magnification of the tube is 1.5 x. PIF-C tubes may be supplied with one of the S1/S20/S25 photocathodes, fabricated either on borosilicate glass, UV-glass, or MgF2 substrate. Its P11 phosphor screen is deposited onto the fiber optic window. EBI of the PIF-C/S1 tube is in the range of 5 (DOT) 10-10 A/cm2.

Degtyareva, Valentina P.; Fedotov, V. I.; Korobkova, T. A.; Polikarkina, Nadejda D.; Prokhorov, Alexander M.; Schelev, Mikhail Y.; Smirnova, A. V.; Soldatov, N. F.; Titkov, Evgenij I.

1993-01-01

163

Comparison of wheat spindle streak mosaic virus (WSSMV) and barley yellow mosaic virus (BaYMV)  

E-print Network

Comparison of wheat spindle streak mosaic virus (WSSMV) and barley yellow mosaic virus (BaYMV): 2 streak mosaic bymovirus (WSSMV). Using different methods both viruses were found to be closely related. Electron microscopy studies revealed that both viruses lead to formation of 2 types of cytoplasmic

Paris-Sud XI, Université de

164

Understanding Baseball Team Standings and Streaks C. Sire 1 and S. Redner 1, 2  

E-print Network

Understanding Baseball Team Standings and Streaks C. Sire 1 and S. Redner 1, 2 1 Laboratoire de Studies and Department of Physics, Boston University, Boston, Massachusetts 02215, USA Can one understand the statistics of wins and losses of baseball teams? Are their consecutive­ game winning and losing streaks self

Redner, Sidney

165

A Generalized Low-Rank Appearance Model for Spatio-Temporally Correlated Rain Streaks  

E-print Network

A Generalized Low-Rank Appearance Model for Spatio-Temporally Correlated Rain Streaks Yi-Lei Chen rain streaks, just exploit the repeatability/similarity of rain steaks taken in the same scene! Our advantages:(1) no pre-processing (e.g., rain detection); (2) training-free (e.g., dictionary learning

Hsu, Chiou-Ting Candy

166

Mass movement within a slope streak on Mars Cynthia B. Phillips,1  

E-print Network

, or by staining of the surface, preserving pre-existing topography within the streak. Theories also vary that transports, lubricates or stains the surface material [Ferguson and Lucchitta, 1984; Ferris et al., 2002 streak formation entailed or caused significant sediment movement and is not simply a surface staining

Perfect, Ed

167

Genetic mechanisms of Maize dwarf mosaic virus resistance in maize  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize resistance to viruses has been well-characterized at the genetic level, and loci responsible for resistance to potyviruses including Maize dwarf mosaic virus (MDMV), Sugarcane mosaic virus (SCMV), Sorghum mosaic virus (SrMV), and Johnsongrass mosaic virus (JGMV), have been mapped in several ge...

168

MaizeGDB: The Maize Genetics and Genomics Database  

Technology Transfer Automated Retrieval System (TEKTRAN)

MaizeGDB is the community database for biological information about the crop plant Zea mays. Genetic, genomic, sequence, gene product, functional characterization, literature reference, and person/organization contact information are among the datatypes stored at MaizeGDB. At the project's website...

169

Molecular population genetics of maize regulatory genes during maize evolution  

E-print Network

of selection than average genes in the maize genome. Second, we investigated sequence evolution of two for the adaptive evolution of organisms. Domestication is a selection process for the adaptation of animal or plant variation at theses genes and their adjacent genomic regions. Maize was domesticated from its wild ancestor

Doebley, John

170

THE MAIZE GENETICS AND GENOMICS DATABASE: A COMMUNITY RESOURCE FOR ACCESS TO DIVERSE MAIZE DATA  

Technology Transfer Automated Retrieval System (TEKTRAN)

MaizeGDB (the Maize Genetics and Genomics Database) is the research database for the maize community. The site features a wealth of resources and data facilitating the scientific study of maize. Among the data sets included in MaizeGDB are sequences, including PlantGDB's EST and GSS contig assemblie...

171

THE MAIZE GENETICS AND GENOMICS DATABASE. THE COMMUNITY RESOURCE FOR ACCESS TO DIVERSE MAIZE DATA  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Maize Genetics and Genomics Database (MaizeGDB) serves the maize (Zea mays) research community by making a wealth of genetics and genomics data available through an intuitive Web-based interface. The goals of the MaizeGDB project are three-fold: to provide a central repository for public maize ...

172

MaizeGDB, the community database for maize genetics and genomics  

E-print Network

MaizeGDB, the community database for maize genetics and genomics Carolyn J. Lawrence1 , Qunfeng Dong1 , Mary L. Polacco3 , Trent E. Seigfried1 and Volker Brendel1,2,* 1 Department of Genetics ABSTRACT The Maize Genetics and Genomics Database (MaizeGDB) is a central repository for maize sequence

Brendel, Volker

173

Efficient and stable expression of GFP through Wheat streak mosaic virus-based vectors in cereal hosts using a range of cleavage sites: Formation of dense fluorescent aggregates for sensitive virus tracking  

Technology Transfer Automated Retrieval System (TEKTRAN)

A series of Wheat streak mosaic virus (WSMV)-based expression vectors were developed by engineering cycle 3 GFP (GFP) cistron between P1 and HC-Pro cistrons with several catalytic/cleavage peptides at the C-terminus of GFP. WSMV-GFP vectors with the Foot-and-mouth disease virus 1D/2A or 2A catalytic...

174

Root Infection and Systemic Colonization of Maize by Colletotrichum graminicola?  

PubMed Central

Colletotrichum graminicola is a filamentous ascomycete that causes anthracnose disease of maize. While the fungus can cause devastating foliar leaf blight and stalk rot diseases, little is known about its ability to infect roots. Previously published reports suggest that C. graminicola may infect maize roots and that root infections may contribute to the colonization of aboveground plant tissues, leading to disease. To determine whether C. graminicola can infect maize roots and whether root infections can result in the colonization of aboveground plant tissues, we developed a green fluorescent protein-tagged strain and used it to study the plant root colonization and infection process in vivo. We observed structures produced by other root pathogenic fungi, including runner hyphae, hyphopodia, and microsclerotia. A mosaic pattern of infection resulted from specific epidermal and cortical cells becoming infected by intercellular hyphae while surrounding cells were uninfected, a pattern that is distinctly different from that described for leaves. Interestingly, falcate conidia, normally restricted to acervuli, were also found filling epidermal cells and root hairs. Twenty-eight percent of plants challenged with soilborne inoculum became infected in aboveground plant parts (stem and/or leaves), indicating that root infection can lead to asymptomatic systemic colonization of the plants. Many of the traits observed for C. graminicola have been previously reported for other root-pathogenic fungi, suggesting that these traits are evolutionally conserved in multiple fungal lineages. These observations suggest that root infection may be an important component of the maize anthracnose disease cycle. PMID:18065625

Sukno, Serenella A.; García, Verónica M.; Shaw, Brian D.; Thon, Michael R.

2008-01-01

175

Aflatoxin resistance in maize: what have we learned lately?  

Technology Transfer Automated Retrieval System (TEKTRAN)

Aflatoxin contamination of maize grain is a huge economic and health problem, causing death and increased disease burden in much of the developing world and income loss in the developed world. Despite the gravity of the problem, deployable solutions are still being sought. In the past 15 years, much...

176

Metabolic pathway resources at MaizeGDB  

Technology Transfer Automated Retrieval System (TEKTRAN)

Two maize metabolic networks are available at MaizeGDB: MaizeCyc (http://maizecyc.maizegdb.org, also at Gramene) and CornCyc (http://corncyc.maizegdb.org, also at the Plant Metabolic Network). MaizeCyc was developed by Gramene, and CornCyc by the Plant Metabolic Network, both in collaboration with M...

177

The MaizeGDB Genome Browser  

Technology Transfer Automated Retrieval System (TEKTRAN)

MaizeGDB (http://www.maizegdb.org) is the community database for maize genetics and genomics. As part of an effort to develop MaizeGDB as a more sequence-centric resource, we implemented a genome browser based on information we gathered by surveying the community of maize geneticists. Based on commu...

178

Maize variety and method of production  

DOEpatents

The disclosure relates to a maize plant, seed, variety, and hybrid. More specifically, the disclosure relates to a maize plant containing a Cal-1 allele, whose expression results in increased cell wall-derived glucan content in the maize plant. The disclosure also relates to crossing inbreds, varieties, and hybrids containing the Cal-1 allele to produce novel types and varieties of maize plants.

Pauly, Markus; Hake, Sarah; Kraemer, Florian J

2014-05-27

179

StreakDet data processing and analysis pipeline for space debris optical observations  

NASA Astrophysics Data System (ADS)

We describe a novel data processing and analysis pipeline for optical observations of space debris. The monitoring of space object populations requires reliable acquisition of observational data, to support the development and validation of space debris environment models, the build-up and maintenance of a catalogue of orbital elements. In addition, data is needed for the assessment of conjunction events and for the support of contingency situations or launches. The currently available, mature image processing algorithms for detection and astrometric reduction of optical data cover objects that cross the sensor field-of-view comparably slowly, and within a rather narrow, predefined range of angular velocities. By applying specific tracking techniques, the objects appear point-like or as short trails in the exposures. However, the general survey scenario is always a “track before detect” problem, resulting in streaks, i.e., object trails of arbitrary lengths, in the images. The scope of the ESA-funded StreakDet (Streak detection and astrometric reduction) project is to investigate solutions for detecting and reducing streaks from optical images, particularly in the low signal-to-noise ratio (SNR) domain, where algorithms are not readily available yet. For long streaks, the challenge is to extract precise position information and related registered epochs with sufficient precision. Although some considerations for low-SNR processing of streak-like features are available in the current image processing and computer vision literature, there is a need to discuss and compare these approaches for space debris analysis, in order to develop and evaluate prototype implementations. In the StreakDet project, we develop algorithms applicable to single images (as compared to consecutive frames of the same field) obtained with any observing scenario, including space-based surveys and both low- and high-altitude populations. The proposed processing pipeline starts from the segmentation of the acquired image (i.e., the extraction of all sources), followed by the astrometric and photometric characterization of the candidate streaks, and ends with orbital validation of the detected streaks. A central concept of the pipeline is streak classification which guides the actual characterization process by aiming to identify the interesting sources and to filter out the uninteresting ones, as well as by allowing the tailoring of algorithms for specific streak classes (e.g. point-like vs. long, disintegrated streaks). To validate the single-image detections, the processing is finalized by orbital analysis, resulting in preliminary orbital classification (Earth-bound vs. non-Earth-bound orbit) for the detected streaks.

Virtanen, Jenni; Flohrer, Tim; Muinonen, Karri; Granvik, Mikael; Torppa, Johanna; Poikonen, Jonne; Lehti, Jussi; Santti, Tero; Komulainen, Tuomo; Naranen, Jyri

180

Proteomic analysis of the maize rachis: Potential roles of constitutive and induced proteins in resistance to Aspergillus flavus and aflatoxin  

Technology Transfer Automated Retrieval System (TEKTRAN)

Infection of the maize (Zea mays L.) with aflatoxigenic fungus Aspergillus flavus and consequent contamination with carcinogenic aflatoxin is a persistent and serious agricultural problem causing disease and significant crop losses worldwide. The rachis (cob) is an important structure of maize ear ...

181

Roles of Stolbur phytoplasma and Reptalus panzeri (Cixiinae, Auchenorrhyncha) in the epidemiology of Maize redness in Serbia  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize redness (MR), a disease causing midrib, leaf and stalk reddening and abnormal ear development in maize, has been reported from Serbia, Romania and Bulgaria for 50 years. Recent epiphytotics reduced yields by 40-90% in southern Banat, Serbia. MR was recently associated with the presence of th...

182

Roles of Stolbur Phytoplasma and Reptalus Panzeri (Cixiinae, Auchenorrhyncha) in the Epidemiology of Maize Redness in Serbia  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize redness (MR), a disease causing midrib, leaf and stalk reddening and abnormal ear development in maize, has been reported from Serbia, Romania and Bulgaria for 50 years. Recent epiphytotics reduced yields by 40-90% in southern Banat, Serbia. MR was recently associated with the presence of th...

183

Effects of elevated [CO2 ] on maize defence against mycotoxigenic Fusarium verticillioides.  

PubMed

Maize is by quantity the most important C4 cereal crop; however, future climate changes are expected to increase maize susceptibility to mycotoxigenic fungal pathogens and reduce productivity. While rising atmospheric [CO2 ] is a driving force behind the warmer temperatures and drought, which aggravate fungal disease and mycotoxin accumulation, our understanding of how elevated [CO2 ] will effect maize defences against such pathogens is limited. Here we report that elevated [CO2 ] increases maize susceptibility to Fusarium verticillioides proliferation, while mycotoxin levels are unaltered. Fumonisin production is not proportional to the increase in F.?verticillioides biomass, and the amount of fumonisin produced per unit pathogen is reduced at elevated [CO2 ]. Following F.?verticillioides stalk inoculation, the accumulation of sugars, free fatty acids, lipoxygenase (LOX) transcripts, phytohormones and downstream phytoalexins is dampened in maize grown at elevated [CO2 ]. The attenuation of maize 13-LOXs and jasmonic acid production correlates with reduced terpenoid phytoalexins and increased susceptibility. Furthermore, the attenuated induction of 9-LOXs, which have been suggested to stimulate mycotoxin biosynthesis, is consistent with reduced fumonisin per unit fungal biomass at elevated [CO2 ]. Our findings suggest that elevated [CO2 ] will compromise maize LOX-dependent signalling, which will influence the interactions between maize and mycotoxigenic fungi. PMID:24689748

Vaughan, Martha M; Huffaker, Alisa; Schmelz, Eric A; Dafoe, Nicole J; Christensen, Shawn; Sims, James; Martins, Vitor F; Swerbilow, Jay; Romero, Maritza; Alborn, Hans T; Allen, Leon Hartwell; Teal, Peter E A

2014-12-01

184

High-speed TV cameras for streak tube readout  

SciTech Connect

Two fast framing TV cameras have been characterized and compared as readout media for imaging of 40 mm diameter streak tube (P-11) phosphor screens. One camera is based upon a Focus-Projection-Scan (FPS) high-speed electrostatic deflected vidicon with 30-mm-diameter PbO target. The other uses an interline transfer charge-coupled device (CCD) with 8.8 {times} 11.4 mm rectangular Si target. The field-of-view (FOV), resolution, responsivity, and dynamic range provided by both cameras when exposed to short duration ({approx} 10 {mu} full width at half maximum (FWHM)) transient illumination followed by a single field readout period of {lt}3 ms are presented. 11 refs., 8 figs., 3 tabs.

Yates, G.J.; Gallegos, R.A.; Holmes, V.H. (Los Alamos National Lab., NM (United States)); Turko, B.T. (Lawrence Berkeley Lab., CA (United States))

1991-01-01

185

Doppler streak mode Fourier domain optical coherence tomography  

NASA Astrophysics Data System (ADS)

Doppler Fourier domain optical coherence tomography is able to be used for in vivo blood flow measurement. In conventional methods, the highest velocity that can be measured is limited to the range the phase shift between two successively recorded depth profiles at the same probe-beam location, which cannot exceed (-?, ?), otherwise phase wrapping will occur. This phase-wrapping limit is determined by the time interval between two consecutive A-scans. We present a novel approach to shorten the time interval between two consecutive A-scans and thus increase the phase-wrapping limit by using an area scan camera to record the interference spectrum in a streak mode. To demonstrate the effectiveness of this method, the blood flows in HH18 and HH19 chick hearts were imaged and phase wrapping free Doppler images were obtained.

Wang, Rui; Yun, Julie X.; Goodwin, Richard; Markwald, Roger; Runyan, Raymond B.; Gao, Bruce

2012-01-01

186

Streaking in Cascadia ETS Events and Implications for the Subduction Plate Interface  

NASA Astrophysics Data System (ADS)

The manner in which episodic tremor and slow slip (ETS) propagates across the subduction plate interface provides constraints on its properties and the physical processes involved. We have been examining catalogs of tremor locations to study propagation patterns during ETS. Tremor in the large Cascadia ETS events propagates mainly via three modes: 1) the slow along-strike advance of ETS, 2) rapid tremor reversals (RTRs) that propagate back from the tremor front in an opposite direction to the along-strike advance, but at speeds 10-40 times faster (Houston et al., Nature Geoscience, 2011), and 3) streaks, even faster migrations of tremor parallel to the plate-convergence direction at speeds ~ 70 km/hr (Ghosh et al., G3, 2011). The UW Seismology group has recently deployed an EarthScope-funded seismic experiment, the Array of Arrays, to image tremor more precisely with eight subarrays. A 15-month catalog of high-resolution tremor locations has been generated based on the triangulation of back-projected beams from the subarrays. We detect tremor streaks in this catalog automatically and systematically determine streak propagation properties. Key issues for constraining streak-generation processes include systematic differences between up- and down-dip traveling streaks, how streak properties may depend on depth, and whether streaks accelerate or decelerate during propagation. Stacking automatically-detected streaks can address some of these issues. Two approaches to automatically detecting streaks have been developed and applied to the M6.8 2010 ETS. One method declares a streak when averaged epicenters continue to move in a roughly constant direction for more than 10 km. The second declares a streak if epicenters during a specified time interval, say 20 min, are sufficiently well-correlated with time. The two methods agree well and detect several streaks per day of 15-30 min duration with speeds consistent with those inferred for the 2008 ETS. Although the detection methods have no azimuthal bias, most of the detected streaks align with one direction; furthermore, that direction lies much closer to the plate convergence direction than directly down-dip (the down-dip and plate convergence directions differ significantly along most of Cascadia). Many more streaks are detected in the actual catalog than in randomized versions, in which the times within each hour are permuted. These results lend substantial credence to convergence-parallel streaks as real features of ETS. Streak propagation patterns suggest the plate interface is anisotropic along the slip direction. The ubiquity of streaking parallel to plate convergence implies control by corrugated or smeared structures on the plate interface. This could occur via such structures controlling the orientation of an advancing slip pulse, which could carry streaks along its peak (Rubin, G3, 2011), or more directly via heterogeneous physical properties (such as rheology or permeability) elongated in the convergence direction. In this connection, we note that daily tremor bands in Cascadia ETS are also often oriented parallel to the convergence direction whether the ETS is advancing north or south, even though the direction of ETS advance would be expected to affect the orientation of a slip pulse on a homogeneous interface.

Houston, H.; Ghosh, A.

2011-12-01

187

Roles of stolbur phytoplasma and Reptalus panzeri (Cixiinae, Auchenorrhyncha) in the epidemiology of Maize redness in Serbia  

Microsoft Academic Search

Maize redness (MR), a disease causing midrib, leaf and stalk reddening and abnormal ear development in maize, has been reported\\u000a from Serbia, Romania and Bulgaria for 50 years. Recent epiphytotics reduced yields by 40%–90% in southern Banat, Serbia. MR\\u000a was recently associated with the presence of the stolbur phytoplasma, although the epidemiology of the disease remained unknown.\\u000a Diseased fields in southern

J. Jovi?; T. Cvrkovic ´; M. Mitrovi?; S. Krnjajic ´; Margaret G. Redinbaugh; R. C. Pratt; R. E. Gingery; S. A. Hogenhout; I. Toševski

2007-01-01

188

Ultra Fast X-ray Streak Camera for TIM Based Platforms  

SciTech Connect

Ultra fast x-ray streak cameras are a staple for time resolved x-ray measurements. There is a need for a ten inch manipulator (TIM) based streak camera that can be fielded in a newer large scale laser facility. The LLNL ultra fast streak camera's drive electronics have been upgraded and redesigned to fit inside a TIM tube. The camera also has a new user interface that allows for remote control and data acquisition. The system has been outfitted with a new sensor package that gives the user more operational awareness and control.

Marley, E; Shepherd, R; Fulkerson, E S; James, L; Emig, J; Norman, D

2012-05-02

189

Ultra fast x-ray streak camera for ten inch manipulator based platformsa)  

NASA Astrophysics Data System (ADS)

Ultra fast x-ray streak cameras are a staple for time resolved x-ray measurements. There is a need for a ten inch manipulator (TIM) based streak camera that can be fielded in a newer large scale laser facility. The Lawrence Livermore National Laboratory ultra fast streak camera's drive electronics have been upgraded and redesigned to fit inside a TIM tube. The camera also has a new user interface that allows for remote control and data acquisition. The system has been outfitted with a new sensor package that gives the user more operational awareness and control.

Marley, E. V.; Shepherd, R.; Fulkerson, S.; James, L.; Emig, J.; Norman, D.

2012-10-01

190

Emissivity spectrum of a large "dark streak" from themis infrared imagery  

SciTech Connect

'Dark streaks', also known as 'slope streaks', are unusual surface features found on Mars that are known to appear and fade away on timescales of years. Various explanations have been proposed for their origin and composition, including dry avalanches and wet debris or precipitates from brines. Previous investigations have been based on analysis of panchromatic imagery and altimetry from Viking and Mars Global Surveyor missions. We have obtained an infrared emissivity spectrum of a large dark streak on the north western edge of Olympus Mons, using imagery from the THEMIS instrument on the Mars Odyssey 2001 spacecraft.

Brumby, Steven P.; Vaniman, D. T. (David T.); Bish, D. L. (David L.)

2003-01-01

191

Ultra fast x-ray streak camera for ten inch manipulator based platforms  

SciTech Connect

Ultra fast x-ray streak cameras are a staple for time resolved x-ray measurements. There is a need for a ten inch manipulator (TIM) based streak camera that can be fielded in a newer large scale laser facility. The Lawrence Livermore National Laboratory ultra fast streak camera's drive electronics have been upgraded and redesigned to fit inside a TIM tube. The camera also has a new user interface that allows for remote control and data acquisition. The system has been outfitted with a new sensor package that gives the user more operational awareness and control.

Marley, E. V. [Physics and Life Science, Lawrence Livermore National Laboratory, M.S. L-490, Livermore, California 94550 (United States); University of California Davis, One Shields Avenue, Davis, California 95616 (United States); Shepherd, R.; Fulkerson, S.; James, L.; Emig, J.; Norman, D. [Physics and Life Science, Lawrence Livermore National Laboratory, M.S. L-490, Livermore, California 94550 (United States)

2012-10-15

192

Streak camera crosstalk reduction using a multiple delay optical fiber bundle.  

PubMed

The streak camera is one of the fastest photodetection systems, while its capability of multiplexing is particularly attractive to many applications requiring parallel data acquisition. The degree of multiplexing in a streak camera is limited by the crosstalk between input channels. We developed a technique that introducing a fixed time delay between adjacent fiber channels in a customized two-dimensional to one-dimensional fiber array to significantly reduce crosstalk both at the sample plane and at the input of a streak camera. A prototype system has been developed that supports 100 input channels, and its performance in fluorescence microscopy is demonstrated. PMID:22854483

Tsikouras, Anthony; Ning, Jin; Ng, Sandy; Berman, Richard; Andrews, David W; Fang, Qiyin

2012-01-15

193

Identification of functional sequences in the pregenomic RNA promoter of the Banana streak virus Cavendish strain (BSV-Cav).  

PubMed

The promoter regions of plant pararetroviruses direct transcription of the full-length viral genome into a pregenomic RNA that is an intermediate in the replication of the virus. It serves as template for reverse transcription and as polycistronic mRNA for translation to viral proteins. We have identified functional promoter elements in the intergenic region of the Cavendish isolate of Banana streak virus (BSV-Cav), a member of the genus Badnavirus. Potential binding sites for plant transcription factors were found both upstream and downstream of the transcription start site by homology search in the PLACE database of plant cis-acting elements. The functionality of these putative cis-acting elements was tested by constructing loss-of-function and "regain"-of-function mutant promoters whose activity was quantified in embryogenic sugarcane suspension cells. Four regions that are important for activity of the BSV-Cav promoter were identified: the region containing an as-1-like element, the region around -141 and down to -77, containing several putative transcription factor binding sites, the region including the CAAT-box, and the leader region. The results could help explain the high BSV-Cav promoter activity that was observed previously in transgenic sugarcane plants and give more insight into the plant cell-mediated replication of the viral genome in banana streak disease. PMID:15681068

Remans, Tony; Grof, Christopher P L; Ebert, Paul R; Schenk, Peer M

2005-03-01

194

Effects of elevated [CO2] on maize defence against mycotoxigenic Fusarium verticillioides  

PubMed Central

Maize is by quantity the most important C4 cereal crop; however, future climate changes are expected to increase maize susceptibility to mycotoxigenic fungal pathogens and reduce productivity. While rising atmospheric [CO2] is a driving force behind the warmer temperatures and drought, which aggravate fungal disease and mycotoxin accumulation, our understanding of how elevated [CO2] will effect maize defences against such pathogens is limited. Here we report that elevated [CO2] increases maize susceptibility to Fusarium verticillioides proliferation, while mycotoxin levels are unaltered. Fumonisin production is not proportional to the increase in F.?verticillioides biomass, and the amount of fumonisin produced per unit pathogen is reduced at elevated [CO2]. Following F.?verticillioides stalk inoculation, the accumulation of sugars, free fatty acids, lipoxygenase (LOX) transcripts, phytohormones and downstream phytoalexins is dampened in maize grown at elevated [CO2]. The attenuation of maize 13-LOXs and jasmonic acid production correlates with reduced terpenoid phytoalexins and increased susceptibility. Furthermore, the attenuated induction of 9-LOXs, which have been suggested to stimulate mycotoxin biosynthesis, is consistent with reduced fumonisin per unit fungal biomass at elevated [CO2]. Our findings suggest that elevated [CO2] will compromise maize LOX-dependent signalling, which will influence the interactions between maize and mycotoxigenic fungi. Elevated [CO2] increases maize susceptibility to Fusarium verticillioides proliferation but mycotoxin levels are unaltered. The attenuation of maize 13-LOXs and JA production correlates with reduced terpenoid phytoalexins and increased susceptibility. Furthermore, the attenuated induction of 9-LOXs, which have been suggested to stimulate mycotoxin biosynthesis, is consistent with reduced fumonisin per unit fungal biomass at elevated [CO2]. PMID:24689748

Vaughan, Martha M; Huffaker, Alisa; Schmelz, Eric A; Dafoe, Nicole J; Christensen, Shawn; Sims, James; Martins, Vitor F; Swerbilow, Jay; Romero, Maritza; Alborn, Hans T; Allen, Leon HARTWELL; Teal, Peter EA

2014-01-01

195

Standard design for National Ignition Facility x-ray streak and framing camerasa)  

NASA Astrophysics Data System (ADS)

The x-ray streak camera and x-ray framing camera for the National Ignition Facility were redesigned to improve electromagnetic pulse hardening, protect high voltage circuits from pressure transients, and maximize the use of common parts and operational software. Both instruments use the same PC104 based controller, interface, power supply, charge coupled device camera, protective hermetically sealed housing, and mechanical interfaces. Communication is over fiber optics with identical facility hardware for both instruments. Each has three triggers that can be either fiber optic or coax. High voltage protection consists of a vacuum sensor to enable the high voltage and pulsed microchannel plate phosphor voltage. In the streak camera, the high voltage is removed after the sweep. Both rely on the hardened aluminum box and a custom power supply to reduce electromagnetic pulse/electromagnetic interference (EMP/EMI) getting into the electronics. In addition, the streak camera has an EMP/EMI shield enclosing the front of the streak tube.

Kimbrough, J. R.; Bell, P. M.; Bradley, D. K.; Holder, J. P.; Kalantar, D. K.; MacPhee, A. G.; Telford, S.

2010-10-01

196

Detection and analysis of irregular streaks in dermoscopic images of skin lesions.  

PubMed

Irregular streaks are important clues for Melanoma (a potentially fatal form of skin cancer) diagnosis using dermoscopy images. This paper extends our previous algorithm to identify the absence or presence of streaks in a skin lesions, by further analyzing the appearance of detected streak lines, and performing a three-way classification for streaks, Absent, Regular, and Irregular, in a pigmented skin lesion. In addition, the directional pattern of detected lines is analyzed to extract their orientation features in order to detect the underlying pattern. The method uses a graphical representation to model the geometric pattern of valid streaks and the distribution and coverage of the structure. Using these proposed features of the valid streaks along with the color and texture features of the entire lesion, an accuracy of 76.1% and weighted average area under ROC curve (AUC) of 85% is achieved for classifying dermoscopy images into streaks Absent, Regular, or Irregular on 945 images compiled from atlases and the internet without any exclusion criteria. This challenging dataset is the largest validation dataset for streaks detection and classification published to date. The data set has also been applied to the two-class sub-problems of Absent/Present classification (accuracy of 78.3% with AUC of 83.2%) and to Regular/Irregular classification (accuracy 83.6% with AUC of 88.9%). When the method was tested on a cleaned subset of 300 images randomly selected from the 945 images, the AUC increased to 91.8%, 93.2% and 90.9% for the Absent/Regular/Irregular, Absent/Present, and Regular/Irregular problems, respectively. PMID:23335664

Sadeghi, Maryam; Lee, Tim K; McLean, David; Lui, Harvey; Atkins, M Stella

2013-05-01

197

Split ring resonator based THz-driven electron streak camera featuring femtosecond resolution.  

PubMed

Through combined three-dimensional electromagnetic and particle tracking simulations we demonstrate a THz driven electron streak camera featuring a temporal resolution on the order of a femtosecond. The ultrafast streaking field is generated in a resonant THz sub-wavelength antenna which is illuminated by an intense single-cycle THz pulse. Since electron bunches and THz pulses are generated with parts of the same laser system, synchronization between the two is inherently guaranteed. PMID:25010060

Fabia?ska, Justyna; Kassier, Günther; Feurer, Thomas

2014-01-01

198

Update on the Maize Genome Sequencing Project The Maize Genome Sequencing Project  

E-print Network

Update on the Maize Genome Sequencing Project The Maize Genome Sequencing Project Vicki L. Chandler Genome Sequencing Project. The momentum for this endeavor has been building within the maize (Zea mays and human genomes (Gregory et al., 2002). Our current picture of the maize genome is largely derived from

Brendel, Volker

199

Many maize genes are expressed in an oat background carrying a specific maize chromosome  

Technology Transfer Automated Retrieval System (TEKTRAN)

Oat-maize addition (OMA) lines are derived from oat x maize sexual hybrids in which individual maize chromosomes have been retained in plants containing a full complement of oat chromosomes. Many of the OMA lines display specific phenotypes, which indicate that maize genes are likely expressed and c...

200

Effects of Hot Streak Shape on Rotor Heating in a High-Subsonic Single-Stage Turbine  

NASA Technical Reports Server (NTRS)

Experimental data have shown that combustor temperature non-uniformities can lead to the excessive heating of first-stage rotor blades in turbines. This heating of the rotor blades can lead to thermal fatigue and degrade turbine performance. The results of recent studies have shown that variations in the circumferential location (clocking) of the hot streak relative to the first-stage vane airfoils can be used to minimize the adverse effects of the hot streak. The effects of the hot streak/airfoil count ratio on the heating patterns of turbine airfoils have also been evaluated. In the present investigation, three-dimensional unsteady Navier-Stokes simulations have been performed for a single-stage high-pressure turbine operating in high subsonic flow. In addition to a simulation of the baseline turbine, simulations have been performed for circular and elliptical hot streaks of varying sizes in an effort to represent different combustor designs. The predicted results for the baseline simulation show good agreement with the available experimental data. The results of the hot streak simulations indicate: that a) elliptical hot streaks mix more rapidly than circular hot streaks, b) for small hot streak surface area the average rotor temperature is not a strong function of hot streak temperature ratio or shape, and c) hot streaks with larger surface area interact with the secondary flows at the rotor hub endwall, generating an additional high temperature region.

Dorney, Daniel J.; Gundy-Burlet, Karen L.; Norvig, Peter (Technical Monitor)

1999-01-01

201

New observations of Bolivian wind streaks by JPL Airborne SAR: Preliminary results  

NASA Technical Reports Server (NTRS)

In 1993 NASA's Jet Propulsion Laboratory Airborne Synthetic Aperture Radar system (AIRSAR) was deployed to South America to collect multi-parameter radar data over pre-selected targets. Among the sites targeted was a series of wind streaks located in the Altiplano of Bolivia. The objective of this investigation is to study the effect of wavelength, polarization, and incidence angle on the visibility of wind streaks in radar data. Because this is a preliminary evaluation of the recently acquired data we will focus on one scene and, thus, only on the effects of wavelength and polarization. Wind streaks provide information on the near-surface prevailing winds and on the abundance of winderodible material, such as sand. The potential for a free-flyer radar system that could provide global radar images in multiple wavelengths, polarizations, and incidence angles requires definition of system parameters for mission planning. Furthermore, thousands of wind streaks were mapped from Magellan radar images of Venus; their interpretation requires an understanding of the interaction of radar with wind streaks and the surrounding terrain. Our experiment was conducted on wind streaks in the Altiplano of Bolivia to address these issues.

Blumberg, Dan G.; Greeley, Ronald

1995-01-01

202

Spatial relationships among the cellular tapetum, visual streak and rod density in dogs.  

PubMed

The dog visual system is well suited to dim light conditions due to rod-dominated retina and the reflective tapetum. The topographical distributions of rods and thickness of the tapetum of the dog were quantified in retinal whole mounts stained with thionine, and spatial relationships among the tapetum, rod density and visual streak of high ganglion cell density were elucidated. The relationship between the retina and tapetum was analyzed in parasagittal sections stained with thionine or hematoxylin-eosin. The tapetum was thick in its center, and the thickest part consisted of 9 to 12 tapetal cell layers. Rod density ranged from 200,000 to 540,000/mm(2). Maximum rod density was found in the area dorsal to the visual streak, and the density in that area was significantly higher than the rod density in the visual streak and accorded spatially with the thickest part of the tapetum. The horizontal visual streak was found over the horizontal line through the optic disc in the temporal half and extended slightly into the nasal half. The central area of the highest density of ganglion cells was approximately located midway between the nasal and temporal ends of the visual streak. The visual streak was located within the tapetal area, but ventrally to the thick part of the tapetum. PMID:25728250

Yamaue, Yasuhiro; Hosaka, Yoshinao Z; Uehara, Masato

2015-03-01

203

Spatial relationships among the cellular tapetum, visual streak and rod density in dogs.  

