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1

Complete nucleotide sequence of Croton yellow vein mosaic virus and DNA-? associated with yellow vein mosaic disease of Jatropha gossypifolia in India  

Microsoft Academic Search

A severe yellow vein mosaic disease was noticed on several Jatropha gossypifolia plants growing nearby agriculture fields at Lucknow, India. Diseased plants exhibited yellow vein mosaic, leaf deformation,\\u000a vein swelling and stunting. A population of whiteflies (Bemisia tabaci) was also noticed in the vicinities; therefore, begomovirus infection was suspected. To confirm begomovirus association,\\u000a total DNA was isolated from symptomatic leaf

S. K. Snehi; M. S. Khan; S. K. Raj; V. Prasad

2011-01-01

2

Complete nucleotide sequence of Croton yellow vein mosaic virus and DNA-? associated with yellow vein mosaic disease of Jatropha gossypifolia in India.  

PubMed

A severe yellow vein mosaic disease was noticed on several Jatropha gossypifolia plants growing nearby agriculture fields at Lucknow, India. Diseased plants exhibited yellow vein mosaic, leaf deformation, vein swelling and stunting. A population of whiteflies (Bemisia tabaci) was also noticed in the vicinities; therefore, begomovirus infection was suspected. To confirm begomovirus association, total DNA was isolated from symptomatic leaf samples and subjected to PCR using DNA-A, DNA-B and DNA-?-specific primers. DNA-A and DNA-? was successfully amplified but several attempts failed to amplify DNA-B indicating monopartite nature of the begomovirus. The sequence analysis of amplicons revealed the presence of 2757 nucleotides of DNA-A genome (EU727086) and 1315 nt of DNA-? molecule (EU604296). The sequence analysis of DNA-A (EU727086) revealed the highest 96% identities and closest relationship with Croton yellow vein mosaic virus (CYVMV, AJ507777) infecting Croton bonplandianum in India. The DNA-? (EU604296) showed the highest 96% sequence identity and closest phylogenetic relationship with CYVMV-associated DNA-? (AM410551) isolated from Croton sp. in Pakistan. Based on the highest sequence identities and closest phylogenetic relationships of the DNA-A genome and DNA-? molecule with respective sequences of various isolates of Croton yellow vein mosaic virus, the begomovirus associated with yellow vein mosaic disease of J. gossypifolia was identified as an isolate of Croton yellow vein mosaic virus. PMID:21479677

Snehi, S K; Khan, M S; Raj, S K; Prasad, V

2011-08-01

3

Detection and Discrimination of Wheat Spindle Streak Mosaic Virus and Wheat Yellow Mosaic Virus Using Multiplex RT-PCR  

Microsoft Academic Search

Wheat spindle streak mosaic virus (WSSMV) and wheat yellow mosaic virus (WYMV) are two closely related bymoviruses which cause significant yield losses in wheat. There is no molecular diagnostic protocol available for either virus nor are serological methods able to discriminate them. A multiplex reverse transcription-polymerase chain reaction (RT-PCR) protocol was developed for their detection and discrimination. Twenty-three isolates of

Gerard Clover; Christine Henry

1999-01-01

4

Low genetic diversity of Squash vein yellowing virus in wild and cultivated cucurbits in the U.S. suggests a recent introduction.  

PubMed

Squash vein yellowing virus (SqVYV) isolates were collected from cultivated and weedy cucurbits representing major hosts and locations in the U.S. and analyzed to better understand the diversity and population structure. No differences in symptoms were observed in field-collected isolate source plants or subsequently inoculated greenhouse plants, and the complete genome of an SqVYV isolate from a wild cucurbit host (smellmelon, Cucumis melo var. dudaim) was highly similar (99.4% nucleotide identity, 99.3% amino acid identity) to the previously published type isolate from squash. Although analysis of the coat protein (CP) and two serine proteases (P1a and P1b) sequences for 41 isolates showed little diversity across seven years of sampling, it revealed two distinct groups of SqVYV isolates with low intra-group diversity. Our analyses also suggested that recombination had occurred between SqVYV isolates, similar to other ipomoviruses. Selection pressures on the genome regions analyzed were negative indicating purifying selection was occurring. The magnitude of negative selection in SqVYV was consistent with what has been reported for other ipomoviruses, and was greatest for the CP and least for the P1b. The observed genetic diversity was similar to that reported for Cucumber vein yellowing virus but less than that reported for Sweet potato mild mottle virus, Cassava brown streak virus and Ugandan cassava brown streak virus. Collectively, these results indicate that the current U.S. population of SqVYV has undergone a recent genetic bottleneck and was introduced from elsewhere. PMID:22142477

Webster, Craig G; Adkins, Scott

2012-02-01

5

Genetic analysis of lethal tip necrosis induced by Clover yellow vein virus infection in pea  

Microsoft Academic Search

Clover yellow vein virus (ClYVV) elicits lethal tip necrosis in the pea line PI 118501. Pea line PI 118501 develops necrotic lesions and veinal necrosis\\u000a on inoculated leaves, followed by systemic necrosis, leading to plant death. To understand the genetic basis of this lethal\\u000a tip necrosis, we crossed lines PI 226564 and PI 250438, which develop mosaic symptoms in response

Gerald Ravelo; Uiko Kagaya; Tsuyoshi Inukai; Masanao Sato; Ichiro Uyeda

2007-01-01

6

Identification of potyvirus isolates from faba bean ( Vicia faba L.), and the relationships between bean yellow mosaic virus and clover yellow vein virus  

Microsoft Academic Search

Summary Clover yellow vein virus (CYVV) isolate H and the related potyvirus isolates E178, E197, and E242 could be distinguished from bean yellow mosaic (BYMV) isolates by their wider host range among non-legume test plant species, the peculiar enlargement of the nucleolus in infected plants, and the larger size of their coat protein as evidenced by slower migration in SDS-PAGE.

M. Fortass; L. Bos; R. W. Goldbach

1991-01-01

7

Replication promiscuity of DNA  satellites associated with monopartite begomoviruses; deletion mutagenesis of the Ageratum yellow vein virus DNA  satellite localizes sequences involved in replication  

Microsoft Academic Search

Pseudorecombination studies in Nicotiana benthamiana demonstrate that Ageratum yellow vein virus (AYVV) and Eupatorium yellow vein virus (EpYVV) can functionally interact with DNA-b satellites associated with AYVV, EpYVV, cotton leaf curl Multan virus (CLCuMV) and honeysuckle yellow vein virus (HYVV). In contrast, CLCuMV shows some specificity in its ability to interact with distinct satellites and HYVV is able to interact

Keith Saunders; Rob W. Briddon; John Stanley

2008-01-01

8

The genome sequence of pepper vein yellows virus (family Luteoviridae, genus Polerovirus).  

PubMed

The complete genome of pepper vein yellows virus (PeVYV) was sequenced using random amplification of RNA samples isolated from vector insects (Aphis gossypii) that had been given access to PeVYV-infected plants. The PeVYV genome consisted of 6244 nucleotides and had a genomic organization characteristic of members of the genus Polerovirus. PeVYV had highest amino acid sequence identities in ORF0 to ORF3 (75.9 - 91.9%) with tobacco vein distorting polerovirus, with which it was only 25.1% identical in ORF5. These sequence comparisons and previously studied biological properties indicate that PeVYV is a distinctly different virus and belongs to a new species of the genus Polerovirus. PMID:21400195

Murakami, Ritsuko; Nakashima, Nobuhiko; Hinomoto, Norihide; Kawano, Shinji; Toyosato, Tetsuya

2011-05-01

9

Complete nucleotide sequences of a distinct bipartite begomovirus, bitter gourd yellow vein virus, infecting Momordica charantia.  

PubMed

Momordica charantia (Cucurbitaceae), a vegetable crop commonly cultivated throughout Pakistan, and begomoviruses, a serious threat to crop plants, are natives of tropical and subtropical regions of the world. Leaf samples of M. charantia with yellow vein symptoms typical of begomovirus infections and samples from apparently healthy plants were collected from areas around Lahore in 2004. Full-length clones of a bipartite begomovirus were isolated from symptomatic samples. The complete nucleotide sequences of the components of one isolate were determined, and these showed the arrangement of genes typical of Old World begomoviruses. The complete nucleotides sequence of DNA A showed the highest nucleotide sequence identity (86.9%) to an isolate of Tomato leaf curl New Delhi virus (ToLCNDV), confirming it to belong to a distinct species of begomovirus, for which the name Bitter gourd yellow vein virus (BGYVV) is proposed. Sequence comparisons showed that BGYVV likely emerged as a result of inter-specific recombination between ToLCNDV and tomato leaf curl Bangladesh virus (ToLCBDV). The complete nucleotide sequence of DNA B showed 97.2% nucleotide sequence identity to that of an Indian strain of Squash leaf curl China virus. PMID:20924621

Tahir, Muhammad; Haider, Muhammad Saleem; Briddon, Rob W

2010-11-01

10

Highly sensitive immunoassays for detection of barley stripe mosaic virus and beet necrotic yellow vein virus.  

PubMed

Enzyme immunoassays based on the use of monoclonal antibodies (MAbs) were developed for the detection of the barley stripe mosaic virus (BSMV) and the beet necrotic yellow vein virus (BNYVV). Assays employing conjugates of MAbs to horseradish peroxidase (HRP) were compared to systems with biotinylated MAbs and streptavidin conjugated either to monomeric HRP or to HRP homopolymers with different polymerisation degrees including those of 20, 40 and 80. In the ELISA with streptavidin-polymeric HRP conjugates the assay detection limit was about 12-25 times as good as in the monoclonal double antibody sandwich ELISA. The system for BSMV detection with polymeric HRP was sufficiently sensitive to detect a single infected seed among more than 10(4) healthy ones. The assay detection limit was 1 ng/ml. The immunoenzyme system for BNYVV allowed virus detection in 1:12000 diluted extracts from BNYVV-infected leaves. PMID:8882650

Sukhacheva, E; Novikov, V; Plaksin, D; Pavlova, I; Ambrosova, S

1996-02-01

11

A greenhouse test for screening sugar-beet (Beta vulgaris) for resistance to beet necrotic yellow vein virus (BNYVV)  

Microsoft Academic Search

Small differences in activity between batches of purified beet necrotic yellow vein virus (BNYVV) were observed in ELISA. A four-parameter modelled dose-response curve of purified BNYVV was used for the conversion of ELISA values to virus concentrations. Seedlings of the susceptible cultivar Regina and the partially resistant cultivars Nymphe and Rima were tested for resistance to BNYVV in a mixture

H. Paul; B. Henken; M. F. J. Alderlieste

1992-01-01

12

Inheritance of resistance to beet necrotic yellow vein virus in Beta vulgaris conferred by a second gene for resistance  

Microsoft Academic Search

Rhizomania is a serious disease of sugar beet, caused by beet necrotic yellow vein virus (BNYVV). The disease can only be\\u000a controlled by the use of resistant cultivars. The accession Holly contains a single dominant gene for resistance, called Rz. The identification of a locus for resistance that differs from Rz would provide possibilities to produce cultivars with multiple resistance

O. E. Scholten; Th. S. M. De Bock; R. M. Klein-Lankhorst; W. Lange

1999-01-01

13

Association of an alphasatellite with tomato yellow leaf curl virus and ageratum yellow vein virus in Japan is suggestive of a recent introduction.  

PubMed

Samples were collected in 2011 from tomato plants exhibiting typical tomato leaf curl disease symptoms in the vicinity of Komae, Japan. PCR mediated amplification, cloning and sequencing of all begomovirus components from two plants from different fields showed the plants to be infected by Tomato yellow leaf curl virus (TYLCV) and Ageratum yellow vein virus (AYVV). Both viruses have previously been shown to be present in Japan, although this is the first identification of AYVV on mainland Japan; the virus previously having been shown to be present on the Okinawa Islands. The plant harboring AYVV was also shown to contain the betasatellite Tomato leaf curl Java betasatellite (ToLCJaB), a satellite not previously shown to be present in Japan. No betasatellite was associated with the TYLCV infected tomato plants analyzed here, consistent with earlier findings for this virus in Japan. Surprisingly both plants were also found to harbor an alphasatellite; no alphasatellites having previously been reported from Japan. The alphasatellite associated with both viruses was shown to be Sida yellow vein China alphasatellite which has previously only been identified in the Yunnan Province of China and Nepal. The results suggest that further begomoviruses, and their associated satellites, are being introduced to Japan. The significance of these findings is discussed. PMID:24424499

Shahid, Muhammad Shafiq; Ikegami, Masato; Waheed, Abdul; Briddon, Rob W; Natsuaki, Keiko T

2014-01-01

14

Association of an Alphasatellite with Tomato Yellow Leaf Curl Virus and Ageratum Yellow Vein Virus in Japan is Suggestive of a Recent Introduction  

PubMed Central

Samples were collected in 2011 from tomato plants exhibiting typical tomato leaf curl disease symptoms in the vicinity of Komae, Japan. PCR mediated amplification, cloning and sequencing of all begomovirus components from two plants from different fields showed the plants to be infected by Tomato yellow leaf curl virus (TYLCV) and Ageratum yellow vein virus (AYVV). Both viruses have previously been shown to be present in Japan, although this is the first identification of AYVV on mainland Japan; the virus previously having been shown to be present on the Okinawa Islands. The plant harboring AYVV was also shown to contain the betasatellite Tomato leaf curl Java betasatellite (ToLCJaB), a satellite not previously shown to be present in Japan. No betasatellite was associated with the TYLCV infected tomato plants analyzed here, consistent with earlier findings for this virus in Japan. Surprisingly both plants were also found to harbor an alphasatellite; no alphasatellites having previously been reported from Japan. The alphasatellite associated with both viruses was shown to be Sida yellow vein China alphasatellite which has previously only been identified in the Yunnan Province of China and Nepal. The results suggest that further begomoviruses, and their associated satellites, are being introduced to Japan. The significance of these findings is discussed.

Shahid, Muhammad Shafiq; Ikegami, Masato; Waheed, Abdul; Briddon, Rob W.; Natsuaki, Keiko T.

2014-01-01

15

Host Range Studies for Tomato chlorosis virus , and Cucumber vein yellowing virus Transmitted by Bemisia  tabaci (Gennadius)  

Microsoft Academic Search

The Bemisia  tabaci (Gennadius) biotype B transmitted host range of Tomato chlorosis virus (ToCV), genus Crinivirus, Family Closteroviridae, and Cucumber vein yellowing virus (CVYV), genus Ipomovirus, Family Potyviridae, was studied. New experimental hosts were identified for each of these viruses. Seventeen species in eight plant families\\u000a were assessed as potential hosts for ToCV. Infection in asymptomatic Anthriscus  cereifolium (chervil) test

Jane Morris; Elspeth Steel; Penny Smith; Neil Boonham; Nicola Spence; Ian Barker

2006-01-01

16

Breaking of Beet necrotic yellow vein virus resistance in sugar beet is independent of virus and vector inoculum densities  

Microsoft Academic Search

Beet necrotic yellow vein virus (BNYVV) is transmitted by Polymyxa betae to sugar beet, causing rhizomania disease. Resistance-breaking strains of BNYVV, overcoming single (Rz1) or double (e.g. Rz1?\\u000a +?\\u000a Rz2) major resistance genes in sugar beet have been observed in France and recently in the USA and Spain. To demonstrate if resistance-breaking\\u000a is dependent on inoculum density, the inoculum concentration

Friederike Pferdmenges; Mark Varrelmann

2009-01-01

17

Yellow  

Microsoft Academic Search

IT would seem to me that the great difficulty of conceiving yellow as a compound colour is the brightness or lightness of yellow, as compared with its components. In the spectrum, we have the maximum of light in the yellow, and it is against our experience to put two dark colours together and form one light one, as, for example,

C. J. Woodward

1871-01-01

18

Tobacco streak virus isolated from lettuce.  

PubMed

Tobacco streak virus (TSV) is an ilarvirus with a worldwide distribution. This virus infects many plants and causes significant yield losses. In this study, 300 samples of lettuce were collected from lettuce fields in Tehran Province. Infected plants show symptoms such as: mosaic, vein clearing, vein necrosis, yellowing and leaf distortion. DAS-ELISA (Double Antibody Sandwich-ELISA) was used with a polyclonal antiserum against TSV. Five isolates (T1, T2, T3, T4 and T5), which are collected, respectively from Mohammad Abad (Karaj), Malek Abad (Karaj), Hashtgerd (Karaj), Tarand Balla (Varamin) and Deh mah sin (Pishva) were inoculated on 29 species of Cucurbitaceae, Amaranthaceae, Solanacea, Compositae, Leguminosae and Chenopodiacea. Chenopodium quinoa 6 days after inoculation showed necrotic local lesions. Gomphrena globosa 10 days after inoculation developed chlorotic local lesions. Systemic symptoms were produced in Datura stramonium. Phaseolus vulgaris cv. Red Kidney 5 days after inoculation developed necrotic local lesions. Nicotiana tabacum 7 days after inoculation showed necrotic and chlorotic local lesions. Nicotiana clevelandii 15 days after inoculation developed leaf distortion and vein necrosis. Lactuca sativa 10-15 days after inoculation developed leaf istortion and mosaic. Reverse Transcription Polymerase Chain Reaction (RT-PCR) was performed using one primer pairs designed by DSMZ. An approximately 710 bp fragment was amplified with a specific primer. PMID:19634475

Abtahi, F S; Khodai Motlagh, M

2009-05-01

19

Molecular Variation of Satellite DNA? Molecules Associated with Malvastrum yellow vein virus and Their Role in Pathogenicity? †  

PubMed Central

Previous studies have found that the diversity of begomovirus-associated DNA? satellites is related to host and geographical origin. In this study, we have cloned and sequenced 20 different isolates of DNA? molecules associated with Malvastrum yellow vein virus (MYVV) isolated from Malvastrum coromandelianum plants in different geographical locations of Yunnan Province, China. Analyses of their molecular variation indicate that the satellites are clustered together according to their geographical location but that they have only limited sequence diversity. Infectivity tests using infectious clones of MYVV and its associated DNA? molecule indicate that MYVV DNA? is indispensable for symptom induction in Nicotiana benthamiana, N. glutinosa, Petunia hybrida, and M. coromandelianum plants. Furthermore, we showed that MYVV interacts functionally with heterologous DNA? molecules in N. benthamiana plants.