PubMed

The dog visual system is well suited to dim light conditions due to rod-dominated retina and the reflective tapetum. The topographical distributions of rods and thickness of the tapetum of the dog were quantified in retinal wholemounts stained with thionine, and spatial relationships among the tapetum, rod density and visual streak of high ganglion cell density were elucidated. The relationship between the retina and tapetum was analyzed in parasagittal sections stained with thionine or hematoxylin-eosin. The tapetum was thick in its center, and the thickest part consisted of 9 to 12 tapetal cell layers. Rod density ranged from 200,000 to 540,000/mm(2). Maximum rod density was found in the area dorsal to the visual streak, and the density in that area was accorded significantly higher than the rod density in the visual streak and accorded spatially with the thickest part of the tapetum. The horizontal visual streak was found over the horizontal line through the optic disc in the temporal half and extended slightly into the nasal half. The central area of the highest density of ganglion cells was approximately located midway between the nasal and temporal ends of the visual streak. The visual streak was located within the tapetum, but ventrally to the thick part of the tapetum. PMID:25354794

Yamaue, Yasuhiro; Hosaka, Yoshinao Z; Uehara, Masato

2014-10-30

204

Spatial relationships among the cellular tapetum, visual streak and rod density in dogs  

PubMed Central

The dog visual system is well suited to dim light conditions due to rod-dominated retina and the reflective tapetum. The topographical distributions of rods and thickness of the tapetum of the dog were quantified in retinal whole mounts stained with thionine, and spatial relationships among the tapetum, rod density and visual streak of high ganglion cell density were elucidated. The relationship between the retina and tapetum was analyzed in parasagittal sections stained with thionine or hematoxylin-eosin. The tapetum was thick in its center, and the thickest part consisted of 9 to 12 tapetal cell layers. Rod density ranged from 200,000 to 540,000/mm2. Maximum rod density was found in the area dorsal to the visual streak, and the density in that area was significantly higher than the rod density in the visual streak and accorded spatially with the thickest part of the tapetum. The horizontal visual streak was found over the horizontal line through the optic disc in the temporal half and extended slightly into the nasal half. The central area of the highest density of ganglion cells was approximately located midway between the nasal and temporal ends of the visual streak. The visual streak was located within the tapetal area, but ventrally to the thick part of the tapetum. PMID:25728250

YAMAUE, Yasuhiro; HOSAKA, Yoshinao Z.; UEHARA, Masato

2014-01-01

205

Intravitreal bevacizumab for choroidal neovascularization secondary to angioid streaks: A report of two patients  

PubMed Central

The aim of this study is to report clinical course of choroidal neovascularization secondary to angioid streaks (AS) in two patients who underwent intravitreal bevacizumab therapy. Fundus examination, fluorescein angiography (FA) and optical coherence tomography (OCT) revealed the diagnosis of subfoveal classic choroidal neovascularization (CNV) in the right eye in patient 1 and in the left eye in patient 2. After three consecutive bevacizumab injections, visual acuity improved from 20/40 to 20/25 in patient 1 and from 20/80 to 20/50 in patient 2. After 3 months of therapy, additional bevacizumab injection was administered when the lesion showed recurrence. After a follow-up time of 24-months, patient 1 received 14 intravitreal bevacizumab injections; patient 2 received only 4 injections. Visual acuities remained stable at 20/32 and 20/50 in patient 1 and patient 2, respectively. Though, the patients of CNV secondary to AS showed similar clinical appearance at the beginning, this report provides the data for different responses to intravitreal bevacizumab therapy. While fewer injections were required to control the disease in one patient, the other patient needed much more injections for stabilization of the CNV. Further studies are required to understand the cause of varied treatment responses in those patients. PMID:25473350

Ozkaya, Abdullah; Alkin, Zeynep; Faiz, Miray; Yazici, Ahmet Taylan; Demirok, Ahmet

2013-01-01

206

Quantitative measurements using soft-x-ray streak cameras  

SciTech Connect

A Soft X-Ray Streak Camera (SXRSC) is a fast timing instrument sensitive to x rays from 100 eV to 300 keV. The instrument has excellent time resolution (approx. 15 ps) and large dynamic range (approx. 10/sup 3/) which are well suited for measuring x-ray pulses produced by laser-fusion targets. The SXRSC uses a thin transmission photocathode to convert x-rays to a secondary electron signal which is accelerated, focused, and deflected onto a phosphor producing an image of the x-ray pulse time history. In the past, such instruments have been used only to make relative measurements of the time history. At LLNL we have calibrated the SXRSC in order to make absolute intensity measurements of the soft x-ray flux from laser fusion targets. Such measurements will assist in understanding the laser plasma processes and conditions needed to attain laser-produced fusion. Because of the nature of the instrument, we have calibrated it in the dynamic mode using a small laser-produced pulsed x-ray source.

Kauffman, R.L.; Stradling, G.L.; Pierce, E.L.; Medecki, H.

1981-08-01

207

Molecular characterization of Indian sugarcane streak mosaic virus isolate.  

PubMed

Sugarcane streak mosaic virus (SCSMV), a member of the genus Poacevirus, family Potyviridae, is an important viral pathogen affecting sugarcane cultivation in India. The complete nucleotide sequence of a SCSMV isolate from India (SCSMV-IND) was determined. The linear, assembled, single-stranded positive-sense RNA genome of SCSMV-IND was 9,786 nucleotides in length (excluding the poly (A) tail) and encoded a polyprotein of 3,131 amino acid residues. The genome of SCSMV-IND shared high degree of sequence identity with SCSMV-PAK (93 % at nucleotide and 97 % at amino acid), and shared only 81 % nucleotide and 94 % amino acid identities with all the four SCSMV isolates (SCSMV-JP1, -JP2, -ID, and -THA). Phylogenetic tree analysis of the complete genome sequences of SCSMV isolates revealed that they can be clustered into two groups. SCSMV-IND and -AP isolates showed 18 % (nucleotide) divergence within the highly conserved 3' partial genome, suggesting a high level of genetic diversity among the Indian SCSMV isolates. PMID:23011777

Parameswari, B; Bagyalakshmi, K; Viswanathan, R; Chinnaraja, C

2013-02-01

208

A Maize Cystatin Suppresses Host Immunity by Inhibiting Apoplastic Cysteine Proteases[C][W  

PubMed Central

Ustilago maydis is a biotrophic pathogen causing maize (Zea mays) smut disease. Transcriptome profiling of infected maize plants indicated that a gene encoding a putative cystatin (CC9) is induced upon penetration by U. maydis wild type. By contrast, cc9 is not induced after infection with the U. maydis effector mutant ?pep1, which elicits massive plant defenses. Silencing of cc9 resulted in a strongly induced maize defense gene expression and a hypersensitive response to U. maydis wild-type infection. Consequently, fungal colonization was strongly reduced in cc9-silenced plants, while recombinant CC9 prevented salicylic acid (SA)–induced defenses. Protease activity profiling revealed a strong induction of maize Cys proteases in SA-treated leaves, which could be inhibited by addition of CC9. Transgenic maize plants overexpressing cc9-mCherry showed an apoplastic localization of CC9. The transgenic plants showed a block in Cys protease activity and SA-dependent gene expression. Moreover, activated apoplastic Cys proteases induced SA-associated defense gene expression in naïve plants, which could be suppressed by CC9. We show that apoplastic Cys proteases play a pivotal role in maize defense signaling. Moreover, we identified cystatin CC9 as a novel compatibility factor that suppresses Cys protease activity to allow biotrophic interaction of maize with the fungal pathogen U. maydis. PMID:22454455

van der Linde, Karina; Hemetsberger, Christoph; Kastner, Christine; Kaschani, Farnusch; van der Hoorn, Renier A.L.; Kumlehn, Jochen; Doehlemann, Gunther

2012-01-01

209

Exploiting the Combination of Natural and Genetically Engineered Resistance to Cassava Mosaic and Cassava Brown Streak Viruses Impacting Cassava Production in Africa  

PubMed Central

Cassava brown streak disease (CBSD) and cassava mosaic disease (CMD) are currently two major viral diseases that severely reduce cassava production in large areas of Sub-Saharan Africa. Natural resistance has so far only been reported for CMD in cassava. CBSD is caused by two virus species, Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV). A sequence of the CBSV coat protein (CP) highly conserved between the two virus species was used to demonstrate that a CBSV-CP hairpin construct sufficed to generate immunity against both viral species in the cassava model cultivar (cv. 60444). Most of the transgenic lines showed high levels of resistance under increasing viral loads using a stringent top-grafting method of inoculation. No viral replication was observed in the resistant transgenic lines and they remained free of typical CBSD root symptoms 7 month post-infection. To generate transgenic cassava lines combining resistance to both CBSD and CMD the hairpin construct was transferred to a CMD-resistant farmer-preferred Nigerian landrace TME 7 (Oko-Iyawo). An adapted protocol allowed the efficient Agrobacterium-based transformation of TME 7 and the regeneration of transgenic lines with high levels of CBSV-CP hairpin-derived small RNAs. All transgenic TME 7 lines were immune to both CBSV and UCBSV infections. Further evaluation of the transgenic TME 7 lines revealed that CBSD resistance was maintained when plants were co-inoculated with East African cassava mosaic virus (EACMV), a geminivirus causing CMD. The innovative combination of natural and engineered virus resistance in farmer-preferred landraces will be particularly important to reducing the increasing impact of cassava viral diseases in Africa. PMID:23049780

Vanderschuren, Hervé; Moreno, Isabel; Anjanappa, Ravi B.; Zainuddin, Ima M.; Gruissem, Wilhelm

2012-01-01

210

MaizeGDB's New Genome Browser Project  

Technology Transfer Automated Retrieval System (TEKTRAN)

MaizeGDB (http://www.maizegdb.org) is the community database for maize genetics and genomics. Based upon the 2006 MaizeGDB Working Group Report (available at http://www.maizegdb.org/working_group.php) and the Allerton Report (http://www.maizegdb.org/AllertonReport.doc), it has become evident that th...

211

MAIZEGDB, THE MAIZE GENETICS AND GENOMICS DATABASE  

Technology Transfer Automated Retrieval System (TEKTRAN)

MaizeGDB (http://www.maizegdb.org) is the database that houses data and analysis tools crafted to suit the needs of the community of maize geneticists. Among the data sets included in MaizeGDB are sequences; detailed genetic, physical, recombination nodule, and cytological maps; molecular markers; a...

212

The Genetic Architecture of Maize Flowering Time  

Technology Transfer Automated Retrieval System (TEKTRAN)

Flowering time is the key trait controlling adaptation of plants to their local environment, and, in an outcrossing species like maize, it is a complex trait. Variation for this complex trait was dissected in maize using a novel set of 5000 recombinant inbred lines (maize Nested Association Mapping...

213

A simplified method for simultaneous detection of Rice stripe virus and Rice black-streaked dwarf virus in insect vector.  

PubMed

Rice stripe virus (RSV) and Rice black-streaked dwarf virus (RBSDV) are transmitted by their common vector small brown planthopper (SBPH) that cause serious crop losses in China. A simple reverse transcription-PCR method was developed for the simultaneous detection of RSV and RBSDV in single SBPH. Three primers targeted to RSV-RNA4 and RBSDV-S2 segments were designed to amplify respectively 1114-bp and 414-bp fragments in a reaction. The method is reliable, rapid and inexpensive for detecting the two viruses in vector, which could facilitate better forecasting and control of the virus diseases. Using this method, it was found that SBPH could carry RSV and RBSDV simultaneously. PMID:25455902

Li, Shuo; Wang, Xi; Xu, Jianxiang; Ji, Yinghua; Zhou, Yijun

2015-01-01

214

The sedimentology and dynamics of crater-affiliated wind streaks in western Arabia Terra, Mars and Patagonia, Argentina  

USGS Publications Warehouse

Wind streaks comprise recent aeolian deposits that have been extensively documented on Venus, Earth and Mars. Martian wind streaks are among the most abundant surface features on the planet and commonly extend from the downwind margins of impact craters. Previous studies of wind streaks emerging from crater interior deposits suggested that the mode of emplacement was primarily related to the deposition of silt-sized particles as these settled from plumes. We have performed geologic investigations of two wind streaks clusters; one situated in western Arabia Terra, a region in the northern hemisphere of Mars, and another in an analogous terrestrial site located in southern Patagonia, Argentina, where occurrences of wind streaks emanate from playas within maar craters. In both these regions we have identified bedforms in sedimentary deposits on crater floors, along wind-facing interior crater margins, and along wind streaks. These observations indicate that these deposits contain sand-sized particles and that sediment migration has occurred via saltation from crater interior deposits to wind streaks. In Arabia Terra and in Patagonia wind streaks initiate from crater floors that contain lithic and evaporitic sedimentary deposits, suggesting that the composition of wind streak source materials has played an important role in development. Spatial and topographic analyses suggest that regional clustering of wind streaks in the studied regions directly correlates to the areal density of craters with interior deposits, the degree of proximity of these deposits, and the craters' rim-to-floor depths. In addition, some (but not all) wind streaks within the studied clusters have propagated at comparable yearly (Earth years) rates. Extensive saltation is inferred to have been involved in its propagation based on the studied terrestrial wind streak that shows ripples and dunes on its surface and the Martian counterpart changes orientation toward the downslope direction where it extends into an impact crater. ?? 2009 Elsevier B.V.

Rodriguez, J.A.P.; Tanaka, K.L.; Yamamoto, A.; Berman, D.C.; Zimbelman, J.R.; Kargel, J.S.; Sasaki, S.; Jinguo, Y.; Miyamoto, H.

2010-01-01

215

Mars Eolian Geology at Airphoto Scales: The Large Wind Streaks of Western Arabia Terra  

NASA Technical Reports Server (NTRS)

More than 27,000 pictures at aerial photograph scales (1.5-12 m/pixel) have been acquired by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) since September 1997. The pictures are valuable for testing hypotheses about geologic history and processes of Mars. Of particular interest are eolian features connected to surface albedo patterns. This work is focused on low-albedo wind streaks, some over 100 km long, in western Arabia Terra. Each streak is widest where it originates at an impact crater (typically 25-150 km diameter). The streaks taper downwind. Within the associated craters there is a lower-albedo surface that, in nearly all observed cases, includes barchan dunes indicative of transport in the same direction as the wind streaks. Upwind of the dunes there is usually an outcrop of layered material that might have served as a source for dune sand. MOC images show that the west Arabia streaks consist of a smooth-surfaced, multiple-meters-thick, mantle (smooth at 1.5 m/pixel) that appears to be superposed on local surfaces. No dunes are present, indicating that down-streak transport of sediment via saltation and traction have not occurred. Two models might explain the observed properties: (1) the streaks consist of dark silt- and clay-sized grains deflated from the adjacent crater interiors and deposited from suspension or (2) they are remnants (protected in the lee of impact crater rims) of a formerly much larger, regional covering of low albedo, smooth-surfaced mantle. The latter hypothesis is based on observation of low albedo mantled surfaces occurring south of west Arabia in Terra Meridiani. For reasons yet unknown, a large fraction of the martian equatorial regions are covered by low albedo, mesa-forming material that lies unconformably atop eroded layered and cratered terrain. Both hypotheses are being explored via continued selective targeting of new MOC images as well as analyses of the new data.

Edgett, Kenneth S.

2001-01-01

216

An Optical Streaking Method for Measuring Femtosecond Electron Bunches  

SciTech Connect

The measurement of the ultra-short electron bunch length on the femtosecond time scale constitutes a very challenging problem. In the x-ray free electron laser facilities such as the Linac Coherent Light Source, generation of a sub-ten femtoseconds electron beam with 20pC charge is possible, but direct measurements are very difficult due to the resolution limit of the present diagnostics. We propose a new method here based on the measurement of the electron beam energy modulation induced from laser-electron interaction in a short wiggler. A typical optical streaking method requires a laser wavelength much longer than the electron bunch length. In this paper a laser with its wavelength shorter than the electron bunch length has been adopted, while the slope on the laser intensity envelope is used to distinguish the different periods. With this technique it is possible to reconstruct the bunch longitudinal profile from a single shot measurement. Generation of ultrashort x-ray pulses at femtoseconds (fs) scale is of great interest within synchrotron radiation and free electron laser (FEL) user community. One of the simple methods is to operate the FEL facility at low charge. At the Linac Coherent Light Source (LCLS), we have demonstrated the capability of generating ultrashort electron-beam (e-beam) with a duration of less than 10 fs fwhm using 20 pC charge. The x-ray pulses have been delivered to the x-ray users with a similar or even shorter pulse duration. However, The measurement of such short electron or x-ray pulse length at the fs time-scale constitutes a challenging problem. A standard method using an S-band radio-frequency (rf) transverse deflector has been established at LCLS, which works like a streak camera for electrons and is capable of resolving bunch lengths as short as 25 fs fwhm. With this device, the electrons are transversely deflected by the high-frequency time-variation of the deflecting fields. Increasing the deflecting voltage and rf frequency are the right direction to achieve a better resolution. For example, by choosing an X-band transverse deflecting cavity, the expected resolution for LCLS beam with 4.3 GeV is about 1 fs rms. Typically the rf breakdown threshold and the power source availability prevent going to even higher voltage and frequency. With the highly-developed laser techniques, we can choose to streak the beam at optical frequencies. By jumping from rf to optical frequency, the wavelength is shortening by 4 to 5 orders. With an electron bunch length shorter than half period of the laser, we can apply the similar rf deflecting or zero-phasing method for e-beam bunch length measurements using a high-power laser. A short wiggler is required to provide interaction between the electron and the laser. For example, to measure the e-beam at the order of 1 m rms length, a laser with its wavelength of 10 {mu}m may be considered. For a typical few GeV e-beam, the wiggler period has to be large to satisfy the resonance condition. Also, if the e-beam is longer than one laser period, the different modulation periods will overlap and we cannot distinguish them. So this method is so far limited by the achievable long-wavelength laser power. To get an effective modulation on an e-beam of 4.3 GeV, the required laser power is about a few tens GW. In this paper we propose to adopt a high-power Ti:Sapphire laser (wavelength of 800 nm), and use the slope in the intensity envelope to distinguish the different modulation periods. First an ultrashort electron beam interacts with the Ti:Sapphire laser in a wiggler, where the electron energy is modulated at the same periods of the laser. If the laser pulse is long and the short electron bunch is overlapped (in time) with the middle part of the laser, such as the setup at LCLS laser heater, the different energy modulation periods on the electron beam will be overlapped on the energy profile. In this conditionwe typically have a double-horn distribution of the energy profile, and the electron-bunch length information cannot be retrieved. But if the laser pulse (

Ding, Yuantao; Bane, Karl L.F.; Huang, Zhirong; /SLAC

2011-12-14

217

Complete genome sequence of nine isolates of canna yellow streak virus reveals its relationship to the sugarcane mosaic virus (SCMV) subgroup of potyviruses.  

PubMed

Complete genome sequences were obtained from nine isolates of canna yellow streak virus (CaYSV). CaYSV belongs to the sugarcane mosaic virus (SCMV) subgroup of potyviruses with johnsongrass mosaic virus (JGMV) as its closest relative. Multiple sequence alignments showed a pattern of amino acid substitutions in the CP sequences, which enabled us to relate these isolates to South East Asian or European isolates. Biological characterization of CaYSV identified Nicotiana benthamiana, Chenopodium quinoa and Phaseolus vulgaris as experimental hosts. Given the popularity and global trade of cannas, a clear picture of the genetic diversity of CaYSV is critical to disease management. PMID:25567205

Chauhan, Ravendra P; Rajakaruna, Punsasi; Verchot, Jeanmarie

2015-03-01

218

A single extraction method for the analysis by liquid chromatography/tandem mass spectrometry of fumonisins and biomarkers of disrupted sphingolipid metabolism in tissues of maize seedlings  

Technology Transfer Automated Retrieval System (TEKTRAN)

The fungus Fusarium verticillioides is a pathogen of many plants and produces fumonisins. In addition to their well-studied animal toxicoses these toxins contribute to the development of maize seedling disease in susceptible maize varieties. Fumonisin disruption of sphingolipid biosynthesis occurs ...

219

Global maize production, utilization, and consumption.  

PubMed

Maize (Zea mays), also called corn, is believed to have originated in central Mexico 7000 years ago from a wild grass, and Native Americans transformed maize into a better source of food. Maize contains approximately 72% starch, 10% protein, and 4% fat, supplying an energy density of 365 Kcal/100 g and is grown throughout the world, with the United States, China, and Brazil being the top three maize-producing countries in the world, producing approximately 563 of the 717 million metric tons/year. Maize can be processed into a variety of food and industrial products, including starch, sweeteners, oil, beverages, glue, industrial alcohol, and fuel ethanol. In the last 10 years, the use of maize for fuel production significantly increased, accounting for approximately 40% of the maize production in the United States. As the ethanol industry absorbs a larger share of the maize crop, higher prices for maize will intensify demand competition and could affect maize prices for animal and human consumption. Low production costs, along with the high consumption of maize flour and cornmeal, especially where micronutrient deficiencies are common public health problems, make this food staple an ideal food vehicle for fortification. PMID:24650320

Ranum, Peter; Peña-Rosas, Juan Pablo; Garcia-Casal, Maria Nieves

2014-04-01

220

MAIZEGDB: THE MAIZE COMMUNITY GENETICS AND GENOMICS DATABASE  

Technology Transfer Automated Retrieval System (TEKTRAN)

MaizeGDB (Maize Genetics and Genomics Database) is the research database for the maize community. The site features a wealth of resources and data facilitating the scientific study of maize. Among the data sets included in MaizeGDB are sequences, including integration with various contig assemblies;...

221

Nonstructural protein P7-2 encoded by Rice black-streaked dwarf virus interacts with SKP1, a core subunit of SCF ubiquitin ligase  

PubMed Central

Background Rice black-streaked dwarf virus (RBSDV), a member of the genus Fijivirus within the family Reoviridae, causes severe damage to cereal crops in South East Asia. The protein P7-2, encoded by the second open reading frame of segment S7, is conserved among most plant-infecting fijiviruses, but its function is still obscure. Results In this study, P7-2 was used as bait in two-hybrid screens of a cDNA library expressing Zea mays proteins. It was found that there is a strong interaction between P7-2 and Z. mays SKP1 (SKP1Maize), a core subunit of the multicomponent SCF (SKP1/Cullin1/F-box/Rbx1) E3 ubiquitin ligase. The interaction was then confirmed in leaf epidermal cells of Nicotiana benthamiana by bimolecular fluorescence complementation assay. Further investigations indicated that P7-2 also interacts with SKP1 proteins from other plants, including Arabidopsis thaliana, N. benthamiana,Oryza sativa and Saccharum sinense. The C-terminal fragment of SKP1Maize (residues 97–176) and the middle fragment of P7-2 (residues 79–214) are necessary to sustain the interaction, while the C-terminal putative ?-helix domain spanning residues 214–295 of P7-2 greatly facilitates the interaction. Agrobacterium-mediated transient suppression assay showed that P7-2 has no obvious activity to suppress local RNA silencing. Conclusions Taken together, our results indicated that RBSDV P7-2 can interact with SKP1 proteins from different plants. This is the first report linking a Fijivirus protein to a component of the ubiquitin proteasome system. P7-2 might be a potential F-box protein encoded by RBSDV and involved in the plant-virus interaction through ubiquitination pathway. PMID:24176102

2013-01-01

222

98 PHYTOPATHOLOGY Genetic Variation of Wheat streak mosaic virus  

E-print Network

disease of wheat (Triticum aestivum L.) with a worldwide distribution. WSMV is estimated to cause 5% yield the vector for other Potyvirus spp., including the virus responsible for High plains disease and Triticum

Murray, Timothy D.

223

GPI/V.TEK streak/single-frame image converter camera  

NASA Astrophysics Data System (ADS)

As a part of the joint research projects between General Physics Institute and Yonsei University/V.TEK Company, an experimental prototype of an image converter camera is designed and manufactured. The camera operates both in single frame and single shot streak modes. Single frame exposures are varied in the 250 - 1000 ns range, while recording intervals in streak mode are adjusted within the 2 - 1000 ns range over a 25 mm-wide output screen area. Temporal resolution at maximum streak speed is better than 10 ps. Total camera gain is 5 (DOT) 104. The camera is equipped with a specially designed PIF-V.1 image converter tube. Available are choices among S1, S20, or S25 photocathodes fabricated onto Molibden glass/UV glass, or MgF2 substrate.

Lozovoi, Valerij I.; Postovalov, Valdis E.; Prokhorov, Alexander M.; Schelev, Mikhail Y.; Park, Seung-Han; Kim, Ung; Lee, Jae-Sun

1993-01-01

224

System for photometric calibration of optoelectronic imaging devices especially streak cameras  

DOEpatents

A system for the photometric calibration of streak cameras and similar imaging devices provides a precise knowledge of the camera's flat-field response as well as a mapping of the geometric distortions. The system provides the flat-field response, representing the spatial variations in the sensitivity of the recorded output, with a signal-to-noise ratio (SNR) greater than can be achieved in a single submicrosecond streak record. The measurement of the flat-field response is carried out by illuminating the input slit of the streak camera with a signal that is uniform in space and constant in time. This signal is generated by passing a continuous wave source through an optical homogenizer made up of a light pipe or pipes in which the illumination typically makes several bounces before exiting as a spatially uniform source field. The rectangular cross-section of the homogenizer is matched to the usable photocathode area of the streak tube. The flat-field data set is obtained by using a slow streak ramp that may have a period from one millisecond (ms) to ten seconds (s), but may be nominally one second in duration. The system also provides a mapping of the geometric distortions, by spatially and temporarily modulating the output of the homogenizer and obtaining a data set using the slow streak ramps. All data sets are acquired using a CCD camera and stored on a computer, which is used to calculate all relevant corrections to the signal data sets. The signal and flat-field data sets are both corrected for geometric distortions prior to applying the flat-field correction. Absolute photometric calibration is obtained by measuring the output fluence of the homogenizer with a "standard-traceable" meter and relating that to the CCD pixel values for a self-corrected flat-field data set.

Boni, Robert; Jaanimagi, Paul

2003-11-04

225

Microcallus growth from maize protoplasts  

Microsoft Academic Search

Maize (Zea mays L.) protoplasts obtained from Type I and Type II calli from several genotypes were shown to be capable of synthesizing cell walls and forming small clusters of cells. The medium used also supported cluster formation from protoplasts obtained from root tips. The effects of various additions to the medium (such as casein hydrolysate, coconut water, amino acids,

C. Imbrie-Milligan; K. K. Kamo; T. K. Hodges

1987-01-01

226

AFFYMETRIX MAIZE PILOT EXPRESSION ARRAY  

Technology Transfer Automated Retrieval System (TEKTRAN)

A pilot study was conducted to evaluate design criteria and analytical methods (particularly signal estimators) for gene expression monitoring in a selection of maize inbreds (B73, W23, Mo17, Wf9-BG) and exotic land races using the Affymetrix probe array technology. The key issue was whether eleven ...

227

Flowering and Determinacy in Maize  

Technology Transfer Automated Retrieval System (TEKTRAN)

All plant organs are produced by meristems, groups of stem cells located in the tips of roots and shoots. Indeterminate meristems make an indefinite number of organs, whereas determinate meristems are consumed after making a specific number of organs. Maize is an ideal system to study the genetic co...

228

Maize Genetics and Genomics Database  

Technology Transfer Automated Retrieval System (TEKTRAN)

The 2007 report for MaizeGDB lists the new hires who will focus on curation/outreach and the genome sequence, respectively. Currently all sequence in the database comes from a PlantGDB pipeline and is presented with deep links to external resources such as PlantGDB, Dana Farber, GenBank, the Arizona...

229

Signal averaging x-ray streak camera with picosecond jitter A. Maksimchuk, M. Kim, J. Workman, G. Korn,a)  

E-print Network

resistance, two gold electrodes were deposited on the switch with a gap between the electrodes 4 mm wide picosecond x-ray streak camera using a dc-biased photoconductive switch as a generator of a high-voltage ramp that with the use of a high voltage photoconductive switch, which provides the sweep voltage for an optical streak

Umstadter, Donald

230

A maize wall-associated kinase confers quantitative resistance to head smut.  

PubMed

Head smut is a systemic disease in maize caused by the soil-borne fungus Sporisorium reilianum that poses a grave threat to maize production worldwide. A major head smut quantitative resistance locus, qHSR1, has been detected on maize chromosome bin2.09. Here we report the map-based cloning of qHSR1 and the molecular mechanism of qHSR1-mediated resistance. Sequential fine mapping and transgenic complementation demonstrated that ZmWAK is the gene within qHSR1 conferring quantitative resistance to maize head smut. ZmWAK spans the plasma membrane, potentially serving as a receptor-like kinase to perceive and transduce extracellular signals. ZmWAK was highly expressed in the mesocotyl of seedlings where it arrested biotrophic growth of the endophytic S. reilianum. Impaired expression in the mesocotyl compromised ZmWAK-mediated resistance. Deletion of the ZmWAK locus appears to have occurred after domestication and spread among maize germplasm, and the ZmWAK kinase domain underwent functional constraints during maize evolution. PMID:25531751

Zuo, Weiliang; Chao, Qing; Zhang, Nan; Ye, Jianrong; Tan, Guoqing; Li, Bailin; Xing, Yuexian; Zhang, Boqi; Liu, Haijun; Fengler, Kevin A; Zhao, Jing; Zhao, Xianrong; Chen, Yongsheng; Lai, Jinsheng; Yan, Jianbing; Xu, Mingliang

2015-02-01

231

Maize ZmRACK1 Is Involved in the Plant Response to Fungal Phytopathogens  

PubMed Central

The receptor for activated C kinase 1 (RACK1) belongs to a protein subfamily containing a tryptophan-aspartic acid-domain (WD) repeat structure. Compelling evidence indicates that RACK1 can interact with many signal molecules and affect different signal transduction pathways. In this study, we cloned a maize RACK1 gene (ZmRACK1) by RT-PCR. The amino acid sequence of ZmRACK1 had seven WD repeats in which there were typical GH (glycine-histidine) and WD dipeptides. Comparison with OsRACK1 from rice revealed 89% identity at the amino acid level. Expression pattern analysis by RT-PCR showed that ZmRACK1 was expressed in all analyzed tissues of maize and that its transcription in leaves was induced by abscisic acid and jasmonate at a high concentration. Overexpression of ZmRACK1 in maize led to a reduction in symptoms caused by Exserohilum turcicum (Pass.) on maize leaves. The expression levels of the pathogenesis-related protein genes, PR-1 and PR-5, increased 2.5–3 times in transgenic maize, and reactive oxygen species production was more active than in the wild-type. Yeast two-hybrid assays showed that ZmRACK1 could interact with RAC1, RAR1 and SGT1. This study and previous work leads us to believe that ZmRACK1 may form a complex with regulators of plant disease resistance to coordinate maize reactions to pathogens. PMID:24865494

Wang, Baosheng; Yu, Jingjuan; Zhu, Dengyun; Chang, Yujie; Zhao, Qian

2014-01-01

232

A connected set of genes associated with programmed cell death implicated in controlling the hypersensitive response in maize caused by a maize auto-active resistance gene  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rp1-D21 is a maize auto-active resistance gene that confers a spontaneous hypersensitive response (HR). Depending on the genetic background in which it operates; variable levels of HR are observed. This offers a convenient system to identify alleles that modulate HR and genes involved in disease res...

233

COMPARISON OF THREE CEREALS : WHEAT, MAIZE, BARLEY AND MAIZE-BARLEY, MAIZE-WHEAT MIXTURES  

E-print Network

DRYING TREATMENTS: TWO-STAGES DRYING OR DRYING FOLLOWED BY DELAYED SLOW COOLING In order to increase 20 p. ioo humidity, followed by storage without cooling and drying in a bin (delayed cooling the reception rate of dryers during the period of harvesting, it is possible either to dry the maize till about

Paris-Sud XI, Université de

234

Development of pachytene FISH maps for six maize chromosomes and their integration with other maize maps  

E-print Network

Development of pachytene FISH maps for six maize chromosomes and their integration with other maize in situ hybridization (FISH) maps were devel- oped for chromosomes 1, 3, 4, 5, 6, and 8 of maize using restriction fragment length polymorphism marker-selected Sorghum propinquum bacterial artifi- cial chromosomes

Ronquist, Fredrik

235

Investigations on Genetically Modified Maize (Bt-Maize) in Pig Nutrition: Chemical Composition and Nutritional Evaluation  

Microsoft Academic Search

The objective of the present study was to determine the composition and the nutritional value of parental and transgenic maize seeds fed to pigs. The parental maize line was genetically modified to incorporate a gene from Bacillus thuringiensis (Bt) expressing a toxin against the European corn borer (Ostrinia nubilalis). Both (parental and transgenic) maize lines were analyzed for crude nutrients,

T. Reuter; Karen Aulrich; A. Berk; G. Flachowsky

2002-01-01

236

Reducing photoperiod response of tropical maize germplasm for use in Midwestern maize introgression  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Germplasm Enhancement of Maize Project (GEM) is a cooperative effort of USDA-ARS, public and private sector scientists to broaden the genetic diversity of maize germplasm. Tropical maize germplasm is an important source of alleles for biotic and abiotic stress resistance and numerous value-adde...