Guo, Wei; Jiang, Tong; Zhang, Xian; Li, Guixin; Zhou, Xueping

2008-01-01

20

An integrated approach for the evaluation of biological control of the complex Polymyxa betae\\/Beet Necrotic Yellow Vein Virus, by means of seed inoculants  

Microsoft Academic Search

Rhizomania is an extremely severe sugarbeet disease caused by the complex Polymyxa betae\\/Beet Necrotic Yellow Vein Virus (BNYVV). A relatively small number of recently introduced sugarbeet cultivars characterized by a high tolerance to rhizomania are available on the market. An integrated approach was therefore developed using Pseudomonas fluorescens biological control agents (BCAs) in order to improve yield performance of cultivars

R. Resca; M. Basaglia; S. Poggiolini; P. Vian; S. Bardin; U. F. Walsh; C. M. Enriquez Barreiros; F. O'Gara; M. P. Nuti; S. Casella; U. Peruch

2001-01-01

21

Epidemiology of beet necrotic yellow vein virus in sugar beet at different initial inoculum levels in the presence or absence of irrigation: Dynamics of inoculum  

Microsoft Academic Search

Using field plots where rhizomania had not previously been detected, different inoculum levels of beet necrotic yellow vein virus (BNYVV) were created by application of infested soil. A susceptible sugar beet cultivar (cv. Regina) was grown for two consecutive years (1988 and 1989), in the presence or absence of drip irrigation. In soil samples taken in spring 1989, the different

G. Tuitert; Y. Hofmeester

1992-01-01

22

Effect of sugar beet cultivars with different levels of resistance to beet necrotic yellow vein virus on transmission of virus by Polymyxa betae  

Microsoft Academic Search

The effect of resistance of sugar beet cultivars to beet necrotic yellow vein virus (BNYVV) on virus content of resting spore clusters of the vectorPolymyxa betae was studied in controlled environments and in naturally infested fields. The total number of resting spore clusters formed in roots of a partially resistant and a susceptible cultivar did not differ when assessed 6

G. Tuitert; P. M. S. Musters-van Oorschot; W. Heijbroek

1994-01-01

23

Acquisition, transmission and host range of a begomovirus associated with yellow vein mosaic disease of mesta ( Hibiscus cannabinus and Hibiscus sabdariffa )  

Microsoft Academic Search

Yellow vein mosaic, a disease causing serious reductions in fibre yield of mesta (Hibiscus cannabinus and Hibiscus sabdariffa) and associated with a begomovirus, was effectively transmitted by cleft grafting and whitefly (Bemisia tabaci), but not through seed or by mechanical means. Association of the begomovirus with infected experimental host plants was\\u000a determined by Southern hybridisation using a DNA A targeting

A. Chatterjee; A. Roy; S. K. Ghosh

2008-01-01

24

Molecular analyses of European A, B and P type sources of Beet necrotic yellow vein virus and detection of the rare P type in Kazakhstan  

Microsoft Academic Search

Summary.  ?Nucleotide sequence analyses revealed that the genomes of the various European types of Beet necrotic yellow vein virus (BNYVV), i.e. the A, B and P types, are strongly conserved. Almost identical sequences were found, for instance, for A types\\u000a originating from The Netherlands, Italy and former Yugoslavia; these sequences were also almost identical to those determined\\u000a c. 15 years ago

R. Koenig; B.-L. Lennefors

2000-01-01

25

Detection of beet necrotic yellow vein virus strains, variants and mixed infections by examining single-strand conformation polymorphisms of immunocapture RT-PCR products  

Microsoft Academic Search

Single-strand conformation polymorphism analysis was found to be a powerful tool for rapidly assigning large numbers of beet necrotic yellow vein virus (BNYVV) isolates to a known strain group as well as for detecting mixed infections, minor variants or new strain groups. The prevalence of the B-type in Germany and France and the A-type in most other countries was confirmed.

R. Koenig; P. Liiddecke; A. M. Haeberle

1995-01-01

26

Expression of the Beet necrotic yellow vein virus p25 protein induces hormonal changes and a root branching phenotype in Arabidopsis thaliana  

Microsoft Academic Search

The RNA-3-encoded p25 protein was previously characterized as one of the major symptom determinants of the Beet necrotic yellow vein virus. Previous analyses reported the influence of the p25 protein in root proliferation phenotype observed in rhizomania disease\\u000a on infected sugar beets (Beta vulgaris). A transgenic approach was developed, in which the p25 protein was constitutively expressed in Arabidopsis thaliana

Claire PeltierLaure; Laure Schmidlin; Elodie Klein; Ludivine Taconnat; Els Prinsen; Mathieu Erhardt; Dimitri Heintz; Guy Weyens; Marc Lefebvre; Jean-Pierre Renou; David Gilmer

2011-01-01

27

Replication promiscuity of DNA-beta satellites associated with monopartite begomoviruses; deletion mutagenesis of the Ageratum yellow vein virus DNA-beta satellite localizes sequences involved in replication.  

PubMed

Pseudorecombination studies in Nicotiana benthamiana demonstrate that Ageratum yellow vein virus (AYVV) and Eupatorium yellow vein virus (EpYVV) can functionally interact with DNA-beta satellites associated with AYVV, EpYVV, cotton leaf curl Multan virus (CLCuMV) and honeysuckle yellow vein virus (HYVV). In contrast, CLCuMV shows some specificity in its ability to interact with distinct satellites and HYVV is able to interact only with its own satellite. Using an N. benthamiana leaf disk assay, we have demonstrated that HYVV is unable to trans-replicate other satellites. To investigate the basis of trans-replication compatibility, deletion mutagenesis of AYVV DNA-beta has been used to localize the origin of replication to approximately 360 nt, encompassing the ubiquitous nonanucleotide/stem-loop structure, satellite conserved region (SCR) and part of the intergenic region immediately upstream of the SCR. Additional deletions within this intergenic region have identified a region that is essential for replication. The capacity for DNA-beta satellites to functionally interact with distinct geminivirus species and its implications for disease diversification are discussed. PMID:19008407

Saunders, Keith; Briddon, Rob W; Stanley, John

2008-12-01

28

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

29

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

30

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

31

Infection of Beet necrotic yellow vein virus with RNA4-encoded P31 specifically up-regulates pathogenesis-related protein 10 in Nicotiana benthamiana  

PubMed Central

Background Beet necrotic yellow vein virus (BNYVV) is the infectious agent of sugar beet rhizomania, which consists of four or five plus-sense RNAs. RNA4 of BNYVV is not essential for virus propagation in Nicotiana benthamiana but has a major effect on symptom expression. Early reports showed that RNA4-encoded P31 was associated with severe symptoms, such as curling and dwarfing, in N. benthamiana. Results We discovered that the pathogenesis-related protein 10 (PR-10) gene can be up-regulated in BNYVV-infected N. benthamiana in the presence of RNA4 and that it had a close link with symptom development. Our frame-shift, deletion and substitution analysis showed that only the entire P31 could induce PR-10 up-regulation during BNYVV infection and that all the tryptophans and six cysteines (C174, C183, C186, C190, C197 and C199) in the cysteine-rich P31 had significant effects on PR-10 expression. However, P31 could not interact directly with PR-10 in yeast. Conclusions Our data demonstrated that only integrated P31 specifically induced PR-10 transcription, which coincided closely with the appearance of severe symptoms in BNYVV-infected N. benthamiana, although they could not interact directly with each other in yeast.

2014-01-01

32

Breakdown of host resistance by independent evolutionary lineages of Beet necrotic yellow vein virus involves a parallel c/u mutation in its p25 gene.  

PubMed

ABSTRACT Breakdown of sugar beet Rz1-mediated resistance against Beet necrotic yellow vein virus (BNYVV) infection was previously found, by reverse genetics, to be caused by a single mutation in its p25 gene. The possibility of alternative breaking mutations, however, has not been discarded. To explore the natural diversity of BNYVV in the field and its effects on overcoming Rz1, wild-type (WT) and resistance-breaking (RB) p25 genes from diverse production regions of North America were characterized. The relative titer of WT p25 was inversely correlated with disease expression in Rz1 plants from Minnesota and California. In Minnesota, the predominant WT p25 encoded the A(67)C(68) amino acid signature whereas, in California, it encoded A(67)L(68). In both locations, these WT signatures were associated with asymptomatic BNYVV infections of Rz1 cultivars. Further analyses of symptomatic resistant plants revealed that, in Minnesota, WT A(67)C(68) was replaced by V(67)C(68) whereas, in California, WT A(67)L(68) was replaced by V(67)L(68). Therefore, V(67) was apparently critical in overcoming Rz1 in both pathosystems. The greater genetic distances between isolates from different geographic regions rather than between WT and RB from the same location indicate that the underlying C to U transition originated independently in both BNYVV lineages. PMID:20055646

Acosta-Leal, Rodolfo; Bryan, Becky K; Smith, Jessica T; Rush, Charles M

2010-02-01

33

Analysis of the resistance-breaking ability of different beet necrotic yellow vein virus isolates loaded into a single Polymyxa betae population in soil.  

PubMed

The genome of most Beet necrotic yellow vein virus (BNYVV) isolates is comprised of four RNAs. The ability of certain isolates to overcome Rz1-mediated resistance in sugar beet grown in the United States and Europe is associated with point mutations in the pathogenicity factor P25. When the virus is inoculated mechanically into sugar beet roots at high density, the ability depends on an alanine to valine substitution at P25 position 67. Increased aggressiveness is shown by BNYVV P type isolates, which carry an additional RNA species that encodes a second pathogenicity factor, P26. Direct comparison of aggressive isolates transmitted by the vector, Polymyxa betae, has been impossible due to varying population densities of the vector and other soilborne pathogens that interfere with BNYVV infection. Mechanical root inoculation and subsequent cultivation in soil that carried a virus-free P. betae population was used to load P. betae with three BNYVV isolates: a European A type isolate, an American A type isolate, and a P type isolate. Resistance tests demonstrated that changes in viral aggressiveness towards Rz1 cultivars were independent of the vector population. This method can be applied to the study of the synergism of BNYVV with other P. betae-transmitted viruses. PMID:21303211

Bornemann, Kathrin; Varrelmann, Mark

2011-06-01

34

Wind Streak Changes  

NASA Technical Reports Server (NTRS)

2 September 2004 This pair of Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images shows changes in dark wind streak patterns that occurred between 5 April 1999 (image M00-00534) and 17 August 2004 (image R20-00901). Unlike the spaghetti-like streak patterns made by dust devils, these streaks all begin on their upwind ends as tapered forms that fan outward in the downwind direction, and they all indicate winds that blew from the same direction. In both cases, winds blew from the southeast (lower right) toward the northwest (upper left). These streaks and the small pedestal craters found among them occur in the Memnonia region of Mars near 5.9oS, 162.2oW. The 400 meter scale bar is about 437 yards long. Sunlight illuminates each scene from the upper left.

2004-01-01

35

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

36

Field Evaluation of Transgenic and Classical Sources of Wheat streak mosaic virus Resistance  

Microsoft Academic Search

of the disease include light green and yellow streaking of the leaves as well as curling of the leaves due to mite The development of wheat (Triticum aestivum L.) cultivars that activity. Infected plants typically exhibit stunted growth, are resistant to Wheat streak mosaic virus (WSMV), yet competitive in yield under nondiseased conditions, is an objective for breeding reduced tillering,

G. L. Sharp; J. M. Martin; S. P. Lanning; N. K. Blake; C. W. Brey; E. Sivamani; R. Qu; L. E. Talbert

37

Effect of sugar beet genotype on the Beet necrotic yellow vein virus?P25 pathogenicity factor and evidence for a fitness penalty in resistance-breaking strains.  

PubMed

Beet necrotic yellow vein virus (BNYVV), vectored by Polymyxa betae, causes rhizomania in sugar beet. For disease control, the cultivation of hybrids carrying Rz1 resistance is crucial, but is compromised by resistance-breaking (RB) strains with specific mutations in the P25 protein at amino acids 67-70 (tetrad). To obtain evidence for P25 variability from soil-borne populations, where the virus persists for decades, populations with wild-type (WT) and RB properties were analysed by P25 deep sequencing. The level of P25 variation in the populations analysed did not correlate with RB properties. Remarkably, one WT population contained P25 with RB mutations at a frequency of 11%. To demonstrate selection by Rz1 and the influence of RB mutations on relative fitness, competition experiments between strains were performed. Following a mixture of strains with four RNAs, a shift in tetrad variants was observed, suggesting that strains did not mix or transreplicate. The plant genotype exerted a clear influence on the frequency of RB tetrads. In Rz1 plants, the RB variants outcompeted the WT variants, and mostly vice versa in susceptible plants, demonstrating a relative fitness penalty of RB mutations. The strong genotype effect supports the hypothesized Rz1?RB strain selection with four RNAs, suggesting that a certain tetrad needs to become dominant in a population to influence its properties. Tetrad selection was not observed when an RB strain, with an additional P26 protein encoded by a fifth RNA, competed with a WT strain, supporting its role as a second BNYVV pathogenicity factor and suggesting the reassortment of both types. PMID:23282068

Bornemann, Kathrin; Varrelmann, Mark

2013-05-01

38

Frosty Wind Streaks  

NASA Technical Reports Server (NTRS)

MGS MOC Release No. MOC2-532, 2 November 2003

As seasonal polar frosts sublime away each spring, winds may re-distribute some of the frost or move sediment exposed from beneath the frost. This action creates ephemeral wind streaks that can be used by scientists seeking to study the local circulation of the martian [missing text] surveyor (MGS) Mars Orbiter Camera (MOC) image shows a suite of wind streaks created in subliming carbon dioxide frost. These dark streaks appear to conform to the shape of the slopes on which they occur, suggesting that slope winds play a dominant role in creating and orienting these streaks. This picture is located near 73.8oS, 305.7oW. The image is illuminated by sunlight from the upper left and covers an area 3 km (1.9 mi) wide. Winds responsible for the streaks generally blew from the bottom/right (south/southeast) toward the top/upper left (north/northwest).

2003-01-01

39

Craters and Wind Streaks  

NASA Technical Reports Server (NTRS)

25 March 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a plethora of small wind tails or streaks in the lees of impact craters in northeastern Tharsis near 25.8oN, 89.0oW. The streak tails point toward the east/northeast (right), indicating that the dominant winds blow from the west/southwest (left). This February 2004 picture covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the lower left.

2004-01-01

40

Layers and Streaks  

NASA Technical Reports Server (NTRS)

6 December 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an outcrop of light-toned layered rock and a plethora of dark streaks on the floor of a crater in southern Noachis Terra. The streaks were created by dozens of dust devils which disrupted and perhaps removed some of the thin layer of dust that coats the surface. This view is located near 55.5oS, 333.4oW. The scene is illuminated by sunlight from the lower right. The 500 meter scale bar is approximately 547 yards long.

2004-01-01

41

Quantitative and Qualitative Involvement of P3N-PIPO in Overcoming Recessive Resistance against Clover Yellow Vein Virus in Pea Carrying the cyv1 Gene  

PubMed Central

In pea carrying cyv1, a recessive gene for resistance to Clover yellow vein virus (ClYVV), ClYVV isolate Cl-no30 was restricted to the initially infected cells, whereas isolate 90-1 Br2 overcame this resistance. We mapped the region responsible for breaking of cyv1-mediated resistance by examining infection of cyv1 pea with chimeric viruses constructed from parts of Cl-no30 and 90-1 Br2. The breaking of resistance was attributed to the P3 cistron, which is known to produce two proteins: P3, from the main open reading frame (ORF), and P3N-PIPO, which has the N-terminal part of P3 fused to amino acids encoded by a small open reading frame (ORF) called PIPO in the +2 reading frame. We introduced point mutations that were synonymous with respect to the P3 protein but nonsynonymous with respect to the P3N-PIPO protein, and vice versa, into the chimeric viruses. Infection of plants with these mutant viruses revealed that both P3 and P3N-PIPO were involved in overcoming cyv1-mediated resistance. Moreover, P3N-PIPO quantitatively affected the virulence of Cl-no30 in cyv1 pea. Additional expression in trans of the P3N-PIPO derived from Cl-no30, using White clover mosaic virus as a vector, enabled Cl-no30 to move to systemic leaves in cyv1 pea. Susceptible pea plants infected with chimeric ClYVV possessing the P3 cistron of 90-1 Br2, and which were therefore virulent toward cyv1 pea, accumulated more P3N-PIPO than did those infected with Cl-no30, suggesting that the higher level of P3N-PIPO in infected cells contributed to the breaking of resistance by 90-1 Br2. This is the first report showing that P3N-PIPO is a virulence determinant in plants resistant to a potyvirus.

Choi, Sun Hee; Hagiwara-Komoda, Yuka; Atsumi, Go; Shimada, Ryoko; Hisa, Yusuke; Naito, Satoshi

2013-01-01

42

Comparison of enzyme-linked immunosorbent assay (ELISA) with dot hybridization using 32P- or 2-acetylaminofluorene (AAF)-labelled cDNA probes for the detection and characterization of beet necrotic yellow vein virus.  

PubMed

Beet Necrotic Yellow Vein Virus (BNYVV) was detected by enzyme-linked immunosorbent assay (ELISA) and RNA/DNA dot hybridization using either radiolabelled or non-radioactive probes. Dot hybridization specifically distinguished isolates that could not be distinguished by ELISA. The detection thresholds for ELISA, hybridization with non-radioactive probes and hybridization with radiolabelled probes were 2 ng, 0.2 ng, 0.02 ng of purified virus, respectively. Dot hybridization with non-radioactive probes could be performed on crude infected beet root extracts, thus providing a useful tool for monitoring BNYVV infection and for routine testing in plant breeding programs. PMID:2671680

Sakamoto, H; Lemaire, O; Merdinoglu, D; Guesdon, J L

1989-06-01

43

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

44

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.

Spangler, Tim

2005-04-25

45

An Ion Streak Camera  

Microsoft Academic Search

The possibility of detecting fast ions (protons and a particles) using an X-ray-sensitive streak camera with a CsI photocathode is demonstrated. The spatial resolution of the instrument is 70 µm, and its physical time resolution is 7 ps. The yield of secondary electrons from the photocathode irradiated with a particles is 8 electrons\\/particle. The instrument is able to detect single

A. G. Kravchenko; D. N. Litvin; V. P. Lazarchuk; V. M. Murugov; S. I. Petrov; A. V. Senik; I. G. Pryanishnikov

2004-01-01

46

Streaking tremor in Cascadia  

NASA Astrophysics Data System (ADS)

Details of tremor deep in subduction zones is damnably difficult to glimpse because of the lack of crisp initial arrivals, low waveform coherence, uncertain focal mechanisms, and the probability of simultaneous activity across extended regions. Yet such details hold out the best hope to illuminate the unknown mechanisms underlying episodic tremor and slip. Attacking this problem with brute force, we pointed a small, very dense seismic array down at the migration path of a good-sized episodic tremor and slip (ETS) event. In detail, it was an 84-element, 1300-m-aperture temporary seismic array in northern Washington, and the migration path of the May 2008 ETS event was 30-40 km directly underneath. Our beamforming technique tracked the time, incident angle, and azimuth of tremor radiation in unprecedented detail. We located the tremor by assuming it occurs on the subduction interface, estimated relative tremor moment released by each detected tremor window, and mapped it on the interface [Ghosh et al., GRL, 2009]. Fortunately for our ability to image it, the tremor generally appears to emanate from small regions, and we were surprised by how steadily the regions migrated with time. For the first time in Cascadia, we found convergence-parallel transient streaks of tremor migrating at velocities of several tens of km/hr, with movement in both up- and down-dip directions. Similar patterns have been seen in Japan [Shelly, G3, 2007]. This is in contrast to the long-term along-strike marching of tremor at 10 km/day. These streaks tend to propagate steadily and often repeat the same track on the interface multiple times. They light up persistent moment patches on the interface by a combination of increased amplitude and longer residence time within the patches. The up- and down-dip migration dominates the 2 days of tremor most clearly imaged by our array. The tendency of the streaks to fill in bands is the subject of the presentation of Ghosh et al. here. The physical mechanism causing the streaks, however, is not entirely clear. We suggest surges of fluid released at the megathrust may transmit stress pulses that cause failure by reducing effective normal stress along linear corrugated weak features on the fault. Houston et al., here, will explore the implications of tremor streaks for a source model.

Vidale, J. E.; Ghosh, A.; Sweet, J. R.; Creager, K. C.; Wech, A.; Houston, H.

2009-12-01

47

Black Streak of Edible Burdock Caused by Itersonilia perplexans in Japan  

Microsoft Academic Search

  Black streak disease of edible burdock (Arctium lappa L.) has been observed periodically in Hokkaido Prefecture, Japan since 1988. Symptoms appeared initially as small, dark brown\\u000a to black spots on the leaf veins and petioles. The necrotic spots developed longitudinally along the leaf veins or petioles.\\u000a Diseased leaf veins or petioles occasionally snapped off at the necrotic lesions. An Itersonilia

Harukuni HORITA; Shinji YASUOKA

2002-01-01

48

Bright Streak on Amalthea  

NASA Technical Reports Server (NTRS)

These two images of Jupiter's small, irregularly shaped moon Amalthea, obtained by the camera onboard NASA's Galileo spacecraft in August 1999(left) and November 1999 (right), form a 'stereo pair' that helps scientists determine this moon's shape and the topography of its surface features. Features as small as 3.8 kilometers (2.4 miles) across can be resolved in these images, making them among the highest-resolution images ever taken of Amalthea.

The large impact crater visible in both images, near the right-hand edge of Amalthea's disk, is about 40 kilometers (about 29 miles) across; two ridges, tall enough to cast shadows, extend from the top of the crater in a V-shape reminiscent of a 'rabbit ears' television antenna. To the left of these ridges, in the top center portion of Amalthea's disk, is a second large impact crater similar in size to the first crater. To the left of this second crater is a linear 'streak' of relatively bright material about 50 kilometers (31 miles) long. In previous spacecraft images of Amalthea taken from other viewing directions, this bright feature was thought to be a small, round, bright 'spot' and was given the name Ida. These new images reveal for the first time that Ida is actually a long, linear 'streak.' This bright streak may represent material ejected during the formation of the adjacent impact crater, or it may just mark the crest of a local ridge. Other patches of relatively bright material can be seen elsewhere on Amalthea's disk, although none of these other bright spots has Ida's linear shape.

In both images, sunlight is coming from the left and north is approximately up. Note that the north pole of Amalthea is missing in the right-hand image (it was cut off by the edge of the camera frame). The bright streak, Ida, is on the side of the moon that faces permanently away from Jupiter, and the crater near the right-hand edge of the disk is in the center of Amalthea's leading side (the side of the moon that 'leads' as Amalthea moves in its orbit around Jupiter).

The images are, from left to right: Amalthea taken on August 12, 1999 at a range of 446,000 kilometers (about 277,000 miles) and on November 26, 1999 at a range of 374,000 kilometers (about 232,000 miles).

2000-01-01

49

Wind Streak Changes  

NASA Technical Reports Server (NTRS)

MGS MOC Release No. MOC2-358, 12 May 2003

Mars is a dynamic planet. This pair of Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) pictures, taken 2 Mars years apart, show changes in dark streak patterns caused by wind movement of dust. The top picture was taken in July 1999, the bottom one in March 2003. The pair of images are in Tharsis near 9.5oS, 128.5oW. Sunlight illuminates both from the upper left.

2003-01-01

50

Varicose Veins  

MedlinePLUS

Varicose veins are swollen, twisted veins that you can see just under the skin. They usually occur in ... of the body. Hemorrhoids are a type of varicose vein. Your veins have one-way valves that help ...

51

Circles and Streaks  

NASA Technical Reports Server (NTRS)

MGS MOC Release No. MOC2-544, 14 November 2003

This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image, acquired less than a week ago on 8 November 2003, shows a typical southern middle-to-high latitude scene at this time of year. It is summer in the southern hemisphere, and regions such as Promethei Terra, where this image was acquired, are being streaked by dust devils that remove or disrupt the coating of dust that was deposited over the region in the previous autumn or winter. While no active dust devils were captured in this scene, their tell-tale tracks are scratched all across the image. The circular features are the sites of buried meteor impact craters; their rims form dark rings; the material that fills the craters has become cracked. This picture is located near 68.1oS, 247.9oW. The area shown is approximately 3 km (1.9 mi) across and is illuminated by sunlight from the upper left.

2003-01-01

52

Varicose Veins  

MedlinePLUS

... page from the NHLBI on Twitter. What Are Varicose Veins? Varicose (VAR-i-kos) veins are swollen, twisted ... can form in other parts of the body. Varicose veins are a common condition. They usually cause few ...

53

Dust streaks on Mars: Colors and photometry  

NASA Astrophysics Data System (ADS)

Photometric studies of crater related bright and dark streaks have strongly supported the hypothesis that the bright streaks are excess dust deposits and dark streaks are erosional windows in a partial dust cover. Red-blue (and red-violet) plots show that bright streaks are consistent with mosaics of bright red dust and background material. Here the plains are also consistent with a partial dust cover; the dark streak is the least covered area. Bright and dark streaks both reverse contrast relative to surrounding plains at phase angles over 100 deg in violet filter images. The similar phase behavior of both bright and dark streaks supports the idea that they are both changes in the amount of dust cover. Red-violet plots of bright streaks are most easily explained by mosaics of optically thick dust and plains material. Lengths of bright streaks are independent of their contrasts. This suggests the streak deposition, if in the mosaic patterns indicated above, is a function of available sites of deposition, rather than atmospheric dust loading. Contrasts of dark streaks with plains indicate the plains have fractional dust covers nearly as great as the maximum additional cover in bright streaks. The bright streaks thus store little of the global supply of dust.

Thomas, P.

1984-04-01

54

Streaking into middle school science: The Dell Streak pilot project  

NASA Astrophysics Data System (ADS)

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 Streak could be used as an effective instructional tool, and if it could be considered an effective instructional resource for reviewing and preparing for the science assessments. A mixed method research design was used for the study to analyze both quantitative and qualitative results to determine if the Dell Streaks' utilization could achieve the following: 1. instructional strategies would change, 2. it would be an effective instructional tool, and 3. a comparison of the students' test scores and benchmark assessments' scores would provide statistically significant difference. Through the use of an ANOVA it was determined a statistically significant difference had occurred. A Post Hoc analysis was conducted to identify where the difference occurred. Finally a T-test determined was there was no statistically significance difference between the mean End-of-Grade tests and four quarterly benchmark scores of the control and the experimental groups. Qualitative research methods were used to gather results to determine if the Streaks were an effective instructional tool. Classroom observations identified that the teacher's teaching styles and new instructional strategies were implemented throughout the pilot project. Students had an opportunity to complete a questionnaire three times during the pilot project. Results revealed what the students liked about using the devices and the challenges they were facing. The teacher completed a reflective questionnaire throughout the pilot project and offered valuable reflections about the use of the devices in an educational setting. The reflection data supporting the case study was drawn from the teacher's statements regarding the change in instructional delivery as a respect of using the students' device. The results section of the study will elaborate upon these findings. The study recommendations on the use of the Dell Streak device will address whether further actions as the use of the Streak technology in the classroom and summary section.

Austin, Susan Eudy

55

Properties of martian slope streak populations  

NASA Astrophysics Data System (ADS)

Slope streaks are down-slope mass movements on the surface of Mars that are among the few known examples of contemporary geologic activity on Mars. Here we study slope streak activity over three decades, based on overlapping images in the Lycus Sulci region taken by the Context Camera (CTX) 2007-2010 and the Viking Orbiter Camera in 1977. The number of disappeared slope streaks is nearly equal the number of newly formed slope streaks, suggesting the streak population is balanced. The turnover time of the population is estimated to be four decades. Slope streaks fade gradually over time, with islands of persistence. We also determine the number of observable slope streaks as a function of image resolution based on images by the High Resolution Imaging Science Experiment (HiRISE) camera, and find that the number of discernible slope streaks can increase rapidly with spatial resolution.

Bergonio, Justin R.; Rottas, Kimberly M.; Schorghofer, Norbert

2013-07-01

56

Slope Streaks in Terra Sabaea  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site] Figure 1 Click on image for larger version

This HiRISE image shows the rim of a crater in the region of Terra Sabaea in the northern hemisphere of Mars.

The subimage (figure 1) is a close-up view of the crater rim revealing dark and light-toned slope streaks. Slope streak formation is among the few known processes currently active on Mars. While their mechanism of formation and triggering is debated, they are most commonly believed to form by downslope movement of extremely dry sand or very fine-grained dust in an almost fluidlike manner (analogous to a terrestrial snow avalanche) exposing darker underlying material.

Other ideas include the triggering of slope streak formation by possible concentrations of near-surface ice or scouring of the surface by running water from aquifers intercepting slope faces, spring discharge (perhaps brines), and/or hydrothermal activity.

Several of the slope streaks in the subimage, particularly the three longest darker streaks, show evidence that downslope movement is being diverted around obstacles such as large boulders. Several streaks also appear to originate at boulders or clumps of rocky material.

In general, the slope streaks do not have large deposits of displaced material at their downslope ends and do not run out onto the crater floor suggesting that they have little reserve kinetic energy. The darkest slope streaks are youngest and can be seen to cross cut and superpose older and lighter-toned streaks. The lighter-toned streaks are believed to be dark streaks that have lightened with time as new dust is deposited on their surface.

Observation Geometry Image PSP_001808_1875 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 15-Dec-2006. The complete image is centered at 7.4 degrees latitude, 47.0 degrees East longitude. The range to the target site was 272.1 km (170.1 miles). At this distance the image scale is 54.4 cm/pixel (with 2 x 2 binning) so objects 163 cm across are resolved. The image shown here has been map-projected to 50 cm/pixel and north is up. The image was taken at a local Mars time of 03:36 PM and the scene is illuminated from the west with a solar incidence angle of 53 degrees, thus the sun was about 37 degrees above the horizon. At a solar longitude of 150.7 degrees, the season on Mars is Northern Summer.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo.

2007-01-01

57

Dark streaks on talus slopes, Mars  

NASA Technical Reports Server (NTRS)

High-resolution pictures of talus slopes on Mars show small, dark streaks that characteristically widen downward. These streaks are different from the thin and even streaks of various albedos that stream from cliffs on talus slopes, but gradations between the two streak types occur and not all streaks can be classified with confidence. In order to study the nature and origin of the small, widening, dark streaks, all Viking pictures with a resolution of less than 100 m/pixel were surveyed. To date several hundred streaks were located, but only few are of high enough resolution to be confidently identified as widening downwards. The approximate dimensions of the streaks were measured and their shapes, numbers, position, and spacing on slopes were noted. They were plotted on a topographic map, and their relation to topography, geologic units, and regions of distinct thermal inertia and albedo were studied. Also noted was the season at which images containing streaks were acquired and the direction of illumination. Albedo measurements are in progress. Several streaks can be seen stereoscopically, but none are observed on color images. The observation of small dark streaks on talus slopes on Mars is compatible with an interpretation of their origin as eruptions of small masses of wet debris in places where steep walls intersect aquifers or where seasonal equatorial warming permits the local melting of ground ice.

Ferguson, H. M.; Lucchitta, B. K.

1984-01-01

58

Wind vs. Dust Devil Streaks  

NASA Technical Reports Server (NTRS)

22 February 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image presents a fine illustration of the difference between streaks made by dust devils and streaks made by wind gusts. Dust devils are usually solitary, spinning vortices. They resemble a tornado, or the swirling motion of a familiar, Tasmanian cartoon character. Wind gusts, on the other hand, can cover a larger area and affect more terrain at the same time. The dark, straight, and parallel features resembling scrape marks near the right/center of this image are thought to have been formed by a singular gust of wind, whereas the more haphazard dark streaks that crisscross the scene were formed by dozens of individual dust devils, acting at different times. This southern summer image is located in Noachis Terra near 67.0oS, 316.2oW. Sunlight illuminates the scene from the upper left; the picture covers an area 3 km (1.9 mi) wide.

2004-01-01

59

Varicose Veins and Spider Veins  

MedlinePLUS

... the skin. Symptoms include skin redness; a firm, tender, warm vein; and sometimes pain and swelling. • Deep ... The vein has become swollen, red, or very tender or warm to the touch • There are sores ...

60

Vein Problems Related to Varicose Veins  

MedlinePLUS

... this page from the NHLBI on Twitter. Vein Problems Related to Varicose Veins Many vein problems are ... have varicoceles, see your doctor. Other Related Vein Problems Other types of varicose veins include venous lakes, ...

61

The use of latent class analysis to estimate the sensitivities and specificities of diagnostic tests for Squash vein yellowing virus in cucurbit species when there is no gold standard.  

PubMed

Squash vein yellowing virus (SqVYV) is the causal agent of viral watermelon vine decline, one of the most serious diseases in watermelon (Citrullus lanatus L.) production in the southeastern United States. At present, there is not a gold standard diagnostic test for determining the true status of SqVYV infection in plants. Current diagnostic methods for identification of SqVYV-infected plants or tissues are based on the reverse-transcription polymerase chain reaction (RT-PCR), tissue blot nucleic acid hybridization assays (TB), and expression of visual symptoms. A quantitative assessment of the performance of these diagnostic tests is lacking, which may lead to an incorrect interpretation of results. In this study, latent class analysis (LCA) was used to estimate the sensitivities and specificities of RT-PCR, TB, and visual assessment of symptoms as diagnostic tests for SqVYV. The LCA model assumes that the observed diagnostic test responses are linked to an underlying latent (nonobserved) disease status of the population, and can be used to estimate sensitivity and specificity of the individual tests, as well as to derive an estimate of the incidence of disease when a gold standard test does not exist. LCA can also be expanded to evaluate the effect of factors and was done here to determine whether diagnostic test performances varied among the type of plant tissue being tested (crown versus vine tissue), where plant samples were taken relative to the position of the crown (i.e., distance from the crown), host (i.e., genus), and habitat (field-grown versus greenhouse-grown plants). Results showed that RT-PCR had the highest sensitivity (0.94) and specificity (0.98) of the three tests. TB had better sensitivity than symptoms for detection of SqVYV infection (0.70 versus 0.32), while the visual assessment of symptoms was more specific than TB and, thus, a better indicator of noninfection (0.98 versus 0.65). With respect to the grouping variables, RT-PCR and TB had better sensitivity but poorer specificity for diagnosing SqVYV infection in crown tissue than it did in vine tissue, whereas symptoms had very poor sensitivity but excellent specificity in both tissues for all cucurbits analyzed in this study. Test performance also varied with habitat and genus but not with distance from the crown. The results given here provide quantitative measurements of test performance for a range of conditions and provide the information needed to interpret test results when tests are used in parallel or serial combination for a diagnosis. PMID:23883156

Turechek, William W; Webster, Craig G; Duan, Jingyi; Roberts, Pamela D; Kousik, Chandrasekar S; Adkins, Scott

2013-12-01

62

Focus on Varicose Veins  

MedlinePLUS

What are varicose veins? Varicose veins are the visible and large, bulging, surface veins, felt under the skin. They generally are larger ... and treatment Focus on Varicose Veins How are varicose veins diagnosed? The diagnosis of varicose veins is made ...

63

What Causes Varicose Veins?  

MedlinePLUS

... page from the NHLBI on Twitter. What Causes Varicose Veins? Weak or damaged valves in the veins can ... space. These are varicose veins. Normal Vein and Varicose Vein Figure A shows a normal vein with a ...

64

Yellow Fever  

MedlinePLUS

... tropical and subtropical areas in South America and Africa. The virus is transmitted to humans by the ... Maps Maps of yellow fever endemic areas in Africa and South America Links & References Publications and links ...

65

Yellow fever  

MedlinePLUS

... liver, and kidney. Bleeding disorders, seizures, coma, and delirium may also occur. Symptoms may include: Irregular heartbeats ( ... Bleeding (may progress to hemorrhage) Coma Decreased urination Delirium Fever Headache Yellow skin and eyes (jaundice) Muscle ...

66

Sclerotherapy of Varicose Veins and Spider Veins  

MedlinePLUS

Sclerotherapy of Varicose Veins and Spider Veins • Overview Sclerotherapy is a minimally invasive treatment used to treat varicose and spider veins. The ... cramps. It is the primary treatment for small varicose veins in the legs. top of page • Preparation You ...

67

Bright Streaks and Dark Fans  

NASA Technical Reports Server (NTRS)

The south polar region of Mars is covered every year by a layer of carbon dioxide ice. In a region called the 'cryptic terrain,' the ice is translucent and sunlight can penetrate through the ice to warm the surface below.

The ice layer sublimates (evaporates) from the bottom. The dark fans of dust seen in this image come from the surface below the layer of ice, carried to the top by gas venting from below. The translucent ice is 'visible' by virtue of the effect it has on the tone of the surface below, which would otherwise have the same color and reflectivity as the fans.

Bright streaks in this image are fresh frost. The CRISM team has identified the composition of these streaks to be carbon dioxide.

Observation Geometry Image PSP_003113_0940 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 26-Mar-2007. The complete image is centered at -85.8 degrees latitude, 106.0 degrees East longitude. The range to the target site was 244.9 km (153.0 miles). At this distance the image scale is 49.0 cm/pixel (with 2 x 2 binning) so objects 147 cm across are resolved. The image shown here has been map-projected to 50 cm/pixel . The image was taken at a local Mars time of 06:20 PM and the scene is illuminated from the west with a solar incidence angle of 79 degrees, thus the sun was about 11 degrees above the horizon. At a solar longitude of 207.6 degrees, the season on Mars is Northern Autumn.

2007-01-01

68

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

69

Ozone, jet streaks and severe weather  

NASA Technical Reports Server (NTRS)

Data from three independent observing platforms are synthesized to study the role of jet streaks in severe weather. The three data types are: conventional radiosondes; 6.7 micron water vapor imagery from the GOES satellite; and total ozone imagery from Nimbus 7. Diagnoses are then made of potential vorticity, mid-tropospheric moisture, and total ozone at and below the level of jet streaks. Potential vorticity and total ozone distributions are both tracers of stratospheric air. Theoretically, both should respond to the transverse, vertical circulations expected in the vicinity of jet streaks. Both should increase due to the sinking above the left front quadrant of the streaks. Moisture, on the other hand, increases in the ascent under the left front quadrant. This study shows striking agreement between the three parameters independently observed from three different observing platforms. Moreover, the three severe weather case studies suggest a unique distribution of ozone, potential vorticity, and mid-tropospheric moisture relative to a jet streak. This, in turn, led to the creation of a new ozone/jet streak model which shows that the total ozone distribution provides a signature in the vicinity of jet streaks and permits identification of areas most likely to experience severe weather at a later time. The value of such observations to operational forecasting is discussed.

Sechrist, Frank S.; Petersen, Ralph A.; Brill, Keith F.; Krueger, Arlin J.; Uccellini, Louis W.