237

CHROMOSOME-BY-CHROMOSOME MAIZE GENOME ANALYSIS USING OAT-MAIZE ADDITION LINES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Oat-maize Addition lines (OMA 1 through 10) are available where one maize chromosome has been individually added to the oat genome by a wide cross. By gamma irradiation, several hundred Radiation Hybrid (RH) lines now exist with only a fragment of the maize chromosome resulting from deletions of the...

238

Factors contributing to resistance of exotic maize populations to maize weevil, Sitophilus zeamais  

Microsoft Academic Search

Factors contributing to resistance of maize to infestation by the corn weevilSitophilus zeamais were investigated in four populations of indigenous and improved maize from Belize. Resistance was related to the antifeedant properties of grain as well as sugar content and mechanical hardness. Grain extracts of all populations of maize significantly reduced insect feeding on treated artificial diets when compared to

A. Serratos; J. T. Arnason; C. Nozzolillo; J. D. H. Lambert; B. J. R. Philogène; G. Fulcher; K. Davidson; L. Peacock; J. Atkinson; P. Morand

1987-01-01

239

Comportement de deux virus filamenteux (Carnation Vein Mottle Virus, Carnation Streak  

E-print Network

Comportement de deux virus filamenteux (Carnation Vein Mottle Virus, Carnation Streak Virus) dans Botanique et de Pathologie végétale, Villa Thuret, B.P. 78, 06602 Antibes Cedex. R�SUM� Virus filamenteux, Dosage, Spectrophotométrie, OEillet. L'évolution de la teneur en virus de la Marbrure des Nervures de l

Paris-Sud XI, Université de

240

Simultaneous velocity interferometry and electronic streak photography of laser-launched plates  

SciTech Connect

Laser-launched, miniature, pseudo-one-dimensional flyer plates are evaluated by three distinct optical techniques that may be incorporated into an optical diagnostic system to give a complete understanding of the plate performance. These techniques are: velocity interferometry, streak photography, and pulsed laser stereo photography. 2 refs., 5 figs.

Paisley, D.L.; Stahl, D.B.; Garcia, I.A.

1991-01-01

241

Journal of Theoretical Biology 233 (2005) 253269 Formation of the chick primitive streak as studied in  

E-print Network

as studied in computer simulations L. Bodensteina,Ã?, C.D. Sternb a Olana Technologies Inc.,5424 Arlington demonstrated that cells throughout the evolving streak are derived from Koller's sickle (an arc of cells at the posterior edge of the epiblast--see Appendix A) and the neighboring epiblast (here termed, sickle

Stern, Claudio

242

Carotenoid-based status signaling by females in the tropical streak-backed oriole  

Microsoft Academic Search

In many tropical bird species, both males and females maintain elaborate plumage traits. Although there is considerable evidence that many male plumage traits function as status signals that convey information about fighting ability, less is known about status signaling in females. We tested whether the carotenoid-based orange breast coloration of the female streak-backed oriole (Icterus pustulatus pustulatus) signals status during

Troy G. Murphy; Diego Hernández-Muciño; Marcela Osorio-Beristain; Robert Montgomerie; Kevin E. Omland

2009-01-01

243

FGF Signaling Regulates Mesoderm Cell Fate Specification and Morphogenetic Movement at the Primitive Streak  

Microsoft Academic Search

Although FGF signaling plays an integral role in the migration and patterning of mesoderm at gastrulation, the mechanism and downstream targets of FGF activity have remained elusive. Here, we demonstrate that FGFR1 orchestrates the epithelial to mesenchymal transition and morphogenesis of mesoderm at the primitive streak by controlling Snail and E-cadherin expression. Furthermore, we show that FGFR1 functions in mesoderm

Brian Ciruna; Janet Rossant

2001-01-01

244

SUSCEPTIBILITY OF PERENNIAL SMALL GRAINS TO SOILBORNE WHEAT MOSAIC VIRUS AND WHEAT SPINDLE STREAK MOSAIC VIRUS  

Technology Transfer Automated Retrieval System (TEKTRAN)

An undetermined threat to perennial small grain production is infection by the soilborne viruses, Soilborne wheat mosaic virus (SBWMV) and Wheat spindle streak mosaic virus (WSSMV). We conducted preliminary experiments to assess whether perennial wheat and rye breeding lines were susceptible to SBW...

245

Multiplex Real Time PCR For Detection of Wheat Streak Mosaic Virus and Triticum Mosaic Virus  

Technology Transfer Automated Retrieval System (TEKTRAN)

Wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TRIMV) are widespread throughout the southwestern Great Plains states. Using conventional diagnostics such as Enzyme-Linked Immunosorbent Assays (ELISA), these two viruses are commonly found together in infected wheat samples. Methods for m...

246

WHEAT STREAK MOSAIC VIRUS (DESCRIPTIONS OF PLANT VIRUSES NO. 48, REVISED)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Biological and physical properties of Wheat streak mosaic virus (genus Tritimovirus) are presented in brief monograph form. The publication represents an updated revision of The Description of Plant Viruses No. 48, originally published in 1971 by the Association of Applied Biologists. Topics cover...

247

Interactive Streak Surface Visualization on the GPU Kai Burger, Florian Ferstl, Holger Theisel, and Rudiger Westermann  

E-print Network

, and R¨udiger Westermann Fig. 1. Our method generates adaptively refined integral surfaces in 3D flows generated and rendered in less than 50ms. Figure a) and b) show streak surfaces in unsteady flows. Figure c) shows a stream surface. Abstract--In this paper we present techniques for the visualization of unsteady

248

Interactive Separating Streak Surfaces Florian Ferstl, Kai Burger, Holger Theisel, and Rudiger Westermann  

E-print Network

¨udiger Westermann Fig. 1. Our method generates streak surfaces revealing separating structures in unsteady 3D flow are among the most important features to support 3D unsteady flow exploration, but they are also among exploration of 3D unsteady flows using such surfaces is not feasible. Therefore, in this paper we present

249

Deblurring Low-light Images with Light Streaks Sunghyun Cho2  

E-print Network

for estimating the blur kernel in an optimization framework. Our method also automatically detects useful lightDeblurring Low-light Images with Light Streaks Zhe Hu1 Sunghyun Cho2 Jue Wang2 Ming-Hsuan Yang1 1 University of California, Merced 2 Adobe Research Abstract Images taken in low-light conditions with handheld

Yang, Ming-Hsuan

250

Formation and evolution of a hairpin vortex induced by subharmonic sinuous low-speed streaks  

NASA Astrophysics Data System (ADS)

In this paper, a process of the formation and evolution of hairpin vortices, which originated from the interaction between the spanwise-aligned low-speed streaks with a subharmonic sinuous (SS) oscillation mode, is studied using a direct numerical simulation method in a small periodic local region of an incompressible plane channel flow. The initial artificial perturbations are used to excite the SS-mode oscillation of two spanwise-aligned low-speed streaks in such a flow. A new mechanism of formation and decay of the hairpin vortices is proposed in which the shear layer induced by the spanwise collision and merging between the low-speed streaks is emphasized. Our results show that the streamwise vortices can be induced by the SS-mode streaks and then developed into an X-like pattern at the initial stage due to the mutual induction effect. The X-like vortices further enhance the spanwise oscillation and lift-up of the two streaks that thus lead to the spanwise collision and merging of the low-speed streaks and produce a low-speed region in high-speed fluid. The strong shear layer between the high- and low-speed fluids gives rise to the spanwise vorticity that connects the X-like streamwise vortices and forms the ?-like vortex. Once the low-speed region entirely enters the high-speed fluid, the shear layer shows the ring shape and results in the transition from a ?-like vortex to ?-like one. After that, the viscous diffusion of the low-speed region in the high-speed fluid leads to the decay of the ?-like vortex; the collision and merging of the low-speed streaks simultaneously reoccur upstream and give birth to a secondary ?-like vortex, which exhibits behavior that is nearly similar with that of the primary one. Although the hairpin vortex packet is not observed in the present plane channel flow, the regeneration of the hairpin vortex suggests that this type of vortical structure plays an important role in the wall-bounded flow.

Li, Jian; Dong, Gang; Lu, Ziheng

2014-10-01

251

Fate Mapping Identifies the Origin of SHF/AHF Progenitors in the Chick Primitive Streak  

PubMed Central

Heart development depends on the spatio-temporally regulated contribution of progenitor cells from the primary, secondary and anterior heart fields. Primary heart field (PHF) cells are first recruited to form a linear heart tube; later, they contribute to the inflow myocardium of the four-chambered heart. Subsequently cells from the secondary (SHF) and anterior heart fields (AHF) are added to the heart tube and contribute to both the inflow and outflow myocardium. In amniotes, progenitors of the linear heart tube have been mapped to the anterior-middle region of the early primitive streak. After ingression, these cells are located within bilateral heart fields in the lateral plate mesoderm. On the other hand SHF/AHF field progenitors are situated anterior to the linear heart tube, however, the origin and location of these progenitors prior to the development of the heart tube remains elusive. Thus, an unresolved question in the process of cardiac development is where SHF/AHF progenitors originate from during gastrulation and whether they come from a region in the primitive streak distinct from that which generates the PHF. To determine the origin and location of SHF/AHF progenitors we used vital dye injection and tissue grafting experiments to map the location and ingression site of outflow myocardium progenitors in early primitive streak stage chicken embryos. Cells giving rise to the AHF ingressed from a rostral region of the primitive streak, termed region ‘A’. During development these cells were located in the cranial paraxial mesoderm and in the pharyngeal mesoderm. Furthermore we identified region ‘B’, located posterior to ‘A’, which gave rise to progenitors that contributed to the primary heart tube and the outflow tract. Our studies identify two regions in the early primitive streak, one which generates cells of the AHF and a second from which cardiac progenitors of the PHF and SHF emerge. PMID:23272192

Camp, Esther; Dietrich, Susanne; Münsterberg, Andrea

2012-01-01

252

PLANT SCIENCES: Promiscuous Maize Chromosomes  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. The intricate chromosome dance that characterizes meiotic cell division involves careful coordination of chromosome pairing, recombination, and synapsis. In their Perspective, Martinez-Perez and Moore discuss new work that identifies the PHS1 protein in maize as being a key player in the coordination of these three events (Pawlowski et al.).

Enrique Martinez-Perez (Stanford University; Department of Developmental Biology)

2004-01-02

253

Resistance of maize landraces to the maize weevil Sitophilus zeamais Motsch. (Coleoptera: Curculionidae).  

PubMed

The maize weevil Sitophilus zeamais Motsch. is an important pest of maize that attacks the grain both in the field and during storage. The damage caused by the maize weevil S. zeamais on maize landraces, Amarelo Antigo, Asteca, Caiano, Carioca, and Ferrinho, was evaluated by no-choice tests under laboratory conditions. The commercial varieties Sol da Manhã, BR 106, BR 451, and the synthetics PC 0203 and PC 9903 were evaluated for comparisons with the maize landraces. The parameters evaluated were susceptibility index, number of weevil progeny, development time, weevil progeny dry weight, and grain dry weight loss. The landraces were more susceptible to the maize weevil as compared to the commercial varieties. Based on the cluster analysis, two groups of susceptibility to the maize weevil were observed: one of more susceptible populations formed by local landraces and BR 451, and another less susceptible, with commercial varieties, synthetics, and the landrace Amarelo. PMID:23950091

Mikami, A Y; Carpentieri-Pípolo, V; Ventura, Maurício Ursi

2012-10-01

254

Influence of rice black streaked dwarf virus on the ecological fitness of non-vector planthopper Nilaparvata lugens (Hemiptera: Delphacidae).  

PubMed

Rice black streak dwarf virus (RBSDV) is transmitted by the small brown planthopper (SBPH), Laodelphax striatellus (Fallen). Non-vector rice brown planthopper (BPH), Nilaparvata lugens (Stål), shares the same host rice plants with SBPH in paddy fields. The changes in nutritional composition of rice plants infected by RBSDV and the ecological fitness of BPH feeding on the infected plants were studied under both artificial climate chamber and field conditions. Contents of 16 detected amino acids and soluble sugar in RBSDV infected rice plants were higher than those in the healthy ones. On the diseased plants BPH had significantly higher nymphal survival rates, nymphal duration of the males, weight of the female adults, as well as egg hatchability compared to BPH being fed on healthy plants. However, there was no obvious difference in female nymph duration, longevity and fecundity. Defense enzymes (superoxidase dismutase, SOD and catalase, CAT) and detoxifying enzymes (carboxylesterase, CAE and glutathione S-transferase, GST) in BPH adults fed on diseased plants had markedly higher activities. The results indicate rice plants infected by RBSDV improved the ecological fitness of the brown planthopper, a serious pest but not a transmitter of the RBSDV virus. PMID:23956237

Xu, Hong-Xing; He, Xiao-Chan; Zheng, Xu-Song; Yang, Ya-Jun; Lu, Zhong-Xian

2014-08-01

255

Identification and validation of sugarcane streak mosaic virus-encoded microRNAs and their targets in sugarcane.  

PubMed

Plants have developed several defense mechanisms to cope with various pathogens (bacteria, fungi, virus, and phytoplasma). Among these, RNA interference (RNAi)-mediated defense against viral infection was found to be a major innate immune response. As a counter attack strategy against the host defense, viruses produce suppressors of host RNAi pathway. MicroRNAs (miRNAs) are an abundant class of short (~18-22 nucleotide) non-coding single-stranded RNAs involved in RNAi pathway leading to post-transcriptional regulation of gene expression. Sugarcane streak mosaic virus (SCSMV) is a distinct strain of Potyviridae family which has a single-stranded positive-sense RNA genome causing mosaic disease in sugarcane. In this study, we computationally predicted and experimentally validated the miRNA encoded by the SCSMV genome with detection efficiency of 99.9 % in stem-loop RT-qPCR and predicted their potential gene targets in sugarcane. These sugarcane target genes considerably broaden future investigation of the SCSMV-encoded miRNA function during viral pathogenesis and might be applied as a new strategy for controlling mosaic disease in sugarcane. PMID:24145912

Viswanathan, Chandran; Anburaj, Jeyaraj; Prabu, Gajjeraman

2014-02-01

256

The iojap gene in maize  

SciTech Connect

The classical maize mutant iojap (Iodent japonica) has variegated green and white leaves. Green sectors have cells with normal chloroplasts whereas white sectors have cells where plastids fail to differentiate. These mutant plastids, when transmitted through the female gametophyte, do not recover in the presence of wild type Iojap. We cloned the Ij locus, and we have investigated the mechanism of epigenetic inheritance and phenotypic expression. More recently, a modifier of this type of variegation, ''Inhibitor of striate'', has also been cloned. Both the iojap and inhibitor of striate proteins have homologs in bacteria and are members of ancient conserved families found in multiple species. These tools can be used to address fundamental questions of inheritance and variegation associated with this classical conundrum of maize genetics. Since the work of Rhoades there has been considerable speculation concerning the nature of the Iojap gene product, the origin of leaf variegation and the mechanism behind the material inheritance of defective plastids. This has made Iojap a textbook paradigm for cytoplasmic inheritance and nuclear-organellar interaction for almost 50 years. Cloning of the Iojap gene in maize, and homologs in other plants and bacteria, provides a new means to address the origin of heteroplastidity, variegation and cytoplasmic inheritance in higher plants.

Martienssen, Robert

2001-12-01

257

Tumor necrosis factor-alpha deficiency retards early fatty-streak lesion by influencing the expression of inflammatory factors in apoE-null mice.  

PubMed

Tumor necrosis factor-alpha (TNF-alpha), a key inflammatory cytokine, plays an important role in atherosclerosis. However, its precise characters in primary stage of the disease remain unclear. To assess the influence of TNF-alpha on inflammatory factors in aorta and liver in apoE and TNF-alpha double mutant (AT) mice, a comparative study on early fatty-streak lesion, the mRNA level of target gene in aorta and liver of adolescent AT and apoE-null (apoE(-/-)) mice were achieved. The characteristics of expression of inflammatory factors, and early fatty-streak lesion relevance were analyzed. The plasma cytokines in 6-week-old AT and apoE(-/-) mice were also measured. Lipid accumulation in the intima of the aorta existed as early as 3 weeks of age in apoE(-/-) mice. Fatty-streak lesion was mild in AT mice but prominent in apoE(-/-) mice, at age of 6 weeks. Furthermore, most interesting findings indicate that mRNA levels of pro-atherosclerotic factors, i.e. IL-1beta, IFN-gamma, ICAM-1, VCAM-1, MCP-1, GM-CSF and NF-kappaB (p65) were significantly downregulated in AT mice. Whereas IL-2 and IkappaB-alpha were upregulated in aorta of AT mice versus those in apoE(-/-) mice (p<0.01) and the transcript levels of pro-inflammatory cytokines, such as IL-1beta, IFN-gamma, ICAM-1, VCAM-1, MCP-1 and GM-CSF, increased with atherogenesis progression. On the other hand, the expression of these inflammatory factors in the liver displayed somewhat similar fashion to those in the aorta. Moreover, the plasma lipids profile in AT mice showed less pro-atherogenic than that of apoE(-/-) mice. Our data indicated that TNF-alpha deficiency surely, although not completely, retards fatty-streak lesion formation due to downregulated expression of the pro-atherosclerotic inflammatory factors in the present circumstance. PMID:19157944

Xiao, Ning; Yin, Miao; Zhang, Liang; Qu, Xuebin; Du, Hui; Sun, Xiaoming; Mao, Liufeng; Ren, Guocheng; Zhang, Cong; Geng, Yue; An, Liguo; Pan, Jie

2009-04-01

258

Fusarium verticillioides gene clusters associated with biotransformation of maize allelopathic compounds  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize produces the benzoxazinones DIMBOA and DIBOA, which naturally transform into the more stable benzoxazolinones MBOA and BOA, respectively. These weed-suppressive allelopathic compounds are also implicated in resistance to microbial diseases and insect feeding. Fusarium verticillioides is able t...

259

Deciphering maize genetics and ecology to reduce insect damage and aflatoxin accumulation  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ear-colonizing insects and diseases, which reduce yield and impose health threats via mycotoxin contaminations, are critical impediments for maize production in the southern US states. To address this problem a combination of basic and applied research approaches are being conducted by the interdis...

260

Characterization of strains of Bacillus mojavensis for biocontrol of a maize pathogen  

Technology Transfer Automated Retrieval System (TEKTRAN)

The endophytic bacterium, Bacillus mojavensis controls fungal diseases in maize and other plants. The bacterium and its cultural extracts have been shown to be antagonistic to a pathogenic and mycotoxic fungus, Fusarium verticillioides. Extracts prepared from cultures of B. mojavensis contained an...

261

A MAJOR QTL FOR SUPPRESSION OF LESION MIMIC PHENOTYPE IN MAIZE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize plants are subjected to many stresses in the field during growth. Plant response to these stresses affect yield. Lesion mimics are useful to study plant reactions to stresses because the mutant plants show many symptoms of disease without the presence and complications of a causal organism. M...

262

Maize resistance and susceptibility to multiple ear-damaging pests: Progress and prospects  

Technology Transfer Automated Retrieval System (TEKTRAN)

Three sets of corn germplasm (including both inbred lines and experimental hybrids from diverse genetic background) have been examined separately for major ear-feeding insect and ear-colonizing disease resistance for two years. The ear-feeding insect damage assessment included corn earworm, maize w...

263

Using Maize chlorotic dwarf virus to explore future frontiers in plant virology  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize chlorotic dwarf virus (MCDV) causes a chlorosis and stunting disease of corn throughout the Midwest United States. It is a waikavirus transmitted by the leafhopper Graminella nigrifrons. Although waikaviruses are economically important viruses in corn and rice, little is known about the viru...

264

DROUGHT MANAGEMENT OPTIONS IN MAIZE PRODUCTION IN NORTHERN TANZANIA  

Microsoft Academic Search

The northern zone of Tanzania is one of the major maize producing areas of the country. Population increase is pushing maize production into marginal areas with little and unreliable rainfall. Irrigation, which could support maize production under these conditions, is underdeveloped and expensive to operate by the poor communities. Options available to improve maize production to feed the rising population

T. E. Mmbaga; C. Y. Lyamchai

265

Functional Allelic Variation at Key Photoperiod Response QTL in Maize  

Technology Transfer Automated Retrieval System (TEKTRAN)

Tropical maize represents a valuable genetic resource containing unique alleles not present in elite temperate maize. The strong delay in flowering in response to long daylength photoperiods exhibited by most tropical maize hinders its incorporation into temperate maize breeding programs. We tested ...

266

MaizeGDB's new data types, resources, and activities  

Technology Transfer Automated Retrieval System (TEKTRAN)

MaizeGDB is the Maize Genetics and Genomics Database. Available at MaizeGDB are diverse data that support maize research including maps, gene product information, loci and their various alleles, phenotypes (both naturally occurring and as a result of directed mutagenesis), stocks, sequences, molecul...

267

REGULAR ARTICLE Field decomposition of transgenic Bt maize residue  

E-print Network

REGULAR ARTICLE Field decomposition of transgenic Bt maize residue and the impact on non modified Bacillus thuringiensis Berliner (Bt) maize (Zea mays L.) expressing Cry toxins against various of Bt maize expressing the Cry1Ab protein on both the soil community and maize residue decomposition. We

Richner, Heinz

268

The genetic architecture of maize height  

Technology Transfer Automated Retrieval System (TEKTRAN)

Height is one of the most heritable and easily measured traits in maize (Zea mays L.). Given a pedigree or estimates of the genomic identity-by-state (IBS) among related plants, height is also accurately predictable. But, mapping alleles explaining natural variation in maize height remains a formida...

269

FUNCTIONAL GENOMICS OF ENDOSPERM DEVELOPMENT IN MAIZE  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Maize Endosperm Functional Genomics Project is developing tools for the molecular cloning of seed mutants in maize. Specifically, we are developing normalized and subtracted ESTs from endopserm cDNA libraries, identifying transposon-tagged endosperm mutants from the mutagenic inbred, UniformMu, ...

270

Maize metabolic network construction and transcriptome analysis  

Technology Transfer Automated Retrieval System (TEKTRAN)

A framework for understanding the synthesis and catalysis of metabolites and other biochemicals by proteins is crucial for unraveling the physiology of cells. To create such a framework for Zea mays ssp. mays (maize), we developed MaizeCyc a metabolic network of enzyme catalysts, proteins, carbohydr...

271

Ratings of Commercial Grain Sorghum Hybrids to the Maize Dwarf Mosaic Virus.  

E-print Network

the area as possible. DISEASE DESCRIPTION M aize Dwarf Mosaic Maize dwarf mosaic is caused by an aphid-transmitted virus that overwinters in the rhizomes of johnsongrass. These virus particles are extremely small and contami nate the mouth parts...5.7 LIBRARY SEP 26 1984 nlversity t ? gs of CommerCia Grain Sorghum Hybrids to the Maize Dwarf , Mosaic Virus [EXAS STATE DEPOSITOR'l SEP 1 91984 RETAIN FOR 5 YEARS ~ Texas Agricultural Extension Service. The Texas A&M University System...

Horne, C. Wendell; Frederiksen, Richard A.; Toler, Robert W.; Trampota, Jerry D.

1984-01-01

272

Associations of planting date, drought stress, and insects with Fusarium ear rot and fumonisin B1 contamination in California maize  

Microsoft Academic Search

Fusarium ear rot, caused by Fusarium verticillioides, is one of the most common diseases of maize, causing yield and quality reductions and contamination of grain by fumonisins and other mycotoxins. Drought stress and various insects have been implicated as factors affecting disease severity. Field studies were conducted to evaluate the interactions and relative influences of drought stress, insect infestation, and

M. W. Parsons; G. P. Munkvold

2010-01-01

273

Simultaneous virus-specific detection of the two cassava brown streak-associated viruses by RT-PCR reveals wide distribution in East Africa, mixed infections, and infections in Manihot glaziovii.  

PubMed

The expanding cassava brown streak disease (CBSD) epidemic in East Africa is caused by two ipomoviruses (genus Ipomovirus; Potyviridae), namely, Cassava brown streak virus (CBSV), and Ugandan cassava brown streak virus (UCBSV) that was described recently. A reverse transcription polymerase chain reaction (RT-PCR) based diagnostic method was developed in this study for simultaneous virus-specific detection of the two viruses. Results showed that CBSV and UCBSV are distributed widely in the highlands (> 1000 m above the sea level) of the Lake Victoria zone in Uganda and Tanzania and also in the Indian Ocean costal lowlands of Tanzania. Isolates of UCBSV from the Lake Victoria zone were placed to two phylogenetic clusters in accordance with their origin in Uganda or Tanzania, respectively. Mixed infections with CBSV and UCBSV were detected in many cassava plants in the areas surveyed. CBSV was also detected in the perennial species Manihot glaziovii (DNA-barcoded in this study) in Tanzania, which revealed the first virus reservoir other than cassava. The method for detection of CBSV and UCBSV described in this study has important applications for plant quarantine, resistance breeding of cassava, and studies on epidemiology and control of CBSD in East Africa. PMID:20923689

Mbanzibwa, D R; Tian, Y P; Tugume, A K; Mukasa, S B; Tairo, F; Kyamanywa, S; Kullaya, A; Valkonen, J P T

2011-02-01

274

Production of highly concentrated, heat stable hepatitis B surface antigen in maize  

PubMed Central

Summary Plant-based oral vaccines are a promising emergent technology that could help alleviate disease burden worldwide by providing a low-cost, heat stable, oral alternative to parenterally administered commercial vaccines. Here we describe high-level accumulation of the hepatitis B surface antigen (HBsAg) at a mean concentration of 0.51%TSP in maize T1 seeds using an improved version of the globulin1 promoter. This concentration is more than four-fold higher than any previously reported lines. HBsAg expressed in maize seeds was extremely heat stable, tolerating temperatures up to 55°C for one month without degradation. Optimal heat stability was achieved after oil extraction of ground maize material, either by supercritical fluid extraction or hexane treatment. The contributions of this material towards the development of a practical oral vaccine delivery system are discussed. PMID:22816734

Hayden, Celine A.; Egelkrout, Erin M.; Moscoso, Alessa M.; Enrique, Cristina; Keener, Todd K.; Jimenez-Flores, Rafael; Wong, Jeffrey C.; Howard, John A.

2012-01-01

275

Antimicrobial activity of pyrrocidines from Acremonium zeae against endophytes and pathogens of maize.  

PubMed

Acremonium zeae produces pyrrocidines A and B, which are polyketide-amino acid-derived antibiotics, and is recognized as a seedborne protective endophyte of maize which augments host defenses against microbial pathogens causing seedling blights and stalk rots. Pyrrocidine A displayed significant in vitro activity against Aspergillus flavus and Fusarium verticillioides in assays performed using conidia as inoculum, with pyrrocidine A being more active than B. In equivalent assays performed with conidia or hyphal cells as inoculum, pyrrocidine A revealed potent activity against major stalk and ear rot pathogens of maize, including F. graminearum, Nigrospora oryzae, Stenocarpella (Diplodia) maydis, and Rhizoctonia zeae. Pyrrocidine A displayed significant activity against seed-rotting saprophytes A. flavus and Eupenicillium ochrosalmoneum, as well as seed-infecting colonists of the phylloplane Alternaria alternata, Cladosporium cladosporioides, and Curvularia lunata, which produces a damaging leaf spot disease. Protective endophytes, including mycoparasites which grow asymptomatically within healthy maize tissues, show little sensitivity to pyrrocidines. Pyrrocidine A also exhibited potent activity against Clavibacter michiganense subsp. nebraskense, causal agent of Goss's bacterial wilt of maize, and Bacillus mojaviense and Pseudomonas fluorescens, maize endophytes applied as biocontrol agents, but were ineffective against the wilt-producing bacterium Pantoea stewartii. PMID:19055442

Wicklow, Donald T; Poling, Stephen M

2009-01-01

276

Benzoxazinoids in Root Exudates of Maize Attract Pseudomonas putida to the Rhizosphere  

PubMed Central

Benzoxazinoids, such as 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA), are secondary metabolites in grasses. In addition to their function in plant defence against pests and diseases above-ground, benzoxazinoids (BXs) have also been implicated in defence below-ground, where they can exert allelochemical or antimicrobial activities. We have studied the impact of BXs on the interaction between maize and Pseudomonas putida KT2440, a competitive coloniser of the maize rhizosphere with plant-beneficial traits. Chromatographic analyses revealed that DIMBOA is the main BX compound in root exudates of maize. In vitro analysis of DIMBOA stability indicated that KT2440 tolerance of DIMBOA is based on metabolism-dependent breakdown of this BX compound. Transcriptome analysis of DIMBOA-exposed P. putida identified increased transcription of genes controlling benzoate catabolism and chemotaxis. Chemotaxis assays confirmed motility of P. putida towards DIMBOA. Moreover, colonisation essays in soil with Green Fluorescent Protein (GFP)-expressing P. putida showed that DIMBOA-producing roots of wild-type maize attract significantly higher numbers of P. putida cells than roots of the DIMBOA-deficient bx1 mutant. Our results demonstrate a central role for DIMBOA as a below-ground semiochemical for recruitment of plant-beneficial rhizobacteria during the relatively young and vulnerable growth stages of maize. PMID:22545111

Neal, Andrew L.; Ahmad, Shakoor; Gordon-Weeks, Ruth; Ton, Jurriaan

2012-01-01

277

Effects of diabatic heating on the ageostrophic circulation of an upper tropospheric jet streak  

NASA Technical Reports Server (NTRS)

Interaction between the mass circulation within a mesoscale convective complex (MCC) and a direct mass circulation in the entrance region of an upper tropospheric polar jet streak was examined within the isentropic structure to investigate mechanisms responsible for linking these two scales of motion. The results establish that latent heating in the MCC modifies the direct mass circulation in the jet streak entrance region through the diabatically induced components of ageostrophic motion analyzed within isentropic coordinates. Within the strong mesoscale mass circulation of each MCC, strong horizontal mass flux convergence into the MCC at low levels is balanced by strong horizontal mass flux divergence away from the convergence at upper levels. Locations of large diabatic heating rates correspond well to the MCC position for each case; diabatic heating forces the upward vertical branch for the mesoscale mass circulation.

Keyser, D. A.; Johnson, D. R.

1982-01-01

278

Streaked radiography of an irradiated foam sample on the National Ignition Facility  

NASA Astrophysics Data System (ADS)

Streaked x-ray radiography images of annular patterns in an evolving tantalum oxide foam under the influence of a driven, subsonic radiation wave were obtained on the National Ignition Facility. This is the first successful radiography measurement of the evolution of well-defined foam features under a driven, subsonic wave in the diffusive regime. A continuous record of the evolution was recorded on an x-ray streak camera, using a slot-apertured point-projection backlighter with an 8 ns nickel source (7.9 keV). Radiography images were obtained for four different annular patterns, which were corrected using a source-dependent flat-field image. The evolution of the foam features was well-modeled using the 3D KULL radiation hydrodynamics code. This experimental and modeling platform can be modified for scaled high-energy-density laboratory astrophysics experiments.

Cooper, A. B. R.; Schneider, M. B.; MacLaren, S. A.; Moore, A. S.; Young, P. E.; Hsing, W. W.; Seugling, R.; Foord, M. E.; Sain, J. D.; May, M. J.; Marrs, R. E.; Maddox, B. R.; Lu, K.; Dodson, K.; Smalyuk, V.; Graham, P.; Foster, J. M.; Back, C. A.; Hund, J. F.

2013-03-01

279

Single-shot visualization of evolving laser wakefields using an all-optical streak camera.  

PubMed

We visualize ps-time-scale evolution of an electron density bubble--a wake structure created in atmospheric density plasma by an intense ultrashort laser pulse--from the phase "streak" that the bubble imprints onto a probe pulse that crosses its path obliquely. Phase streaks, recovered in one shot using frequency-domain interferometric techniques, reveal the formation, propagation, and coalescence of the bubble within a 3 mm long ionized helium gas target. 3D particle-in-cell simulations validate the observed density-dependent bubble evolution, and correlate it with the generation of a quasimonoenergetic ? 100 MeV electron beam. The results provide a basis for understanding optimized electron acceleration at a plasma density n(e) ? 2 × 10(19) cm(-3), inefficient acceleration at lower density, and dephasing limits at higher density. PMID:25192102

Li, Zhengyan; Tsai, Hai-En; Zhang, Xi; Pai, Chih-Hao; Chang, Yen-Yu; Zgadzaj, Rafal; Wang, Xiaoming; Khudik, V; Shvets, G; Downer, M C

2014-08-22

280

Single-Shot Visualization of Evolving Laser Wakefields Using an All-Optical Streak Camera  

NASA Astrophysics Data System (ADS)

We visualize ps-time-scale evolution of an electron density bubble—a wake structure created in atmospheric density plasma by an intense ultrashort laser pulse—from the phase "streak" that the bubble imprints onto a probe pulse that crosses its path obliquely. Phase streaks, recovered in one shot using frequency-domain interferometric techniques, reveal the formation, propagation, and coalescence of the bubble within a 3 mm long ionized helium gas target. 3D particle-in-cell simulations validate the observed density-dependent bubble evolution, and correlate it with the generation of a quasimonoenergetic ˜100 MeV electron beam. The results provide a basis for understanding optimized electron acceleration at a plasma density ne?2×1019 cm-3, inefficient acceleration at lower density, and dephasing limits at higher density.

Li, Zhengyan; Tsai, Hai-En; Zhang, Xi; Pai, Chih-Hao; Chang, Yen-Yu; Zgadzaj, Rafal; Wang, Xiaoming; Khudik, V.; Shvets, G.; Downer, M. C.