1987-01-01

70

Atomic and molecular phases through attosecond streaking  

SciTech Connect

In attosecond streaking, an electron is released by a short xuv pulse into a strong near infrared laser field. If the laser couples two states in the target, the streaking technique, which allows for a complete determination of the driving field, also gives an accurate measurement of the relative phase of the atomic or molecular ionization matrix elements from the two states through the interference from the two channels. The interference may change the phase of the photoelectron streaking signal within the envelope of the infrared field, an effect to be accounted for when reconstructing short pulses from the photoelectron signal and in attosecond time-resolved measurements.

Baggesen, Jan Conrad; Madsen, Lars Bojer [Lundbeck Foundation Theoretical Center for Quantum System Research, Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark)

2011-02-15

71

Yellow nails (image)  

MedlinePLUS

Yellow nails are seen in the 'yellow nail syndrome' in which there is thickening and yellow to yellow-green discoloration of all nails. Lymphedema, especially of the ankles, and compromised respiration ...

72

Compact Optical Technique for Streak Camera Calibration  

SciTech Connect

The National Ignition Facility is under construction at the Lawrence Livermore National Laboratory for the U.S. Department of Energy Stockpile Stewardship Program. Optical streak cameras are an integral part of the experimental diagnostics instrumentation. To accurately reduce data from the streak cameras a temporal calibration is required. This article describes a technique for generating trains of precisely timed short-duration optical pulses that are suitable for temporal calibrations.

Curt Allen; Terence Davies; Frans Janson; Ronald Justin; Bruce Marshall; Oliver Sweningsen; Perry Bell; Roger Griffith; Karla Hagans; Richard Lerche

2004-04-01

73

Performance comparison of streak camera recording systems  

SciTech Connect

Streak camera based diagnostics are vital to the inertial confinement fusion program at Sandia National Laboratories. Performance characteristics of various readout systems coupled to an EGG-AVO streak camera were analyzed and compared to scaling estimates. The purpose of the work was to determine the limits of the streak camera performance and the optimal fielding conditions for the Amador Valley Operations (AVO) streak camera systems. The authors measured streak camera limitations in spatial resolution and sensitivity. Streak camera limits on spatial resolution are greater than 18 lp/mm at 4% contrast. However, it will be difficult to make use of any resolution greater than this because of high spatial frequency variation in the photocathode sensitivity. They have measured a signal to noise of 3,000 with 0.3 mW/cm{sup 2} of 830 nm light at a 10 ns/mm sweep speed. They have compared lens coupling systems with and without micro-channel plate intensifiers and systems using film or charge coupled device (CCD) readout. There were no conditions where film was found to be an improvement over the CCD readout. Systems utilizing a CCD readout without an intensifier have comparable resolution, for these source sizes and at a nominal cost in signal to noise of 3, over those with an intensifier. Estimates of the signal-to-noise for different light coupling methods show how performance can be improved.

Derzon, M. [Sandia National Labs., Albuquerque, NM (United States). Diagnostics and Target Experiment Dept.; Barber, T. [K-tech Corp., Albuquerque, NM (United States)

1995-07-01

74

Composition and fine structure of minor veins in Tetragonia leaf  

Microsoft Academic Search

Summary Mesophyll containing the minor veins from leaves ofTetragonia expansa Murr. was examined in preparation for a study of effects of beet yellows virus on the leaf tissues of this plant. The sieve elements throughout the minor veins exhibit the characteristics commonly found in this type of cell in dicotyledons. The cells are connected with one another by sieve plates

Katherine Esau; Lynn L. Hoefert

1971-01-01

75

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

76

Deep Vein Thrombosis  

MedlinePLUS

Deep vein thrombosis, or DVT, is a blood clot that forms in a vein deep in the body. Most deep vein ... the condition is called thrombophlebitis. A deep vein thrombosis can break loose and cause a serious problem ...

77

Comparison of optical streak tube performance  

NASA Astrophysics Data System (ADS)

The ICF program at Livermore has a large inventory of optical streak cameras that were built in the 1970s and 1980s. The cameras include microchannel plate image-intensifier tubes (IIT) that provide signal amplification and early lens-coupled CCD readouts. Today, these cameras are still very functional, but some replacement parts such as the original streak tube, CCD, and IIT are scarce and obsolete. This article describes recent efforts to compare the performance of different commercially available streak tubes in an updated camera employing current advanced CCD readout technologies. Measurements of camera performance characteristics including linearity, spatial and temporal resolution, line-spread function, contrast transfer ratio (CTR), and dynamic range have been made for the same camera configuration: CCD coupled directly to the various streak tubes. Streak tube operation with large average tube current was observed by illuminating the entire slit region through a Ronchi ruling and measuring the CTR. This work was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under Contract No. W-7405-ENG-48.

McDonald, Joseph; Learch, Richard; Andrews, David; Vergel de Dios, Eugene; Griffith, Roger; Bell, Perry

2003-10-01

78

Femtosecond streak tubes designing, manufacturing, and testing  

NASA Astrophysics Data System (ADS)

New generation of streak tubes intended for single-shot and synchroscan operations with femtosecond time resolution was computer modelled, designed, manufactured, tested and adopted for further application in laser research. The developed PV-FS type tubes provide close to 100 fs-time resolution in single-shot streak mode. It is important to note that the PV-FS tubes may be equipped with Peltier cooled S1-photocathodes and their spectral sensitivity may cover the range of 115 - 1550 nm. The developed photocathodes have very low surface resistance (tens of Ohm per square unit). New tubes offer a high (more than 50 line pairs/mm) spatial resolution when recording ultrafast optical images with femtosecond time resolution. Due to keeping the PV-FS external geometry similar to the well-known PV-type tubes it becomes possible to install new devices into available streak cameras (AGAT, Imacon 500, etc.).

Degtyareva, Valentina P.; Belolipetskii, Vladimir S.; Bryukhnevich, Gennadii I.; Ivanova, Svetlana R.; Levina, Galina P.; Makushina, Valentina A.; Polikarkina, Nadejda D.; Semichastnova, Zoya M.; Schelev, Mikhail Y.

2003-07-01

79

Ozone, jet streaks, and severe weather  

NASA Technical Reports Server (NTRS)

Data obtained with the total ozone mapping spectrometer (TOMS) onboard the Nimbus-7 satellite are presented. An attempt is made to relate and synthesize TOMS data with conventional radiosonde analyses and with midtropospheric moisture data available from the VISSR onboard the GOES. Case studies are described which relate the potential vorticity structure of the upper troposphere to the total ozone distribution as measured by TOMS. Cyclogenesis, frontogenesis, and the formation of severe weather outbreaks are then related to jet streaks and their characteristic ozone signature. It is shown that the primary maxima of ozone and potential vorticity are associated with cold advection and subsidence in the main upper-air trough as suggested earlier. The secondary maxima of the three quantities diagnosed in the present work appear in the left front quadrant of a jet streak, revealing the importance of transverse, secondary motions induced by a jet streak above the level of maximum winds in further modifying the potential vorticity and ozone structures.

Sechrist, F. S.; Petersen, R. A.; Krueger, A. J.; Uccellini, L. W.; Brill, K. F.

1986-01-01

80

Martian crater dark streak lengths - Explanation from wind tunnel experiments  

NASA Astrophysics Data System (ADS)

The mechanism determining the length of dark erosional (type-Id) streaks near craters and hills on the surface of Mars is investigated using Mariner-9 images and the results of wind-tunnel studies (Greeley et al., 1974; Iversen et al., 1975 and 1976). An empirical model of time-dependent growth of crater-wake streaks in the downwind direction involving deflation by sand-grain saltation is developed and shown to give relatively good agreement with streak growth rates observed over a 38-day period of Mariner observations and with the streak-length/crater-diameter and streak-length/crater-height ratios analyzed statistically by Lee (1984). This time-dependent mechanism is thus considered a reasonable alternative (for dark streaks) to the blocking model proposed by Lee for both bright and dark streaks. Preliminary analysis of further wind-tunnel experiments (Iversen et al., 1982) supports the blocking model of bright-streak formation.

Iversen, J. D.; Greeley, R.

1984-06-01

81

Yellow nail syndrome (image)  

MedlinePLUS

Yellow nail syndrome is characterized by yellow nails that lack a cuticle, grow slowly, and are loose or detached (onycholysis). Yellow nail syndrome is most commonly associated with lung disorders, and ...

82

Martian Slope Streaks and Gullies: Origins as Dry Granular Flows  

NASA Technical Reports Server (NTRS)

Streaks and gullies are common on Martian slopes, and are geologically young; slope streaks have formed during the last few years of Mars Global Surveyor imaging. Both slope streaks and gullies involve flow of granular material, but it is not clear whether liquid water (or another suspending agent) was involved. The possibility that liquid water was involved makes gullies and slope streaks important for understanding Mars recent climate and for the hope of extant life near its surface. Here, we show that significant features of slope streaks and gullies are consistent with dry flows of granular material. Liquid water may not be required.

Treiman, A. H.; Louge, M. Y.

2004-01-01

83

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

84

Deep Vein Thrombosis  

MedlinePLUS

... veins include: Age Previous history of DVT or PE Metastatic malignancy Vein disease (such as varicose veins) ... lungs, where it is called a pulmonary embolism (PE). A pulmonary embolism is a potentially fatal condition ...

85

Renal vein thrombosis  

MedlinePLUS

Renal vein thrombosis is a blood clot that develops in the vein that drains blood from the kidney. ... Renal vein thrombosis is an uncommon disorder that may be caused by: Abdominal aortic aneurysm Clotting disorders Dehydration (mostly in infants) ...

86

Retinal vein occlusion  

MedlinePLUS

... small veins that carry blood away from the retina. The retina is the layer of tissue at the back ... smaller veins (branch veins or BRVO) in the retina often occurs when retinal arteries that have been ...

87

How Accurate Is the Attosecond Streak Camera?  

NASA Astrophysics Data System (ADS)

An attosecond streak camera holds the promise of time resolving the dynamics of photoionization with a few-attosecond accuracy. But can the attosecond measurement be disentangled from the process it measures? We address this question by deriving simple closed-form analytical expressions for the measurement-related apparent time delays in photoionization, associated with the application of the attosecond streak camera and/or resolution of attosecond beating by interference of two-photon transitions techniques. Our analytical results are accurate on about the 1 asec level and show that both intrinsic and measurement-induced delays depend on the same scattering phase and are, therefore, not independent. We also suggest a procedure for extracting intrinsic time delays from the measurement and a possible resolution of the controversy caused by the experiments of Schultze et al. [Science 328, 1658 (2010)SCIEAS0036-807510.1126/science.1189401].

Ivanov, Misha; Smirnova, Olga

2011-11-01

88

Understanding baseball team standings and streaks  

NASA Astrophysics Data System (ADS)

Can one understand the statistics of wins and losses of baseball teams? Are their consecutive-game winning and losing streaks self-reinforcing or can they be described statistically? We apply the Bradley-Terry model, which incorporates the heterogeneity of team strengths in a minimalist way, to answer these questions. Excellent agreement is found between the predictions of the Bradley-Terry model and the rank dependence of the average number team wins and losses in major-league baseball over the past century when the distribution of team strengths is taken to be uniformly distributed over a finite range. Using this uniform strength distribution, we also find very good agreement between model predictions and the observed distribution of consecutive-game team winning and losing streaks over the last half-century; however, the agreement is less good for the previous half-century. The behavior of the last half-century supports the hypothesis that long streaks are primarily statistical in origin with little self-reinforcing component. The data further show that the past half-century of baseball has been more competitive than the preceding half-century.

Sire, C.; Redner, S.

2009-02-01

89

Preventing Deep Vein Thrombosis  

MedlinePLUS

What is deep vein thrombosis (DVT)? Deep vein thrombosis is a condition in which blood clots (or thrombi) form in deep veins in the legs ... and Gynecologists f AQ • What is deep vein thrombosis (DVT)? • How does a clot form in a ...

90

Inheritance of zucchini yellow mosaic virus resistance in Cucumis melo L  

Microsoft Academic Search

Resistance to zucchini yellow mosaic virus has been found in the muskmelon line ‘PI 414723’ from India. This resistance is effective against the ZYMV strains E15 and 1318 belonging respectively to the NF and F pathotypes. Resistance to E15 (no vein clearing and yellowing symptoms) is governed by one dominant gene (symbol Zym) according to segregations observed in F1, F2

M. Pitrat; H. Lecoq

1984-01-01

91

Compressible laminar streaks with wall suction  

NASA Astrophysics Data System (ADS)

The response of a compressible laminar boundary layer subject to free-stream vortical disturbances and steady mean-flow wall suction is studied. The theoretical frameworks of Leib et al. [J. Fluid Mech. 380, 169-203 (1999)] and Ricco and Wu [J. Fluid Mech. 587, 97-138 (2007)], based on the linearized unsteady boundary-region equations, are adopted to study the influence of suction on the kinematic and thermal streaks arising through the interaction between the free-stream vortical perturbations and the boundary layer. In the asymptotic limit of small spanwise wavelength compared with the boundary layer thickness, i.e., when the disturbance flow is conveniently described by the steady compressible boundary region equations, the effect of suction is mild on the velocity fluctuations and negligible on the temperature fluctuations. When the spanwise wavelength is comparable with the boundary layer thickness, small suction values intensify the supersonic streaks, while higher transpiration levels always stabilize the disturbances at all Mach numbers. At larger spanwise wavelengths, very small amplitudes of wall transpiration have a dramatic stabilizing effect on all boundary layer fluctuations, which can take the form of transiently growing thermal streaks, large amplitude streamwise oscillations, or oblique exponentially growing Tollmien-Schlichting waves, depending on the Mach number and the wavelengths. The range of wavenumbers for which the exponential growth occurs becomes narrower and the location of instability is significantly shifted downstream by mild suction, indicating that wall transpiration can be a suitable vehicle for delaying transition when the laminar breakdown is promoted by these unstable disturbances. The typical streamwise wavelength of these disturbances is instead not influenced by suction, and asymptotic triple deck theory predicts the strong changes in growth rate and the very mild modifications in streamwise wavenumber in the limit of larger downstream distance and small spanwise wavenumber.

Ricco, Pierre; Shah, Daniel; Hicks, Peter D.

2013-05-01

92

Compact optical technique for streak camera calibration  

NASA Astrophysics Data System (ADS)

To produce accurate data from optical streak cameras requires accurate temporal calibration sources. We have reproduced an older technology for generating optical timing marks that had been lost due to component availability. Many improvements have been made which allow the modern units to service a much larger need. Optical calibrators are now available that produce optical pulse trains of 780 nm wavelength light at frequencies ranging from 0.1 to 10 GHz, with individual pulse widths of approximately 25 ps full width half maximum. Future plans include the development of single units that produce multiple frequencies to cover a wide temporal range, and that are fully controllable via an RS232 interface.

Bell, Perry; Griffith, Roger; Hagans, Karla; Lerche, Richard; Allen, Curt; Davies, Terence; Janson, Frans; Justin, Ronald; Marshall, Bruce; Sweningsen, Oliver

2004-10-01

93

X-ray streak crystal spectography  

SciTech Connect

We have built an x-ray streaked crystal spectrograph for making time-resolved x-ray spectral measurements. This instrument can access Bragg angles from 11/sup 0/ to 38/sup 0/ and x-ray spectra from 200 eV to greater than 10 keV. We have demonstrated resolving powers, E/..delta..E > 200 at 1 keV and time resolution less than 20 psec. A description of the instrument and an example of the data is given.

Kauffman, R.L.; Brown, T.; Medecki, H.

1983-07-01

94

Wind streaks: geological and botanical effects on surface albedo contrast  

NASA Astrophysics Data System (ADS)

Two wind streaks in the eastern Mojave Desert of California were examined to gain insight into the origin of the surface brightness contrast that makes them visible, both on the ground and in remote sensing data. The two localities are: a 4-km-long dark streak oriented S43E from the Amboy cinder cone (34°32'N, 115°46'W), located on a Quaternary basalt flow covered with aeolian sand, and a 2-km-long dark streak oriented S22E from a low hill near the southwestern base of Sleeping Beauty Mountain (34°48'N, 116°20'W), located on a sand-covered alluvial surface. In both cases, the dark streaks have enhanced rock abundances on the streak surface, relative to the surroundings. At the Amboy streak, slope wash likely contributed to the rock concentration on the streak surface, shielded from burial under aeolian sand by the cinder cone. At the Sleeping Beauty streak, the relative albedo contrast is strongly emphasized by the presence of Big Galleta grass only outside of the streak. The albedo contrast of the Sleeping Beauty streak can be effectively eliminated by the seasonal presence of annual grass preferentially within the streak. Some plants may have reflectances that are strongly dependent upon viewing and illumination geometry, raising the possibility that certain terrestrial aeolian features may appear variable on a diurnal basis. Alluvial processes appear to have been important at both localities for redistributing surface materials, even given the infrequent rain conditions present in the Mojave Desert.

Zimbelman, James R.; Williams, Steven H.

1996-09-01

95

Radar-visible wind streaks in the Altiplano of Bolivia  

NASA Technical Reports Server (NTRS)

Isolated knobs that are erosional remnants of central volcanoes or of folded rocks occur in several areas of the Altiplano are visible on both optical and images. The optically visible streaks occur in the immediate lee of the knobs, whereas the radar visible streaks occur in the zone downwind between the knobs. Aerial reconnaissance and field studies showed that the optically visible streaks consist of a series of small ( 100 m wide) barchan and barchanoid dunes, intradune sand sheets, and sand hummocks (large shrub coppice dunes) up to 15 m across and 5 m high. On LANDSAT images these features are poorly resolved but combine to form a bright streak. On the radar image, this area also appears brighter than the zone of the radar dark streak; evidently, the dunes and hummocks serve as radar reflectors. The radar dark streak consists of a relatively flat, smooth sand sheet which lacks organized aerolian bedforms, other than occasional ripples. Wind velocity profiles show a greater U value in the optically bright streak zone than in the radar dark streak.

Greeley, R.; Christensen, P.

1984-01-01

96

Integrated streak camera in standard (Bi)CMOS technology  

Microsoft Academic Search

The conventional streak camera (CSC) is an optoelectronic instrument which captures the spatial distribution versus time of a ultra high-speed luminous phenomena with a picosecond temporal resolution and a typical spatial resolution of 60 mum. This paper presents two Integrated Streak Camera (ISC) architectures called MISC (M for Matrix) and VISC (V for Vector) which replicate the functionality of a

Wilfried Uhring; Jean-Pierre Le Normand; Virginie Zint; Martin Zlatanski

2010-01-01

97

Very high long-term stability synchroscan streak camera  

Microsoft Academic Search

In this article, we present the drifts phenomena that affect the temporal resolution of a standard synchroscan streak camera and some techniques to correct them in order to enhance the long-term resolution of these cameras. First, we give a comprehensive list of the components of the synchroscan streak camera which are sensitive to temporal and thermal drift: from the trigger

Wilfried Uhring; Chantal Virginie Zint; Patrick Summ; Bernard Cunin

2003-01-01

98

Fluid dynamical implications of anastomosing slope streaks on Mars  

Microsoft Academic Search

The Mars Global Surveyor mission has imaged slope streaks, some of which have formed in periods as short as 109 days. These features are one of the most currently active surface processes on Mars. Some slope streaks have flow-like morphologic characteristics, which include anastomosing patterns influenced by small topographic barriers. In order to understand what processes gave rise to these

Hideaki Miyamoto; James M. Dohm; Ross A. Beyer; Victor R. Baker

2004-01-01

99

Mesoscale ageostrophic circulations associated with baroclinic jet streaks  

NASA Technical Reports Server (NTRS)

Studies of ageostrophic motion attending jet streaks and convection are examined. Various types of dynamical experiments are carried out with the hybrid isentropic-sigma coordinate model. The effects of vorticity and static stability distributions on the intensity of secondary circulations forced by inertial accelerations as well as the superposition of an amplifying baroclinic wave on the jet streak structure are investigated.