2014-08-01

281

Controlling and Streaking Nanotip Photoemission by Enhanced Single-cycle Terahertz Pulses  

E-print Network

The active control of matter by strong electromagnetic fields is of growing importance, with applications all across the optical spectrum from the extreme-ultraviolet to the far-infrared. In recent years, phase-stable terahertz (THz) fields have shown tremendous potential in the observation and manipulation of elementary excitations in complex systems. The combination of concepts from attosecond science with advanced THz technology facilitates novel spectroscopic schemes, such as THz streaking. In general, driving charges at lower frequency enhances interaction energies and can promote drastically different dynamics. For example, mid-infrared excitation induces field-driven sub-cycle electron dynamics in nanostructure nearfields. Such frequency scalings will also impact nanostructure-based streaking, which has been theoretically proposed. Here, we experimentally demonstrate extensive control over nanostructure photoelectron emission using single-cycle THz transients. The locally enhanced THz near-field at a n...

Wimmer, L; Solli, D R; Yalunin, S V; Echternkamp, K; Ropers, C

2013-01-01

282

An approach for megahertz OCT: streak mode Fourier domain optical coherence tomography  

NASA Astrophysics Data System (ADS)

We report a technique, which uses an area-scan camera to record the interference spectrum. Traditional point-scanning is remained in this streak-mode FDOCT so that the small aperture of the single-mode fiber functions as a confocal gate and screens multiply scattered photons very well. While the sample beam is scanning the specimen laterally, the interference spectrum is physically scanned on the area scan camera using a streak scanner. Therefore, pixels of the camera are illuminated by the spectrum of OCT signal row by row, corresponding to each A-scan at different lateral position. A unidirectional B-scan of 700 lines is obtained in 1 ms; thus, an A-scan time of 1.4 ?s is achieved. A Day 4 chick embryo sampled is imaged using this method. This technique is highly potential for multi-Megahertz OCT imaging.

Wang, Rui; Yun, Julie X.; Yuan, Xiaocong; Goodwin, Richard; Markwald, Roger; Gao, Bruce

2011-03-01

283

4D imaging of embryonic chick hearts by streak-mode Fourier domain optical coherence tomography  

NASA Astrophysics Data System (ADS)

Recently, we developed the streak-mode Fourier domain optical coherence tomography (OCT) technique in which an area-scan camera is used in a streak-mode to record the OCT spectrum. Here we report the application of this technique to in ovo imaging HH18 embryonic chick hearts with an ultrahigh speed of 1,016,000 axial scans per second. The high-scan rate enables the acquisition of high temporal resolution 2D datasets (1,000 frames per second or 1 ms between frames) and 3D datasets (10 volumes per second), without use of prospective or retrospective gating technique. This marks the first time that the embryonic animal heart has been 4D imaged using a megahertz OCT.

Wang, Rui; Yun, Julie X.; Goodwin, Richard; Markwald, Roger; Borg, Thomas K.; Runyan, Raymond B.; Gao, Bruce

2012-02-01

284

Plant growth hormones suppress the development of Harpophora maydis, the cause of late wilt in maize.  

PubMed

Late wilt, a severe vascular disease of maize caused by the fungus Harpophora maydis, is characterized by rapid wilting of maize plants before tasseling and until shortly before maturity. The pathogen is currently controlled by resistant maize cultivars, but the disease is constantly spreading to new areas. The plant's late phenological stage at which the disease appears suggests that plant hormones may be involved in the pathogenesis. This work revealed that plant growth hormones, auxin (Indole-3-acetic acid) and cytokinin (kinetin), suppress H. maydis in culture media and in a detached root assay. Kinetin, and even more auxin, caused significant suppression of fungus spore germination. Gibberellic acid did not alter colony growth rate but had a signal suppressive effect on the pathogens' spore germination. In comparison, ethylene and jasmonic acid, plant senescing and defense response regulators, had minor effects on colony growth and spore germination rate. Their associate hormone, salicylic acid, had a moderate suppressive effect on spore germination and colony growth rate, and a strong influence when combined with auxin. Despite the anti-fungal auxin success in vitro, field experiments with dimethylamine salt of  2,4-dichlorophenoxyacetic acid (that mimics the influence of auxin) failed to suppress the late wilt. The lines of evidence presented here reveal the suppressive influence of the three growth hormones studied on fungal development and are important to encourage further and more in-depth examinations of this intriguing hormonal complex regulatory and its role in the maize-H. maydis interactions. PMID:25649030

Degani, Ofir; Drori, Ran; Goldblat, Yuval

2015-01-01

285

Ultrafast x-ray streak camera for use in ultrashort laser-produced plasma research  

Microsoft Academic Search

In recent years there has been growing interest in energetic (?100 eV), temporally short (<10 ps) x rays produced by ultrashort laser-produced plasmas. The detection and temporal dispersion of the x rays using x-ray streak cameras has been limited to a resolution of 2 ps, primarily due to the transit time dispersion of the electrons between the photocathode and the

Ronnie Shepherd; Rex Booth; Dwight Price; Mark Bowers; Don Swan; Jim Bonlie; Bruce Young; Jim Dunn; Bill White; Richard Stewart

1995-01-01

286

Standard design for National Ignition Facility x-ray streak and framing cameras  

Microsoft Academic Search

The x-ray streak camera and x-ray framing camera for the National Ignition Facility were redesigned to improve electromagnetic pulse hardening, protect high voltage circuits from pressure transients, and maximize the use of common parts and operational software. Both instruments use the same PC104 based controller, interface, power supply, charge coupled device camera, protective hermetically sealed housing, and mechanical interfaces. Communication

J. R. Kimbrough; P. M. Bell; D. K. Bradley; J. P. Holder; D. K. Kalantar; A. G. MacPhee; S. Telford

2010-01-01

287

Ultrafast photonic-crystal fiber light flash for streak-camera fluorescence measurements  

NASA Astrophysics Data System (ADS)

Photonic-crystal fibers (PCFs) provide a high efficiency of frequency upconversion of femtosecond Cr: forsterite laser pulses through the emission of dispersive waves by solitons and third-harmonic generation. Dispersion management allows the central wavelength of the frequency-upconverted signal in PCF output to be tuned within the range of wavelengths from 400 to 900 nm. PCF frequency shifters are employed as excitation sources for time-resolved fluorescence streak-camera measurements on fluorescein solution.

Konorov, Stanislav; Ivanov, Anatoly; Ivanov, Denis; Alfimov, Mikhail; Zheltikov, Aleksei

2005-07-01

288

Mars eolian geology at airphoto scales: The large wind streaks of western Arabia Terra  

Microsoft Academic Search

More than 27,000 pictures at aerial photograph scales (1.5-12 m\\/pixel) have been acquired by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) since September 1997. The pictures are valuable for testing hypotheses about geologic history and processes of Mars. Of particular interest are eolian features connected to surface albedo patterns. This work is focused on low-albedo wind streaks, some

2000-01-01

289

Changes Over a Martian Year -- New Dark Slope Streaks in Lycus Sucli  

NASA Technical Reports Server (NTRS)

Now in its Extended Mission, Mars Global Surveyor (MGS) is into its second Mars year of systematic observations of the red planet. With the Extended Mission slated to run through April 2002, the Mars Orbiter Camera (MOC) is being used, among other things, to look for changes that have occurred in the past martian year. Because Mars is farther from the Sun than Earth, its year is longer--about 687 Earth days.

The two pictures shown here cover the same portion of Lycus Sulci, a rugged, ridged terrain north of the giant Olympus Mons volcano. The interval between the pictures span 92% of a martian year (August 2, 1999 to April 27, 2001). Dark streaks considered to result from the avalanching of dry, fine, bright dust are seen in both images. The disruption of the surface by the avalanching materials is thought to cause them to appear darker than their surroundings, just as the 1997 bouncing of Mars Pathfinder's airbags and the tire tracks made by the Sojourner rover left darkened markings indicating where the martian soil had been disrupted and disturbed. The arrows in the April 2001 picture indicate eight new streaks that formed on these slopes in Lycus Sulci since August 1999. These observations suggest that a new streak forms approximately once per martian year per kilometer (about 0.62 miles) along a slope.

In both images, north is toward the top/upper right and sunlight illuminates each from the left. Dark (as well bright) slope streaks are most common in the dust-covered martian regions of Tharsis, Arabia, and Elysium.

2001-01-01

290

Complete Genome Sequence of an Emerging Genotype of Tobacco Streak Virus in the United States  

PubMed Central

We report here the complete genome sequence of an emerging genotype of tobacco streak virus (TSV) infecting zucchini squash in Florida (TSV_FL13-07), obtained using deep sequencing of short RNAs (sRNAs) and validation by Sanger sequencing. TSV_FL13-07 shares only <90% sequence identity in all three genomic RNAs to several known U.S. isolates. PMID:25377714

Padmanabhan, Chellappan; Gao, Shan; Li, Rugang; Zhang, Shouan; Fei, Zhangjun

2014-01-01

291

High-Speed Observer: Automated Streak Detection for the Aerospike Engine  

NASA Technical Reports Server (NTRS)

A high-frame-rate digital video camera, installed on test stands at Stennis Space Center (SSC), has been used to capture images of the aerospike engine plume during test. These plume images are processed in real time to detect and differentiate anomalous plume events. Results indicate that the High-Speed Observer (HSO) system can detect anomalous plume streaking events that are indicative of aerospike engine malfunction.

Rieckhoff, T. J.; Covan, M. A.; OFarrell, J. M.

2001-01-01

292

Complete genome sequence of an emerging genotype of tobacco streak virus in the United States.  

PubMed

We report here the complete genome sequence of an emerging genotype of tobacco streak virus (TSV) infecting zucchini squash in Florida (TSV_FL13-07), obtained using deep sequencing of short RNAs (sRNAs) and validation by Sanger sequencing. TSV_FL13-07 shares only <90% sequence identity in all three genomic RNAs to several known U.S. isolates. PMID:25377714

Padmanabhan, Chellappan; Gao, Shan; Li, Rugang; Zhang, Shouan; Fei, Zhangjun; Ling, Kai-Shu

2014-01-01

293

Instability of streaks in pipe flow of shear-thinning fluids  

NASA Astrophysics Data System (ADS)

This study is motivated by recent experimental results dealing with the transition to turbulence in a pipe flow of shear-thinning fluids, where a streaky flow with an azimuthal wave number n=1 is observed in the transitional regime. Here, a linear stability analysis of pipe flow of shear-thinning fluids modulated azimuthally by finite amplitude streaks is performed. The shear-thinning behavior of the fluid is described by the Carreau model. The streaky base flows considered are obtained from two-dimensional direct numerical simulation using finite amplitude longitudinal rolls as the initial condition and by extracting the velocity field at time tmax, where the amplitude of the streaks reaches its maximum, denoted by Amax. It is found that the amplitude Amax increases with increasing Reynolds number as well as with increasing amplitude E0 of the initial longitudinal rolls. For sufficiently large streaks amplitude, streamwise velocity profiles develop inflection points, leading to instabilities. Depending on the threshold amplitude Ac, two different modes may trigger the instability of the streaks. If Ac exceeds approximately 41.5% of the centerline velocity, the instability mode is located near the axis of the pipe, i.e., it is a “center mode.” For weaker amplitude Ac, the instability mode is located near the pipe wall, in the region of highest wall normal shear, i.e., it is a “wall mode.” The threshold amplitude Ac decreases with increasing shear-thinning effects. The energy equation analysis indicates that (i) wall modes are driven mainly by the work of the Reynolds stress against the wall normal shear and (ii) for center modes, the contribution of the normal wall shear remains dominant; however, it is noted that the contribution of the Reynolds stress against the azimuthal shear increases with increasing shear-thinning effects.

López Carranza, S. N.; Jenny, M.; Nouar, C.

2013-08-01

294

Instability of streaks in pipe flow of shear-thinning fluids.  

PubMed

This study is motivated by recent experimental results dealing with the transition to turbulence in a pipe flow of shear-thinning fluids, where a streaky flow with an azimuthal wave number n=1 is observed in the transitional regime. Here, a linear stability analysis of pipe flow of shear-thinning fluids modulated azimuthally by finite amplitude streaks is performed. The shear-thinning behavior of the fluid is described by the Carreau model. The streaky base flows considered are obtained from two-dimensional direct numerical simulation using finite amplitude longitudinal rolls as the initial condition and by extracting the velocity field at time t(max), where the amplitude of the streaks reaches its maximum, denoted by A(max). It is found that the amplitude A(max) increases with increasing Reynolds number as well as with increasing amplitude E(0) of the initial longitudinal rolls. For sufficiently large streaks amplitude, streamwise velocity profiles develop inflection points, leading to instabilities. Depending on the threshold amplitude A(c), two different modes may trigger the instability of the streaks. If A(c) exceeds approximately 41.5% of the centerline velocity, the instability mode is located near the axis of the pipe, i.e., it is a "center mode." For weaker amplitude A(c), the instability mode is located near the pipe wall, in the region of highest wall normal shear, i.e., it is a "wall mode." The threshold amplitude A(c) decreases with increasing shear-thinning effects. The energy equation analysis indicates that (i) wall modes are driven mainly by the work of the Reynolds stress against the wall normal shear and (ii) for center modes, the contribution of the normal wall shear remains dominant; however, it is noted that the contribution of the Reynolds stress against the azimuthal shear increases with increasing shear-thinning effects. PMID:24032922

López Carranza, S N; Jenny, M; Nouar, C

2013-08-01

295

Ocean Mixed-Layer Depth and Current Variation Estimated From Imagery of Surfactant Streaks  

Microsoft Academic Search

The ability of high-resolution imaging systems to resolve small-scale structure on the ocean surface suggests the possibility of using characteristics of Langmuir circulation to map the surface mixed-layer depth and near-surface current. We illustrate this using synthetic aperture radar and infrared imagery that are collected across the edge of the Gulf Stream (GS), which reveals surfactant streaks, or ldquowindrows,rdquo that

George O. Marmorino; Jakov V. Toporkov; Geoffrey B. Smith; Mark A. Sletten; Dragana Perkovic; Stephen Frasier; K. Peter Judd

2007-01-01

296

Low Albedo Surfaces and Eolian Sediment: Mars Orbiter Camera Views of Western Arabia Terra Craters and Wind Streaks  

NASA Technical Reports Server (NTRS)

High spatial resolution (1.5 to 12 m/pixel) Mars Global Surveyor Mars Orbiter Camera images obtained September 1997 through June 2001 indicate that the large, dark wind streaks of western Arabia Terra each originate at a barchan dune field on a crater floor. The streaks consist of a relatively thin coating of sediment deflated from the dune fields and their vicinity. This sediment drapes a previous mantle that more thickly covers nearly all of western Arabia Terra. No dunes or eolian bedforms are found within the dark wind streaks, nor do any of the intracrater dunes climb up crater walls to provide sand to the wind streaks. The relations between dunes, wind streak, and subjacent terrain imply that dark-toned grains finer than those which comprise the dunes are lifted into suspension and carried out of the craters to be deposited on the adjacent terrain. Such grains are most likely in the silt size range (3.9-62.5 micrometers). The streaks change in terms of extent, relative albedo, and surface pattern over periods measured in years, but very little evidence for recent eolian activity (dust plumes, storms, dune movement) has been observed.

Edgett, Kenneth S.

2001-01-01

297

Rho kinase activity controls directional cell movements during primitive streak formation in the rabbit embryo  

PubMed Central

During animal gastrulation, the specification of the embryonic axes is accompanied by epithelio-mesenchymal transition (EMT), the first major change in cell shape after fertilization. EMT takes place in disparate topographical arrangements, such as the circular blastopore of amphibians, the straight primitive streak of birds and mammals or in intermediate gastrulation forms of other amniotes such as reptiles. Planar cell movements are prime candidates to arrange specific modes of gastrulation but there is no consensus view on their role in different vertebrate classes. Here, we test the impact of interfering with Rho kinase-mediated cell movements on gastrulation topography in blastocysts of the rabbit, which has a flat embryonic disc typical for most mammals. Time-lapse video microscopy, electron microscopy, gene expression and morphometric analyses of the effect of inhibiting ROCK activity showed – besides normal specification of the organizer region – a dose-dependent disruption of primitive streak formation; this disruption resulted in circular, arc-shaped or intermediate forms, reminiscent of those found in amphibians, fishes and reptiles. Our results reveal a crucial role of ROCK-controlled directional cell movements during rabbit primitive streak formation and highlight the possibility that temporal and spatial modulation of cell movements were instrumental for the evolution of gastrulation forms. PMID:25516971

Stankova, Viktoria; Tsikolia, Nikoloz; Viebahn, Christoph

2015-01-01

298

Signal-to-noise performance analysis of streak tube imaging lidar systems. I. Cascaded model.  

PubMed

Streak tube imaging lidar (STIL) is an active imaging system using a pulsed laser transmitter and a streak tube receiver to produce 3D range and intensity imagery. The STIL has recently attracted a great deal of interest and attention due to its advantages of wide azimuth field-of-view, high range and angle resolution, and high frame rate. This work investigates the signal-to-noise performance of STIL systems. A theoretical model for characterizing the signal-to-noise performance of the STIL system with an internal or external intensified streak tube receiver is presented, based on the linear cascaded systems theory of signal and noise propagation. The STIL system is decomposed into a series of cascaded imaging chains whose signal and noise transfer properties are described by the general (or the spatial-frequency dependent) noise factors (NFs). Expressions for the general NFs of the cascaded chains (or the main components) in the STIL system are derived. The work presented here is useful for the design and evaluation of STIL systems. PMID:23262622

Yang, Hongru; Wu, Lei; Wang, Xiaopeng; Chen, Chao; Yu, Bing; Yang, Bin; Yuan, Liang; Wu, Lipeng; Xue, Zhanli; Li, Gaoping; Wu, Baoning

2012-12-20

299

Optical fiducial timing system for X-ray streak cameras with aluminum coated optical fiber ends  

DOEpatents

An optical fiducial timing system is provided for use with interdependent groups of X-ray streak cameras (18). The aluminum coated (80) ends of optical fibers (78) are positioned with the photocathodes (20, 60, 70) of the X-ray streak cameras (18). The other ends of the optical fibers (78) are placed together in a bundled array (90). A fiducial optical signal (96), that is comprised of 2.omega. or 1.omega. laser light, after introduction to the bundled array (90), travels to the aluminum coated (82) optical fiber ends and ejects quantities of electrons (84) that are recorded on the data recording media (52) of the X-ray streak cameras (18). Since both 2.omega. and 1.omega. laser light can travel long distances in optical fiber with only a slight attenuation, the initial arial power density of the fiducial optical signal (96) is well below the damage threshold of the fused silica or other material that comprises the optical fibers (78, 90). Thus the fiducial timing system can be repeatably used over long durations of time.

Nilson, David G. (Oakland, CA); Campbell, E. Michael (Pleasanton, CA); MacGowan, Brian J. (Livermore, CA); Medecki, Hector (Livermore, CA)

1988-01-01

300

Oct4 Is Required ?E7.5 for Proliferation in the Primitive Streak  

PubMed Central

Oct4 is a widely recognized pluripotency factor as it maintains Embryonic Stem (ES) cells in a pluripotent state, and, in vivo, prevents the inner cell mass (ICM) in murine embryos from differentiating into trophectoderm. However, its function in somatic tissue after this developmental stage is not well characterized. Using a tamoxifen-inducible Cre recombinase and floxed alleles of Oct4, we investigated the effect of depleting Oct4 in mouse embryos between the pre-streak and headfold stages, ?E6.0–E8.0, when Oct4 is found in dynamic patterns throughout the embryonic compartment of the mouse egg cylinder. We found that depletion of Oct4 ?E7.5 resulted in a severe phenotype, comprised of craniorachischisis, random heart tube orientation, failed turning, defective somitogenesis and posterior truncation. Unlike in ES cells, depletion of the pluripotency factors Sox2 and Oct4 after E7.0 does not phenocopy, suggesting that ?E7.5 Oct4 is required within a network that is altered relative to the pluripotency network. Oct4 is not required in extraembryonic tissue for these processes, but is required to maintain cell viability in the embryo and normal proliferation within the primitive streak. Impaired expansion of the primitive streak occurs coincident with Oct4 depletion ?E7.5 and precedes deficient convergent extension which contributes to several aspects of the phenotype. PMID:24244203

DeVeale, Brian; Brokhman, Irina; Mohseni, Paria; Babak, Tomas; Yoon, Charles; Lin, Anthony; Onishi, Kento; Tomilin, Alexey; Pevny, Larysa; Zandstra, Peter W.; Nagy, Andras; van der Kooy, Derek

2013-01-01

301

Oct4 is required ~E7.5 for proliferation in the primitive streak.  

PubMed

Oct4 is a widely recognized pluripotency factor as it maintains Embryonic Stem (ES) cells in a pluripotent state, and, in vivo, prevents the inner cell mass (ICM) in murine embryos from differentiating into trophectoderm. However, its function in somatic tissue after this developmental stage is not well characterized. Using a tamoxifen-inducible Cre recombinase and floxed alleles of Oct4, we investigated the effect of depleting Oct4 in mouse embryos between the pre-streak and headfold stages, ~E6.0-E8.0, when Oct4 is found in dynamic patterns throughout the embryonic compartment of the mouse egg cylinder. We found that depletion of Oct4 ~E7.5 resulted in a severe phenotype, comprised of craniorachischisis, random heart tube orientation, failed turning, defective somitogenesis and posterior truncation. Unlike in ES cells, depletion of the pluripotency factors Sox2 and Oct4 after E7.0 does not phenocopy, suggesting that ~E7.5 Oct4 is required within a network that is altered relative to the pluripotency network. Oct4 is not required in extraembryonic tissue for these processes, but is required to maintain cell viability in the embryo and normal proliferation within the primitive streak. Impaired expansion of the primitive streak occurs coincident with Oct4 depletion ?E7.5 and precedes deficient convergent extension which contributes to several aspects of the phenotype. PMID:24244203

DeVeale, Brian; Brokhman, Irina; Mohseni, Paria; Babak, Tomas; Yoon, Charles; Lin, Anthony; Onishi, Kento; Tomilin, Alexey; Pevny, Larysa; Zandstra, Peter W; Nagy, Andras; van der Kooy, Derek

2013-11-01

302

Effect of mechanical inoculation (air-gun technique) for selecting levels of maize dwarf mosaic virus strain a resistance in sorghum  

E-print Network

CHAPTER TABLE OF CONTENTS Page VI V11 X X111 I INTRODUCTION AND LITERATURE REVIEW Objectives II EFFECT OF LEVEL OF INOCULATION WITH MAIZE DWARF MOSAIC VIRUS STRAIN A ON INCIDENCE, SYMPTOM EXPRESSION, AND YIELD OF SORGHUM . Introduction... CITED VITA LIST OF TABLES TABLE Page 2. 3. 5a. 5b. 5c. 10. 12. 13. Proportion of plants inoculated with maize dwarf mosaic virus strain A per plot . Maize dwarf mosaic virus strain-A disease rating system. Mean proportion of plants...

Mahuku, George Simba

1991-01-01

303

Choosing a Genome Browser for a Model Organism Database (MOD): Surveying the Maize Community  

Technology Transfer Automated Retrieval System (TEKTRAN)

As the maize genome sequencing is nearing its completion, the Maize Genetics and Genomics Database (MaizeGDB), the Model Organism Database for maize, integrated a genome browser to its already existing Web interface and database. The addition of the MaizeGDB Genome Browser to MaizeGDB will allow it ...

304

77 FR 41359 - Monsanto Co.; Availability of Petition for Determination of Nonregulated Status of Maize...  

Federal Register 2010, 2011, 2012, 2013, 2014

...the production of hybrid maize seed, stating that this maize is...the production of hybrid maize seed through the incorporation of...maize as a tool in hybrid maize seed production. Maize event MON...with Council on Environmental Quality regulations (40 CFR part...

2012-07-13

305

Molecular Genetics of Mitochondrial Biogenesis in Maize.  

Technology Transfer Automated Retrieval System (TEKTRAN)

The mitochondrial genome encodes proteins essential for mitochondrial respiration and ATP synthesis. Nuclear gene products, however, are required for the expression of mitochondrial genes and the elaboration of functional mitochondrial protein complexes. We are exploiting a unique collection of maiz...

306

Measuring 8–250 ps short pulses using a high-speed streak camera on kilojoule, petawatt-class laser systems  

SciTech Connect

Short-pulse measurements using a streak camera are sensitive to space-charge broadening, which depends on the pulse duration and shape, and on the uniformity of photocathode illumination. An anamorphic-diffuser-based beam-homogenizing system and a space-charge-broadening calibration method were developed to accurately measure short pulses using an optical streak camera. This approach provides a more-uniform streak image and enables one to characterize space-charge-induced pulse-broadening effects.

Qiao, J.; Jaanimagi, P. A.; Boni, R.; Bromage, J.; Hill, E. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States)] [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States)

2013-07-15

307

No Adjuvant Effect of Bacillus thuringiensis-Maize on Allergic Responses in Mice  

PubMed Central

Genetically modified (GM) foods are evaluated carefully for their ability to induce allergic disease. However, few studies have tested the capacity of a GM food to act as an adjuvant, i.e. influencing allergic responses to other unrelated allergens at acute onset and in individuals with pre-existing allergy. We sought to evaluate the effect of short-term feeding of GM Bacillus thuringiensis (Bt)-maize (MON810) on the initiation and relapse of allergic asthma in mice. BALB/c mice were provided a diet containing 33% GM or non-GM maize for up to 34 days either before ovalbumin (OVA)-induced experimental allergic asthma or disease relapse in mice with pre-existing allergy. We observed that GM-maize feeding did not affect OVA-induced eosinophilic airway and lung inflammation, mucus hypersecretion or OVA-specific antibody production at initiation or relapse of allergic asthma. There was no adjuvant effect upon GM-maize consumption on the onset or severity of allergic responses in a mouse model of allergic asthma. PMID:25084284

Dekan, Gerhard; Epstein, Michelle M.

2014-01-01

308

Can Transgenic Maize Affect Soil Microbial Communities?  

PubMed Central

The aim of the experiment was to determine if temporal variations of belowground activity reflect the influence of the Cry1Ab protein from transgenic maize on soil bacteria and, hence, on a regulatory change of the microbial community (ability to metabolize sources belonging to different chemical guilds) and/or a change in numerical abundance of their cells. Litter placement is known for its strong influence on the soil decomposer communities. The effects of the addition of crop residues on respiration and catabolic activities of the bacterial community were examined in microcosm experiments. Four cultivars of Zea mays L. of two different isolines (each one including the conventional crop and its Bacillus thuringiensis cultivar) and one control of bulk soil were included in the experimental design. The growth models suggest a dichotomy between soils amended with either conventional or transgenic maize residues. The Cry1Ab protein appeared to influence the composition of the microbial community. The highly enhanced soil respiration observed during the first 72 h after the addition of Bt-maize residues can be interpreted as being related to the presence of the transgenic crop residues. This result was confirmed by agar plate counting, as the averages of the colony-forming units of soils in conventional treatments were about one-third of those treated with transgenic straw. Furthermore, the addition of Bt-maize appeared to induce increased microbial consumption of carbohydrates in BIOLOG EcoPlates. Three weeks after the addition of maize residues to the soils, no differences between the consumption rate of specific chemical guilds by bacteria in soils amended with transgenic maize and bacteria in soils amended with conventional maize were detectable. Reaped crop residues, comparable to post-harvest maize straw (a common practice in current agriculture), rapidly influence the soil bacterial cells at a functional level. Overall, these data support the existence of short Bt-induced ecological shifts in the microbial communities of croplands' soils. PMID:17009863

Mulder, Christian; Wouterse, Marja; Raubuch, Markus; Roelofs, Willem; Rutgers, Michiel

2006-01-01

309

MaizeGDB: The Maize Model Organism Database for Basic, Translational, and Applied Research  

Technology Transfer Automated Retrieval System (TEKTRAN)

In 2001, maize became the number one production crop in the world (with over 614 million tons produced; http://faostat.fao.org). Its success is due to the high productivity per acre in tandem with a wide variety of commercial uses: not only is maize an excellent source of food, feed, and fuel, its...

310

Expression of an anthranilate synthase from maize mutant bf-1 in maize line HiII  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize mutant bf-1 was one of a series of maize mutants generated by radiation from the Bikini Atoll atomic bomb test in 1946. It is characterized by blue fluorescence in seedlings and anthers under ultraviolet illumination and by mutant plants giving off a characteristic grape-like odor due to the ...

311

Perturbation of Maize Phenylpropanoid Metabolism by an AvrE Family Type III Effector from Pantoea stewartii1[OPEN  

PubMed Central

AvrE family type III effector proteins share the ability to suppress host defenses, induce disease-associated cell death, and promote bacterial growth. However, despite widespread contributions to numerous bacterial diseases in agriculturally important plants, the mode of action of these effectors remains largely unknown. WtsE is an AvrE family member required for the ability of Pantoea stewartii ssp. stewartii (Pnss) to proliferate efficiently and cause wilt and leaf blight symptoms in maize (Zea mays) plants. Notably, when WtsE is delivered by a heterologous system into the leaf cells of susceptible maize seedlings, it alone produces water-soaked disease symptoms reminiscent of those produced by Pnss. Thus, WtsE is a pathogenicity and virulence factor in maize, and an Escherichia coli heterologous delivery system can be used to study the activity of WtsE in isolation from other factors produced by Pnss. Transcriptional profiling of maize revealed the effects of WtsE, including induction of genes involved in secondary metabolism and suppression of genes involved in photosynthesis. Targeted metabolite quantification revealed that WtsE perturbs maize metabolism, including the induction of coumaroyl tyramine. The ability of mutant WtsE derivatives to elicit transcriptional and metabolic changes in susceptible maize seedlings correlated with their ability to promote disease. Furthermore, chemical inhibitors that block metabolic flux into the phenylpropanoid pathways targeted by WtsE also disrupted the pathogenicity and virulence activity of WtsE. While numerous metabolites produced downstream of the shikimate pathway are known to promote plant defense, our results indicate that misregulated induction of phenylpropanoid metabolism also can be used to promote pathogen virulence. PMID:25635112

Asselin, Jo Ann E.; Lin, Jinshan; Perez-Quintero, Alvaro L.; Gentzel, Irene; Majerczak, Doris; Opiyo, Stephen O.; Zhao, Wanying; Paek, Seung-Mann; Kim, Min Gab; Coplin, David L.; Blakeslee, Joshua J.; Mackey, David

2015-01-01

312

Perturbation of Maize Phenylpropanoid Metabolism by an AvrE Family Type III Effector from Pantoea stewartii.  

PubMed

AvrE family type III effector proteins share the ability to suppress host defenses, induce disease-associated cell death, and promote bacterial growth. However, despite widespread contributions to numerous bacterial diseases in agriculturally important plants, the mode of action of these effectors remains largely unknown. WtsE is an AvrE family member required for the ability of Pantoea stewartii ssp. stewartii (Pnss) to proliferate efficiently and cause wilt and leaf blight symptoms in maize (Zea mays) plants. Notably, when WtsE is delivered by a heterologous system into the leaf cells of susceptible maize seedlings, it alone produces water-soaked disease symptoms reminiscent of those produced by Pnss. Thus, WtsE is a pathogenicity and virulence factor in maize, and an Escherichia coli heterologous delivery system can be used to study the activity of WtsE in isolation from other factors produced by Pnss. Transcriptional profiling of maize revealed the effects of WtsE, including induction of genes involved in secondary metabolism and suppression of genes involved in photosynthesis. Targeted metabolite quantification revealed that WtsE perturbs maize metabolism, including the induction of coumaroyl tyramine. The ability of mutant WtsE derivatives to elicit transcriptional and metabolic changes in susceptible maize seedlings correlated with their ability to promote disease. Furthermore, chemical inhibitors that block metabolic flux into the phenylpropanoid pathways targeted by WtsE also disrupted the pathogenicity and virulence activity of WtsE. While numerous metabolites produced downstream of the shikimate pathway are known to promote plant defense, our results indicate that misregulated induction of phenylpropanoid metabolism also can be used to promote pathogen virulence. PMID:25635112

Asselin, Jo Ann E; Lin, Jinshan; Perez-Quintero, Alvaro L; Gentzel, Irene; Majerczak, Doris; Opiyo, Stephen O; Zhao, Wanying; Paek, Seung-Mann; Kim, Min Gab; Coplin, David L; Blakeslee, Joshua J; Mackey, David

2015-03-01

313

Absolute calibration method for nanosecond-resolved, time-streaked, fiber optic light collection, spectroscopy systems.  

PubMed

This paper describes a convenient and accurate method to calibrate fast (<1 ns resolution) streaked, fiber optic light collection, spectroscopy systems. Such systems are inherently difficult to calibrate due to the lack of sufficiently intense, calibrated light sources. Such a system is used to collect spectral data on plasmas generated in electron beam diodes fielded on the RITS-6 accelerator (8-12MV, 140-200kA) at Sandia National Laboratories. On RITS, plasma light is collected through a small diameter (200 ?m) optical fiber and recorded on a fast streak camera at the output of a 1 meter Czerny-Turner monochromator. For this paper, a 300 W xenon short arc lamp (Oriel Model 6258) was used as the calibration source. Since the radiance of the xenon arc varies from cathode to anode, just the area around the tip of the cathode ("hotspot") was imaged onto the fiber, to produce the highest intensity output. To compensate for chromatic aberrations, the signal was optimized at each wavelength measured. Output power was measured using 10 nm bandpass interference filters and a calibrated photodetector. These measurements give power at discrete wavelengths across the spectrum, and when linearly interpolated, provide a calibration curve for the lamp. The shape of the spectrum is determined by the collective response of the optics, monochromator, and streak tube across the spectral region of interest. The ratio of the spectral curve to the measured bandpass filter curve at each wavelength produces a correction factor (Q) curve. This curve is then applied to the experimental data and the resultant spectra are given in absolute intensity units (photons/sec/cm(2)/steradian/nm). Error analysis shows this method to be accurate to within +?- 20%, which represents a high level of accuracy for this type of measurement. PMID:22938275

Johnston, Mark D; Oliver, Bryan V; Droemer, Darryl W; Frogget, Brent; Crain, Marlon D; Maron, Yitzhak

2012-08-01

314

Absolute calibration method for nanosecond-resolved, time-streaked, fiber optic light collection, spectroscopy systems  

NASA Astrophysics Data System (ADS)

This paper describes a convenient and accurate method to calibrate fast (<1 ns resolution) streaked, fiber optic light collection, spectroscopy systems. Such systems are inherently difficult to calibrate due to the lack of sufficiently intense, calibrated light sources. Such a system is used to collect spectral data on plasmas generated in electron beam diodes fielded on the RITS-6 accelerator (8-12MV, 140-200kA) at Sandia National Laboratories. On RITS, plasma light is collected through a small diameter (200 ?m) optical fiber and recorded on a fast streak camera at the output of a 1 meter Czerny-Turner monochromator. For this paper, a 300 W xenon short arc lamp (Oriel Model 6258) was used as the calibration source. Since the radiance of the xenon arc varies from cathode to anode, just the area around the tip of the cathode ("hotspot") was imaged onto the fiber, to produce the highest intensity output. To compensate for chromatic aberrations, the signal was optimized at each wavelength measured. Output power was measured using 10 nm bandpass interference filters and a calibrated photodetector. These measurements give power at discrete wavelengths across the spectrum, and when linearly interpolated, provide a calibration curve for the lamp. The shape of the spectrum is determined by the collective response of the optics, monochromator, and streak tube across the spectral region of interest. The ratio of the spectral curve to the measured bandpass filter curve at each wavelength produces a correction factor (Q) curve. This curve is then applied to the experimental data and the resultant spectra are given in absolute intensity units (photons/sec/cm2/steradian/nm). Error analysis shows this method to be accurate to within +/- 20%, which represents a high level of accuracy for this type of measurement.

Johnston, Mark D.; Oliver, Bryan V.; Droemer, Darryl W.; Frogget, Brent; Crain, Marlon D.; Maron, Yitzhak

2012-08-01

315

Leaf transpiration efficiency of some drought-resistant maize lines  

Technology Transfer Automated Retrieval System (TEKTRAN)

Field measurements of leaf gas exchange in maize often indicate stomatal conductances higher than required to provide substomatal carbon dioxide concentrations saturating to photosynthesis. Thus maize leaves often operate at lower transpiration efficiency (TE) than potentially achievable for specie...

316

FLORETS AND ROSETTES: MERISTEM GENES IN MAIZE AND ARABIDOPSIS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize and Arabidopsis genes that regulate inflorescence development are contrasted. Genes that regulate meristem size are often conserved, whereas genes that regulate meristem identity in maize do not have readily identifiable orthologs in Arabidopsis....

317

Response to aflatoxin and grain composition of exotic maize germplasm  

E-print Network

for response to aflatoxin. Exotic adapted maize lines, known as LAMA lines, were found to accumulate less aflatoxin than US hybrids in tests across Southern Texas. Exotic introgression lines developed by The International Center for Maize and Wheat...

Corn, Rebecca Joann

2009-06-02

318

Temporal Characterization of Electron Beam Bunches with a Fast Streak Camera at the JLab FEL Facility  

SciTech Connect

The design and construction of an optical transport that brings synchrotron radiation from electron bunches to a fast streak camera in a remote area has become a useful tool for online observation of bunch length and stability. This paper will report on the temporal measurements we have done, comparison with simulations, and the on-going work for another imaging optical transport system that will make possible the direct measurement of the longitudinal phase space by measuring the bunch length as a function of energy

S. Zhang; S.V. Benson; D. Douglas; D. Hardy; C. Hernandez-Garcia; K. Jordan; G. Neil; Michelle D. Shinn

2005-08-21

319

Follow-up Observatory for Low Earth Orbit Objects with a Detection Algorithm Using Streaks  

NASA Astrophysics Data System (ADS)

This paper proposes a simplified facility for a follow-up observation method. A tri-axis altazimuth mount instrument is required in the conventional observation facility to keep a target as a light spot during a visible pass. The tri-axis instrument enables the facility to observe the target with a high signal-to-noise-ratio. However, such instrument becomes costly due to its complexity. The proposed method uses a bi-axis altazimuth to guide a telescope into an observation target region. It should be noted that the bi-axis altazimth does not guide the telescope toward the target continuously therefore the target appears as streaks in images. Intensities in the streak are degraded in signal-to-noise-ratio in comparison to that in the light spot taken by a telescope on a tri-axis altazimuth because original intensity was divided into the pixels. The proposed method recovers such low signal-to-noise-ratio using 1) an image-processing algorithm and 2) multi-telescope. The image-processing algorithm developed for this study aims to detect an object appeared as faint streaks in images. The initial study also found that the algorithm requires primary orbit information of the target to complete detection calculation in reasonable time consumption. The algorithm can recovers signal-to-noise-ratio. However, it is still lower than that of continuous guiding observation result. The multi-telescope denotes an observation using two or more telescopes toward same region. We can improve signal-to-noise-ratio by summing images taken by the telescopes. We found that the image-processing algorithm improves signal-to-noise-ratio proportional to square root of streaks length. The multi-telescope observation method also improves signal-to-noise-ratio proportional to square root of number of the telescope. The proposed method combines the algorithm and the technique to recover degraded signal-to-noise-ratio. This paper discusses a feasibility of the proposed method and summarizes a mission scenario.

Tagawa, M.; Yanagisawa, T.; Kurosaki, H.; Oda, H.; Hanada, T.

2014-09-01

320

Physics and roller coasters-The Blue Streak at Cedar Point  

NASA Astrophysics Data System (ADS)

The use of a roller coaster for external classroom studies of kinematics, forces, dynamics, and energy conservation is discussed. Experimental accelerometer measurements of the vertical forces acting on riders of the Blue Streak at Cedar Point in Sandusky, Ohio are presented. Theoretically, the track profile is used to calculate/predict the vertical forces acting on a rider at the hilltops, valley bottoms, and several other points of interest along the track. Finally the experimental results and theoretical predictions are compared in the context of a rider's experiences.

Speers, Robert R.

1991-06-01

321

Design of a streaked radiography instrument for ICF ablator tuning measurements  

SciTech Connect

A streaked radiography diagnostic has been proposed as a technique to determine the ablator mass remaining in an inertial confinement fusion ignition capsule at peak velocity. This instrument, the 'HXRI-5', has been designed to fit within a National Ignition Facility Diagnostic Instrument Manipulator. The HXRI-5 will be built at Sandia National Laboratories (SNL), and initial testing will be done at the SNL Z-Beamlet Facility. In this paper, we will describe the National Ignition Campaign requirements for this diagnostic, the instrument design, and the planned test experiments.

Olson, R. E.; Geissel, M.; Kellogg, J. W.; Bennett, G. R.; Edens, A. D.; Atherton, B. W.; Leeper, R. J. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Hicks, D. G.; Spears, B. K.; Celliers, P. M.; Holder, J. P.; Landen, O. L. [Lawrence Livermore National Laboratories, Livermore, California 94550 (United States)

2008-10-15

322

Streaked Optical Pyrometer System for Laser-Driven Shock-Wave Experiments on OMEGA  

SciTech Connect

The temperature of laser-driven shock waves is of interest to inertial confinement fusion and high-energy-density physics. We report on a streaked optical pyrometer that measures the self-emission of laser-driven shocks simultaneously with a velocity interferometer system for any reflector (VISAR). Together these diagnostics are used to obtain the temporally and spatially resolved temperatures of ~Mbar shocks driven by the OMEGA laser. We provide a brief description of the diagnostic and how it is used with VISAR. Key spectral calibration results are discussed and important characteristics of the recording system are presented.

Miller, J.E.; Boehly, T.R.; Melchior, Meyerhofer, D.D.; Celliers, P.M.; Eggert, J.H.; Hicks, D.G.; Sorce, C.M.; Oertel, J.A.; Emmel, P.M.

2007-03-23

323

Participatory plant breeding with maize in Mexico and Honduras  

Microsoft Academic Search

Maize is a staple food crop in many developing countries. However, if seven major maize producing countries are excluded from\\u000a this group, data indicate that only 34% of the maize area is planted with improved seed despite considerable effort invested\\u000a in maize breeding. This has led researchers to investigate other options, such as farmer-participatory plant breeding, for\\u000a delivering the benefits

Margaret E. Smith; Fernando G. Castillo; Francisco Gómez

2001-01-01

324

Transcriptional activity of transposable elements in maize  

PubMed Central

Background Mobile genetic elements represent a high proportion of the Eukaryote genomes. In maize, 85% of genome is composed by transposable elements of several families. First step in transposable element life cycle is the synthesis of an RNA, but few is known about the regulation of transcription for most of the maize transposable element families. Maize is the plant from which more ESTs have been sequenced (more than two million) and the third species in total only after human and mice. This allowed us to analyze the transcriptional activity of the maize transposable elements based on EST databases. Results We have investigated the transcriptional activity of 56 families of transposable elements in different maize organs based on the systematic search of more than two million expressed sequence tags. At least 1.5% maize ESTs show sequence similarity with transposable elements. According to these data, the patterns of expression of each transposable element family is variable, even within the same class of elements. In general, transcriptional activity of the gypsy-like retrotransposons is higher compared to other classes. Transcriptional activity of several transposable elements is specially high in shoot apical meristem and sperm cells. Sequence comparisons between genomic and transcribed sequences suggest that only a few copies are transcriptionally active. Conclusions The use of powerful high-throughput sequencing methodologies allowed us to elucidate the extent and character of repetitive element transcription in maize cells. The finding that some families of transposable elements have a considerable transcriptional activity in some tissues suggests that, either transposition is more frequent than previously expected, or cells can control transposition at a post-transcriptional level. PMID:20973992

2010-01-01

325

Flavone-rich maize: an opportunity to improve the nutritional value of an important commodity crop.  

PubMed

Agricultural outputs have resulted in food production continuously expanding. To satisfy the needs of a fast growing human population, higher yields, more efficient food processing, and food esthetic value, new crop varieties with higher caloric intake have and continue to be developed, but which lack many phytochemicals important for plant protection and adequate human nutrition. The increasing incidence of chronic diseases such as obesity, diabetes and cardiovascular diseases, combined with social disparity worldwide prompted the interest in developing enhanced crops that can simultaneously address the two sides of the current malnutrition sword, increasing yield while providing added nutritional value. Flavones, phytochemicals associated with the beneficial effects of the Mediterranean diet, have potent anti-inflammatory and anti-carcinogenic activities. However, many Mediterranean diet-associated vegetables are inaccessible, or lowly consumed, in many parts of the world. Maize is the most widely grown cereal crop, yet most lines used for hybrid maize production lack flavones. As a first step toward a sustainable strategy to increasing the nutritional value of maize-based diets, we investigated the accumulation and chemical properties of flavones in maize seeds of defined genotypes. We show that the pericarps of the P1-rr genotype accumulate flavones at levels comparable to those present in some flavone-rich vegetables, and are mostly present in their C- and O-glycosylated forms. Some of these glycosides can be readily converted into the corresponding more active health beneficial aglycones during food processing. Our results provide evidence that nutritionally beneficial flavones could be re-introduced into elite lines to increase the dietary benefits of maize. PMID:25250036

Casas, María I; Duarte, Silvia; Doseff, Andrea I; Grotewold, Erich

2014-01-01

326

Flavone-rich maize: an opportunity to improve the nutritional value of an important commodity crop  

PubMed Central

Agricultural outputs have resulted in food production continuously expanding. To satisfy the needs of a fast growing human population, higher yields, more efficient food processing, and food esthetic value, new crop varieties with higher caloric intake have and continue to be developed, but which lack many phytochemicals important for plant protection and adequate human nutrition. The increasing incidence of chronic diseases such as obesity, diabetes and cardiovascular diseases, combined with social disparity worldwide prompted the interest in developing enhanced crops that can simultaneously address the two sides of the current malnutrition sword, increasing yield while providing added nutritional value. Flavones, phytochemicals associated with the beneficial effects of the Mediterranean diet, have potent anti-inflammatory and anti-carcinogenic activities. However, many Mediterranean diet-associated vegetables are inaccessible, or lowly consumed, in many parts of the world. Maize is the most widely grown cereal crop, yet most lines used for hybrid maize production lack flavones. As a first step toward a sustainable strategy to increasing the nutritional value of maize-based diets, we investigated the accumulation and chemical properties of flavones in maize seeds of defined genotypes. We show that the pericarps of the P1-rr genotype accumulate flavones at levels comparable to those present in some flavone-rich vegetables, and are mostly present in their C- and O-glycosylated forms. Some of these glycosides can be readily converted into the corresponding more active health beneficial aglycones during food processing. Our results provide evidence that nutritionally beneficial flavones could be re-introduced into elite lines to increase the dietary benefits of maize. PMID:25250036

Casas, María I.; Duarte, Silvia; Doseff, Andrea I.; Grotewold, Erich

2014-01-01

327

Comprehensive genotyping of the USA national maize inbred seed bank  

Technology Transfer Automated Retrieval System (TEKTRAN)

The germplasm bank at the USDA-ARS North Central Regional Plant Introduction Station (NCRPIS) in Ames, Iowa, preserves maize inbred lines from breeding programs from all over the world, including some of the key lines from the breeding history of maize. We genotyped 2,815 maize inbred accessions, mo...

328

A single domestication for maize shown by multilocus microsatellite genotyping  

Microsoft Academic Search

There exists extraordinary morphological and genetic diversity among the maize landraces that have been developed by pre-Columbian cultivators. To explain this high level of diversity in maize, several authors have proposed that maize landraces were the products of multiple independent domestications from their wild relative (teosinte). We present phylogenetic analyses based on 264 individual plants, each genotyped at 99 microsatellites,

Yoshihiro Matsuoka; Yves Vigouroux; Major M. Goodman; Jesus Sanchez G; Edward Buckler; John Doebley

2002-01-01

329

Biochar mitigation of allelopathy induced yield loss in continuous maize  

Technology Transfer Automated Retrieval System (TEKTRAN)

Continuous maize yields are limited by the release of phytotoxic compounds as the previous year’s maize residue decomposes. We tested the hypothesis that soil biochar applications could help mitigate maize autotoxicity and the associated yield depression. Eighteen small field plots (23.7 m2) were es...

330

MaizeGDB: everything old is new again! [abstract  

Technology Transfer Automated Retrieval System (TEKTRAN)

The focus of genetic, genomic, and breeding research evolves over time, making it necessary to continually redefine the paradigm for data access and data analysis tools. Here we report the reinvention of MaizeGDB, the maize genetics and genomics database, to meet maize researchers’ ever changing nee...

331

OATS WITH MAIZE CHROMOSOME AND CHROMOSOME SEGMENT ADDITIONS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Oat (Avena sativa L., 2n = 6x = 42) plants crossed with maize (Zea mays L., 2n = 2x = 20) yields both haploid oat plants and plants with one or more maize chromosomes added to a haploid oat genome. Recovery of plants requires embryo rescue following partial or full elimination of the maize chromosom...

332

Characterization of high temperature tolerance mechanisms in Maize  

Technology Transfer Automated Retrieval System (TEKTRAN)

High temperature, combined with drought, is a major environmental stress that greatly depresses yield and reduces the quality of maize plants in the Southern Plains area. Maize inbred lines vary greatly in thermotolerance based on field observations. Two contrasting maize inbred lines, B76, heat-to...

333

Maize Authentication: Quality Control Methods and Multivariate Analysis (Chemometrics)  

Microsoft Academic Search

Maize is one of the most important cereals because of its numerous applications in processed foods where it is the major or minor component. Apart from maize authenticity issues related to cultivar and geographical origin (national and\\/or international level), there is another important issue related to genetically modified maize. Various objective parameters such as fatty acids, phenolic compounds, pigments, heavy

Ioannis S. Arvanitoyannis; Antonios Vlachos

2009-01-01

334

Frequency-Domain Streak Camera and Tomography for Ultrafast Imaging of Evolving and Channeled Plasma Accelerator Structures  

NASA Astrophysics Data System (ADS)

We demonstrate a prototype Frequency Domain Streak Camera (FDSC) that can capture the picosecond time evolution of the plasma accelerator structure in a single shot. In our prototype Frequency-Domain Streak Camera, a probe pulse propagates obliquely to a sub-picosecond pump pulse that creates an evolving nonlinear index "bubble" in fused silica glass, supplementing a conventional Frequency Domain Holographic (FDH) probe-reference pair that co-propagates with the "bubble". Frequency Domain Tomography (FDT) generalizes Frequency-Domain Streak Camera by probing the "bubble" from multiple angles and reconstructing its morphology and evolution using algorithms similar to those used in medical CAT scans. Multiplexing methods (Temporal Multiplexing and Angular Multiplexing) improve data storage and processing capability, demonstrating a compact Frequency Domain Tomography system with a single spectrometer.

Li, Zhengyan; Zgadzaj, Rafal; Wang, Xiaoming; Reed, Stephen; Dong, Peng; Downer, Michael C.

2010-11-01

335

DISTRIBUTION OF AND ASSOCIATION BETWEEN THE LARGER GRAIN BORER PROSTEPHANUS TRUNCATUS (HORN) (COLEOPTERA: BOSTRICHIDAE) AND THE MAIZE WEEVIL SITOPHILUS ZEAMAIS MOTSCHULSKY (COLEOPTERA: CURCULIONIDAE) IN MAIZE STORES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Interspecific interactions between the larger grain borer Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) and the maize weevil Sitophilus zeamais Motschulsky (Coleoptera Curculionidae) were studied during two storage seasons in maize stores, in Bénin. Maize ears, randomly sampled from far...

336

A Genome-Wide Association Study Reveals Genes Associated with Fusarium Ear Rot Resistance in a Maize Core Diversity Panel  

PubMed Central

Fusarium ear rot is a common disease of maize that affects food and feed quality globally. Resistance to the disease is highly quantitative, and maize breeders have difficulty incorporating polygenic resistance alleles from unadapted donor sources into elite breeding populations without having a negative impact on agronomic performance. Identification of specific allele variants contributing to improved resistance may be useful to breeders by allowing selection of resistance alleles in coupling phase linkage with favorable agronomic characteristics. We report the results of a genome-wide association study to detect allele variants associated with increased resistance to Fusarium ear rot in a maize core diversity panel of 267 inbred lines evaluated in two sets of environments. We performed association tests with 47,445 single-nucleotide polymorphisms (SNPs) while controlling for background genomic relationships with a mixed model and identified three marker loci significantly associated with disease resistance in at least one subset of environments. Each associated SNP locus had relatively small additive effects on disease resistance (±1.1% on a 0–100% scale), but nevertheless were associated with 3 to 12% of the genotypic variation within or across environment subsets. Two of three identified SNPs colocalized with genes that have been implicated with programmed cell death. An analysis of associated allele frequencies within the major maize subpopulations revealed enrichment for resistance alleles in the tropical/subtropical and popcorn subpopulations compared with other temperate breeding pools. PMID:24048647

Zila, Charles T.; Samayoa, L. Fernando; Santiago, Rogelio; Butrón, Ana; Holland, James B.

2013-01-01

337

Regulation of pathogenesis by light in Cercospora zeae-maydis: Identification of a photoreceptor required for infection of maize  

Technology Transfer Automated Retrieval System (TEKTRAN)

Cercospora zeae-maydis causes gray leaf spot, one of the most prevalent and damaging foliar diseases of maize throughout the world. Light plays a key role in the virulence of C. zeae-maydis by inducing the biosynthesis of cercosporin, a photosensitizing, non-host-specific phytotoxin. We determined t...

338

Complete Genome Sequence of “Candidatus Sulcia muelleri” ML, an Obligate Nutritional Symbiont of Maize Leafhopper (Dalbulus maidis)  

PubMed Central

“Candidatus Sulcia muelleri” is a symbiont of sap-feeding insects in the suborder Auchenorrhyncha. The strain “Ca. Sulcia muelleri” ML is associated with the maize leafhopper (Dalbulus maidis), collected in Brazil, which is a disease vector that affects corn production. Here, we report the complete genome sequence of this bacterium. PMID:25635014

Chang, Hsing-Hua; Cho, Shu-Ting; Canale, Maria C.; Mugford, Sam T.; Lopes, João R. S.; Hogenhout, Saskia A.

2015-01-01

339

Maize Dwarf Mosaic Can Reduce Weed Suppressive Ability of Sweet Corn Martin M. Williams II and Jerald K. Pataky*  

E-print Network

Maize Dwarf Mosaic Can Reduce Weed Suppressive Ability of Sweet Corn Martin M. Williams II prevalent viral disease of sweet corn grown in many regions of North America and Europe. Although some weeds escape control in most sweet corn fields, the extent to which MDM influences the weed suppressive ability

Sims, Gerald K.

340

Bioguided isolation, characterization, and biotransformation by Fusarium verticillioides of maize kernel compounds that inhibit fumonisin production.  

PubMed

Fusarium verticillioides infects maize ears, causing ear rot disease and contamination of grain with fumonisin mycotoxins. This contamination can be reduced by the presence of bioactive compounds in kernels that are able to inhibit fumonisin biosynthesis. To identify such compounds, we used kernels from a maize genotype with moderate susceptibility to F. verticillioides, harvested at the milk-dough stage (i.e., when fumonisin production initiates in planta), and applied a bioguided fractionation approach. Chlorogenic acid was the most abundant compound in the purified active fraction and its contribution to fumonisin inhibitory activity was up to 70%. Moreover, using a set of maize genotypes with different levels of susceptibility, chlorogenic acid was shown to be significantly higher in immature kernels of the moderately susceptible group. Altogether, our data indicate that chlorogenic acid may considerably contribute to either maize resistance to Fusarium ear rot, fumonisin accumulation, or both. We further investigated the mechanisms involved in the inhibition of fumonisin production by chlorogenic acid and one of its hydrolyzed products, caffeic acid, by following their metabolic fate in supplemented F. verticillioides broths. Our data indicate that F. verticillioides was able to biotransform these phenolic compounds and that the resulting products can contribute to their inhibitory activity. PMID:25014591

Atanasova-Penichon, Vessela; Bernillon, Stéphane; Marchegay, Gisèle; Lornac, Aurélia; Pinson-Gadais, Laetitia; Ponts, Nadia; Zehraoui, Enric; Barreau, Christian; Richard-Forget, Florence

2014-10-01

341

Wind Streaks  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site]

Released 12 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth.

Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms.

Windstreaks are features caused by the interaction of wind and topographic landforms. The raised rims and bowls of impact craters causes a complex interaction such that the wind vortex in the lee of the crater can both scour away the surface dust and deposit it back in the center of the lee. If you look closely, you will see evidence of this in a darker 'rim' enclosing a brighter interior.

Image information: VIS instrument. Latitude 6.9, Longitude 69.4 East (290.6 West). 19 meter/pixel resolution.

Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

2004-01-01

342

Effect of maize variety and storage form on the development of the maize weevil, Sitophilus zeamais Motschulsky  

Microsoft Academic Search

The effects of maize variety and storage form on development of the maize weevil, Sitophilus zeamais Motschulsky, were studied under artificial infestation at 25 ± 2 °C and 70 ± 5% r.h. in the laboratory. Three improved West African maize varieties, Abeleehi, EV8725-SR, Pop63-SR and the local variety, Volta Local, stored shelled and as cobs without husks (=unshelled) were used.

K. A. Vowotor; N. A. Bosque-Pérez; J. N. Ayertey

1995-01-01

343

An Optical Streak Diagnostic for Observing Anode-Cathode Plasmas for Radiographic Source Development  

SciTech Connect

National Security Technologies, LLC, and Sandia National Laboratories are collaborating in the development of pulsed power–driven flash x-ray radiographic sources that utilize high-intensity electron beam diodes. The RITS 6 (Radiographic Integrated Test Stand) accelerator at Sandia is used to drive a self magnetic pinch diode to produce a Bremsstrahlung x-ray source. The high electric fields and current densities associated with these short A-K gap pinch beam diodes present many challenges in diode development. Plasmas generated at both the anode and cathode affect the diode performance, which is manifested in varying spot (source) sizes, total dose output, and impedance profiles. Understanding the nature of these plasmas including closure rates and densities is important in modeling their behavior and providing insight into their mitigation. In this paper we describe a streak camera–based optical diagnostic that is capable of observing and measuring plasma evolution within the A-K gap. By imaging a region of interest onto the input slit of a streak camera, we are able to produce a time-resolved one-dimensional image of the evolving plasma. Typical data are presented.

Droemer, Darryl W. [National Security Technologies, LLC; Crain, Marlon D.; Lare, Gregory A. [National Security Technologies, LLC; Bennett, Nichelle L. [National Security Technologies, LLC; Johnston, Mark D. [Sandia National Laboratories

2013-06-13

344

Gas-phase lifetimes of nucleobase analogues by picosecond pumpionization and streak techniques.  

PubMed

The picosecond (ps) timescale is relevant for the investigation of many molecular dynamical processes such as fluorescence, nonradiative relaxation, intramolecular vibrational relaxation, molecular rotation and intermolecular energy transfer, to name a few. While investigations of ultrafast (femtosecond) processes of biological molecules, e.g. nucleobases and their analogues in the gas phase are available, there are few investigations on the ps time scale. We have constructed a ps pump-ionization setup and a ps streak camera fluorescence apparatus for the determination of lifetimes of supersonic jet-cooled and isolated molecules and clusters. The ps pump-ionization setup was used to determine the lifetimes of the nucleobase analogue 2-aminopurine (2AP) and of two 2AP?(H2O)n water cluster isomers with n=1 and 2. Their lifetimes lie between 150 ps and 3 ns and are strongly cluster-size dependent. The ps streak camera setup was used to determine accurate fluorescence lifetimes of the uracil analogue 2-pyridone (2PY), its self-dimer (2PY)2, two isomers of its trimer (2PY)3 and its tetramer (2PY)4, which lie in the 7-12 ns range. PMID:24983611

Blaser, Susan; Frey, Hans-Martin; Heid, Cornelia G; Leutwyler, Samuel

2014-01-01

345

Tumors of bilateral streak gonads in patients with disorders of sex development containing y chromosome material.  

PubMed

The presence of Y chromosome material in patients with disorders of sex development (DSD) has been associated with a high risk of gonadoblastoma. Therefore, gonadectomy is recommended in females with bilateral streak gonads and Y chromosome material. The aim of this study was to present our experience with prophylactic gonadectomy in those patients and evaluate their risk of gonadal tumors. We reviewed the charts of 11 female patients who had bilateral gonadectomy (by laparoscopically in 9 patients, by laparotomy in 2 patients) between 1991 and 2012 at our hospital. Seven patients with Turner syndrome (TS) who carry a Y mosaic karyotype in peripheral blood, 3 patients with Swyer syndrome and one patient with Frasier syndrome were included. All patients had an unambiguous female phenotype. Age at surgery and follow-up ranged from 2 to 23 (mean 11) and 0.5 to 20 (mean 8) yr, respectively. Pathologic examination revealed gonadal tumors in 6 of 11 patients (56%), including 4 with TS, the youngest of which was 2 yr old, one with Swyer syndrome and one with Frasier syndrome. A gonadoblastoma was detected in 8 gonads, and an association of dysgerminoma with gonadoblastoma was detected in 2 gonads. Imaging studies showed no metastasis, and the postoperative course was uneventful in all patients. In our series of DSD patients with bilateral streak gonads and Y chromosome material, the risk of gonadal tumor was high. Considering the early occurrence of gonadoblastoma and its high potential for malignant transformation, early prophylactic gonadectomy is strongly recommended. PMID:25110393

Matsumoto, Fumi; Shimada, Kenji; Ida, Shinobu

2014-07-01

346

Tumors of Bilateral Streak Gonads in Patients with Disorders of Sex Development Containing Y Chromosome Material  

PubMed Central

Abstract The presence of Y chromosome material in patients with disorders of sex development (DSD) has been associated with a high risk of gonadoblastoma. Therefore, gonadectomy is recommended in females with bilateral streak gonads and Y chromosome material. The aim of this study was to present our experience with prophylactic gonadectomy in those patients and evaluate their risk of gonadal tumors. We reviewed the charts of 11 female patients who had bilateral gonadectomy (by laparoscopically in 9 patients, by laparotomy in 2 patients) between 1991 and 2012 at our hospital. Seven patients with Turner syndrome (TS) who carry a Y mosaic karyotype in peripheral blood, 3 patients with Swyer syndrome and one patient with Frasier syndrome were included. All patients had an unambiguous female phenotype. Age at surgery and follow-up ranged from 2 to 23 (mean 11) and 0.5 to 20 (mean 8) yr, respectively. Pathologic examination revealed gonadal tumors in 6 of 11 patients (56%), including 4 with TS, the youngest of which was 2 yr old, one with Swyer syndrome and one with Frasier syndrome. A gonadoblastoma was detected in 8 gonads, and an association of dysgerminoma with gonadoblastoma was detected in 2 gonads. Imaging studies showed no metastasis, and the postoperative course was uneventful in all patients. In our series of DSD patients with bilateral streak gonads and Y chromosome material, the risk of gonadal tumor was high. Considering the early occurrence of gonadoblastoma and its high potential for malignant transformation, early prophylactic gonadectomy is strongly recommended. PMID:25110393

Matsumoto, Fumi; Shimada, Kenji; Ida, Shinobu

2014-01-01

347

Means of extending streak camera recording into the important 1300 to 1600 nm wavelength regime: parametric frequency upconversion  

SciTech Connect

We present preliminary data demonstrating the feasibility of coupling an optical parametric frequency upconverter to a streak camera, thereby realizing a hybrid recording system that can sensitively record very fast (approx. 10 ps) single-shot infrared events. The data presented in this paper represent experimental work in the upconversion of 845-nm light. This wavelength was chosen for experimental convenience to expedite our proof of principle demonstration. Our results give an estimated upconversion quantum efficiency of about 25%. We also discuss details of our future experiments in upconversion/streak camera recording at 1300 nm.

Lowry, M.E.; Rotter, M.D.; Jander, D.R.

1984-07-01

348

Genome-wide nested association mapping of quantitative resistance to northern leaf blight in maize  

PubMed Central

Quantitative resistance to plant pathogens, controlled by multiple loci of small effect, is important for food production, food security, and food safety but is poorly understood. To gain insights into the genetic architecture of quantitative resistance in maize, we evaluated a 5,000-inbred-line nested association mapping population for resistance to northern leaf blight, a maize disease of global economic importance. Twenty-nine quantitative trait loci were identified, and most had multiple alleles. The large variation in resistance phenotypes could be attributed to the accumulation of numerous loci of small additive effects. Genome-wide nested association mapping, using 1.6 million SNPs, identified multiple candidate genes related to plant defense, including receptor-like kinase genes similar to those involved in basal defense. These results are consistent with the hypothesis that quantitative disease resistance in plants is conditioned by a range of mechanisms and could have considerable mechanistic overlap with basal resistance. PMID:21482771

Poland, Jesse A.; Bradbury, Peter J.; Buckler, Edward S.; Nelson, Rebecca J.

2011-01-01

349

Mapping resistance to Southern rust in a tropical by temperate maize recombinant inbred topcross population  

Microsoft Academic Search

Southern rust, caused by Puccinia polysora Underw, is a foliar disease that can severely reduce grain yield in maize (Zea mays L.). Major resistance genes exist, but their effectiveness can be limited in areas where P. polysora is multi-racial. General resistance could be achieved by combining quantitative and race-specific resistances. This would\\u000a be desirable if the resistance alleles maintained resistance

M. P. Jines; P. Balint-Kurti; L. A. Robertson-Hoyt; T. Molnar; J. B. Holland; M. M. Goodman

2007-01-01

350

Genetically transformed maize plants from protoplasts.  

PubMed

Genetically transformed maize plants were obtained from protoplasts treated with recombinant DNA. Protoplasts that were digested from embryogenic cell suspension cultures of maize inbred A188 were combined with plasmid DNA containing a gene coding for neomycin phosphotransferase (NPT II) next to the 35S promoter region of cauliflower mosaic virus. A high voltage electrical pulse was applied to the protoplasts, which were then grown on filters placed over feeder layers of maize suspension cells (Black Mexican Sweet) and selected for growth in the presence of kanamycin. Selected cell lines showed NPT II activity. Plants were regenerated from transformed cell lines and grown to maturity. Southern analysis of DNA extracted from callus and plants indicated the presence of the NPT II gene. PMID:2832947

Rhodes, C A; Pierce, D A; Mettler, I J; Mascarenhas, D; Detmer, J J

1988-04-01

351

Transcriptome Analysis of Maize Leaf Systemic Symptom Infected by Bipolaris zeicola.  