Johnson, D. R.

1984-01-01

100

Optociliary veins and central retinal vein occlusion  

Microsoft Academic Search

In a follow up of 94 patients with central retinal vein occlusion (CRVO) whose onset had taken place less than 1 year earlier, optociliary veins (OCVs) were found in 7.4% at first examination. Among the 79 eyes in which the fundus of the eye was very visible after a follow up of more than 1 year OCVs were found in

G Giuffrè; C Palumbo; G Randazzo-Papa

1993-01-01

101

Varicose Veins and Venous Insufficiency  

MedlinePLUS

... venous system. Varicose Vein Treatments Minimally Invasive Vein Ablation Treatment Endovenous (or vein) ablation is a minimally ... leg, re-establishing normal flow. Benefits of Vein Ablation Treatment The treatment takes less than an hour ...

102

Endoscopic Saphenous Vein Harvesting  

Microsoft Academic Search

Although the use of arterial conduit has decreased the amount of saphenous vein required for routine coronary artery bypass grafting, the saphenous vein as a bypass conduit remains an essential component of most practices. We describe the technique of endoscopic vein harvest that, in our initial experience with 30 patients, has improved patient satisfaction and decreased the complications associated with

Keith B Allen; Carl J Shaar

1997-01-01

103

The study of streak camera dynamic distortion  

NASA Astrophysics Data System (ADS)

Dynamic distortion, which is caused by space-charge effect, widely exists in streak camera. When input light intensity becomes too large, the electric field caused by electric beam turns out analogous to that caused by image converter tube, which leads to the dynamic distortion. In this article, we analyze the theory of the dynamic distortion by experiments and simulations upon CST Particle Studio software. Results show that: the intensity of current and the space position along the photocathode shall affect the dynamic distortion, leading to defocusing effect and reduce both the spatial resolution and the temporal resolution. All above assist us to better understand the electric-optic system of image converter tube, and provide ideas for further experimental diagnose design.

Deng, Bo; Li, Jing; Chen, Tao; Hu, Xin; Liu, Shenye

2012-10-01

104

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

2009-01-01

105

Attosecond streaking of correlated two-electron transitions in helium.  

PubMed

We present fully ab initio simulations of attosecond streaking for ionization of helium accompanied by shakeup of the second electron. This process represents a prototypical case for strongly correlated electron dynamics on the attosecond time scale. We show that streaking spectroscopy can provide detailed information on the Eisenbud-Wigner-Smith time delay as well as on the infrared-field dressing of both bound and continuum states. We find a novel contribution to the streaking delay that stems from the interplay of electron-electron and infrared-field interactions in the exit channel. We quantify all the contributions with attosecond precision and provide a benchmark for future experiments. PMID:22680715

Pazourek, Renate; Feist, Johannes; Nagele, Stefan; Burgdörfer, Joachim

2012-04-20

106

The formation of streak defects on anodized aluminum extrusions  

NASA Astrophysics Data System (ADS)

Streaking is a common surface defect on anodized extrusions of 6xxx series soft alloys. Very often, the defects only become apparent after anodizing, which makes it difficult to identify their root cause. In industry practice, a trial-and-error method has been taken to reduce the intensities of the streak defects, greatly increasing the fabrication cost. This paper describes the formation mechanism of various streak defects on the basis of a literature review and experimental results. This provides a basis for developing effective measures for preventing the formation of these defects for the extrusion industry.

Zhu, Hanliang; Zhang, Xinquan; Couper, Malcolm J.; Dahle, Arne K.

2010-05-01

107

Streak camera in standard (Bi)CMOS (bipolar complementary metal-oxide-semiconductor) technology  

Microsoft Academic Search

The conventional streak camera (CSC) is an optoelectronic instrument that captures the spatial distribution as a function of time of an ultra high-speed luminous phenomenon with picosecond temporal resolution and a typical spatial resolution of several tens of micrometers. This paper presents two tubeless streak camera architectures called MISC (matrix integrated streak camera) and VISC (vector integrated streak camera), which

M. Zlatanski; W. Uhring; J. P. Le Normand; C. V. Zint; D. Mathiot

2010-01-01

108

Active Processes: Bright Streaks and Dark Fans  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2

In a region of the south pole known informally as 'Ithaca' numerous fans of dark frost form every spring. HiRISE collected a time lapse series of these images, starting at Ls = 185 and culminating at Ls = 294. 'Ls' is the way we measure time on Mars: at Ls = 180 the sun passes the equator on its way south; at Ls = 270 it reaches its maximum subsolar latitude and summer begins.

In the earliest image (figure 1) fans are dark, but small narrow bright streaks can be detected. In the next image (figure 2), acquired at Ls = 187, just 106 hours later, dramatic differences are apparent. The dark fans are larger and the bright fans are more pronounced and easily detectable. The third image in the sequence shows no bright fans at all.

We believe that the bright streaks are fine frost condensed from the gas exiting the vent. The conditions must be just right for the bright frost to condense.

Observation Geometry Image PSP_002622_0945 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 16-Feb-2007. The complete image is centered at -85.2 degrees latitude, 181.5 degrees East longitude. The range to the target site was 246.9 km (154.3 miles). At this distance the image scale is 49.4 cm/pixel (with 2 x 2 binning) so objects 148 cm across are resolved. The image shown here has been map-projected to 50 cm/pixel . The image was taken at a local Mars time of 05:46 PM and the scene is illuminated from the west with a solar incidence angle of 88 degrees, thus the sun was about 2 degrees above the horizon. At a solar longitude of 185.1 degrees, the season on Mars is Northern Autumn.

2007-01-01

109

Temporal Contrast Changes in Dark Slope Streaks on Mars  

NASA Astrophysics Data System (ADS)

Dark slope streaks on Mars are among the most active and dynamic processes observed on the planet's surface. While various formation models have been suggested [1][2][3], dust avalanches seem to best explain streak origin and characteristics[4][5]. New streaks have the highest contrast suggesting they fade over time. One theory for this is atmospheric dust fallout slowly raising the albedo of the surface exposed by the dust avalanche, progressively increasing streak albedo until the streak becomes indistinguishable from the surrounding surface. In this study, we attempt an initial evaluation of changes in streak brightness relative to surroundings with a first order correction for incidence angle[6]. CRISM images were identified for spatial overlap and temporal range, then further selected for image sets with well-matched viewing geometries. The 1 micron wavelength band was used to reduce atmospheric interference and brightness values then collected at multiple locations within and alongside individual streaks, with on-streak/off-streak pairs at points of similar elevation. Values were then divided by the cosine of the corresponding MOLA incidence angle for brightness variation correction due to topography. Measurements for overlapping images established local and overall averages for the rate of change in contrast ratio. Results showed a range of trends including streaks that darkened, brightened, brightened then darkened or vice versa. We continue to explore the possibility of non-linear brightening as well as streak reactivation and localized events, surface characteristics, and topography. Further study will focus on these and other morphological changes observed from vast data sets of other instruments including the Mars Reconnaissance Orbter HiRISE and CTX, Mars Express HRSC, Mars Odyssey THEMIS (visible), and the Mars Global Surveyor MOC. [1] Morris (1982) JGR, 87, 1164-1178. [2] Ferguson and Lucchita (1984) NASA Tech. Memo., TM-86246, 188-190. [3] Miyamoto, H. et al. (2004) JGR, 109, E06008. [4] Sullivan, R. et al. (2001) JGR, 106, 23607-23633. [5] Baratoux, N. M. et al. (2006) Icarus, 183, 30-45. [6] Brown, A. et al. (2010) JGR, 115, E00D13.

Chilton, Heather; Phillips, C. B.; Brown, A.; Fenton, L.

2013-01-01

110

Optical fiducial timing system for x-ray streak cameras  

Microsoft Academic Search

An optical fiducial timing system is provided for use with interdependent groups of x-ray streak cameras. The aluminium coated ends of optical fibers are positioned with the photocathodes of the x-ray streak cameras. The other ends of the optical fibers are placed together in a bundled array. A fiducial optical signal, that is comprised of 2..omega.. or 1..omega.. laser light,

D. G. Nilson; E. M. Campbell; B. J. MacGowan; H. Medecki

1986-01-01

111

Microprocessor-controlled wide-range streak camera  

Microsoft Academic Search

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

Amy E. Lewis; Craig Hollabaugh

2006-01-01

112

[The iliac vein occlusion].  

PubMed

Basing on roentgenological and morphological investigations the causes of the iliac veins passability disorder were studied up. In 45.1% of observations the stenosis was revealed of the left and in 1.2% of the right common iliac vein. Among the stenosis causes were osteal or cartilagenous prominences of vertebral column, intravascular structures (webs, membranes) in the left common iliac vein, the external iliac vein squeeze by internal iliac artery, retroperitoneal fibrosis, the right common iliac artery aneurysm, anomalous branching of parietal pelvic artery. PMID:10370311

Baeshko, A A; Rogov, Iu I; Kriukov, A G; Sysoev, A V; Puchkov, A F; Berlov, G A

1999-01-01

113

Deep vein thrombosis.  

PubMed

Deep vein thrombosis (DVT) is a thrombus or blood clot that can occur in any of the deep veins in the body. DVTs occur most commonly in the leg or pelvis but also travel to the lungs, causing pulmonary embolism. PMID:24938985

Jackson, Mike

2014-06-18

114

Recurrent varicose veins  

Microsoft Academic Search

When Doppler ultrasound was introduced for the assessment of patients with varicose veins, a more accurate clinical appraisal of the pathophysiology of this condition became possible. In particular, it enabled identification of those patients with recurrent varicose veins who had had inappropriate or inadequate initial treatment. It facilitated planning of appropriate further treatment.

John P. Royle

1986-01-01

115

How Are Varicose Veins Treated?  

MedlinePLUS

... page from the NHLBI on Twitter. How Are Varicose Veins Treated? Varicose veins are treated with lifestyle changes and medical procedures. ... relieve symptoms, prevent complications, and improve appearance. If varicose veins cause few symptoms, your doctor may simply suggest ...

116

Travelers' Health: Yellow Book  

MedlinePLUS

... Home CDC 24/7: Saving Lives. Protecting People.™ Travelers' Health All CDC Topics Search The CDC Note: Javascript ... message, please visit this page: About CDC.gov . Travelers' Health: Travel Safe, Travel Smart Share Compartir Yellow Book ...

117

Yellow spinal fluid  

Microsoft Academic Search

HE OBSERYA'fIOX of yellow discoloration in cerebrospinal fluid (CSF) dates back to the earliest of lumbar punctures. In 1902 Milian and Chiray, 1 in their description of the supernatant fluid in subarachnoid hemorrhage, proposed the term \\

Donald G. Rosenberg; John T. Galambos

1960-01-01

118

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

119

Characteristics of an ultrafast x-ray streak camera  

SciTech Connect

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 acceleration grid. The transit time spread of the electrons traveling from the photocathode to the acceleration grid is inversely proportional to the accelerating field. By increasing the field by a factor of 7, we have minimized the effects of transit time dispersion in the photocathode/accelerating grid region and produce an x-ray streak camera with sub-picosecond temporal resolution ({approximately}900 fs). The streak camera has been calibrated using a Michelson interferometer and 100 fs, 400 nm laser light. Time resolved x-ray data is shown from an aluminum target heated at 10{sup 18} W/cm{sup 2} with a 100 fs, 400 nm laser .

Shepherd, R.; Booth, R.; Price, D. [and others

1994-06-01

120

Attosecond nanoplasmonic streaking of localized fields near metal nanospheres  

NASA Astrophysics Data System (ADS)

Collective electron dynamics in plasmonic nanosystems can unfold on timescales in the attosecond regime and the direct measurement of plasmonic near-field oscillations is highly desirable. We report on numerical studies on the application of attosecond nanoplasmonic streaking spectroscopy to the measurement of collective electron dynamics in isolated Au nanospheres. The plasmonic field oscillations are induced by a few-cycle near-infrared (NIR) driving field and are mapped by the energy of photoemitted electrons using a synchronized, time-delayed attosecond extreme ultraviolet (XUV) pulse kinetic. By a detailed analysis of the amplitudes and phase shifts, we identify the different regimes of nanoplasmonic streaking and study the dependence on particle size, XUV in streaking spectrograms photoelectron energy, and emission position. The simulations indicate that the near fields around the nanoparticles can be spatiotemporally reconstructed and may give detailed insight into the build-up and decay of collective electron motion.

Süßmann, Frederik; Kling, Matthias F.

2011-09-01

121

Attosecond streaking in a nano-plasmonic field  

NASA Astrophysics Data System (ADS)

A theoretical study of the application of attosecond streaking spectroscopy to time-resolved studies of the plasmonic fields surrounding isolated, resonantly excited spherical nanoparticles is presented. A classification of the different regimes in attosecond streaking is proposed and identified in our results that are derived from Mie calculations of plasmon fields, coupled to classical electron trajectory simulations. It is shown that in an attosecond streaking experiment, the electrons are almost exclusively sensitive to the component of the field parallel to the direction in which they are detected. This allows one to probe the different components of the field individually by resolving the angle of emission of the electrons. Finally, simulations based on fields calculated by finite-difference time-domain (FDTD) are compared with the results obtained using Mie fields. The two are found to be in good agreement with each other, supporting the notion that FDTD methods can be used to reliably investigate non-spherical structures.

Kelkensberg, F.; Koenderink, A. F.; Vrakking, M. J. J.

2012-09-01

122

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

123

Fluorescence lifetime imaging microscopy using a streak camera  

NASA Astrophysics Data System (ADS)

We present the development of a fluorescence lifetime imaging microscopy system using a streak camera (SC-FLIM), which uses ultrafast infrared laser for multiphoton excitation and a streak camera for lifetime measurement. A pair of galvo mirrors are employed to accomplish quick time-resolved scanning on a line and 2D fluorescence lifetime imaging. The SC-FLIM system was calibrated using an F-P etalon and several standard fluorescent dyes, and was also used to perform fluorescence lifetime imaging of fluorescent microspheres and a prepared plant stem slide.

Liu, Lixin; Li, Yahui; Sun, Luogeng; Li, Heng; Peng, Xiao; Qu, Junle

2014-02-01

124

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

125

Deep vein thrombosis - discharge  

MedlinePLUS

Deep venous thrombosis (DVT) is when a blood clot forms in a vein that is not on the surface of the ... al. Executive Summary: Antithrombotic Therapy and Prevention of Thrombosis. 9th ed. American College of Chest Physicians Evidence- ...

126

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

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. 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.

1992-06-01

127

Synchroscan streak camera temporal resolution improvement by phase locked loop technique  

Microsoft Academic Search

Different temporal instabilities, which degrade the temporal resolution of s a synchroscan streak camera, have been studied. Each of the 3 main components: the laser, the trigger and the streak camera, have their intrinsic instability, thus a degradation of the final temporal resolution is occurred. An internal PLL in the streak camera has been developed in order to improve the

Wilfried Uhring; Chantal Virginie Zint; Patrick Summ; Bernard Cunin

2003-01-01

128

Radial Streaks in Electron Diffraction Patterns Observation and Theory.  

National Technical Information Service (NTIS)

Electron diffraction patterns from cold-rolled aluminum and chromium specimens showed sharply defined radial streaks, rather than spots, on each Debye-Scherer ring. These patterns were obtained using only the two condenser lenses of a Siemens Elmiskop 1 a...

J. F. Nankivell M. R. Kindermann P. A. Doyle

1971-01-01

129

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

130

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

131

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. 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.

Charest, Michael R. Jr.; Torres, Peter III; Silbernagel, Christopher T. [National Security Technologies, LLC, 161-A S. Vasco Rd., Livermore, California 94551 (United States); Kalantar, Daniel H. [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94551 (United States)

2008-10-15

132

Strong Electrical Currents Leave the Primitive Streak of Chick Embryos  

Microsoft Academic Search

The electrical fields above chick embryos were explored with a vibrating probe. These fields indicate that steady currents with exit densities of the order of 100 microamperes per square centimeter leave the whole streak and return elsewhere through the epiblast. The epicenter of these strong exit currents lies near Hensen's node. They are probably pumped into the intraembryonic space by

Lionel F. Jaffe; Claudio D. Stern

1979-01-01

133

The Cause of Streaks upon Lath and Plaster Walls  

Microsoft Academic Search

IN reply to Mr. Thomas D. Cope's letter in NATURE of January 21, it may be stated that he is correct in supposing that the best explanation of the streaks on the plaster he refers to is that they are due to the hot-air molecules driving the dust particles into contact with the plaster, and the colder the plaster the

John Aitken

1915-01-01

134

Wind Tunnel Simulations of Light and Dark Streaks on Mars  

Microsoft Academic Search

Wind tunnel experiments have revealed a characteristic flow field pattern over raised-rim craters which causes distinctive zones of aeolian erosion and deposition. Comparisons of the results with Mariner 9 images of Mars show that some crater-associated dark zones result from wind erosion and that some crater-associated light streaks are depositional.

Ronald Greeley; James D. Iversen; James B. Pollack; Nancy Udovich; Bruce White

1974-01-01

135

Reliable and Repeatable Characterication 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.

Kalantar, D; Charest, M; Torres III, P; Charest, M

2008-05-06

136

Yellow Sea Thermal Structure.  

National Technical Information Service (NTIS)

There exists a need in the oceanography community to be able to produce climatologies of remote or poorly sampled shallow water areas through remote sensing techniques. Our goal was to construct a three-dimensional thermal structure of the Yellow Sea base...