PubMed

Bipolaris zeicola is a fungal pathogen that causes Northern corn leaf spot (NCLS), which is a serious foliar disease in maize and one of the most significant pathogens affecting global food security. Here, we report a genome-wide transcriptional profile analysis using next-generation sequencing (NGS) of maize leaf development after inoculation with B. zeicola. We performed High-Throughput Digital Gene Expression analysis to identify differentially expressed genes (DEGs) in resistant inbred Mo17 lines after infection with B. zeicola at four successive disease development stages-CP (contact period), PP (penetration period), IP (incubation period), and DP (disease period); the expression of the genes was compared with those in a CK (mock-treatment) control. In addition, a sensitive maize line (Zheng58) was used for the comparisons with the Mo17. Among all tested genes, 466 differentially expressed genes were identified in all libraries, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of these genes suggested that they are involved in many biological processes related to systemic symptom development, such as plant hormone signal transduction, starch and sucrose metabolism, phenylpropanoid biosynthesis and photosynthesis. Our systematic analysis provides comprehensive transcriptomic information regarding systemic symptom development in fungal-infected plants. This information will help in furthering our understanding of the detailed mechanisms of plant responses to fungal infection. PMID:25781606

Liu, Ming; Gao, Jian; Yin, Fuqiang; Gong, Guoshu; Qin, Cheng; Ye, Kunhao; Zhang, Min; Sun, Xiaofang; Zhou, You; Zhang, Youju

2015-01-01

352

Transcriptome Analysis of Maize Leaf Systemic Symptom Infected by Bipolaris zeicola  

PubMed Central

Bipolaris zeicola is a fungal pathogen that causes Northern corn leaf spot (NCLS), which is a serious foliar disease in maize and one of the most significant pathogens affecting global food security. Here, we report a genome-wide transcriptional profile analysis using next-generation sequencing (NGS) of maize leaf development after inoculation with B. zeicola. We performed High-Throughput Digital Gene Expression analysis to identify differentially expressed genes (DEGs) in resistant inbred Mo17 lines after infection with B. zeicola at four successive disease development stages—CP (contact period), PP (penetration period), IP (incubation period), and DP (disease period); the expression of the genes was compared with those in a CK (mock-treatment) control. In addition, a sensitive maize line (Zheng58) was used for the comparisons with the Mo17. Among all tested genes, 466 differentially expressed genes were identified in all libraries, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of these genes suggested that they are involved in many biological processes related to systemic symptom development, such as plant hormone signal transduction, starch and sucrose metabolism, phenylpropanoid biosynthesis and photosynthesis. Our systematic analysis provides comprehensive transcriptomic information regarding systemic symptom development in fungal-infected plants. This information will help in furthering our understanding of the detailed mechanisms of plant responses to fungal infection. PMID:25781606

Gong, Guoshu; Qin, Cheng; Ye, Kunhao; Zhang, Min; Sun, Xiaofang; Zhou, You; Zhang, Youju

2015-01-01

353

Silicon Improves Maize Photosynthesis in Saline-Alkaline Soils  

PubMed Central

The research aimed to determine the effects of Si application on photosynthetic characteristics of maize on saline-alkaline soil, including photosynthetic rate (Pn), stomatal conductance (gs), transpiration rate (E), and intercellular CO2 concentration (Ci) of maize in the field with five levels (0, 45, 90, 150, and 225?kg·ha?1) of Si supplying. Experimental results showed that the values of Pn, gs, and Ci of maize were significantly enhanced while the values of E of maize were dramatically decreased by certain doses of silicon fertilizers, which meant that Si application with proper doses significantly increased photosynthetic efficiency of maize in different growth stages under stressing environment of saline-alkaline soil. The optimal dose of Si application in this experiment was 150?kg·ha?1?Si. It indicated that increase in maize photosynthesis under saline-alkaline stress took place by Si application with proper doses, which is helpful to improve growth and yield of maize. PMID:25629083

Xie, Zhiming; Song, Ri; Shao, Hongbo; Song, Fengbin; Xu, Hongwen; Lu, Yan

2015-01-01

354

GPU-accelerated Faint Streak Detection for Uncued Surveillance of LEO  

NASA Astrophysics Data System (ADS)

By astronomical standards, small objects (<10cm) in LEO illuminated by the Sun under terminator conditions are quite bright, depositing 100's to 1000's of photons per second into small telescope apertures (< 1m diameter). The challenge in discovering these objects with no a priori knowledge of their orbit (i.e. uncued surveillance) is that their relative motion with respect to a ground-based telescope makes them appear to have large angular rates of motion, up to and exceeding 1 degree per second. Thus in even a short exposure, the signal from the object is smeared out in a streak with low signal-to-noise per pixel. Go Green Termite (GGT), Inc. of Gilroy, CA, in collaboration with the University of New Mexico (UNM), is building two proof-of-concept wide-field imaging systems to test, develop and prove a novel streak detection technique. The imaging systems are built from off-the-shelf optics and detectors resulting in a 350mm aperture and a 6 square degree field of view. For streak detection, field of view is of critical importance because the maximum exposure time on the object is limited by its crossing time. In this way, wider fields of view impact surveys for LEO objects both by increasing the survey volume and increasing sensitivity. Using our newly GPU-accelerated detection scheme, the proof-of-concept systems are expected to be able to detect objects fainter than 12th magnitude moving at 1 degree per second and possibly as faint as 13th magnitude for slower moving objects. Meter-class optical systems using these techniques should be able to detect objects fainter than 14th magnitude, which is roughly equivalent to a golf ball at 1000km altitude. The goal of this work is to demonstrate a scalable system for near real time detection of fast moving objects that can be then handed off to other instruments capable of tracking and characterizing them. The two proof-of-concept systems, separated by ~30km, work together by taking simultaneous images of the same volume to constrain the orbits of detected objects using parallax measurements. These detections will then be followed-up by photometric observations taken at UNM to independently assess the objects and the quality of the derived orbits. We believe this will demonstrate the potential of small telescope arrays for detecting and cataloguing heretofore unknown LEO objects.

Zimmer, P.; Ackermann, M.; McGraw, J. T.

2013-09-01

355

Effects of wheat streak mosaic virus on root development and water-use efficiency of hard red winter wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

Greenhouse and field studies were conducted to determine the effects of Wheat streak mosaic virus (WSMV), a member of the family Potyviridae, on root development and water-use efficiency (WUE) of two hard red winter wheat (Triticum aestivum) cultivars, one susceptible and one resistant to WSMV. In t...

356

Wheat streak mosaic virus genotypes introduced to Argentina are closely related to isolates from the American Pacific Northwest and Australia  

Technology Transfer Automated Retrieval System (TEKTRAN)

Wheat streak mosaic virus (WSMV) was first detected in Argentina in 2002. Comparison of 78 WSMV coat protein sequences revealed that three Argentine isolates were closely related to isolates from the American Pacific Northwest (APNW) and Australia. Complete sequences were determined for one Argen...

357

Diagnosing coupled jet-streak circulations for a northern plains snow band from the operational nested-grid model  

NASA Technical Reports Server (NTRS)

On 17 March 1989, moderate to heavy snow developed in a 100- to 200-km-wide band extending from South Dakota to northern Michigan. The 4- to 8-inch snowfall within this band was not associated with major cyclogenesis, and developed 500 to 600 km north of a stationary surface front. A diagnostic analysis based on an application of the General Meteorological Package (GEMPAK 5.0) to a numerical simulation from the operational nested-grid model (NGM) is utilized to show that the development of this snow band is related to the interaction of two upper-tropospheric jet streaks and their associated transverse circulation patterns. The eastward propagation of a jet streak from the West Coast toward the middle United States and to the south of a slower-moving jet along the U.S.-Canadian border led to a merger of the ascent maxima associated with the direct and indirect circulations of the northern and southern jets, respectively. The snow band developed as the ascending branches of the jet-streak circulation patterns merged, with the eastward propagation of the heaviest snow linked to the motion of the coupled circulation pattern. The study also demonstrates the usefulness of the operational NGM for providing the higher-resolution datasets required to relate the evolution of jet-streak circulation patterns to the development of mesoscale precipitation bands.

Hakim, Gregory J.; Uccellini, Louis W.

1992-01-01

358

Determination of shaped-jet characteristics by double orthogonal synchro streak technique and double x-ray technique  

Microsoft Academic Search

This paper presents a method that allows very accurate measurements for a full characterization of shaped charge jets. A double visualization of the jets is achieved by means of both a modified high speed camera CORDIN in Double Orthogonal Synchro Streak Technique (DOSST) configuration and a classical Double XRays Technique (DXRT). The interests of this method are twofold: Firstly, the

Robert Tosello; Mohamed Mehaddi; Henry Marrot

1995-01-01

359

Two Dimensions Are Not Better than One: STREAK and the Univariate Signal Detection Model of Remember/Know Performance  

ERIC Educational Resources Information Center

We evaluated STREAK and the univariate signal detection model of Remember/Know (RK) judgments in terms of their ability to fit empirical data and produce psychologically meaningful parameter estimates. Participants studied pairs of words and completed item recognition tests with RK judgments as well as associative recognition tests. Fits to the RK…

Starns, Jeffrey J.; Ratcliff, Roger

2008-01-01

360

Compositions of Low Albedo Intracrater Materials and Wind Streaks on Mars: Examination of MGS TES Data in Western Arabia Terra  

NASA Technical Reports Server (NTRS)

Basalt and andesite surface compositions are identified within individual low albedo intracrater features and adjacent dark wind streaks. High resolution mapping of compositional heterogeneities may help constrain origin hypotheses for these features. Additional information is contained in the original extended abstract.

Bandfield, J. L.; Wyatt, M. B.; Christensen, P.; McSween, H. Y., Jr.

2001-01-01

361

Avoiding acidic region streaking in two-dimensional gel electrophoresis: Case study with two bacterial whole cell protein  

E-print Network

Avoiding acidic region streaking in two-dimensional gel electrophoresis: Case study with two by two-dimensional gel electrophoresis. J. Commun. Dis. 38 255­262 Blokpoel MC, Smeulders MJ, Hubbard JA of IEF-program for 7 cm and 17 cm IPG strips. #12;Supplementary figure 6. 2DE gel images of E. coli WCPE

Pal, Debnath

362

COMPLETE DELETION OF WHEAT STREAK MOSAIC VIRUS HC-PRO: A NULLL MUTANT IS VIABLE FOR SYSTEMIC INFECTION  

Technology Transfer Automated Retrieval System (TEKTRAN)

A Wheat streak mosaic virus (WSMV) genome lacking HC-Pro was constructed and confirmed by RT-PCR to systemically infect wheat, oat, and corn. Coupled in vitro transcription/translation reactions indicated that WSMV P1 proteinase cleaved the polyprotein at the P1/P3 junction of the HC-Pro null mutan...

363

A 'chemotactic dipole' mechanism for large-scale vortex motion during primitive streak formation in the chick embryo  

NASA Astrophysics Data System (ADS)

Primitive streak formation in the chick embryo involves significant coordinated cell movement lateral to the streak, in addition to the posterior-anterior movement of cells in the streak proper. Cells lateral to the streak are observed to undergo 'polonaise movements', i.e. two large counter-rotating vortices, reminiscent of eddies in a fluid. In this paper, we propose a mechanism for these movement patterns which relies on chemotactic signals emitted by a dipolar configuration of cells in the posterior region of the epiblast. The 'chemotactic dipole' consists of adjacent regions of cells emitting chemo-attractants and chemo-repellents. We motivate this idea using a mathematical analogy between chemotaxis and electrostatics, and test this idea using large-scale computer simulations. We implement active cell response to both neighboring mechanical interactions and chemotactic gradients using the Subcellular Element Model. Simulations show the emergence of large-scale vortices of cell movement. The length and time scales of vortex formation are in reasonable agreement with experimental data. We also provide quantitative estimates for the robustness of the chemotaxis dipole mechanism, which indicate that the mechanism has an error tolerance of about 10% to variation in chemotactic parameters, assuming that only 1% of the cell population is involved in emitting signals. This tolerance increases for larger populations of cells emitting signals.

Sandersius, S. A.; Chuai, M.; Weijer, C. J.; Newman, T. J.

2011-08-01

364

Identification of distinct functions of Wheat streak mosaic virus coat protein in virion assembly and virus movement  

Technology Transfer Automated Retrieval System (TEKTRAN)

Wheat streak mosaic virus (WSMV) is the type member of Tritimovirus genus of the family Potyviridae. The WSMV coat protein (CP) was subjected to point and deletion mutation analyses. WSMV mutants changing aspartic acid residues at amino acid (aa) positions 289, 290, 326, 333, and 334 to alanine elic...

365

Quantification of yield loss caused by Triticum mosaic virus and Wheat streak mosaic virus in winter wheat under field conditions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Triticum mosaic virus (TriMV) and Wheat streak mosaic virus (WSMV) infect winter wheat in the Great Plains region of the United States. The two viruses are transmitted by wheat curl mites, which also transmit High Plains virus. In a field study conducted in 2011 and 2012, winter wheat cultivars Mi...

366

Modified ecometric technique (four-quadrant sequential streak) to evaluate Campylobacter enrichment broth proficiency in suppressing background microflora  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ecometric technique is a semi-quantitative scoring method used for quality control of culture media in microbiological laboratories. The technique involves inoculation with defined populations of specific culture onto solid media via a standardized chronological streaking technique, leading to ever-...

367

Making electrocompetent cells 1. Streak out desired strain from frozen stock and incubate overnight (include drug if  

E-print Network

Making electrocompetent cells 1. Streak out desired strain from frozen stock and incubate overnight with colony from step one (include drug if present) and shake/incubate overnight. 3. Subculture 5 ml into 500 ml of media (include drug if present). 4. Shake/incubate until an OD600 of 0.5 is reached (this takes

Segall, Anca

368

All Maize Is Not Equal: Maize Variety Choices and Mayan Foodways in Rural Yucatan, Mexico  

Microsoft Academic Search

\\u000a Foodways have changed substantially over the past several centuries in the Yucatan Peninsula and other areas of Mesoamerica,\\u000a but one constant is the presence of maize (Zea mays) at the heart of rural economy, ecology, and culture. The domestication and diversification of maize – the world’s most productive\\u000a grain crop – by indigenous farmers ranks as one of the greatest

John Tuxill; Luis Arias Reyes; Luis Latournerie Moreno; Vidal Cob Uicab; Devra I. Jarvis

369

Foliar Diseases of Apiaceae Crops in Coastal California  

Technology Transfer Automated Retrieval System (TEKTRAN)

The number of outbreaks of leaf spot, blight and streak diseases on celery, cilantro, fennel and parsley has been increasing throughout central coastal California and particularly in Monterey County since 2002. Two different bacterial pathogens (Pseudomonas syringae pv. apii, and P. syringae pv. cor...

370

Laser-produced plasma x-ray diagnostics with an x-ray streak camera at the Iskra-4 plant  

NASA Astrophysics Data System (ADS)

An X.raj streak camera with an Xray streak tube used for laser-produced plasma soft Xrays measurement is described, and experimental results are given. In investigating short-Jived high temperature plasma, and inertial control of thermonuclear fusion in particular, measurement techniques based on registration of X-.rays emitted by the investigated object are of great value. They make it possible to get much information on the dynamics of plasma evolution, its form, dimensions, temperature, and density. The instrumentation used for these purposes must meet the following main requirements: it must provide measuring X-.rays time, intensity and spatial coordinate; its spectral range must be wide, from relatively hard to extremely soft X-rays (tens of keV to tens of eV quantum energy); its tiive resolution must be high (of the order of 10 s). At present the only type of an instrument satisfying the above requirements is a streak camera with an X-ray' streak tube (X'RST). The XRST operation principle has been known long ago: the photocathode converts the incident X-rays into an electron beam, which is accelerated and focused by the electric fields onto the output phosphor screen, where a visible image of the incident radiation cross-.section appears. The image travels very rapidly over the screen, resulting in a time sweep. The design and development of such kind of instrumentation was begun in our country more than 10 years ago. In 1986 the All-Union Research Institute of experimental Physics, in collaboration with the Research Institute of Pulse Technique, designed and built first instruments with satisfactory parameters. These instruments found use in laser thermonuclear fusion research. Mainly two types of X-.ray streak tubes are used for X-.ray spatial-temporal structure registration: special type X-ray streak tubes with X-ray sensitive photocathodes and transparent for X-ray input windows, and X-ray streak tubes with X-ray sensitive photocathodes and without an input win dow; these tubes are joined to a continuously pumped-out vacuum plant with an X-ray source inside it. The quantum energy lower limit of the registered X-rays depends on the input window thickness and. material, which determine its transparency for the radiation being investigated.

Berkovski, Arkadi G.; Gubanov, Yuri I.; Pryanishnikov, Ivan G.; Murugov, Vasili M.; Petrov, Sergej I.; Senik, Alexei V.

1991-04-01

371

Time-resolved spectra of single-bubble sonoluminescence in sulfuric acid with a streak camera.  

PubMed

The time-resolved spectra of single-bubble sonoluminescence (SBSL) in sulfuric acid have been observed with a streak camera after a spectrograph. The spectral center evolves from infrared to ultraviolet gradually within a SBSL duration, which corresponds to an increase of temperature. The peak temperature within one sonoluminescence (SL) duration is 5-9 times higher than the average temperature based on the average spectrum in our experiment. Furthermore, the ratio of the peak temperature to average temperature increases with the increase of driving pressure. The SBSL flash dies out after a dramatic heating-up, and there is no cooling procedure observed at the time resolution of 110 SL duration, which is incompatible with the radius-related adiabatic heating model as the mechanism of SBSL. PMID:18851095

Chen, Weizhong; Huang, Wei; Liang, Yue; Gao, Xianxian; Cui, Weicheng

2008-09-01

372

Streaking temporal double slit interference by an orthogonal two-color laser field  

E-print Network

We investigate electron momentum distributions from single ionization of Ar by two orthogonally polarized laser pulses of different color. The two-color scheme is used to experimentally control the interference between electron wave packets released at different times within one laser cycle. This intracycle interference pattern is typically hard to resolve in an experiment. With the two-color control scheme these features become the dominant contribution to the electron momentum distribution. Furthermore the second color can be used for streaking of the otherwise interfering wave packets establishing a which-way marker. Our investigation shows that the visibility of the interference fringes depends on the degree of the which-way information determined by the controllable phase between the two pulses.

Richter, Martin; Schöffler, Markus; Jahnke, Till; Schmidt, Lothar P H; Li, Min; Liu, Yunquan; Dörner, Reinhard

2015-01-01

373

Microstructure investigations of streak formation in 6063 aluminum extrusions by optical metallographic techniques.  

PubMed

The present study investigates the effect of the solidification strategy for AA 6063 alloy on the surface appearance of anodized extrusions. The microstructure of the samples was analyzed using both light optical microscopy and scanning electron microscopy. Results show that if heavy segregation occurs from rapid solidification, coarse Mg2Si particles form, thus reducing the potential for precipitation strengthening by the finer ?-Mg2Si developed in the solid state. Differentially-strained regions formed during hot extrusion induce differences in particle size for magnesium silicide (Mg2Si) precipitates. Anodizing generates surface roughness due to Mg2Si particle dissolution and AlFeSi decohesion, which is related to both particle size and deformation. During anodizing, an oxide layer forms on the surface of the extruded products, which can lead to streak formation, usually a subject of rejection due to unacceptable heterogeneous reflectivity. PMID:23481588

Vander Voort, George; Suárez-Peña, Beatriz; Asensio-Lozano, Juan

2013-04-01

374

Mapping of Digitaria streak virus transcripts reveals different RNA species from the same transcription unit.  

PubMed Central

All, except 19 [corrected] bp, of the Digitaria streak virus (DSV) genome is transcribed. Two RNA transcripts (1+ and 2+) are encoded by the virion DNA strand and up to five (1- to 5-) by the complementary DNA strand [corrected]. Detailed mapping of these RNAs has revealed evidence for splicing in one species (RNA 4-), which together with its more abundant unspliced counterpart (RNA 2-) could synthesize both a 30.5 and 41 kd polypeptide from the same transcription unit. This extensive overlapping of spliced and unspliced RNAs could indicate that the initiation and splicing of transcripts is temporally regulated. At least one transcript (RNA 1-) may have a non-translational role. Transcription of the DSV genome shows similarities to some animal DNA viruses, particularly the papovaviruses. Images PMID:2472960

Accotto, G P; Donson, J; Mullineaux, P M

1989-01-01

375

Development of a probe-based blotting technique for the detection of tobacco streak virus.  

PubMed

Digoxigenin (DIG)-labeled DNA probe was developed for a sensitive and rapid detection of the tobacco streak virus (TSV) isolates in India by dot-blot and tissue print hybridization techniques. DIG-labeled DNA probe complementary to the coat protein (CP) region of TSV sunflower isolate was designed and used to detect the TSV presence at field levels. Dot-blot hybridization was used to check a large number of TSV isolates with a single probe. In addition, a sensitivity of the technique was examined with the different sample extraction methods. Another technique, the tissue blot hybridization offered a simple, reliable procedure and did not require a sample processing. Thus, both non-radioactively labeled probe techniques could facilitate the sample screening during TSV outbreaks and offer an advantage in quarantine services. PMID:20822316

Sarovar, B; Saigopal, D V R

2010-01-01

376

Myosin-II-mediated cell shape changes and cell intercalation contribute to primitive streak formation.  

PubMed

Primitive streak formation in the chick embryo involves large-scale highly coordinated flows of more than 100,000 cells in the epiblast. These large-scale tissue flows and deformations can be correlated with specific anisotropic cell behaviours in the forming mesendoderm through a combination of light-sheet microscopy and computational analysis. Relevant behaviours include apical contraction, elongation along the apical-basal axis followed by ingression, and asynchronous directional cell intercalation of small groups of mesendoderm cells. Cell intercalation is associated with sequential, directional contraction of apical junctions, the onset, localization and direction of which correlate strongly with the appearance of active myosin II cables in aligned apical junctions in neighbouring cells. Use of class specific myosin inhibitors and gene-specific knockdown shows that apical contraction and intercalation are myosin II dependent and also reveal critical roles for myosin I and myosin V family members in the assembly of junctional myosin II cables. PMID:25812521

Rozbicki, Emil; Chuai, Manli; Karjalainen, Antti I; Song, Feifei; Sang, Helen M; Martin, René; Knölker, Hans-Joachim; MacDonald, Michael P; Weijer, Cornelis J

2015-03-27

377

Streaked x-ray spectrometer having a discrete selection of Bragg geometries for Omega  

SciTech Connect

The streaked x-ray spectrometer (SXS) is used with streak cameras [D. H. Kalantar, P. M. Bell, R. L. Costa, B. A. Hammel, O. L. Landen, T. J. Orzechowski, J. D. Hares, and A. K. L. Dymoke-Bradshaw, in 22nd International Congress on High-Speed Photography and Photonics, edited by D. L. Paisley and A. M. Frank (SPIE, Bellingham, WA, 1997), Vol. 2869, p. 680] positioned with a ten-inch manipulator on OMEGA [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] and OMEGA EP [L. J. Waxer et al., Presented at CLEO/QELS 2008, San Jose, CA, 4-9 May 2008 (Paper JThB1)] for time-resolved, x-ray spectroscopy of laser-produced plasmas in the 1.4- to 20-keV photon-energy range. These experiments require measuring a portion of this photon-energy range to monitor a particular emission or absorption feature of interest. The SXS relies on a pinned mechanical reference system to create a discrete set of Bragg reflection geometries for a variety of crystals. A wide selection of spectral windows is achieved accurately and efficiently using this technique. It replaces the previous spectrometer designs that had a continuous Bragg angle adjustment and required a tedious alignment calibration procedure. The number of spectral windows needed for the SXS was determined by studying the spectral ranges selected by OMEGA users over the last decade. These selections are easily configured in the SXS using one of the 25 discrete Bragg reflection geometries and one of the six types of Bragg crystals, including two curved crystals.

Millecchia, M.; Regan, S. P.; Bahr, R. E.; Romanofsky, M.; Sorce, C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299 (United States)

2012-10-15

378

Biological Control of Fusarium moniliforme in Maize  

Microsoft Academic Search

Fusarium moniliforme Sheldon, a biological species of the mating populations within the Gibberella fujikuroi species complex, i.e., population A (= G. moniliformis (Sheld.) Wineland), is an example of a facultative fungal endophyte. During the biotrophic endophytic association with maize, as well as during saprophytic growth, F. moniliforme produces the fumonisins. The fungus is transmitted vertically and horizontally to the next

Charles W. Bacon; Ida E. Yates; Dorothy M. Hinton; Filmore Meredith

2001-01-01

379

Regulatory modules controlling maize inflorescence architecture  

Technology Transfer Automated Retrieval System (TEKTRAN)

Genetic control of branching is a primary determinant of yield, regulating seed number and harvesting ability, yet little is known about the molecular networks that shape grain-bearing inflorescences of cereal crops. Here, we used the maize (Zea mays) inflorescence to investigate gene networks that...

380

Seed Calorific Value in Different Maize Genotypes  

Microsoft Academic Search

Biomass represents an important source of renewable energy, and in most countries it is now considered essential for environmental policies to include sustainable energy production. The direct burning of maize grains contaminated by mycotoxins for house heating or for harvested grain drying may represent an interesting and economically efficient way to salvage an otherwise unusable product. This work aims to

D. Panzeri; V. Cesari; I. Toschi; R. Pilu

2011-01-01

381

The genetic architecture of maize stalk strength  

Technology Transfer Automated Retrieval System (TEKTRAN)

Stalk strength is an important trait in maize (Zea mays L.). Strong stalks reduce lodging and maximize harvestable yield. Studies show rind penetrometer resistance (RPR), or the force required to pierce a stalk rind with a spike, is a valid approximation of strength. We measured RPR across 4,892 rec...

382

Registration of maize inbred line GT603  

Technology Transfer Automated Retrieval System (TEKTRAN)

GT603 (Reg. No. xxxx, PI xxxxxx) is a yellow dent maize (Zea mays L.) inbred line developed and released by the USDA-ARS Crop Protection and Management Research Unit in cooperation with the University of Georgia Coastal Plain Experiment Station in 2010. GT603 was developed through seven generations ...

383

REGISTRATION OF MAIZE GERMPLASM LINE MP717  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize (Zea mays L.) germplasm line Mp717 was released by USDA-ARS and the Mississippi Agricultural and Forestry Experiment Station in July 2005 as a source of resistance to Aspergillus flavus infection and aflatoxin contamination. Mp717 was developed from a cross of MP420 and Tx601 by selfing for ei...

384

GENETIC VARIABILITY IN MAIZE CHLOROTIC DWARF VIRUS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize chlorotic dwarf virus (MCDV) (genus Waikavirus; family Sequiviridae) is a picorna-like virus transmitted by the black-faced leafhopper, Graminella nigrifrons, in a semi-persistent manner using a virus-encoded helper protein. The MCDV genome contains one large open reading frame encoding a poly...

385

A first generation haplotype map of maize  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize (Zea mays L.) is the top production crop in the world and possesses more genetic diversity than any other major crop species. By using low-copy-enrichment and rapid sequencing-by-synthesis (SBS) approaches, we simultaneously discovered and genotyped several million sequence polymorphisms among...

386

Hormonal responses during early embryogenesis in maize.  

PubMed

Plant hormones have been shown to regulate key processes during embryogenesis in the model plant Arabidopsis thaliana, but the mechanisms that determine the peculiar embryo pattern formation of monocots are largely unknown. Using the auxin and cytokinin response markers DR5 and TCSv2 (two-component system, cytokinin-responsive promoter version #2), as well as the auxin efflux carrier protein PIN1a (PINFORMED1a), we have studied the hormonal response during early embryogenesis (zygote towards transition stage) in the model and crop plant maize. Compared with the hormonal response in Arabidopsis, we found that detectable hormone activities inside the developing maize embryo appeared much later. Our observations indicate further an important role of auxin, PIN1a and cytokinin in endosperm formation shortly after fertilization. Apparent auxin signals within adaxial endosperm cells and cytokinin responses in the basal endosperm transfer layer as well as chalazal endosperm are characteristic for early seed development in maize. Moreover, auxin signalling in endosperm cells is likely to be involved in exogenous embryo patterning as auxin responses in the endosperm located around the embryo proper correlate with adaxial embryo differentiation and outgrowth. Overall, the comparison between Arabidopsis and maize hormone response and flux suggests intriguing mechanisms in monocots that are used to direct their embryo patterning, which is significantly different from that of eudicots. PMID:24646239

Chen, Junyi; Lausser, Andreas; Dresselhaus, Thomas

2014-04-01

387

The transcriptome landscape of early maize meiosis  

Technology Transfer Automated Retrieval System (TEKTRAN)

Meiosis, particularly meiotic recombination, is a major factor affecting yield and breeding of plants. To gain insight into the transcriptome landscape during early initiation steps of meiotic recombination, we profiled early prophase I meiocytes from maize using RNA-seq. Our analyses of genes prefe...

388

Digital gene expression signatures for maize development  

Technology Transfer Automated Retrieval System (TEKTRAN)

Genome-wide expression signatures detect specific perturbations in developmental programs and contribute to functional resolution of key regulatory networks. In maize (Zea mays) inflorescences, mutations in the RAMOSA (RA) genes affect determinacy of axillary meristems and thus alter branching patt...

389

Use of tropical maize for bioethanol production.  

PubMed

Tropical maize is an alternative energy crop being considered as a feedstock for bioethanol production in the North Central and Midwest United States. Tropical maize is advantageous because it produces large amounts of soluble sugars in its stalks, creates a large amount of biomass, and requires lower inputs (e.g. nitrogen) than grain corn. Soluble sugars, including sucrose, glucose and fructose were extracted by pressing the stalks at dough stage (R4). The initial extracted syrup fermented faster than the control culture grown on a yeast extract/phosphate/sucrose medium. The syrup was subsequently concentrated 1.25-2.25 times, supplemented with urea, and fermented using Saccharomyces cerevisiae for up to 96 h. The final ethanol concentrations obtained were 8.1 % (v/v) to 15.6 % (v/v), equivalent to 90.3-92.2 % of the theoretical yields. However, fermentation productivity decreased with sugar concentration, suggesting that the yeast might be osmotically stressed at the increased sugar concentrations. These results provide in-depth information for utilizing tropical maize syrup for bioethanol production that will help in tropical maize breeding and development for use as another feedstock for the biofuel industry. PMID:23508398

Chen, Ming-Hsu; Kaur, Prabhjot; Dien, Bruce; Below, Frederick; Vincent, Michael L; Singh, Vijay

2013-08-01

390

Genetic adjustment to changing climates: MAIZE  

Technology Transfer Automated Retrieval System (TEKTRAN)

The prospects for more widespread and frequent drought in the near future are placing considerable pressure on maize breeding programs to develop more drought tolerant germplasm. Despite the complexity of the plant’s responses to water limited conditions, rational application of molecular/genomic ap...

391

Genetic perturbation of the maize methylome.  

PubMed

DNA methylation can play important roles in the regulation of transposable elements and genes. A collection of mutant alleles for 11 maize (Zea mays) genes predicted to play roles in controlling DNA methylation were isolated through forward- or reverse-genetic approaches. Low-coverage whole-genome bisulfite sequencing and high-coverage sequence-capture bisulfite sequencing were applied to mutant lines to determine context- and locus-specific effects of these mutations on DNA methylation profiles. Plants containing mutant alleles for components of the RNA-directed DNA methylation pathway exhibit loss of CHH methylation at many loci as well as CG and CHG methylation at a small number of loci. Plants containing loss-of-function alleles for chromomethylase (CMT) genes exhibit strong genome-wide reductions in CHG methylation and some locus-specific loss of CHH methylation. In an attempt to identify stocks with stronger reductions in DNA methylation levels than provided by single gene mutations, we performed crosses to create double mutants for the maize CMT3 orthologs, Zmet2 and Zmet5, and for the maize DDM1 orthologs, Chr101 and Chr106. While loss-of-function alleles are viable as single gene mutants, the double mutants were not recovered, suggesting that severe perturbations of the maize methylome may have stronger deleterious phenotypic effects than in Arabidopsis thaliana. PMID:25527708

Li, Qing; Eichten, Steven R; Hermanson, Peter J; Zaunbrecher, Virginia M; Song, Jawon; Wendt, Jennifer; Rosenbaum, Heidi; Madzima, Thelma F; Sloan, Amy E; Huang, Ji; Burgess, Daniel L; Richmond, Todd A; McGinnis, Karen M; Meeley, Robert B; Danilevskaya, Olga N; Vaughn, Matthew W; Kaeppler, Shawn M; Jeddeloh, Jeffrey A; Springer, Nathan M

2014-12-01

392

Use and impact of Bt maize  

Technology Transfer Automated Retrieval System (TEKTRAN)

This is an invited article for a free science library and personal training tool sponsored by Nature Publishing Group, which will be included under the topics Agriculture and Biotechnology (http://www.nature.com/scitable). The focus of this article is on Bacillus thuringiensis (Bt) maize. Growers of...

393

Simulating nitrogen uptake and distribution in maize  

Technology Transfer Automated Retrieval System (TEKTRAN)

Nitrogen is a dominant factor in the nutritional status of a maize crop. It is the most easily absorbed nutrient by corn crop and has the largest effect on yield. Leaf area development and light capture is dependent on the nitrogen status of the plant. Knowledge of the factors governing corn crop N ...

394

MOLECULAR POPULATION GENETICS OF MAIZE DOMESTICATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

The domestication of maize resulted in a dramatic change in its plant architecture and inflorescence development as compared to its wild ancestor, teosinte, with the most remarkable difference being in their female inflorescence (ear) structure. Only a few genes have been uncovered to be associated ...

395

Maize Genetics Outreach to American Indians  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize is an excellent vehicle for plant genomics outreach to those American Indian tribes who use and appreciate it nutritionally, culturally, and spiritually. During the summer 2006 season we mentored six Native American Indian students for eight weeks. All six worked at the USDA-ARS North Centra...

396

MAIZE MUTANT MAPPING WITH SSR MARKERS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Zea mays provides an ideal system for characterizing genes to determine genetic structure and expression in a higher crop plant. Thousands of independently isolated mutants in maize are available for research. We are facilitating this resource by establishing linkage information between these genes ...

397

DEVELOPMENTS OF STARCH GRANULES IN MAIZE KERNELS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize kernels of self-pollinated inbred line B73, grown in Ames IA, were harvested on 0, 5, 6, 8, 10 12, 14, 20 and 30 days after pollination (DAP). The kernels were used for starch granule development studies. Starch in the endosperm was first observed on 6 DAP. Starch granules in the kernels th...

398

Genetic Combining Analysis of Food-Grade Maize: Colored and Quality Protein  

E-print Network

Maize genetic diversity includes an array of kernel colors (red, blue, purple) with blue concentrated in the aleurone and red primarily in the pericarp. Quality protein maize (QPM) is improved over normal maize in regards to grain concentration...

Mahan, Adam Lyle

2012-10-19

399

Comparative Analysis of the Performance of Aspergillus flavus on Resistant and Susceptible Maize Genotypes during Infection  

Technology Transfer Automated Retrieval System (TEKTRAN)

Aspergillus, a mycotoxicogenic fungal genus, produces carcinogenic aflatoxins in crops like peanuts and maize. Development of fungal resistant maize cultivars is one strategy used to decrease contamination. Successful development and identification of resistant maize genotypes requires evaluation o...

400

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.  

Code of Federal Regulations, 2012 CFR

...false Certified seed potatoes, and seed corn or maize. 10.57 Section 10.57...ETC. General Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification...

2012-04-01

401

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.  

Code of Federal Regulations, 2010 CFR

...false Certified seed potatoes, and seed corn or maize. 10.57 Section 10.57...ETC. General Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification...

2010-04-01

402

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.  

Code of Federal Regulations, 2011 CFR

...false Certified seed potatoes, and seed corn or maize. 10.57 Section 10.57...ETC. General Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification...

2011-04-01

403

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.  

Code of Federal Regulations, 2014 CFR

...false Certified seed potatoes, and seed corn or maize. 10.57 Section 10.57...ETC. General Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification...

2014-04-01

404

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.  

Code of Federal Regulations, 2013 CFR

...false Certified seed potatoes, and seed corn or maize. 10.57 Section 10.57...ETC. General Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification...

2013-04-01

405

P.A. Iji et al.Nutritive value of drying maize in broilerchickens Original article  

E-print Network

maize was im- proved (P enzyme supplement (MES). There was no effect / broiler chicks / digestibility / digestive enzymes / drying temperature / grain quality / maize Reprod function and body growth of broiler chickens on diets based on maize dried at different temperatures

Paris-Sud XI, Université de

406

Development of recombinant coat protein antibody based IC-RT-PCR for detection and discrimination of sugarcane streak mosaic virus isolates from Southern India.  

PubMed

Sugarcane streak mosaic virus (SCSMV), causes mosaic disease of sugarcane and is thought to belong to a new undescribed genus in the family Potyviridae. The coat protein (CP) gene from the Andhra Pradesh (AP) isolate of SCSMV (SCSMV-AP) was cloned and expressed in Escherichia coli. The recombinant coat protein was used to raise high quality antiserum. The CP antiserum was used to develop an immunocapture reverse transcription-polymerase chain reaction (IC-RT-PCR) based assay for the detection and discrimination of SCSMV isolates in South India. The sequence of the cloned PCR products encoding 3'untranslated region (UTR) and CP regions of the virus isolates from three different locations in South India viz. Tanuku (Coastal Andhra Pradesh), Coimbatore (Tamil Nadu) and Hospet (Karnataka) was compared with that of SCSMV-AP. The analysis showed that they share 89.4, 89.5 and 90% identity respectively at the nucleotide level. This suggests that the isolates causing mosaic disease of sugarcane in South India are indeed strains of SCSMV. In addition, the sensitivity of the IC-RT-PCR was compared with direct antigen coating-enzyme linked immunosorbent assay (DAC-ELISA) and dot-blot immunobinding assays and was found to be more sensitive and hence could be used to detect the presence of virus in sugarcane breeding, germplasm centres and in quarantine programs. PMID:12756623

Hema, M; Kirthi, N; Sreenivasulu, P; Savithri, H S

2003-06-01

407

The 50th Annual Maize Genetics Conference  

SciTech Connect

The 50th Annual Maize Genetics Conference was held February 27 - March 2, 2008 at the Marriott Wardman Park Hotel in Washington, D.C. As the golden anniversary of the Conference and coinciding with the release of a draft of the maize genome sequence, this was a special meeting. To publicize this unique occasion, meeting organizers hosted a press conference, which was attended by members of the press representing science and non-science publications, and an evening reception at the Smithsonian National Museum of Natural History, where the draft sequence was announced and awards were presented to Dr. Mary Clutter and Senator Kit Bond to thank them for their outstanding contributions to maize genetics and genomics research. As usual, the Conference provided an invigorating forum for exchange of recent research results in many areas of maize genetics, e.g., cytogenetics, development, molecular genetics, transposable element biology, biochemical genetics, and genomics. Results were shared via both oral and poster presentations. Invited talks were given by four distinguished geneticists: Vicki Chandler, University of Arizona; John Doebley, University of Wisconsin; Susan Wessler, University of Georgia; and Richard Wilson, Washington University. There were 46 short talks and 241 poster presentations. The Conference was attended by over 500 participants. This included a large number of first-time participants in the meeting and an increasingly visible presence by individuals from underrepresented groups. Although we do not have concrete counts, there seem to be more African American, African and Hispanic/Latino attendees coming to the meeting than in years past. In addition, this meeting attracted many participants from outside the U.S. Student participation continues to be hallmark of the spirit of free exchange and cooperation characteristic of the maize genetics community. With the generous support provided by DOE, USDA NSF, and corporate/private donors, organizers were able to defray lodging and meal costs for 133 graduate and undergraduate students and 66 postdocs

Cone, Karen

2014-03-26

408

Addition of Individual Chromosomes of Maize Inbreds B73 and Mo17 to Oat Cultivars Starter and SunII: Maize Chromosome Retention, Transmission, and Plant Phenotype  

Technology Transfer Automated Retrieval System (TEKTRAN)

Oat-maize addition (OMA) lines with one, or occasionally more, chromosomes of maize (Zea mays L., 2n = 2x = 20) added to an oat (Avena sativa L., 2n = 6x = 42) genomic background can be produced from sexual crosses of oat x maize. Self-fertile disomic addition lines for maize chromosomes 1, 2, 3, 4,...

409

Processing maize flour and corn meal food products  

PubMed Central

Corn is the cereal with the highest production worldwide and is used for human consumption, livestock feed, and fuel. Various food technologies are currently used for processing industrially produced maize flours and corn meals in different parts of the world to obtain precooked refined maize flour, dehydrated nixtamalized flour, fermented maize flours, and other maize products. These products have different intrinsic vitamin and mineral contents, and their processing follows different pathways from raw grain to the consumer final product, which entail changes in nutrient composition. Dry maize mechanical processing creates whole or fractionated products, separated by anatomical features such as bran, germ, and endosperm. Wet maize processing separates by chemical compound classification such as starch and protein. Various industrial processes, including whole grain, dry milling fractionation, and nixtamalization, are described. Vitamin and mineral losses during processing are identified and the nutritional impacts outlined. Also discussed are the vitamin and mineral contents of corn. PMID:24329576

Gwirtz, Jeffrey A; Garcia-Casal, Maria Nieves

2014-01-01

410

Classification of Peruvian highland maize races using plant traits  

Microsoft Academic Search

The maize of Latin America, with its enormous diversity, has played an important role in the development of modern maize cultivars\\u000a of the American continent. Peruvian highland maize shows a high degree of variation stemming from its history of cultivation\\u000a by Andean farmers. Multivariate statistical methods for classifying accessions have become powerful tools for classifying\\u000a genetic resources conservation and the

R. Ortiz; José Crossa; Jorge Franco; Ricardo Sevilla; Juan Burgueño

2008-01-01

411

Ultraweak photon emission from herbivory-injured maize plants  

NASA Astrophysics Data System (ADS)

Following perception of herbivory or infection, plants exhibit a wide range of inducible responses. In this study, we found ultraweak photon emissions from maize leaves damaged by Helicoverpa armigera (Noctuidae). Interestingly, mechanically damaged maize leaves treated with caterpillar regurgitants emitted the same intensity and pattern of photon emissions as those from maize leaves damaged by caterpillars. Furthermore, two-dimensional imaging of the leaf section treated with the oral secretions clearly shows that photon emissions were observed specifically at the lip of the wound exposed to the secretions. These results suggest that the direct interaction between maize leaf cells and chemicals contained in caterpillar regurgitants triggers these photon emissions.

Yoshinaga, Naoko; Kato, Kimihiko; Kageyama, Chizuko; Fujisaki, Kenji; Nishida, Ritsuo; Mori, Naoki

2006-01-01

412

Temporal performances of A 400 kHz Triggered streak camera used with a mode-locked cavity dumped dye laser  

Microsoft Academic Search

The influence of the cavity length of the dye laser on the overall time resolution of the measuring system is discussed. Streak camera measurements for repetitive mode and for single shot operations are compared to autocorrelation data.

P. Geist; F. Heisel; A. Martz; J. A. Miehe

1983-01-01

413

Comparative diversity of arthropods on Bt maize and non-Bt maize in two different cropping systems in South Africa.  

PubMed

The biodiversity of an agroecosystem is not only important for its intrinsic value but also because it influences ecological functions that are vital for crop production in sustainable agricultural systems and the surrounding environment. A concern about genetically modified (GM) crops is the potential negative impact that such crops could have on diversity and abundance of nontarget organisms, and subsequently on ecosystem functions. Therefore, it is essential to assess the potential environmental risk of the release of a GM crop and to study its effect on species assemblages within that ecosystem. Assessment of the impact of Bt maize on the environment is hampered by the lack of basic checklists of species present in maize agroecosystems. The aims of the study were to compile a checklist of arthropods that occur on maize in South Africa and to compare the diversity and abundance of arthropods and functional groups on Bt maize and non-Bt maize. Collections of arthropods were carried out during two growing seasons on Bt maize and non-Bt maize plants at two localities. Three maize fields were sampled per locality during each season. Twenty plants, each of Bt maize and non-Bt maize, were randomly selected from the fields at each site. The arthropods collected during this study were classified to morphospecies level and grouped into the following functional groups: detritivores, herbivores, predators, and parasitoids. Based on feeding strategy, herbivores and predators were further divided into sucking herbivores or predators (piercing-sucking mouthparts) and chewing herbivores or predators (chewing mouthparts). A total of 8,771 arthropod individuals, comprising 288 morphospecies and presenting 20 orders, were collected. Results from this short-term study indicated that abundance and diversity of arthropods in maize and the different functional guilds were not significantly affected by Bt maize, either in terms of diversity or abundance. PMID:24472209

Truter, J; Van Hamburg, H; Van Den Berg, J

2014-02-01

414

Dietary linoleic acid, immune inhibition and disease  

PubMed Central

Review of the evidence available in published literature supports a radical change in viewpoint with respect to disease in countries where maize is the predominant dietary component. In these countries, the pattern of disease is largely determined by a change in immune profile caused by metabolites of dietary linoleic acid. High intake of linoleic acid in a diet deficient in other polyunsaturated fatty acids and in riboflavin results in high tissue production of prostaglandin E2, which in turn causes inhibition of the proliferation and cytokine production of Th1 cells, mediators of cellular immunity. Tuberculosis, measles, hepatoma, secondary infection in HIV and kwashiorkor are all favoured by this reduction in cellular immunity. Diet-associated inhibition of the Th1 subset is a major contributor to the high prevalence of these diseases found in areas of sub-Saharan Africa where maize is the staple.???Keywords: maize; linoleic acid; prostaglandin E2; cellular immunity; kwashiorkor; diet PMID:10448487

Sammon, A.

1999-01-01

415

Characterization and genetic diversity of sugarcane streak mosaic virus causing mosaic in sugarcane.  

PubMed

Sixty-three sugarcane leaf samples were collected from fifty-eight sugarcane varieties, evolved from eleven major sugarcane growing states in India, Australia, South Africa and USA. In RT-PCR, using gene specific primers for sugarcane streak mosaic virus (SCSMV)-CP, 58 of 63 sugarcane samples were found positive to the virus infection and rest of the five samples were negative. Partial CP gene sequences of 42 SCSMV isolates including an isolate from aphid colony (Melanaphis indosacchari) infested on sugarcane variety from this study were characterized after cloning and sequencing for selective isolates represented by at least one isolate from each location. The new sequences identified in the study were named as SCSMV-CB isolates. Fifty two sequences including the 10 database sequences (complete CP cds) deposited earlier from this institute were compared with each other as well as GenBank database sequences of Potyviridae members viz., Rymovirus, Potyvirus, Ipomovirus, Tritimovirus and eight sequences of SCSMV reported from elsewhere. Among the SCSMV-CB isolates sequenced in the study, 85.7-100% (nucleotide) and 89.9-100% (amino acid) sequence identities were observed and with the other data base sequences of SCSMV, the respective identities were 82.2-97.5 and 89.7-98.6%. Grouping of the isolates by the maximum likelihood with molecular clock model, distributed 60 SCSMV sequences including the eight database sequences deposited by other SCSMV working groups from India and USA in 16 different phylogenetic groups. Although the isolates of SCSMV were relatively close to Ipomovirus and Tritimovirus, they were sandwiched between Rymovirus and Ipomovirus. The sequence comparison and phylogenetic studies revealed that the relatedness of SCSMV with the potyviral related genera was comparatively low to consider it as a member of earlier described potyviral genera, hence the genus "Susmovirus" (sugarcane streak mosaic virus) has been proposed, with SCSMV as the sole species to be included. The 52 SCSMV-CB isolates from this institute were distributed in 14 phylogenetic groups and the grouping pattern revealed that the virus isolates could not be grouped based on geographical origin of the host varieties or longevity of the host variety. PMID:18427969

Viswanathan, R; Balamuralikrishnan, M; Karuppaiah, R

2008-06-01

416

Dust Devils Seen Streaking Across Mars: PART II--They're the Work of the Devil!  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site]

[figure removed for brevity, see original site]

In December 1999, the MOC team finally had an answer! A dust devil, shown in the above left figure, was caught in the act of creating a swirly, dark streak! An eerie sensation washed over the first team members who saw this picture--here was an event on Mars 'caught in the act' just hours before the picture was played back to Earth. A 'smoking gun.'

The first dust devil seen making a streak--located in Promethei Terra (above, left)--was traveling from right (east) to left (west). A columnar shadow was cast by sunlight coming from the upper left. This shadow indicates the true shape of the dust devil. The bright dust devil itself does not look like a column because the picture was taken from a camera looking straight down on it. The dust devil is less than 100 meters (less than 100 yards) wide and the picture covers an area approximately 1.5 by 1.7 kilometers (about 1 by 1 mile).

Dust devils are spinning, columnar vortices of wind that move across the landscape, pick up dust, and look somewhat like miniature tornadoes. Dust devils are a common occurrence in dry and desert landscapes on Earth as well as Mars. They form when the ground heats up during the day, warming the air immediately above the surface. As the warmed air nearest the surface begins to rise, it spins. The spinning column begins to move across the surface and picks up loose dust (if any is present). The dust makes the vortex visible and gives it the 'dust devil' or tornado-like appearance. On Earth, dust devils typically last for only a few minutes.

The fourth picture (above, right) shows a surface in southwestern Terra Sirenum near 63oS, 168oW, that has seen the activity of so many dust devils that it looks like a plate of dark gray spaghetti. This image, taken in early summer during February 2000, covers an area 3 km wide and 30 km long (1.9 by 19 miles). In fact, a dust devil can be seen in the upper right of this image. Like the other pictures shown here, the Terra Sirenum image is illuminated by sunlight from the upper left.

2000-01-01

417

The President's Day cyclone 17-19 February 1979: An analysis of jet streak interactions prior to cyclogenesis  

NASA Technical Reports Server (NTRS)

The President's Day cyclone, produced record breaking snowfall along the East Coast of the United States in February 1979. Conventional radiosonde data, SMS GOES infrared imagery and LFM 2 model diagnostics were used to analyze the interaction of upper and lower tropospheric jet streaks prior to cyclogenesis. The analysis reveals that a series of complex scale interactive processes is responsible for the development of the intense cyclone. The evolution of the subsynoptic scale mass and momentum fields prior to and during the period of rapid development of the President's Day cyclone utilizing conventional data and SMS GOES imagery is documented. The interaction between upper and lower tropospheric jet streaks which occurred prior to the onset of cyclogenesis is discussed as well as the possible effects of terrain modified airflow within the precyclogenesis environment. Possible deficiencies in the LFM-2 initial wind fields that could have been responsible, in part, for the poor numerical forecast are examined.

Uccellini, L. W.; Kocin, P. J.; Walsh, C. H.

1981-01-01

418

Tracing transgenic maize as affected by breadmaking process and raw material for the production of a traditional maize bread, broa.  

PubMed

Broa is a maize bread highly consumed and appreciated, especially in the north and central zones of Portugal. In the manufacturing of broa, maize flour and maize semolina might be used, besides other cereals such as wheat and rye. Considering the needs for genetically modified organism (GMO) traceability in highly processed foods, the aim of this work was to assess DNA degradation, DNA amplification and GMO quantification along breadmaking process of broa. DNA degradation was noticed by its decrease of integrity after dough baking and in all parts of bread sampling. The PCR amplification results of extracted DNA from the three distinct maize breads (broa 1, 2 and 3) showed that sequences for maize invertase gene and for events MON810 and TC1507 were easily detected with strong products. Real-time PCR revealed that quantification of GMO was feasible in the three different breads and that sampling location of baked bread might have a limited influence since the average quantitative results of both events after baking were very close to the actual values in the case of broa 1 (prepared with maize semolina). In the other two maize breads subjected to the same baking treatment, the contents of MON810 maize were considerably underestimated, leading to the conclusion that heat-processing was not the responsible parameter for that distortion, but the size of particle and mechanical processing of raw maize play also a major role in GMO quantification. PMID:23265541

Fernandes, Telmo J R; Oliveira, M Beatriz P P; Mafra, Isabel

2013-05-01

419

FGF signalling through RAS\\/MAPK and PI3K pathways regulates cell movement and gene expression in the chicken primitive streak without affecting E-cadherin expression  

Microsoft Academic Search

Background  FGF signalling regulates numerous aspects of early embryo development. During gastrulation in amniotes, epiblast cells undergo\\u000a an epithelial to mesenchymal transition (EMT) in the primitive streak to form the mesoderm and endoderm. In mice lacking FGFR1,\\u000a epiblast cells in the primitive streak fail to downregulate E-cadherin and undergo EMT, and cell migration is inhibited. This\\u000a study investigated how FGF signalling

Katharine M Hardy; Tatiana A Yatskievych; JH Konieczka; Alexander S Bobbs; Parker B Antin

2011-01-01

420

Maize arabinoxylan gels as protein delivery matrices.  

PubMed

The laccase induced gelation of maize bran arabinoxylans at 2.5% (w/v) in the presence of insulin or beta-lactoglobulin at 0.1% (w/v) was investigated. Insulin and beta-lacto-globulin did not modify either the gel elasticity (9 Pa) or the cross-links content (0.03 and 0.015 microg di- and triferulic acids/mg arabinoxylan, respectively). The protein release capability of the gel was also investigated. The rate of protein release from gels was dependent on the protein molecular weight. The apparent diffusion coefficient was 0.99 x 10(-7) and 0.79 x 10(-7) cm(2)/s for insulin (5 kDa) and beta-lactoglobulin (18 kDa), respectively. The results suggest that maize bran arabinoxylan gels can be potential candidates for the controlled release of proteins. PMID:19384279

Berlanga-Reyes, Claudia M; Carvajal-Millán, Elizabeth; Lizardi-Mendoza, Jaime; Rascón-Chu, Agustin; Marquez-Escalante, Jorge A; Martínez-López, Ana Luisa

2009-01-01

421

Phenotyping maize for adaptation to drought  

PubMed Central

The need of a better adaptation of crops to drought is an issue of increasing urgency. However, enhancing the tolerance of maize has, therefore, proved to be somewhat elusive in terms of plant breeding. In that context, proper phenotyping remains as one of the main factors limiting breeding advance. Topics covered by this review include the conceptual framework for identifying secondary traits associated with yield response to drought and how to measure these secondary traits in practice. PMID:22934056

Araus, Jose L.; Serret, María D.; Edmeades, Gregory O.

2012-01-01

422

Intraspecific variation of recombination rate in maize  

PubMed Central

Background In sexually reproducing organisms, meiotic crossovers ensure the proper segregation of chromosomes and contribute to genetic diversity by shuffling allelic combinations. Such genetic reassortment is exploited in breeding to combine favorable alleles, and in genetic research to identify genetic factors underlying traits of interest via linkage or association-based approaches. Crossover numbers and distributions along chromosomes vary between species, but little is known about their intraspecies variation. Results Here, we report on the variation of recombination rates between 22 European maize inbred lines that belong to the Dent and Flint gene pools. We genotype 23 doubled-haploid populations derived from crosses between these lines with a 50 k-SNP array and construct high-density genetic maps, showing good correspondence with the maize B73 genome sequence assembly. By aligning each genetic map to the B73 sequence, we obtain the recombination rates along chromosomes specific to each population. We identify significant differences in recombination rates at the genome-wide, chromosome, and intrachromosomal levels between populations, as well as significant variation for genome-wide recombination rates among maize lines. Crossover interference analysis using a two-pathway modeling framework reveals a negative association between recombination rate and interference strength. Conclusions To our knowledge, the present work provides the most comprehensive study on intraspecific variation of recombination rates and crossover interference strength in eukaryotes. Differences found in recombination rates will allow for selection of high or low recombining lines in crossing programs. Our methodology should pave the way for precise identification of genes controlling recombination rates in maize and other organisms. PMID:24050704

2013-01-01

423

The Birth of Maize Molecular Genetics  

Microsoft Academic Search

Long before recombinant DNA technology was invented, maize genetics was a vibrant and exciting science dominated by controlling\\u000a elements, cytogenet-ics, gene mapping and heterosis. Genes were understood as mutationally-defined units of function that\\u000a could be placed on chromosomes. Incorporation of the concept of DNA as genetic material and the central dogma of genetics\\u000a (DNA ? RNA ? protein) into the

L. Curtis Hannah; Drew Schwartz

424

Peptide regulation of Maize defense reponses  

Technology Transfer Automated Retrieval System (TEKTRAN)

ZmPEP1 is a peptide signal encoded by a previously uncharacterized maize gene that we have named ZmPROPEP1. The ZmPROPEP1 gene was identified by homology to the Arabidopsis AtPROPEP1 gene that encodes the precursor protein to the peptide signal AtPEP1. Together with its receptors, AtPEPR1 and AtPEP...

425

The complete genome sequence of the Tanzanian strain of Cassava brown streak virus and comparison with the Ugandan strain sequence  

Microsoft Academic Search

The complete genome sequence for an isolate of the Ugandan and Tanzanian strain \\u000a types of Cassava brown streak virus have been determined using the novel approach \\u000a of non-directed next generation sequencing. Comparison of the genome sequences revealed that CBSV is highly heterogeneous\\u000a at the isolate level as well as the strain level. The isolate of the Ugandan strain was found

Wendy A. MongerT; T. Alicai; J. Ndunguru; Z. M. Kinyua; M. Potts; R. H. Reeder; D. W. Miano; I. P. Adams; N. Boonham; R. H. Glover; J. Smith

2010-01-01

426

Determination of intrinsic fluorescence lifetime parameters of crude oils using a laser fluorosensor with a streak camera detection system  

SciTech Connect

A laser fluorosensor system has been developed for remotely detecting and identifying crude oils and oil based products from an airborne platform. A streak camera system is the essential detection element in the laser fluorosensor. The capability of this device for rapidly measuring intrinsic temporal characteristics of oil fluorescence has been investigated. These characteristics have been used with spectral parameters for oil spill identification. 3 refs., 7 figs.

Quinn, M.F.; Al-Otaibi, A.S.; Abdullah, A. [Kuwait Institute for Scientific Research, Safat (Kuwait)] [and others

1995-12-31

427

Continuum model of mixing and size segregation in a rotating cylinder: concentration-flow coupling and streak formation  

Microsoft Academic Search

The effect of segregation and concentration-flow coupling on structure development in binary mixtures of different sized particles (S-systems) in a rotating cylinder is studied. The system is a prototype of tumbling mixers widely used in industry for mixing, coating and reaction. Experiments with S-systems have shown the formation of radial streaks of the small particles when the size ratio is

D. V Khakhar; Ashish V Orpe; J. M Ottino

2001-01-01

428

A Multiscale Numerical Study of Hurricane Andrew (1992). Part VI: Small-Scale Inner-Core Structures and Wind Streaks  

Microsoft Academic Search

The objectives of Part VI of this series of papers are to (a) simulate the finescale features of Hurricane Andrew (1992) using a cloud-resolving grid length of 2 km, (b) diagnose the formation of small-scale wind streaks, and (c) perform sensitivity experiments of varying surface fluxes on changes in storm inner-core structures and intensity. As compared to observations and a

M. K. Yau; Yubao Liu; Da-Lin Zhang; Yongsheng Chen

2004-01-01

429

Sequence analysis of shorter than genome length episomal Banana streak OL virus like sequences isolated from banana in India.  

PubMed

Electron microscopy and sequencing of reverse transcriptase and ribonuclease H (RT/RNase H) region of Badnavirus genome from two banana cultivars: Poovan (triploid: AAB) and Safed velchi (diploid: AB), exhibiting leaf streak symptoms, confirmed the association of Banana streak OL virus (BSOLV). As per ICTV species demarcation threshold of 80 % identity in RT/RNase H region, both the isolates were identified as BSOLV. Rolling circle and end-to-end amplification showed the association of two short episomal BSOLV variants: BSOLV-IN1 and BSOLV-IN2 from Poovan and Safed velchi banana, respectively. The genome sizes of both isolates were 6,950 nucleotides long, but shorter than the typical BSOLV genome of 7,389 bp. Open reading frames (ORFs) 1 and 2 of shorter BSOLV isolates shared almost complete nucleotide identity (>99 %) to that of BSOLV. However, the ORF 3 (5,130 bp) and intergenic region (IGR), 886 bp, showed deletions compared with ORF 3 (5,499 bp) and IGR (956 bp) of BSOLV. In phylogenetic analysis for ORF 3 polyprotein, both the isolates clustered with BSOLV, Banana streak CA virus (BSCAV), and Sugarcane bacilliform GA virus (SCBGAV). Identical ORF 1, ORF 2, and the presence of all the conserved domains in short ORF 3 and promoter elements in IGR indicated that these isolates represent replicationally competent shorter variants of BSOLV. These two shorter-than-BSOLV genome sequences and two other identical banana streak virus sequences in GenBank (BSV-TRY; DQ859899 and BSV-GD; DQ451009) might have evolved due to error-prone reverse transcription and splicing or excision from the integrated sequences by homologous recombination in natural banana hybrids under field conditions. PMID:24101342

Baranwal, Virendra K; Sharma, Susheel K; Khurana, Deepti; Verma, Raj

2014-02-01

430

Distributed Blowing and Suction for the Purpose of Streak Control in a Boundary Layer Subjected to a Favorable Pressure Gradient  

NASA Technical Reports Server (NTRS)

An analysis of the optimal control by blowing and suction in order to generate stream- wise velocity streaks is presented. The problem is examined using an iterative process that employs the Parabolized Stability Equations for an incompressible uid along with its adjoint equations. In particular, distributions of blowing and suction are computed for both the normal and tangential velocity perturbations for various choices of parameters.

Forgoston, Eric; Tumin, Anatoli; Ashpis, David E.

2005-01-01

431

4D display of the outflow track of embryonic-chick hearts (HH 14-19) using a high speed streak mode OCT  

NASA Astrophysics Data System (ADS)

Congenital Heart Disease (CHD) is the most common congenital malformation in newborns in the US. Although knowledge of CHD is limited, altered hemodynamic conditions are suspected as the factor that stimulates cardiovascular cell response, resulting in the heart morphology remodeling that ultimately causes CHDs. Therefore, one of recent efforts in CHD study is to develop high-speed imaging tools to correlate the rapidly changing hemodynamic condition and the morphological adaptations of an embryonic heart in vivo. We have developed a high-speed streak mode OCT that works at the center wavelength of 830 nm and is capable of providing images (292x220 ?m2) of the outflow tract of an embryonic chick heart at the rate of 1000 Hz. The modality can provide a voxel resolution in the range of 10 ?m3, and the spectral resolution allows a depth range of 1.63 mm. In the study reported here, each of the 4D images of an outflow tract was recorded for 2 seconds. The recording was conducted every 2 hours (HH17 to HH18), 3 hours (HH14 to HH17), and 4 hours (HH18 to HH19). Because of the fast scan speed, there is no need for postacquisition processing such as use of gating techniques to provide a fine 3D structure. In addition, more details of the outflow tract are preserved in the recorded images. The 4D images can be used in the future to determine the role of blood flow in CHD development.

Ma, Siyu; Wang, Rui; Goodwin, Richard L.; Markwald, Roger R.; Borg, Thomas K.; Runyan, Raymond B.; Gao, Zhi

2013-02-01

432

Aflatoxin control in maize by Trametes versicolor.  

PubMed

Aspergillus flavus is a well-known ubiquitous fungus able to contaminate both in pre- and postharvest period different feed and food commodities. During their growth, these fungi can synthesise aflatoxins, secondary metabolites highly hazardous for animal and human health. The requirement of products with low impact on the environment and on human health, able to control aflatoxin production, has increased. In this work the effect of the basidiomycete Trametes versicolor on the aflatoxin production by A. flavus both in vitro and in maize, was investigated. The goal was to propose an environmental loyal tool for a significant control of aflatoxin production, in order to obtain feedstuffs and feed with a high standard of quality and safety to enhance the wellbeing of dairy cows. The presence of T. versicolor, grown on sugar beet pulp, inhibited the production of aflatoxin B1 in maize by A. flavus. Furthermore, treatment of contaminated maize with culture filtrates of T. versicolor containing ligninolytic enzymes, showed a significant reduction of the content of aflatoxin B1. PMID:25525683

Scarpari, Marzia; Bello, Cristiano; Pietricola, Chiara; Zaccaria, Marco; Bertocchi, Luigi; Angelucci, Alessandra; Ricciardi, Maria Rosaria; Scala, Valeria; Parroni, Alessia; Fabbri, Anna A; Reverberi, Massimo; Zjalic, Slaven; Fanelli, Corrado

2014-01-01

433

Aflatoxin Control in Maize by Trametes versicolor  

PubMed Central

Aspergillus flavus is a well-known ubiquitous fungus able to contaminate both in pre- and postharvest period different feed and food commodities. During their growth, these fungi can synthesise aflatoxins, secondary metabolites highly hazardous for animal and human health. The requirement of products with low impact on the environment and on human health, able to control aflatoxin production, has increased. In this work the effect of the basidiomycete Trametes versicolor on the aflatoxin production by A. flavus both in vitro and in maize, was investigated. The goal was to propose an environmental loyal tool for a significant control of aflatoxin production, in order to obtain feedstuffs and feed with a high standard of quality and safety to enhance the wellbeing of dairy cows. The presence of T. versicolor, grown on sugar beet pulp, inhibited the production of aflatoxin B1 in maize by A. flavus. Furthermore, treatment of contaminated maize with culture filtrates of T. versicolor containing ligninolytic enzymes, showed a significant reduction of the content of aflatoxin B1. PMID:25525683

Scarpari, Marzia; Bello, Cristiano; Pietricola, Chiara; Zaccaria, Marco; Bertocchi, Luigi; Angelucci, Alessandra; Ricciardi, Maria Rosaria; Scala, Valeria; Parroni, Alessia; Fabbri, Anna A.; Reverberi, Massimo; Zjalic, Slaven; Fanelli, Corrado

2014-01-01

434

Differential Localization of Antioxidants in Maize Leaves.  

PubMed Central

The aim of this work was to determine the compartmentation of antioxidants between the bundle-sheath and mesophyll cells of maize (Zea mays L.) leaves. Rapid fractionation of the mesophyll compartment was used to minimize modifications in the antioxidant status and composition due to extraction procedures. The purity of the mesophyll isolates was assessed via the distribution of enzyme and metabolite markers. Ribulose-1,5 bisphosphate and ribulose-1,5-bisphosphate carboxylase/oxygenase were used as bundle-sheath markers and phosphoenolpyruvate carboxylase was used as the mesophyll marker enzyme. Glutathione reductase and dehydroascorbate reductase were almost exclusively localized in the mesophyll tissue, whereas ascorbate, ascorbate peroxidase, and superoxide dismutase were largely absent from the mesophyll fraction. Catalase, reduced glutathione, and monodehydroascorbate reductase were found to be approximately equally distributed between the two cell types. It is interesting that, whereas H2O2 levels were relatively high in maize leaves, this oxidant was largely restricted to the mesophyll compartment. We conclude that the antioxidants in maize leaves are partitioned between the two cell types according to the availability of reducing power and NADPH and that oxidized glutathione and dehydroascorbate produced in the bundle-sheat tissues have to be transported to the mesophyll for re-reduction to their reduced forms. PMID:12223757

Doulis, A. G.; Debian, N.; Kingston-Smith, A. H.; Foyer, C. H.