C. R. Fralick

1994-01-01

137

Evaluation of the DipStreak, a New Device with an Original Streaking Mechanism for Detection, Counting, and Presumptive Identification of Urinary Tract Pathogens  

Microsoft Academic Search

DipStreak is a new urine culture device with two types of agar attached back-to-back on a plastic paddle. It combines dip-slide technology and an original streaking inoculation mechanism, allowing for bacterial count- ing and colony isolation. The performance of the DipStreak device with two different medium formulations, CHROMagar and MacConkey media in study A and UriSelect 3 and MacConkey media

Claudio Scarparo; Paola Piccoli; Paolo Ricordi; Mariuccia Scagnelli

2002-01-01

138

Pelvic Vein Embolisation in the Management of Varicose Veins  

SciTech Connect

Pelvic vein incompetence is common in patients with atypical varicose veins, contributing to their recurrence after surgery. Therefore, refluxing pelvic veins should be identified and treated. We present our experience with pelvic vein embolisation in patients presenting with varicose veins. Patients presenting with varicose veins with a duplex-proven contribution from perivulval veins undergo transvaginal duplex sonography (TVUS) to identify refluxing pelvic veins. Those with positive scans undergo embolisation before surgical treatment of their lower limb varicose veins. A total of 218 women (mean age of 46.3 years) were treated. Parity was documented in the first 60 patients, of whom 47 (78.3%) were multiparous, 11 (18.3%) had had one previous pregnancy, and 2 (3.3%) were nulliparous. The left ovarian vein was embolised in 78%, the right internal iliac in 64.7%, the left internal iliac in 56.4%, and the right ovarian vein in 42.2% of patients. At follow-up TVUS, mild reflux only was seen in 16, marked persistent reflux in 6, and new reflux in 3 patients. These 9 women underwent successful repeat embolisation. Two patients experienced pulmonary embolisation of the coils, of whom 1 was asymptomatic and 1 was successfully retrieved; 1 patient had a misplaced coil protruding into the common femoral vein; and 1 patient had perineal thrombophlebitis. The results of our study showed that pelvic venous embolisation by way of a transjugular approach is a safe and effective technique in the treatment of pelvic vein reflux.

Ratnam, Lakshmi A. [St. George's Hospital, Department of Radiology (United Kingdom); Marsh, Petra; Holdstock, Judy M.; Harrison, Charmaine S. [Stirling House, Whiteley Clinic (United Kingdom); Hussain, Fuad F. [Royal Surrey County Hospital, Department of Radiology (United Kingdom); Whiteley, Mark S. [Stirling House, Whiteley Clinic (United Kingdom); Lopez, Anthony, E-mail: consultant@radiologist.co.u [Royal Surrey County Hospital, Department of Radiology (United Kingdom)

2008-11-15

139

RELATION OF BEET YELLOWS VIRUS TO THE PHLOEM AND TO MOVEMENT IN THE SIEVE TUBE  

Microsoft Academic Search

In minor veins of leaves of Beta vulgaris L. (sugar beet) yellows virus particles were found both in parenchyma cells and in mature sieve elements. In parenchyma cells the particles were usually confined to the cytoplasm, that is, they were absent from the vacuoles. In the sieve elements, which at maturity have no vacuoles, the particles were scattered through- out

K. Esau; J. CRONSHAW; L. L. HOEFERT

1967-01-01

140

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

141

Along-vein necrosis as indicator symptom on water spinach caused by nickel in water culture  

Microsoft Academic Search

Water spinach (Ipomoea aquatica Forsk, cv. Bamboo-Leaf) grown in aerated nutrient solution in green- house was treated with various levels of nickel, copper, zinc, chromium, cadmium, manganese, arsenic, aluminum, and lead. Injury symptoms caused by these metals were compared with each other. Among these metals, only nickel produced specific symptoms of along-vein necrosis on leaves and stems. Leaf yellowing or

En-Jang Sun; Fen-Yi Wu

1998-01-01

142

Epidemiology of varicose veins  

Microsoft Academic Search

The prevalence rate of varicose veins in adults varies from less than 1% in lowland New Guinea women to over 50% in women in south Wales. Within populations the prevalence increases with age, is generally greater in women, is directly related to body mass, has an inconsistent relationship with occupation, and usually increases with increasing parity. None of these factors

Robert Beaglehole

1986-01-01

143

Streak cameras for soft x-ray and optical radiation  

SciTech Connect

The principal component of a streak camera is the image converter tube. A slit-shaped photocathode transforms the radiation into a proportional emission of electrons. An electron - optics arrangement accelerates the electrons and projects them into a phosphor screen creating the image of the slit. A pair of deflection plates deflects the electronic beam along a direction perpendicular to the main dimension of the slit. Different portions of the phosphor screen show the instantaneous image of the slit with brightness proportional to the number of emitted electrons and, consequently, to the intensity of the radiation. For our x-ray streak cameras, we use the RCA C73435A image conventer tube intended for the measurement of the radiation of light and modified to have an x-ray sensitive photocathode. Practical considerations lead to the use of transparent rather than reflecting photocathodes. Several of these camera tubes are briefly described.

Medecki, H.

1983-09-01

144

Streaked x-ray microscopy of laser-fusion targets  

SciTech Connect

An ultrafast soft x-ray streak camera has been coupled to a Wolter axisymmetric x-ray microscope. This system was used to observe the dynamics of laser fusion targets both in self emission and backlit by laser produced x-ray sources. Spatial resolution was 7 ..mu..m and temporal resolution was 20 ps. Data is presented showing the ablative acceleration of foils to velocities near 10/sup 7/ cm/sec and the collision of an accelerated foil with a second foil, observed using 3 keV streaked x-ray backlighting. Good agreement was found between hydrocode simulations, simple models of the ablative acceleration and the observed velocities of the carbon foils.

Price, R.H.; Campbell, E.M.; Rosen, M.D.; Auerbach, J.M.; Phillion, D.W.; Whitlock, R.R.; Obenshain, S.P.; McLean, E.A.; Ripin, B.H.

1982-08-01

145

The diversity of Banana streak virus isolates in Uganda.  

PubMed

In a study of the variation among isolates of Banana streak virus (BSV) in Uganda, 140 sequences were obtained from 49 samples by PCR across the conserved reverse transcriptase/RNaseH region of the genome. Pairwise comparison of these sequences suggested that they represented 15 different species and phylogenetic analyses showed that all species fell into three major clades based on 28% sequence difference. In addition to the Ugandan sequences, clade I also contained BSV species that are known as both integrated sequences and episomal viruses; clade II also contained integrated BSV sequences but which have not previously been identified as episomal viruses. Clade III comprised of Sugarcane bacilliform virus isolates and Ugandan BSV sequences and for which there is no evidence of integration. The possible reasons for the extraordinary levels of virus sequence variation and the potential origins and epidemiology of these viruses causing banana streak disease are discussed. PMID:16096705

Harper, G; Hart, D; Moult, S; Hull, R; Geering, A; Thomas, J

2005-12-01

146

Megahertz streak-mode Fourier domain optical coherence tomography  

PubMed Central

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.

2011-01-01

147

Numerical Modelling of Vein Microstructures  

Microsoft Academic Search

Mineral veins occur in a variety of forms (syntaxial, antitaxial, etc.), and with various microstructures (fibrous, stretched crystals, vuggy, etc.). These structures can, if correctly interpreted, provide useful insight into the geological and tectonic conditions at which the veins formed (Oliver and Bons 2001). Durney and Ramsay (1973) defined the base for the modern classification and interpretation of vein (micro-)

P. D. Bons

2005-01-01

148

Virus Necrosis of Tobacco Veins.  

National Technical Information Service (NTIS)

Virus necrosis of tobacco veins (browning of tobacco veins) occurs all over Poland and causes major economic losses. Studies of a number of orders show that the necrosis of tobacco veins is caused by a virus, which belongs to the group of potato virus Y (...

J. Berbec

1964-01-01

149

Pineal veins in vertebral angiography.  

PubMed

Angiographic patterns of pineal veins in normal and pathological conditions are examined. The diagnostic value of these veins for midline growths is limited owing to their inconstant visualization, multifarious angiographic patterns and minute size. With this in mind, greater significance of classical displacements of the internal and basal veins is outlined. PMID:1196485

Turtas, S

1975-11-21

150

Streak Camera: A Multidetector for Diffuse Optical Tomography  

Microsoft Academic Search

We describe an experimental setup for time-resolved diffuse optical tomography that uses a seven-channel light guide to transmit scattered light to a streak camera. This setup permits the simultaneous measurement of the time profiles of photons reemitted at different boundary sites of the objects studied. The instrument, its main specifications, and detector-specific data analysis before image reconstruction are described. The

C. Virginie Zint; Wilfried Uhring; Murielle Torregrossa; Bernard Cunin; Patrick Poulet

2003-01-01

151

Detection of episomal banana streak badnavirus by IC-PCR  

Microsoft Academic Search

A polymerase chain reaction (PCR) based strategy to detect episomal banana streak badnavirus (BSV) in banana and plantain plants that carry integrated BSV sequences was developed. Antisera used in immuno-capture polymerase chain reaction (IC-PCR) are capable of binding a large number of BSV serotypes. The primers used for PCR are capable of annealing to and amplifying across the aspartic protease-reverse

Glyn Harper; Ganesh Dahal; George Thottappilly; R. Hull

1999-01-01

152

Attosecond nanoplasmonic streaking of localized fields near metal nanospheres  

Microsoft Academic Search

Collective electron dynamics in plasmonic nanosystems can unfold on timescales in the attosecond regime and the direct measurement of plasmonic near-field oscillations is highly desirable. We report on numerical studies on the application of attosecond nanoplasmonic streaking spectroscopy to the measurement of collective electron dynamics in isolated Au nanospheres. The plasmonic field oscillations are induced by a few-cycle near-infrared (NIR)

Frederik Süßmann; Matthias F. Kling

2011-01-01

153

Streaked horned lark Eremophila  alpestris  strigata has distinct mitochondrial DNA  

Microsoft Academic Search

The Streaked Horned Lark (STHL; Eremophila  alpestris  strigata) is a federal candidate for listing under the Endangered Species Act. We evaluated the conservation status and level of genetic\\u000a diversity of the STHL using the complete mitochondrial ND2 gene. We sampled 32 STHLs from the southern Puget Sound region,\\u000a the Pacific coast, and Whites Island in the Columbia River of Washington,

Sergei V. Drovetski; Scott F. Pearson

2005-01-01

154

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

155

Missed Diagnostic Opportunities of Streak Camera Imaging in Tokamaks  

NASA Astrophysics Data System (ADS)

The streak camera imaging of tokamak plasmas is shown to provide diagnostic opportunities based on the existence of a long-lived (i.e., identifiable during time period comparable with slow MHD times, e.g., with the period of plasma toroidal rotation) fine structure of filaments (of luminosity) in plasmas. The skeletal structure of such filaments have been found [1] in visible light images taken with a streak camera in former experiments in tokamaks TM-2, T-4, T-6, with effective time resolution one microsecond. The above phenomenon enables us to suggest a new method of streak camera imaging which allows the determination of time evolution of direction and magnitude of rotation velocity of these structures. This exploits the «blurring» of bright spots (within these filaments) in toroidal and poloidal directions, for a wide enough slit. The above determination in a single discharge requires a special optical scheme and preliminary optimization, trying only few discharges, of the time-dependent velocity of pulling the exposed film (or its electronic analog). The examples are presented of evaluating the velocities from the data from tokamak T-6 experiments in the ordinary scheme which requires trying many discharges to optimize the imaging. [1] Proc. 27th EPS PPCF, Budapest, 2000 (http://sgi30.rmki.kfki.hu/EPS2000/P2_029.pdf).

Rantsev-Kartinov, Valentin A.

2002-11-01

156

Design of microcontroller based system for automation of streak camera.  

PubMed

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. PMID:20815627

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

2010-08-01

157

Streak artifact reduction in cardiac cone beam CT  

NASA Astrophysics Data System (ADS)

Cone beam reconstructed cardiac CT images suffer from characteristic streak artifacts that affect the quality of coronary artery imaging. These artifacts arise from inhomogeneous distribution of noise. While in non-tagged reconstruction inhomogeneity of noise distribution is mainly due to anisotropy of the attenuation of the scanned object (e.g. shoulders), in cardiac imaging it is largely influenced by the non-uniform distribution of the acquired data used for reconstructing the heart at a given phase. We use a cardiac adaptive filter to reduce these streaks. In difference to previous methods of adaptive filtering that locally smooth data points on the basis of their attenuation values, our filter is applied as a function of the noise distribution of the data as it is used in the phase selective reconstruction. We have reconstructed trans-axial images without adaptive filtering, with a regular adaptive filter and with the cardiac adaptive filter. With the cardiac adaptive filter significant reduction of streaks is achieved, and thus image quality is improved. The coronary vessel is much more pronounced in the cardiac adaptive filtered images, in slab MIP the main coronary artery branches are more visible, and non-calcified plaque is better differentiated from vessel wall. This improvement is accomplished without altering significantly the border definition of calcified plaques.

Shechter, Gilad; Naveh, Galit; Lessick, Jonathan; Altman, Ami

2005-04-01

158

Streak camera based SLR receiver for two color atmospheric measurements  

NASA Astrophysics Data System (ADS)

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

1993-06-01

159

Extrahepatic portal vein aneurysm.  

PubMed

Portal vein aneurysms (PVAs) are usually incidental on imaging and asymptomatic. If it is symptomatic or associated with a pathologic finding, a treatment is recommended. We report a case of a 75-year-old Caucasian man presenting with symptomatic and size-increasing portosplenomesenteric aneurysms. Interventional radiology was not indicated because of the large size. A surgical approach was chosen for the patient. Surgical technique consists of an aneurysmorrhaphy in the first time and in the second time, a Goretex prosthesis placement involving the vein. Early complication was treated with a radiologic approach. Six months after surgery, patient had no more symptoms. PVA management remains a surgical challenge for surgeon, for timing and type of treatment. PMID:24456867

Levi Sandri, Giovanni Battista; Sulpice, Laurent; Rayar, Michel; Bosquet, Elise; Boudjema, Karim; Meunier, Bernard

2014-07-01

160

Warm streaks in the U.S. temperature record: What are the chances?  

NASA Astrophysics Data System (ADS)

A recent observation in NOAA's National Climatic Data Center's monthly assessment of the state of the climate was that contiguous U.S. average monthly temperatures were in the top third of monthly ranked historical temperatures for 13 straight months from June 2011 to June 2012. The chance of such a streak occurring randomly was quoted as (1/3)13, or about one in 1.6 million. The streak continued for three more months before the October 2012 value dropped below the upper tercile. The climate system displays a degree of persistence that increases this probability relative to the assumption of independence. This paper puts forth different statistical techniques that more accurately quantify the probability of this and other such streaks. We consider how much more likely streaks are when an underlying warming trend is accounted for in the record, the chance of streaks occurring anywhere in the record, and the distribution of the record's longest streak.

Craigmile, Peter F.; Guttorp, Peter; Lund, Robert; Smith, Richard L.; Thorne, Peter W.; Arndt, Derek

2014-05-01

161

On the nature and visibility of crater-associated streaks on Mars  

NASA Technical Reports Server (NTRS)

The paper considers Mariner 9 and Viking data that contradict Kuzmin's (1975) hypothesis that all crater-associated wind streaks on Mars are depositional and consist of unresolved barchan-like dunes. According to Kuzmin's hypothesis, any streak can appear either bright or dark relative to its surroundings depending on the sun's position. The spacecraft images, however, show examples of dark and light streaks visible at the same azimuth angle of the sun. Evidence that bright and dark streaks differ both in morphology and in character is considered. It is suggested that the common ragged dark streaks are probably erosion scars while most bright streaks probably represent accumulations of bright dust-storm fallout.

Veverka, J.; Thomas, P.; Sagan, C.

1978-01-01

162

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

163

Leg wound infections following greater saphenous vein harvesting: minimally invasive vein harvesting versus conventional vein harvesting.  

PubMed

Wound complications associated with long incisions used to harvest the greater saphenous vein are common and well documented. We compared leg wound infection rates, wound healing disturbances (WHDs), length of vein harvested, vein harvest time, and total surgical time between minimally invasive saphenous vein harvesting (MIVH) and conventional vein harvesting (CVH) techniques. This meta-analysis showed a significant reduction in wound infections in favor of the MIVH group (odds ratio = 0.19; 95% confidence interval = 0.14-0.25) and a significant reduction in WHDs in favor of the MIVH group (odds ratio = 0.26; 95% confidence interval = 0.20-0.34). The MIVH and CVH techniques are equivalent with respect to saphenous vein harvest time, saphenous vein harvest length, and total surgical time. A visual inspection of "funnel" plots suggests a mild to moderate publication bias. This meta-analysis suggests that leg wound infections and wound healing disturbances are reduced using MIVH techniques. PMID:18815201

Reed, James F

2008-12-01

164

Density-driven spontaneous streak segregation patterns in a thin rotating drum  

NASA Astrophysics Data System (ADS)

Granular mixtures may segregate because of external driving forces, which play an important role in industry and geophysics. We investigate experimentally the mechanism of density-driven spontaneous streak segregation patterns in a thin rotating drum. We find that a spontaneous streak segregation pattern can occur in such a system, which we call a D-system. A phase diagram identifies three segregation pattern regimes in this study: the mixing regime, the core segregation regime, and the streak segregation regime.

Liao, C. C.; Hsiau, S. S.; Nien, H. C.

2014-06-01

165

Development of picosecond time resolution optical and X-ray streak cameras  

Microsoft Academic Search

We describe the development of an optical and an X-ray streak camera with picosecond time resolution. The entire peripheral\\u000a electronics and testing systems have been developed indigenously. Both the streak cameras provide ? 15 mm\\/1 ns streak rate\\u000a with a sweep voltage of ? 1 kV amplitude and rise time of 1 ns. The time and spatial resolution of the

V N Rai; M Shukla; H C Pant; D D Bhawalkar

1995-01-01

166

Surface properties of the Pettit wind streak on Mars Implications for sediment transport  

NASA Astrophysics Data System (ADS)

Satellite imagery of the Pettit streak on Amazonis Planitia are discussed in terms of the details of wind streaks and their associated sediments. Increasingly more detailed blow-ups of the available imagery demonstrate that the Pettit streak holds both a Type I bright streak (at the crater rim) and a Type II dark streak beginning at the dark patch within the crater. The lowest albedos measured, 0.20-0.22, are associated with the highest thermal inertia, indicative of grain diameters similar to medium sand, i.e., ranging from 250-350 microns. The brightest portions of the streak have albedos over 0.26 and a low thermal inertia, in the range 3-4, which implies the presence of fine-grained sand, diameters from 50-100 microns. The particle grains are less than 50 microns diameter in the surrounding plains, which have an approximately uniform albedo (0.27) and a thermal inertia of 2.5, characteristics typical of silt or clay. Current streak models describe the dark streak well, but do not account for the bright streak, which may be optically thick patches of very fine dust.

Zimbelman, J. R.

1986-04-01

167

Surface properties of the Pettit wind streak on Mars Implications for sediment transport  

NASA Technical Reports Server (NTRS)

Satellite imagery of the Pettit streak on Amazonis Planitia are discussed in terms of the details of wind streaks and their associated sediments. Increasingly more detailed blow-ups of the available imagery demonstrate that the Pettit streak holds both a Type I bright streak (at the crater rim) and a Type II dark streak beginning at the dark patch within the crater. The lowest albedos measured, 0.20-0.22, are associated with the highest thermal inertia, indicative of grain diameters similar to medium sand, i.e., ranging from 250-350 microns. The brightest portions of the streak have albedos over 0.26 and a low thermal inertia, in the range 3-4, which implies the presence of fine-grained sand, diameters from 50-100 microns. The particle grains are less than 50 microns diameter in the surrounding plains, which have an approximately uniform albedo (0.27) and a thermal inertia of 2.5, characteristics typical of silt or clay. Current streak models describe the dark streak well, but do not account for the bright streak, which may be optically thick patches of very fine dust.