1997-01-01

435

Lipids in Aspergillus flavus-maize interaction  

PubMed Central

In some filamentous fungi, the pathways related to the oxidative stress and oxylipins production are involved both in the process of host-recognition and in the pathogenic phase. In fact, recent studies have shown that the production of oxylipins in filamentous fungi, yeasts and chromists is also related to the development of the organism itself and to mechanisms of communication with the host at the cellular level. The oxylipins, also produced by the host during defense reactions, are able to induce sporulation and to regulate the biosynthesis of mycotoxins in several pathogenic fungi. In A. flavus, the oxylipins play a crucial role as signals for regulating the biosynthesis of aflatoxins, the conidiogenesis and the formation of sclerotia. To investigate the involvement of an oxylipins based cross-talk into Z. mays and A. flavus interaction, we analyzed the oxylipins profile of the wild type strain and of three mutants of A. flavus that are deleted at the Aflox1 gene level also during maize kernel invasion. A lipidomic approach has been addressed through the use of LC-ToF-MS, followed by a statistical analysis of the principal components (PCA). The results showed the existence of a difference between the oxylipins profile generated by the WT and the mutants onto challenged maize. In relation to this, aflatoxin synthesis which is largely hampered in vitro, is intriguingly restored. These results highlight the important role of maize oxylipin in driving secondary metabolism in A. flavus. PMID:24578700

Scarpari, Marzia; Punelli, Marta; Scala, Valeria; Zaccaria, Marco; Nobili, Chiara; Ludovici, Matteo; Camera, Emanuela; Fabbri, Anna A.; Reverberi, Massimo; Fanelli, Corrado

2014-01-01

436

Historical genomics of North American maize  

PubMed Central

Since the advent of modern plant breeding in the 1930s, North American maize has undergone a dramatic adaptation to high-input agriculture. Despite the importance of genetic contributions to historical yield increases, little is known about the underlying genomic changes. Here we use high-density SNP genotyping to characterize a set of North American maize lines spanning the history of modern breeding. We provide a unique analysis of genome-wide developments in genetic diversity, ancestry, and selection. The genomic history of maize is marked by a steady increase in genetic differentiation and linkage disequilibrium, whereas allele frequencies in the total population have remained relatively constant. These changes are associated with increasing genetic separation of breeding pools and decreased diversity in the ancestry of individual lines. We confirm that modern heterotic groups are the product of ongoing divergence from a relatively homogeneous landrace population, but show that differential landrace ancestry remains evident. Using a recent association approach, we characterize signals of directional selection throughout the genome, identifying a number of candidate genes of potential agronomic relevance. However, overall we find that selection has had limited impact on genome-wide patterns of diversity and ancestry, with little evidence for individual lines contributing disproportionately to the accumulation of favorable alleles in today's elite germplasm. Our data suggest breeding progress has mainly involved selection and recombination of relatively common alleles, contributed by a representative but limited set of ancestral lines. PMID:22802642

van Heerwaarden, Joost; Hufford, Matthew B.; Ross-Ibarra, Jeffrey

2012-01-01

437

Distribution of expansins in graviresponding maize roots  

NASA Technical Reports Server (NTRS)

To test if expansins, wall loosening proteins that disrupt binding between microfibrils and cell wall matrix, participate in the differential elongation of graviresponding roots, Zea mays L. cv. Merit roots were gravistimulated and used for immunolocalization with anti-expansin. Western blots showed cross-reaction with two proteins of maize, one of the same mass as cucumber expansin (29 kDa), the second slightly larger (32 kDa). Maize roots contained mainly the larger protein, but both were found in coleoptiles. The expansin distribution in cucumber roots and hypocotyls was similar to the distribution in maize. Roots showed stronger expansin signals on the expanding convex side than the concave flank as early as 30 min after gravistimulation. Treatment with brefeldin A, a vesicle transport inhibitor, or the auxin transport inhibitor, naphthylphthalamic acid, showed delayed graviresponse and the appearance of differential staining. Our results indicate that expansins may be transported and secreted to cell walls via vesicles and function in wall expansion.

Zhang, N.; Hasenstein, K. H.

2000-01-01

438

Gibberellins and Heterosis in Maize 1  

PubMed Central

Under controlled environment and/or field conditions, vegetative growth (height, internode length, leaf area, shoot dry weight, grain yield) was greater in an F1 maize hybrid than in either parental inbred. Endogenous gibberellin (GA)-like substances in apical meristem cylinders were also higher in the hybrid than in either inbred, both on a per plant and per gram dry weight basis. There were no apparent qualitative differences in GA-like substances, however. Levels of GA-like substances in all genotypes were highest prior to tassel initiation. Chromatographic comparisons of the GA-like substances and authentic standards of GA native to maize on gradient-eluted SiO2 partition and reverse-phase C18 high-pressure liquid chromatography columns are described. No consistent differences in abscisic acid levels of the three genotypes were observed. This correlation of heterosis for endogenous GA-like substances with heterosis for growth suggests that amounts of endogenous GA may be related to hybrid vigor in maize. Images Fig. 1 PMID:16662880

Rood, Stewart B.; Pharis, Richard P.; Koshioka, Masaji; Major, David J.

1983-01-01

439

Hydroxamic Acid Glucosyltransferases from Maize Seedlings 1  

PubMed Central

Hydroxamic acids occur in several forms in maize (Zea mays L.) with 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA) being the predominant form and others including 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA) being found at lower concentrations. Two enzymes capable of glucosylating hydroxamic acids were identified in maize protein extracts and partially purified and characterized. The total enzyme activity per seedling increased during the first 4 days of germination and was concurrent with the accumulation of DIMBOA. Purification of the enzymes by ammonium sulfate precipitation followed by Sephadex G-200 and Q-Sepharose gel chromatography resulted in a 13-fold increase in specific activity. The enzymes are initially separated into two peaks (peak 1 and peak 2) of activity by Q-Sepharose gel chromatography. The peak 1 glucosyltransferase had 3.6% of the DIMBOA glucosylating activity when DIBOA was used as substrate, whereas this percentage increased to 57% for the peak 2 enzyme. The enzyme in peak 2 has a Km of 174 micromolar for DIMBOA and a Km of 638 micromolar for DIBOA; the enzyme in peak 1 has a Km of 217 micromolar for DIMBOA and its activity on DIBOA was too low to determine a Km. The identification of two glucosyltransferases capable of glucosylating hydroxamic acids in vitro serves as an initial step in the characterization of the enzymes involved in production of hydroxamic acids in maize. PMID:16666853

Bailey, Bryan A.; Larson, Russell L.

1989-01-01

440

Aflatoxin Regulations in a Network of Global Maize Trade  

PubMed Central

Worldwide, food supplies often contain unavoidable contaminants, many of which adversely affect health and hence are subject to regulations of maximum tolerable levels in food. These regulations differ from nation to nation, and may affect patterns of food trade. We soughtto determine whether there is an association between nations' food safety regulations and global food trade patterns, with implications for public health and policymaking. We developed a network model of maize trade around the world. From maize import/export data for 217 nations from 2000–2009, we calculated basic statistics on volumes of trade; then examined how regulations of aflatoxin, a common contaminant of maize, are similar or different between pairs of nations engaging in significant amounts of maize trade. Globally, market segregation appears to occur among clusters of nations. The United States is at the center of one cluster; European countries make up another cluster with hardly any maize trade with the US; and Argentina, Brazil, and China export maize all over the world. Pairs of nations trading large amounts of maize have very similar aflatoxin regulations: nations with strict standards tend to trade maize with each other, while nations with more relaxed standards tend to trade maize with each other. Rarely among the top pairs of maize-trading nations do total aflatoxin standards (standards based on the sum of the levels of aflatoxins B1, B2, G1, and G2) differ by more than 5 µg/kg. These results suggest that, globally, separate maize trading communities emerge; and nations tend to trade with other nations that have very similar food safety standards. PMID:23049773

Wu, Felicia; Guclu, Hasan

2012-01-01

441

Nodal signal is required for morphogenetic movements of epiblast layer in the pre-streak chick blastoderm.  

PubMed

During axis formation in amniotes, posterior and lateral epiblast cells in the area pellucida undergo a counter-rotating movement along the midline to form primitive streak (Polonaise movements). Using chick blastoderms, we investigated the signaling involved in this cellular movement in epithelial-epiblast. In cultured posterior blastoderm explants from stage X to XI embryos, either Lefty1 or Cerberus-S inhibited initial migration of the explants on chamber slides. In vivo analysis showed that inhibition of Nodal signaling by Lefty1 affected the movement of DiI-marked epiblast cells prior to the formation of primitive streak. In Lefty1-treated embryos without a primitive streak, Brachyury expression showed a patchy distribution. However, SU5402 did not affect the movement of DiI-marked epiblast cells. Multi-cellular rosette, which is thought to be involved in epithelial morphogenesis, was found predominantly in the posterior half of the epiblast, and Lefty1 inhibited the formation of rosettes. Three-dimensional reconstruction showed two types of rosette, one with a protruding cell, the other with a ventral hollow. Our results suggest that Nodal signaling may have a pivotal role in the morphogenetic movements of epithelial epiblast including Polonaise movements and formation of multi-cellular rosette. PMID:21492150

Yanagawa, Nariaki; Sakabe, Masahide; Sakata, Hirokazu; Yamagishi, Toshiyuki; Nakajima, Yuji

2011-04-01

442

A secreted Ustilago maydis effector promotes virulence by targeting anthocyanin biosynthesis in maize  

PubMed Central

The biotrophic fungus Ustilago maydis causes smut disease in maize with characteristic tumor formation and anthocyanin induction. Here, we show that anthocyanin biosynthesis is induced by the virulence promoting secreted effector protein Tin2. Tin2 protein functions inside plant cells where it interacts with maize protein kinase ZmTTK1. Tin2 masks a ubiquitin–proteasome degradation motif in ZmTTK1, thus stabilizing the active kinase. Active ZmTTK1 controls activation of genes in the anthocyanin biosynthesis pathway. Without Tin2, enhanced lignin biosynthesis is observed in infected tissue and vascular bundles show strong lignification. This is presumably limiting access of fungal hyphae to nutrients needed for massive proliferation. Consistent with this assertion, we observe that maize brown midrib mutants affected in lignin biosynthesis are hypersensitive to U. maydis infection. We speculate that Tin2 rewires metabolites into the anthocyanin pathway to lower their availability for other defense responses. DOI: http://dx.doi.org/10.7554/eLife.01355.001 PMID:24473076

Tanaka, Shigeyuki; Brefort, Thomas; Neidig, Nina; Djamei, Armin; Kahnt, Jörg; Vermerris, Wilfred; Koenig, Stefanie; Feussner, Kirstin; Feussner, Ivo; Kahmann, Regine

2014-01-01

443

Effects of dietary red clover on blood factors and cardiovascular fatty streak formation in hypercholesterolemic rabbits.  

PubMed

Phytoestrogens with a biological activity like estradiol are naturally found in many plants. This study was designed to investigate the effect of red clover, a phytoestrogen-rich member of the legume family (Trifolium pratense) on the development of atherosclerosis in male hyperlipidemic rabbits. Twenty rabbits were semi-randomly distributed into four groups of five each. Two groups received either normal diet or normal diet supplemented with red clover. Two other groups received similar diets to both of which 1% cholesterol was added. Dietary use of red clover (RC) in hyperlipidemic rabbits significantly decreased C-reactive protein (CRP), triglyceride (TG), total cholesterol and LDL-cholesterol (LDL-C) whereas, HDL-cholesterol (HDL-C) was significantly increased in those animals (p < 0.05). Fatty streak formation was also significantly lower in aorta and left and right coronary arteries in the same animals due to use of dietary RC supplementation. These findings suggest that dietary RC may reduce cardiovascular risk factors. PMID:17486681

Asgary, S; Moshtaghian, J; Naderi, G; Fatahi, Z; Hosseini, M; Dashti, G; Adibi, S

2007-08-01

444

New Experimental Hosts of Tobacco streak virus and Absence of True Seed Transmission in Leguminous Hosts.  

PubMed

Of 70 plant species tested, 50 species were susceptible to Tobacco streak virus (TSV) on sap inoculation. Both localized (necrotic and chlorotic spots) and systemic (necrotic spots, axillary shoot proliferation, stunting, total necrosis and wilt) symptoms are observed by majority of plant species. Eleven new experimental hosts were identified viz., Amaranthus blitum var. oleracea (Chaulai sag), Celosia cristata (Cocks comb), Beta vulgaris var. bengalensis (Palak/Indian spinach), Calendula officinalis (Pot marigold), Chrysanthemum indicum, Cosmos sulphurens (Yellow cosmos), Citrullus lunatus (Watermelon), Lagenaria siceraria (Bottle gourd), Coriandrum sativum (Coriander), Hibiscus subderiffa var. subderiffa (Roselle) and Portulaca oleraceae (Little hogweed). Detected groundnut seed infection with TSV for the first time by Direct antigen coated immunosorbent assay (DAC-ELISA) using whole seed. The seed infection ranged from 18.9 to 28.9% among the seeds collected from naturally infected and sap inoculated groundnut varieties (JL 24, TMV 2, Prasuna, Kadiri 6, Kadiri 9, Anantha and Kadiri 7 Bold) belonging to spanish and virginia types. Further, TSV was detected both in pod shell and seed testa and none of the samples showed the presence of TSV either in cotyledon or embryo. Grow-out and bio-assay tests proved the absence of seed transmission in groundnut and other legume crops. Hence, TSV isolate was not a true seed transmission case under Indian conditions in legumes. PMID:23637490

Vemana, K; Jain, R K

2010-10-01

445

Characterization of tomato yellow vein streak virus, a begomovirus from Brazil.  

PubMed

Tomato yellow vein streak virus (ToYVSV) is a tentative begomovirus (Family Geminiviridae) species that seriously affects tomato and potato production in Brazil. Here, we have determined the genomic and biological characteristics of a ToYVSV isolate (Ba3) from a potato plant sampled in Rio Grande do Sul State, Brazil. The DNA-A nucleotide sequence of Ba3 and another previously reported ToYVSV isolate share 89.7% sequence identity. These ToYVSV isolates should be classified as a new species in that they are most closely related to Soybean blistering mosaic virus with which they share only approximately 80% identity. Cloned constructs containing 1.5 mer copies of the ToYVSV genomic components were found, by biolistic bombardment, to be infectious in at least 11 plant species in 2 families (Solanaceae and Malvaceae). Symptoms on tomato and potato plants were identical to those originally observed on field-infected plants. ToYVSV was also sap-transmissible from Nicotiana benthamiana to N. benthamiana and tomato, but not to potato plants. PMID:19937269

Albuquerque, L C; Martin, D P; Avila, A C; Inoue-Nagata, A K

2010-02-01

446

On the scaling of streamwise streaks and their efficiency to attenuate Tollmien-Schlichting waves  

NASA Astrophysics Data System (ADS)

Streaky boundary layers generated by an array of miniature vortex generators (MVGs) mounted on a flat plate have recently shown to have a stabilizing effect on both two- and three-dimensional disturbances. An experimental study on the effect of the geometrical parameters of MVGs on the generated streamwise streaks in the flat plate boundary layer is carried out, and the corresponding stabilizing effect on Tollmien-Schlichting (TS) wave disturbances is quantified. The new experimental configurations have led to an improved empirical scaling law, which includes additional geometrical parameters of the MVGs compared to the previously reported relation. It is found that the MVG configuration can be optimized with respect to the attenuation of disturbances. In addition, the streamwise location of branch I of the neutral stability curve, with regard to the location of the MVG array, is found to be correlated with the initial receptivity of TS waves on the MVG array and the attenuation of the TS wave amplitude in the unstable region.

Sattarzadeh, Sohrab S.; Fransson, Jens H. M.

2015-03-01

447

Improving the diffraction of full-length human selenomethionyl metavinculin crystals by streak-seeding  

SciTech Connect

Metavinculin is an alternatively spliced isoform of vinculin that has a 68-residue insert in its tail domain (1134 total residues) and is exclusively expressed in cardiac and smooth muscle tissue, where it plays important roles in myocyte adhesion complexes. Mutations in the metavinculin-specific insert are associated with dilated cardiomyopathy (DCM) in man. Crystals of a DCM-associated mutant of full-length selenomethionine-labeled metavinculin grown by hanging-drop vapor diffusion diffracted poorly and were highly sensitive to radiation, preventing the collection of a complete X-ray diffraction data set at the highest possible resolution. Streak-seeding markedly improved the stability, crystal-growth rate and diffraction quality of DCM-associated mutant metavinculin crystals, allowing complete data collection to 3.9 {angstrom} resolution. These crystals belonged to space group P4{sub 3}2{sub 1}2, with two molecules in the asymmetric unit and unit-cell parameters a = b = 170, c = 211 {angstrom}, {alpha} = {beta} = {gamma} = 90{sup o}.

Rangarajan, Erumbi S.; Izard, Tina (Scripps)

2012-06-28

448

Compositional mapping of cholesteryl ester droplets in the fatty streaks of human aorta.  

PubMed Central

Frozen sections prepared from human aortic tissue containing fatty streak lesions were examined on a thermally controlled stage with a polarizing light microscope. Distinct birefringent droplets, 0.5-5 mum in diameter, were observed, many apparently aggregated into clusters. The clusters were about 20 X 20 mum in diameter (the approximate size of foam cells). Upon being heated, each smectic droplet exhibited a sudden change of birefringence, indicating a change of state. The transition temperatures were compared to assess compositional distributions in the tissue. We found that for 52% of the clusters the standard deviation of the cluster's droplet melting point distribution was less than half that observed in the surrounding microscopic field. If clusters were intracellular lipid inclusions, this observation indicates that the lipid composition within a foam cell is more homogeneous than that of the overall field. However, using statistical methods, we compared droplet melting populations from cluster to cluster and found significant heterogeneity. The observations can be interpreted to suggest that many foam cells modify the cholesteryl ester fatty acid composition of their accumulations be selective uptake, temporal sampling, or chemical reaction. Furthermore, the intercellular heterogeneity suggests that different cells in the lesion may have different metabolic and transport enzyme affinities or be in different states. Images PMID:965482

Hillman, G M; Engelman, D M

1976-01-01

449

Strawberry necrotic shock virus is a distinct virus and not a strain of Tobacco streak virus.  

PubMed

Fragaria (strawberry) and Rubus species (blackberry, wild blackberry, red raspberry and black raspberry) were thought to be infected with distinct isolates of Tobacco streak virus (TSV). Employing serology and nucleic acid hybridization it has been shown that these isolates form a cluster distinct from other strains of TSV. In this study we have cloned and sequenced the complete RNA 3 of an isolate of TSV from strawberry (Fragaria) as well as the coat protein (CP) gene of 14 additional isolates of TSV originating from Fragaria and Rubus species. Our data suggest that the isolates of TSV that infect Fragaria and Rubus belong to a distinct virus for which we propose the name Strawberry necrotic shock virus (SNSV). The RNA 3 of SNSV contains 2248 nucleotides, 43 more than the type isolate of TSV from white clover (TSV-WC), with a CP gene that is 669 nucleotides long, in contrast to the 714-7 nucleotides of the TSV CP sequences found in the database. The movement protein gene of SNSV is 897 nucleotides in length, 27 more than that of the TSV-WC isolate of TSV. The CP genes of the 15 Fragaria and Rubus isolates that we studied form two distinct phylogenetic clusters that share about 95% amino acid sequence identity, while they only share 60-65% amino acid sequence identity with TSV-WC. PMID:15669110

Tzanetakis, I E; Mackey, I C; Martin, R R

2004-10-01

450

Secretome of trichoderma interacting with maize roots: role in induced systemic resistance.  

PubMed

Trichoderma virens is a biocontrol agent used in agriculture to antagonize pathogens of crop plants. In addition to direct mycoparasitism of soil-borne fungal pathogens, T. virens interacts with roots. This interaction induces systemic resistance (ISR), which reduces disease in above-ground parts of the plant. In the molecular dialog between fungus and plant leading to ISR, proteins secreted by T. virens provide signals. Only a few such proteins have been characterized previously. To study the secretome, proteins were characterized from hydroponic culture systems with T. virens alone or with maize seedlings, and combined with a bioassay for ISR in maize leaves infected by the pathogen Cochliobolus heterostrophus. The secreted protein fraction from coculture of maize roots and T. virens (Tv+M) was found to have a higher ISR activity than from T. virens grown alone (Tv). A total of 280 fungal proteins were identified, 66 showing significant differences in abundance between the two conditions: 32 were higher in Tv+M and 34 were higher in Tv. Among the 34 found in higher abundance in Tv and negatively regulated by roots were 13 SSCPs (small, secreted, cysteine rich proteins), known to be important in the molecular dialog between plants and fungi. The role of four SSCPs in ISR was studied by gene knockout. All four knockout lines showed better ISR activity than WT without affecting colonization of maize roots. Furthermore, the secreted protein fraction from each of the mutant lines showed improved ISR activity compared with WT. These SSCPs, apparently, act as negative effectors reducing the defense levels in the plant and may be important for the fine tuning of ISR by Trichoderma. The down-regulation of SSCPs in interaction with plant roots implies a revision of the current model for the Trichoderma-plant symbiosis and its induction of resistance to pathogens. PMID:25681119

Lamdan, Netta-Li; Shalaby, Samer; Ziv, Tamar; Kenerley, Charles M; Horwitz, Benjamin A

2015-04-01

451

Strategies for the Production of Maize-derived Pharmaceuticals using Cytoplasmic Male Sterile Lines: in vitro Tissue Culture/Transformation and Field Breeding Approaches  

Technology Transfer Automated Retrieval System (TEKTRAN)

Plant-made pharmaceuticals (PMPs) offer great promise as efficient and cost-effective products for the treatment of human and animal diseases. Maize seed is known for its large storage capacity and stability of proteins and starches; hence, it is considered an ideal organ for manufacturing recombin...

452

A single extraction method for the analysis by liquid chromatography/tandem mass spectrometry of fumonisins and biomarkers of disrupted sphingolipid metabolism in tissues of maize seedlings  

Technology Transfer Automated Retrieval System (TEKTRAN)

The fungus Fusarium verticillioides is a pathogen of many plants and is known to produce fumonisins. These toxins have been shown to contribute to the development of maize seedling disease. Fumonisin disruption of sphingolipid biosynthesis has been demonstrated to occur during such pathogenesis. A l...

453

Analysis of the Fusarium graminearum species complex from wheat, barley, and maize in South Africa provides evidence of species-specific differences in host preference  

Technology Transfer Automated Retrieval System (TEKTRAN)

Species identity and trichothecene toxin potential of 560 members of the Fusarium graminearum species complex (FGSC) collected from diseased wheat, barley and maize in South Africa was determined using a microsphere-based multilocus genotyping assay. Although three trichothecene types (3-ADON, 15-AD...

454

Lipid-lowering effect of maize-based traditional Mexican food on a metabolic syndrome model in rats  

PubMed Central

Background Maize-based food is typical in Mexico and other Mesoamerican countries. Used for millennia, they have recently been replaced by modern food that is associated with an increase in the prevalence of non-communicable chronic diseases. This study was carried out in order to evaluate the effects of traditional food on lipid profiles. Methods Metabolic syndrome was induced in animals given a 30% sucrose solution. The animals were given maize tortillas (n=5) and maize pozol (n=5), traditional Mexican food items. A control group was given a 30% sucrose solution in the laboratory diet (n=5) and a witness group was given plain water and pellets. Triglycerides, cholesterol and glucose in tail blood were recorded each month between weeks 12 to 24. Blood was obtained from the cardiac cavity on week 28 and triglycerides, total cholesterol, LDL, HDL, C-reactive protein, alanine amino transferase, glucose and glycated hemoglobin were recorded. Results The animals provided with supplementary traditional food presented a lower increase in triglycerides up to week 24 (p<0.001). Data recorded on week 28 showed lower values of LDL (p<0.05), a lower percentage of glycated hemoglobin when maize tortillas were provided (p<0.01) and lower values of alanine amino transferase when both food items were provided (p<0.01). Conclusions Providing traditional Mexican food generated a protective effect against the intake of a 30% sucrose solution over a long period. PMID:23497051

2013-01-01

455

MaizeGDB: Curation and outreach go hand-in-hand  

Technology Transfer Automated Retrieval System (TEKTRAN)

This is a brief synopsis of the formal and informal interactions among MaizeGDB (www.maizegdb.org) and maize researchers; and among MaizeGDB and other stakeholders, especially the MaizeGDB Working Group and farmers growing this important crop. Particular note is made of the efficacy in distribution ...

456

Sequence Resources at MaizeGDB with Emphasis on POPcorn: A Project Portal for Corn  

Technology Transfer Automated Retrieval System (TEKTRAN)

MaizeGDB is the maize research community’s centralized, long-term repository for genetic and genomic information about the crop plant and model organism Zea mays ssp. mays. The MaizeGDB team endeavors to meet the needs of the maize research community based on feedback and guidance. Recent work has f...

457

MaizeGDB: enabling access to basic, translational, and applied research information  

Technology Transfer Automated Retrieval System (TEKTRAN)

MaizeGDB is the Maize Genetics and Genomics Database (available online at http://www.maizegdb.org). The MaizeGDB project is not simply an online database and website but rather an information service to maize researchers that supports customized data access and analysis needs to individual research...

458

Nixtamalized Flour From Quality Protein Maize ( Zea mays L). Optimization of Alkaline Processing  

Microsoft Academic Search

Quality of maize proteins is poor, they are deficient in the essential amino acids lysine and tryptophan. Recently, in México were successfully developed nutritionally improved 26 new hybrids and cultivars called quality protein maize (QPM) which contain greater amounts of lysine and tryptophan. Alkaline cooking of maize with lime (nixtamalization) is the first step for producing several maize products (masa,

J. MILÁN-CARRILLO; R. GUTIÉRREZ-DORADO; E. O. CUEVAS-RODRÍGUEZ; J. A. GARZÓN-TIZNADO; C. REYES-MORENO

2004-01-01

459

Past and potential impacts of maize research in sub-Saharan Africa: a critical assessment  

Microsoft Academic Search

Over the past twenty years, research progress in maize, the single most important food staple in sub-Saharan Africa, has been comparable to progress in other primarily smallholder maize systems in the developing world. Both the number of varietal releases per million hectares of maize and the adoption of improved maize varieties and hybrids are similar to the rates achieved in

Paul W. Heisey

1996-01-01

460

Genetic analyses with oat-maize addition and radiation hybrid lines  

Technology Transfer Automated Retrieval System (TEKTRAN)

Oat-maize addition lines, with individual maize (Zea mays L.) chromosomes added to the oat (Avena sativa L.) genome via wide hybridization and embryo rescue, simplify the maize genome by 10-fold. Radiation hybrids have less than a complete maize chromosome in an oat genomic background, derived throu...

461

Mining natural variation for maize improvement: Selection on phenotypes and genes  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize is highly genetically and phenotypically diverse. Tropical maize and teosinte are important genetic resources that harbor unique alleles not found in temperate maize hybrids. To access these resources, breeders must be able to extract favorable unique alleles from tropical maize and teosinte f...

462

Colinearity and Its Exceptions in Orthologous adh Regions of Maize and Sorghum  

Microsoft Academic Search

Orthologous adh regions of the sorghum and maize genomes were sequenced and analyzed. Nine known or candidate genes, including adh1, were found in a 225-kilobase (kb) maize sequence. In a 78-kb space of sorghum, the nine homologues of the maize genes were identified in a colinear order, plus five additional genes. The major fraction of DNA in maize, occupying 166

Alexander P. Tikhonov; Phillip J. Sanmiguel; Yuko Nakajima; Nina M. Gorenstein; Jeffrey L. Bennetzen; Zoya Avramova

1999-01-01

463

EXPRESSION OF C4 PHOTOSYNTHETIC ENZYMES IN OAT-MAIZE CHROMOSOME ADDITION LINES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Oat-maize addition lines have been successfully generated, and they are available for every maize chromosome, 1 through 10. Addition lines are oat plants (C3 photosynthesis) that include one or more chromosomes from maize (C4 photosynthesis). These oat-maize addition lines and derivative radiation h...

464

Ancient maize from Chacoan great houses: Where was it grown?  

Microsoft Academic Search

In this article, we compare chemical (87Sr\\/86Sr and elemental) analyses of archaeological maize from dated contexts within Pueblo Bonito, Chaco Canyon, New Mexico, to potential agricultural sites on the periphery of the San Juan Basin. The oldest maize analyzed from Pueblo Bonito probably was grown in an area located 80 km to the west at the base of the Chuska

Larry Benson; Linda Cordell; Kirk Vincent; Howard Taylor; John Stein; G. Lang Farmer; Kiyoto Futa

2003-01-01

465

Can Maize Anthocyanins Function as Resistance Molecules to Corn Earworm?  

Technology Transfer Automated Retrieval System (TEKTRAN)

Insect herbivory of valuable crops increases the probability of fungal infection in damaged tissues. Mycotoxins produced by some fungi are harmful to livestock and humans. Anthocyanin biosynthesis in maize protects tissues from biotic and abiotic stresses. Constitutive expression of the maize B1 ...

466

Plant breeding Brown-midrib genes of maize: a review  

E-print Network

Plant breeding Brown-midrib genes of maize: a review Y Barrière* O Argillier INRA, Station d'Amélioration des Plantes Fourragères, F86600 Lusignan, France (Received 21 May 1993; accepted 23 September 1993 incrustration. Four brown-midrib genes (bm1, bm2, bm3 and bm4) have been described in maize. Brown-midrib plants

Paris-Sud XI, Université de

467

Identifying maize germplasm with resistance to aflatoxin accumulation  

Technology Transfer Automated Retrieval System (TEKTRAN)

Contamination of maize, Zea mays L., grain with aflatoxin, a toxin produced by the fungus Aspergillus flavus, reduces its value and marketability. Growing hybrids with resistance is generally considered a highly desirable way to reduce A. flavus infection and aflatoxin accumulation. Identifying maiz...

468

Molecular and Ultrastructural Properties of Maize White Line Virus  

Technology Transfer Automated Retrieval System (TEKTRAN)

This paper reports the complete nucleotide sequence of the genome of Maize white line mosaic virus (MWLMV) and describes the ultrastructural features of infected maize cells. The viral genome is an RNA molecule 4293 nt in size with the same structural organization of members of the Aureusvirus and ...

469

Comparative population genomics of maize domestication and improvement  

Technology Transfer Automated Retrieval System (TEKTRAN)

Domestication and modern breeding represent exemplary case studies of evolution in action. Maize is an outcrossing species with a complex genome, and an understanding of maize evolution is thus relevant for both plant and animal systems. This study is the largest plant resequencing effort to date, ...

470

RESPONSE OF MAIZE AND WHEAT TO SULFUR DIOXIDE  

EPA Science Inventory

Four hybrids of maize and seven cultivars of wheat were exposed to relatively low concentrations of sulfur dioxide (0.1 to 0.6 ppm) for up to 100 hours. Maize was found to be tolerant to sulfur dioxide and only minor differences were observed in dry mass, foliar injury, and total...

471

Relationship between desiccation and viability of maize pollen  

Microsoft Academic Search

Controlling pollination is necessary to ensure maximum kernel set and high levels of genetic purity in maize. Current approaches for measuring maize pollen production are fairly simple and accurate, but they do not evaluate pollen viability. A simple and reliable technique to assess loss of pollen viability during its transport in air is required to simulate the pollination process and

Agustin E. Fonseca; Mark E. Westgate

2005-01-01

472

AN INTEGRATED COMPREHENSIVE MAP OF THE MAIZE GENOME  

Technology Transfer Automated Retrieval System (TEKTRAN)

With the completion of the rice genome sequencing project in December 2004, the next cereal genome to be sequenced will be maize. The maize genome (~2000 Mb) is nearly five times bigger than that of rice (~400 Mb) and is rich in nested retrotransposons, which comprise approximately 80 percent of th...

473

Maize flour fortification in Africa: markets, feasibility, coverage, and costs.  

PubMed

The economic feasibility of maize flour and maize meal fortification in Kenya, Uganda, and Zambia is assessed using information about the maize milling industry, households' purchases and consumption levels of maize flour, and the incremental cost and estimated price impacts of fortification. Premix costs comprise the overwhelming share of incremental fortification costs and vary by 50% in Kenya and by more than 100% across the three countries. The estimated incremental cost of maize flour fortification per metric ton varies from $3.19 in Zambia to $4.41 in Uganda. Assuming all incremental costs are passed onto the consumer, fortification in Zambia would result in at most a 0.9% increase in the price of maize flour, and would increase annual outlays of the average maize flour-consuming household by 0.2%. The increases for Kenyans and Ugandans would be even less. Although the coverage of maize flour fortification is not likely to be as high as some advocates have predicted, fortification is economically feasible, and would reduce deficiencies of multiple micronutrients, which are significant public health problems in each of these countries. PMID:24102661

Fiedler, John L; Afidra, Ronald; Mugambi, Gladys; Tehinse, John; Kabaghe, Gladys; Zulu, Rodah; Lividini, Keith; Smitz, Marc-Francois; Jallier, Vincent; Guyondet, Christophe; Bermudez, Odilia

2014-04-01

474

Metabolomic Analysis of Low Phytic Acid Maize Kernels  

Microsoft Academic Search

Phytic acid, or hexaphosphorylated myo-inositol, is the major storage form of phosphorous (P) in maize kernels. Phytic acid in foods or animal feeds can complex with proteins and mineral cations resulting in reduced bioavailablility of important nutrients. Classic mutation breeding has been used to develop maize plants that produce kernels with significantly less phytic acid. An extensive survey of the

Jan Hazebroek; Teresa Harp; Jinrui Shi; Hongyu Wang

475

Development and mapping of SSR markers for maize  

Microsoft Academic Search

Microsatellite or simple sequence repeat (SSR) markers have wide applicability for genetic analysis in crop plant improvement strategies. The objectives of this project were to isolate, characterize, and map a comprehensive set of SSR markers for maize (Zea mays L.). We developed 1051 novel SSR markers for maize from microsatellite-enriched libraries and by identification of microsatellite-containing sequences in public and

Natalya Sharopova; Michael D. McMullen; Linda Schultz; Steve Schroeder; Hector Sanchez-Villeda; Jack Gardiner; Dean Bergstrom; Katherine Houchins; Susan Melia-Hancock; Theresa Musket; Ngozi Duru; Mary Polacco; Keith Edwards; Thomas Ruff; James C. Register; Cory Brouwer; Richard Thompson; Riccardo Velasco; Emily Chin; Michael Lee; Wendy Woodman-Clikeman; Mary Jane Long; Emmanuel Liscum; Karen Cone; Georgia Davis; Edward H. Coe

2002-01-01