Zimbelman, J. R.

1986-01-01

168

Attosecond-streaking time delays: Finite-range property and comparison of classical and quantum approaches  

NASA Astrophysics Data System (ADS)

We theoretically study time delays obtained using the attosecond-streaking technique. To this end, we compute time delays by numerically solving the corresponding time-dependent Schrödinger equation and analyze the delays using two classical methods, namely, a perturbative approach and a full numerical solution of Newton's equation describing the motion of the photoelectron in the continuum. A good agreement between the quantum streaking results and those from the full classical solution is found. This indicates that the streaking time delay arises from the continuum dynamics of the electron in the coupled potential of the Coulomb and streaking fields, while the transition of the photoelectron from the bound state to the continuum occurs instantaneously upon absorption of the photon. We further analyze the variation of the time delay with respect to the delay between the ionizing XUV pulse and a long streaking pulse, its dependence on the polarization direction of the streaking pulse, and the influence of the shape of the streaking pulse and/or additional static electric fields on the numerically obtained time delays. The results are interpreted based on the previously revealed property that the attosecond-streaking time delay depends on the finite region in space over which the electron propagates between its instant of transition into the continuum and the end of the streaking pulse.

Su, Jing; Ni, Hongcheng; Becker, Andreas; Jaro?-Becker, Agnieszka

2014-01-01

169

Defrosting Polar Dunes--Dark Spots and Wind Streaks  

NASA Technical Reports Server (NTRS)

The first time that the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC)team saw dark spots on defrosting dune surfaces was in August and September of 1998. At that time, it was the north polar seasonal frost cap that was subliming away (more recent images from 1999 have shown the south polar frosts). This picture (above) shows a small portion of the giant dune field that surrounds the north polar region, as it appeared on August 23, 1998. At the time, it was early northern spring and the dunes were still covered with winter frost.

Dark spots had appeared on the north polar dunes, and many of them exhibited a radial or semi-radial pattern of dark streaks and streamers. At first, there was speculation that the streaks indicated that the defrosting process might somehow involve explosions! The dark spots seemed to resemble small craters with dark, radial ejecta. It seemed possible that frozen carbon dioxide trapped beneath water ice might somehow heat up, turn to gas, expand, and then 'explode' in either a small blast or at least a 'puff' of air similar to that which comes from the blowhole of a surfacing whale or seal.

The image shown here changed the earlier impression. The dark spots and streaks do not result from explosions. The spots--though not well understood--represent the earliest stages of defrosting on the sand dunes. The streaks, instead of being caused by small explosions, are instead the result of wind. In this picture, the fine, dark streaks show essentially identical orientations from spot to spot (e.g., compare the spots seen in boxes (a) and (b)). Each ray of dark material must result from wind blowing from a particular direction--for example, all of the spots in this picture exhibit a ray that points toward the upper left corner of the image, and each of these rays indicates the same wind regime. Each spot also has a ray pointing toward the lower right and top/upper-right. These, too, must indicate periods when the wind was strong enough to move materials, consistently, in only one direction.

The sand that makes up the north polar dunes is dark. Each spot and streak is composed of the dune sand. The bright surfaces are all covered with frost. This picture is located near 76.9oN, 271.2oW, in the north polar sand sea. Illumination is from the lower left. The 200 meter scale also indicates a distance of 656 feet.

Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

1999-01-01

170

Evaluation of the DipStreak, a New Device with an Original Streaking Mechanism for Detection, Counting, and Presumptive Identification of Urinary Tract Pathogens  

PubMed Central

DipStreak is a new urine culture device with two types of agar attached back-to-back on a plastic paddle. It combines dip-slide technology and an original streaking inoculation mechanism, allowing for bacterial counting and colony isolation. The performance of the DipStreak device with two different medium formulations, CHROMagar and MacConkey media in study A and UriSelect 3 and MacConkey media in study B, was evaluated and compared to that of the reference streak method by using plates of cystine-lactose-electrolyte-deficient (CLED) agar, tryptic soy agar with 5% sheep blood, and UriSelect 3 medium. In study A, 2,000 urine specimens were processed and 511 cultures were found positive. The DipStreak device and the UriSelect 3 and CLED medium plates gave the same detection rate, 99.7%. For the direct identification of Escherichia coli, Proteus mirabilis, and Enterococcus sp. isolates, the DipStreak device and the UriSelect 3 medium plate showed overall sensitivities of 97 and 93.4%, respectively. In study B, 3,000 urine specimens were processed and 714 cultures were found positive. The DipStreak device and the UriSelect 3 and CLED medium plates gave detection rates of 99.4, 99.9, and 99.2%, respectively. For the direct identification of E. coli, P. mirabilis, and Enterococcus sp. isolates, the DipStreak device and the UriSelect 3 medium plate showed overall sensitivities of 88 and 94.4%, respectively. In conclusion, the DipStreak device with both medium formulations represents an attractive and excellent screening method for the reliable detection, counting, and presumptive identification of urinary tract pathogens. It enables bedside urine inoculation and provides a valid means of transporting the sample back to the laboratory, decreasing drastically the rate of false-positive results due to bacterial overgrowth and reducing associated costs.

Scarparo, Claudio; Piccoli, Paola; Ricordi, Paolo; Scagnelli, Mariuccia

2002-01-01

171

Streaked radiography measurements of convergent ablator performance (invited)  

SciTech Connect

The velocity and remaining ablator mass of an imploding capsule are critical metrics for assessing the progress toward ignition of an inertially confined fusion experiment. These and other ablator rocket parameters have been measured using a single streaked x-ray radiograph. A regularization technique has been used to determine the ablator density profile {rho}(r) at each time step; moments of {rho}(r) then provide the areal density, average radius, and mass of the unablated, or remaining, ablator material, with the velocity determined from the time derivative of the average radius. The technique has been implemented on experiments at the OMEGA laser facility.

Hicks, D. G. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Spears, B. K.; Braun, D. G.; Olson, R. E.; Sorce, C. M.; Celliers, P. M.; Collins, G. W.; Landen, O. L. [Sandia National Laboratory, Albuquerque, New Mexico 87185 (United States)

2010-10-15

172

Picotron 100 streak tubes as a 150-channel photometer  

SciTech Connect

The characterization of a streak camera based upon Picotron 100 tube types is given. Both a large (30 cm 1 x 10 cm dia.) and a small (18 cm 1 x 5 cm dia.) version of this design has been tested. Over 150 channels of information are simultaneously time resolved with system S.N.R. of 3 at 100 picosecond time resolution without post intensification. Absolute photometric evaluation is given in the dynamic mode, i.e. while operating in the picosecond time domain. Such quantitative data has been lacking in the past, particularly for multiple channel applications.

Majumdar, S.; Weiss, P.B.; Black, J.P.

1982-01-01

173

Streaks of Aftershocks Following the 2004 Sumatra-Andaman Earthquake  

NASA Astrophysics Data System (ADS)

Five years after the devastating 26 December, 2004 M 9.3 Sumatra-Andaman earthquake, regional and global seismic networks have recorded tens of thousands of aftershocks. We use bulletin data from the International Seismological Centre (ISC) and the National Earthquake Information Center (NEIC), and waveforms from IRIS, to relocate more than 20,000 hypocenters between 1964 and 2008 using teleseimic cross-correlation and double-difference methods. Relative location uncertainties of a few km or less allow for detailed analysis of the seismogenic faults activated as a result of the massive stress changes associated with the mega-thrust event. We focus our interest on an area of intense aftershock activity off-shore Banda Aceh in northern Sumatra, where the relocated epicenters reveal a pattern of northeast oriented streaks. The two most prominent streaks are ~70 km long with widths of only a few km. Some sections of the streaks are formed by what appear to be small, NNE striking sub-streaks. Hypocenter depths indicate that the events locate both on the plate interface and in the overriding Sunda plate, within a ~20 km wide band overlying the plate interface. Events on the plate interface indicate that the slab dip changes from ~20° to ~30° at around 50 km depth. Locations of the larger events in the overriding plate indicate an extension of the steeper dipping mega thrust fault to the surface, imaging what appears to be a major splay fault that reaches the surface somewhere near the western edge of the Aceh basin. Additional secondary splay faults, which branch off the plate interface at shallower depths, may explain the diffuse distribution of smaller events in the overriding plate, although their relative locations are less well constrained. Focal mechanisms support the relocation results. They show a narrowing range of fault dips with increasing distance from the trench. Specifically, they show reverse faulting on ~30° dipping faults above the shallow (20°) dipping plate interface. The observation of active splay faults associated with the mega thrust event is consistent with co- and post-seismic motion data, and may have significant implications on the generation and size of the tsunami that caused 300,000 deaths.

Waldhauser, F.; Schaff, D. P.; Engdahl, E. R.; Diehl, T.

2009-12-01

174

Yellow intraocular filters in fishes.  

PubMed

Yellow intraocular filters are common among the teleosts, especially highly diurnal species. This yellow pigmentation may be uniform, more dense dorsally, or localized to a narrow dorsal ring near the limbus. Certain species possess occlusable yellow corneas and can vary the corneal colour in response to the level of illumination. Yellow lenses and corneas function as hi-pass filters, with the cutoff points varying depending on species. Thus, the amount of short-wavelength light reaching the retina can be regulated. Three distinct yellow pigments may be present in each of the lens, cornea and the retina of certain South American cichlids. The spectral absorbance of the yellow corneal pigment bears a close resemblance to that of beta-carotene. Possible functions of these yellow filters are: a reduction in chromatic aberration, the reduction of glare and dazzle, the improvement of detail by the absorption of "blue haze", the improvement of contrast vision, and the rendering of bioluminescence more conspicuous. Yellow intraocular filters may result in a loss of scotopic sensitivity due to absorption of short wavelengths. Various adaptations in diurnal teleosts to avoid the loss of sensitivity resulting from a yellow filter are presented. Normally, bottom-dwelling fishes lack yellow filters. These filters cause the effective absorbance maximum of scotopic visual pigments to be shifted to longer wavelengths. No correlation has been found between the presence of such filters and the water colour, diet or spectral absorbance of the visual pigment. A possible explanation for the lack of correlation with visual pigments is discussed. Investigation of cone spectral sensitivities may possibly reveal such a correlation. PMID:6398222

Heinermann, P H

1984-01-01

175

Multiple vortex vein ampulla varicosities  

PubMed Central

Vortex vein ampulla varicosities are asymptomatic, harmless, findings in the retina. They are incidentally picked up on routine eye examination or when presenting for unrelated ocular symptoms. Clinicians and other eye care professionals unaware of this condition may be alarmed and may subject patients to unnecessary anxiety and expensive investigations. We present a rare case of varicosity of two vortex veins involving one quadrant of the retina. We have also shown simple clinical methods of establishing the diagnosis of vortex vein varicosity.

Vahdani, K; Kapoor, B; Raman, V S

2010-01-01

176

Popliteal vein aneurysm.  

PubMed

Although popliteal venous aneurysms are uncommon, they are also potentially fatal because they can cause a pulmonary embolism. The authors report a case of a popliteal vein aneurysm in a healthy, asymptomatic 32-year-old patient as well as a review of the literature. Popliteal venous aneurysms are a rare but treatable cause of recurrent pulmonary embolism, with their true incidence probably being underestimated. Whenever possible, we recommend early surgical repair of both symptomatic and asymptomatic popliteal venous aneurysms because they are associated with an ill-defined risk of pulmonary embolism and death if left untreated. PMID:20103062

Roche-Nagle, Graham; Wooster, Douglas; Oreopoulos, George

2010-01-01

177

Symptomatic popliteal vein aneurysm.  

PubMed

Popliteal vein aneurysms (PVAs) can have serious consequences, including pulmonary embolism and death. We report a case of PVA in a previously healthy 58-year-old female with a history of pain in her right popliteal fossa for the past 3 years. Patient had no history of trauma or claudication of the right leg. Following a preoperative venogram to confirm the diagnosis, the PVA was dissected circumferentially through a posterior incision. The aneurysm was resected and repaired with lateral venorrhaphy. Patient had an uneventful recovery. Due to the possibility of severe consequences, if left untreated, early surgical repair is highly recommended whether the patient has symptoms or not. PMID:24420057

Premaratne, Shyamal; Tan, Tze-Woei; Coulter, Amy H; Doumite, Darin; Zhang, Wayne W

2014-04-01

178

Pattern compensation in Drosophila wing vein development  

Microsoft Academic Search

Much interest in developmental genetics has focused on the formation of patterns. Using the wing vein pattern of Drosophila melanogasler as our model system, we show that vein placement is essentially independent of cell lineage. In studying vein placement in a variety of wing vein mutants, we observed that the position of a vein can move to compensate for the

James N Thompson; Joe V Toney; G Bradley Schaefer

1980-01-01

179

Microprocessor-controlled wide-range streak camera  

NASA Astrophysics Data System (ADS)

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.

Lewis, Amy E.; Hollabaugh, Craig

2006-09-01

180

Recurrent varicose veins following high ligation of long saphenous vein: a duplex ultrasound study  

Microsoft Academic Search

Duplex scanning was used to study recurrent varicose veins in 244 limbs with previous high ligation of the long saphenous vein. The recurrent varicose veins were classified into two types according to the presence or absence of a residual long saphenous vein. Varicose veins with a residual long saphenous vein (type I) occurred in 168 limbs (68.9%). A residual long

Y. Tong; J. Royle

1995-01-01

181

Performances of a solid streak camera in standard CMOS technology with nanosecond time resolution  

Microsoft Academic Search

The classical streak cameras use a vacuum tube making thus fragile, cumbersome and expensive. The FAst MOS Imager (FAMOSI) project consists in reproducing completely this streak camera functionality with a single CMOS chip. The advantages of on-chip functionalities lead to a power reduction, a lower cost and miniaturization. In this paper, we show the capabilities of a prototype fabricated in

Frédéric Morel; Chantal-Virginie Zint; Wilfried Uhring; Jean-Pierre Le Normand

2008-01-01

182

Effects of Variations in the Photocathode Voltages of Electronic Streak Cameras.  

National Technical Information Service (NTIS)

Electronic streak cameras are used to record subnanosecond data at the Nevada Test Site. It has been found that externally induced variations in the photocathode voltage of the streak tube can produce both temporal and spatial errors on the output image. ...

M. W. Bowers G. L. Biggs J. J. Ronchetto A. T. Teruya

1988-01-01

183

Streamwise streaks and secondary instability in a two-dimensional bent channel  

NASA Astrophysics Data System (ADS)

Streamwise streaks generated from a pair of oblique waves and secondary instability of the streaks are studied in a two-dimensional bent channel. Nonlinear parabolized stability equations (NPSE) are employed to investigate streamwise streaks and vortices. A pair of oblique waves from linear stability analysis is imposed as initial disturbances. Generation of streamwise streaks and vortices and subsequent development are described in detail. The case of plane channel is also studied to provide comparable data. Through comparison, the effect of bent region is clearly highlighted. Results of parametric studies to examine the effect of Reynolds number, radius of curvature, and bent angle are also given and discussed in detail. Secondary instability analysis for the modified mean flow due to the streamwise streaks is carried out by solving a two-dimensional eigenvalue problem. Several unstable modes which can be classified into fundamental and subharmonic mode of secondary instability are identified. Among several unstable modes, two modes are turned out to be dominant modes. Details on these two modes including generation mechanism, typical pattern, and dependency on wave number and streak amplitude are discussed. It is found that the presence of bent channel can lead to early oblique-mode breakdown via strong growth of the streamwise streaks due to the curved section. Such large amplitude of streaks and its secondary instability eventually could trigger transition even for small amplitude oblique waves at subcritical channel Reynolds numbers.

Park, Donghun; Park, Seung O.

2014-06-01

184

Temporal characteristics of picosecond continuum as revealed by a two-dimensional analysis of streak images  

NASA Astrophysics Data System (ADS)

A two-dimensional analysis has been made for streak images of picosecond continua generated in D 2O, CCl 4, saturated aqueous solution of KDP, H 3PO 4 and quartz block. Their pulse width and distribution of arrival time at the streak camera were determined as a function of the wavelength.

Masuhara, Hiroshi; Miyasaka, Hiroshi; Karen, Akiya; Uemiya, Taka; Mataga, Noboru; Koishi, Musubu; Takeshima, Akira; Tsuchiya, Yutaka

1983-02-01

185

Infrared imaging of varicose veins  

NASA Astrophysics Data System (ADS)

It has been established that varicose veins are better visualized with infrared photography. As near-infrared films are nowadays hard to get and to develop in the digital world, we investigated the use of digital photography of varicose veins. Topics that are discussed are illumination setup, photography and digital image enhancement and analysis.

Noordmans, Herke Jan; de Zeeuw, Raymond; Verdaasdonk, Ruud M.; Wittens, Cees H. A.

2004-06-01

186

Infrared imaging of varicose veins  

Microsoft Academic Search

It has been established that varicose veins are better visualized with infrared photography. As near-infrared films are nowadays hard to get and to develop in the digital world, we investigated the use of digital photography of varicose veins. Topics that are discussed are illumination setup, photography and digital image enhancement and analysis.

Herke Jan Noordmans; Raymond de Zeeuw; Ruud M. Verdaasdonk; Cees H. A. Wittens

2004-01-01

187

Hepatic vein obstruction (Budd-Chiari)  

MedlinePLUS

Hepatic vein obstruction is a blockage of the hepatic vein, which carries blood away from the liver. ... Hepatic vein obstruction prevents blood from flowing out of the liver and back to the heart. This blockage can ...

188

How Is Deep Vein Thrombosis Treated?  

MedlinePLUS

... the NHLBI on Twitter. How Is Deep Vein Thrombosis Treated? Doctors treat deep vein thrombosis (DVT) with medicines and other devices and therapies. ... wear compression stockings. Rate This Content: Deep Vein Thrombosis Clinical Trials Clinical trials are research studies that ...

189

Selecting Superior Yellow Birch Trees.  

National Technical Information Service (NTIS)

The report describes procedures to follow and characteristics to consider in selecting superior yellow birch trees. The first selection should be on the basis of tree quality. Characteristics to consider are as follows: for the stem - straightness, roundn...

K. E. Clausen R. M. Godman

1967-01-01

190

Yellow Fever Virus Infection  

PubMed Central

A sequential and quantitative survey of brain and liver of suckling mice for infective virus and complement-fixing antigen, after infection with yellow fever virus, showed that while there was progressive increase of infective virus content in both organs, only the brain showed a corresponding rise in CF antigen. Histopathological examination revealed that the liver was not significantly involved. The target organ was the brain, where the progressive pathological changes culminated in an acute encephalitis by the 3rd day of experiment. Organ destruction began with the molecular layer of the grey matter. But by the 4th day after infection the entire cerebral cortex was involved. At the initial stages the hippocampus was particularly affected. Tissue damage did not appear to be entirely due to the differential quantitative localization of infective virus. It was hypothesized that the CF antigen acting singly or in conjunction with some hypothetical proteins may be principally involved in the pathological outcome of the disease. ImagesFigs. 7-9Figs. 3-6

David-West, Tam. S.; Smith, J. A.

1971-01-01

191

Turnip Yellow Mosaic Virus  

NASA Technical Reports Server (NTRS)

The bumpy exterior of the turnip yellow mosaic virus (TYMV) protein coat, or capsid, was defined in detail by Dr. Alexander McPherson of the University of California, Irvin using proteins crystallized in space for analysis on Earth. TYMV is an icosahedral virus constructed from 180 copies of the same protein arranged into 12 clusters of five proteins (pentamers), and 20 clusters of six proteins (hexamers). The final TYMV structure led to the unexpected hypothesis that the virus releases its RNA by essentially chemical-mechanical means. Most viruses have fairly flat coats, but in TYNV, the fold in each protein, called the jellyroll, is clustered at the points where the protein pentamers and hexamers join. The jellyrolls are almost standing on end, producing a bumpy surface with knobs at all of the pentamers and hexamers. At the inside surface of the pentamers is a void that is not present at the hexamers. The coating had been seen in early stuties of TYMV, but McPherson's atomic structure shows much more detail. The inside surface is strikingly, and unexpectedly, different than the outside. While the pentamers contain a central void on the inside, the hexameric units contain peptides linked to each other, forming a ring or, more accurately, rings to fill the void. Credit: Dr. Alexander McPherson, University of California, Irvine

2000-01-01

192

Aerosols Over Yellow Sea Sediments  

NASA Technical Reports Server (NTRS)

This SeaWiFS image shows complex phytoplankton distribution patterns in the Bohai and Yellow seas. A wide band of brownish water along the coast north and south of the mouth of the Yangtze River indicates a heavy load of suspended sediment. The air over eastern central China and the Yellow Sea is thick with aerosols. Farther north over the Manchurian Plain and Greater Khingan Range, the air is much clearer.

2002-01-01

193

Varicose Veins - Multiple Languages: MedlinePlus  

MedlinePLUS

... sharing features on this page, please enable JavaScript. Varicose Veins - Multiple Languages Russian (???????) Spanish (español) Russian (???????) Concerns and Discomforts of Pregnancy (Varicose Veins) English ???????? ? ?????????? ??? ???????????? - ?????????? ???? - ...

194

Genetic variants of Banana streak virus in Mauritius.  

PubMed

Genetic variations among isolates of Banana streak virus (BSV) were assessed using two sets of primers. The virus, found in banana accessions in Mauritius, was compared to a Nigerian isolate from cultivar Obino l'Ewai (BSOEV). On the basis of the observed size of amplicons, some Mauritius strains were different from l'Ewai BSOEV. Both Southern blot hybridization and the nucleotide sequences of the PCR products confirmed that they were of episomal BSV origin. An isolate of sugarcane bacilliform virus (SCBV) was found to be also very similar to the BSV isolated from banana samples. Nucleotide sequence analysis showed that even the same size PCR products had differing sequences. The dendrogram placed the isolates from Mauritius in a cluster separate from BSV and SCBV from other geographical locations. PMID:16143419

Jaufeerally-Fakim, Y; Khorugdharry, Ashwin; Harper, Glyn

2006-01-01

195

Attosecond Streaking in the Low-Energy Region  

NASA Astrophysics Data System (ADS)

The low-energy photonelectron (PEs) ionized by a single attosecond pulse can be controlled by a moderately intense infrared field (IR). The electric field of the IR pulse can drive part of the PEs back to the parent ion and induce multiple rescattering of the electrons. Interesting interference patterns are observed in the photoelectron momentum distributions, which are formed by the rescattered electrons and the directly ionized PEs. By analyzing the interference patterns with a simple semiclassical model, which considers the particular PE trajectories incorporating the rescattering with the core, we demonstrate that the low-energy attosecond streaking offers a promising method of holographic imaging of atomic and molecular potential. In addition, we show that neither strong field approximation (SFA) or Coulomb-Volkov approximation (CVA) is able to reproduce these interesting structures at the low energy region.

Geng, Ji-Wei; Peng, Liang-You; Xu, Ming-Hui; Gong, Qihuang

2014-04-01

196

Leiomyosarcoma of the Cephalic Vein  

PubMed Central

A 78-year-old man presented with a mass on his right forearm. A 5 x 4 x 3 cm3 mass was excised en bloc with extensions along the course of the cephalic vein and its tributaries. Histological analysis revealed the mass to be a high-grade leiomyosarcoma arising within the cephalic vein. The tumour was controlled locally and distally until the patient died 10 months later, from an unrelated illness. This is the first reported case of a venous leiomyosarcoma of the cephalic vein.

Dixon, John H.

2001-01-01

197

Evaluation of the DipStreak, a new device with an original streaking mechanism for detection, counting, and presumptive identification of urinary tract pathogens.  

PubMed

DipStreak is a new urine culture device with two types of agar attached back-to-back on a plastic paddle. It combines dip-slide technology and an original streaking inoculation mechanism, allowing for bacterial counting and colony isolation. The performance of the DipStreak device with two different medium formulations, CHROMagar and MacConkey media in study A and UriSelect 3 and MacConkey media in study B, was evaluated and compared to that of the reference streak method by using plates of cystine-lactose-electrolyte-deficient (CLED) agar, tryptic soy agar with 5% sheep blood, and UriSelect 3 medium. In study A, 2,000 urine specimens were processed and 511 cultures were found positive. The DipStreak device and the UriSelect 3 and CLED medium plates gave the same detection rate, 99.7%. For the direct identification of Escherichia coli, Proteus mirabilis, and Enterococcus sp. isolates, the DipStreak device and the UriSelect 3 medium plate showed overall sensitivities of 97 and 93.4%, respectively. In study B, 3,000 urine specimens were processed and 714 cultures were found positive. The DipStreak device and the UriSelect 3 and CLED medium plates gave detection rates of 99.4, 99.9, and 99.2%, respectively. For the direct identification of E. coli, P. mirabilis, and Enterococcus sp. isolates, the DipStreak device and the UriSelect 3 medium plate showed overall sensitivities of 88 and 94.4%, respectively. In conclusion, the DipStreak device with both medium formulations represents an attractive and excellent screening method for the reliable detection, counting, and presumptive identification of urinary tract pathogens. It enables bedside urine inoculation and provides a valid means of transporting the sample back to the laboratory, decreasing drastically the rate of false-positive results due to bacterial overgrowth and reducing associated costs. PMID:12037082

Scarparo, Claudio; Piccoli, Paola; Ricordi, Paolo; Scagnelli, Mariuccia

2002-06-01

198

How Are Varicose Veins Diagnosed?  

MedlinePLUS

... pain you're having. Diagnostic Tests and Procedures Duplex Ultrasound Your doctor may recommend duplex ultrasound to check blood flow in your veins and to look for blood clots. Duplex ultrasound combines traditional with Doppler ultrasound. Traditional ultrasound ...

199

Diagnosis of Deep Vein Thrombosis.  

National Technical Information Service (NTIS)

Clinical and laboratory diagnostic methods were studied in 301 consecutive patients with suspected deep vein thrombosis (DVT). Unexpectedly, phlebography (the reference method) was found to cause DVT in estimated 48 % of patients without initial DVT. Usin...

C. G. Olsson

1979-01-01

200

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

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

201

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

202

Smog Yellows Taj Mahal  

NASA Technical Reports Server (NTRS)

Built as a monument to the favorite wife of the Mughal Emperor Shah Jahan, the Taj Mahal has watched over the city of Agra, India, since the mid-seventeenth century with its pillars of gleaming white marble. By the spring of 2007, however, one of the world's most visited landmarks was turning yellow, and a panel of India's parliament had little trouble identifying the culprit: pollution. The panel blamed particles of soot and dirt suspended high in the atmosphere for the Taj Mahal's dinginess. The Taj Mahal's home, Agra, sits not far from the base of the Himalaya, and smog regularly collects along the southern side of the mountain range. On May 16, 2007, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured this image of the area around Agra, India. The closeup image shows the immediate vicinity of the Taj Majal. The larger image shows the surrounding area. In both pictures, dingy, gray-beige haze obscures the satellite's view of the land surface. India had tried to minimize the adverse impact of air pollution on the famous landmark. According to the BBC, in the late 1990s, India's Supreme Court ordered the closure of thousands of iron foundries and kilns that had belched smoke near the monument. Many of the 3 million tourists who visited the Taj Majal each year approached the monument on horse-drawn carriages or battery-operated buses as fossil-fuel-powered vehicles could not drive within 2 kilometers (1.5 miles). Since those efforts have failed to save the Taj Majal's complexion, Indian officials have considered applying a cleansing mud pack to the monument's surface to draw out the dirt. As India industrializes, smog results, and the Taj Mahal's gleaming whiteness is only one casualty. Pollution has been blamed for a decrease in Indian rice harvests, which had soared during the 'Green Revolution' of the 1960s and 1970s. Haze and dust also appear to bring on the region's monsoon rains earlier than normal.

2007-01-01

203

Enhancing the contrast of subcutaneous veins  

Microsoft Academic Search

A technique for enhancing the contrast of subcutaneous veins has been demonstrated. This technique uses a near infrared light source and one or more infrared sensitive CCD TV cameras to produce a contrast enhanced image of the subcutaneous veins. This video image of the veins is projected back onto the patient's skin using an LCD vein projector. The use of

Herbert D. Zeman; Gunnar Lovhoiden

1999-01-01

204

Palm vein authentication technology and its applications  

Microsoft Academic Search

This paper discusses the contactless palm vein authentication device that uses blood vessel patterns as a personal identifying factor. The vein information is hard to duplicate since veins are internal to the human body. The palm vein authentication technology offers a high level of accuracy, and delivers the following results: a false rejection rate (FRR) of 0.01%, and a false

Masaki Watanabe; Toshio Endoh; Morito Shiohara; Shigeru Sasaki

2005-01-01

205

Benefits of Endoscopic Vein Harvesting  

Microsoft Academic Search

.   The purpose of this study was to evaluate and compare the benefits of endoscopic saphenous vein harvesting (EVH) with the\\u000a traditional incision technique (TIT) for coronary artery bypass grafting (CABG) in respect to the technical procedure and\\u000a clinical outcome. In a prospective nonrandomized, case-matched study the greater saphenous vein was harvested for CABG in\\u000a 22 patients using the endoscopic

Bettina Marty; Ludwig Karl von Segesser; Piergiorgio Tozzi; Juan Guzmann; Philippe Frascarolo; Xavier Muller; Daniel Hayoz

2000-01-01

206

Open versus endoscopic saphenous vein harvesting: wound complications and vein quality  

Microsoft Academic Search

Background. The saphenous vein is an important conduit for coronary artery bypass grafting. Wound complications from traditional open vein harvesting occur often. Minimally invasive endoscopic saphenous vein harvesting may decrease wound complications. Vein quality may be an issue with endoscopic harvesting.Methods. We reviewed 568 patients who had bypass grafting and saphenous vein harvesting either endoscopic (group A, n = 180)

John D Crouch; Daniel P O’Hair; James P Keuler; Thomas P Barragry; Paul H Werner; Leonard H Kleinman

1999-01-01

207

Open Versus Endoscopic Saphenous Vein Harvesting: Wound Complications and Vein Quality  

Microsoft Academic Search

Background. The saphenous vein is an important con- duit for coronary artery bypass grafting. Wound compli- cations from traditional open vein harvesting occur often. Minimally invasive endoscopic saphenous vein harvest- ing may decrease wound complications. Vein quality may be an issue with endoscopic harvesting. Methods. We reviewed 568 patients who had bypass grafting and saphenous vein harvesting either endo- scopic

John D. Crouch; Daniel P. O'Hair; James P. Keuler; Thomas P. Barragry; Paul H. Werner; Leonard H. Kleinman

2010-01-01

208

Adaptive evolution by recombination is not associated with increased mutation rates in Maize streak virus  

PubMed Central

Background Single-stranded (ss) DNA viruses in the family Geminiviridae are proving to be very useful in real-time evolution studies. The high mutation rate of geminiviruses and other ssDNA viruses is somewhat mysterious in that their DNA genomes are replicated in host nuclei by high fidelity host polymerases. Although strand specific mutation biases observed in virus species from the geminivirus genus Mastrevirus indicate that the high mutation rates in viruses in this genus may be due to mutational processes that operate specifically on ssDNA, it is currently unknown whether viruses from other genera display similar strand specific mutation biases. Also, geminivirus genomes frequently recombine with one another and an alternative cause of their high mutation rates could be that the recombination process is either directly mutagenic or produces a selective environment in which the survival of mutants is favoured. To investigate whether there is an association between recombination and increased basal mutation rates or increased degrees of selection favoring the survival of mutations, we compared the mutation dynamics of the MSV-MatA and MSV-VW field isolates of Maize streak virus (MSV; Mastrevirus), with both a laboratory constructed MSV recombinant, and MSV recombinants closely resembling MSV-MatA. To determine whether strand specific mutation biases are a general characteristic of geminivirus evolution we compared mutation spectra arising during these MSV experiments with those arising during similar experiments involving the geminivirus Tomato yellow leaf curl virus (Begomovirus genus). Results Although both the genomic distribution of mutations and the occurrence of various convergent mutations at specific genomic sites indicated that either mutation hotspots or selection for adaptive mutations might elevate observed mutation rates in MSV, we found no association between recombination and mutation rates. Importantly, when comparing the mutation spectra of MSV and TYLCV we observed similar strand specific mutation biases arising predominantly from imbalances in the complementary mutations G???T: C???A. Conclusions While our results suggest that recombination does not strongly influence mutation rates in MSV, they indicate that high geminivirus mutation rates are at least partially attributable to increased susceptibility of all geminivirus genomes to oxidative damage while in a single stranded state.

2012-01-01

209

Wind streaks in Tharsis and Elysium - Implications for sediment transport by slope winds  

NASA Technical Reports Server (NTRS)

Detailed maps of wind streaks in Tharsis and Elysium have been compiled from Viking Orbiter observations spanning one complete Martian year. The streak pattern is controlled by slope winds on the central volcanoes and on the flanks of the Tharsis bulge, while the global circulation dominates in Elysium. Dust erosion by downslope winds occurs over much of Tharsis and in the vicinity of Elysium Mons; this process is effective even at the low atmospheric pressures found near the summits of the large volcanoes. Erosional streaks are largely absent in Elysium Planitia; net deposition of dust might have occurred during the period of the observations. Surface properties such as slope, thermal inertia, and roughness may influence the efficiency of slope wind production sufficiently to account for the pronounced differences in streak types and patterns present in these two regions.

Lee, S. W.; Thomas, P. C.; Veverka, J.

1982-01-01

210

Errors in Streak Photography Measurements Caused by Subject and Camera Misalighment.  

National Technical Information Service (NTIS)

Streak-camera photography can be used to determine velocity and acceleration of projectiles during impact. The values obtained from these photographs are subject to errors such as caused by the trajectory canted relative to the camera slit (aximuthal misa...

D. J. Mary

1972-01-01

211

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

SciTech Connect

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. [Lawrence Livermore National Laboratory, Livermore, California 94551-0808 (United States)

2010-10-15

212

Airbourne Visual Reconnaissance with Yellow Sunglasses.  

National Technical Information Service (NTIS)

The study investigated airborne visual reconnaissance with and without yellow sunglasses under conditions of moderate haze and high ambient, midday illumination. One group of five observers wore Bausch and Lomb Kalichrome C yellow glasses. A second group ...

D. F. McKechnie E. P. Hanavan H. C. Self J. L. Porterfield S. A. Heckart

1971-01-01

213

Development of soft x-ray streak cameras at Lawrence Livermore National Laboratory  

SciTech Connect

Soft x-ray streak cameras are used in conjunction with several instruments for the diagnostic of laser irradiated targets. A program was undertaken to develop cameras satisfying the requirements of the laser facility, to improve the reliability and performance of the camera and to reduce the level of effort required to set and operate each diagnostic. The implemented soft x-ray streak cameras can be operated either manually or automatically.

Medecki, H.; Phillips, G.E.; Bushman, J.F.

1983-06-27

214

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

PubMed Central

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.

Fabianska, Justyna; Kassier, Gunther; Feurer, Thomas

2014-01-01

215

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

216

Automatic spatial characterization of low-speed streaks from thermal images  

Microsoft Academic Search

Flow visualization is an important tool for investigating turbulent flow, and, specifically, for characterizing low-speed\\u000a streaks in the boundary layer. The span-wise spatial characteristics of these streaks are commonly extracted by human visual\\u000a inspection, which is time consuming and subject to human errors and biases. Attempts to develop automatic methods have relied\\u000a exclusively on spectral techniques, using mostly the autocorrelation

M. Zacksenhouse; G. Abramovich; G. Hetsroni

2001-01-01

217

Effect of Aging on Fatty Streak Formation in a Diet-Induced Mouse Model of Atherosclerosis  

Microsoft Academic Search

Age is considered to be a major risk factor for atherosclerosis, but it is unclear whether age has a direct effect on susceptibility to atherosclerosis. Wild-type mice develop fatty streak lesions in the aortic root only when fed a cholate-containing high fat\\/cholesterol diet. To investigate the influence of age on fatty streak formation, young (10 weeks) and old (53 weeks)

Yuhua Li; Timothy R. Gilbert; Alan H. Matsumoto; Weibin Shi

2008-01-01

218

Absence of retromandibular vein associated with atypical formation of external jugular vein in the parotid region  

PubMed Central

Veins of the head and neck exhibiting anatomical variations or malformations are clinically significant. Anatomical variation in the external jugular vein is very common. However, anatomical variation in the retromandibular vein is rare. In this paper, we report a rare case of complete absence of the retromandibular vein. In the absence of the retromandibular vein, the maxillary vein divided into anterior and posterior divisions. The posterior division joined the superficial temporal vein to form an atypical external jugular vein, and the anterior division joined the facial vein to form an anonymous vein. In clinical practice, radiologists and surgeons use the retromandibular vein as a guide to expose the branches of the facial nerve during superficial parotidectomy. Therefore, absence of the retromandibular vein is a hurdle during this procedure and may affect the venous drainage pattern from the head and neck.

Patil, Jyothsna; Swamy, Ravindra S.; D'Souza, Melanie R.; Guru, Anitha; Nayak, Satheesha B.

2014-01-01

219

Polar Dunes In Summer Exhibit Frost Patches, Wind Streaks  

NASA Technical Reports Server (NTRS)

Mars Global Surveyor passes over the north polar region of the red planet twelve times each day, offering many opportunities to observe how the polar cap frosts and dunes are changing as the days goby. Right now it is summer in the north. This picture, taken the second week of April 1999, shows darks and dunes and remnant patches of bright frost left over from the winter that ended in July 1998. Dark streaks indicate recent movement of sand. The picture covers an area only 1.4 kilometers (0.9 miles)across and is illuminated from the upper right.

Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

1999-01-01

220

Intial synchroscan streak camera imaging at the A0 photoinjector  

SciTech Connect

At the Fermilab A0 photoinjector facility, bunch-length measurements of the laser micropulse and the e-beam micropulse have been done in the past with a single-sweep module of the Hamamatsu C5680 streak camera with an intrinsic shot-to-shot trigger jitter of 10 to 20 ps. We have upgraded the camera system with the synchroscan module tuned to 81.25 MHz to provide synchronous summing capability with less than 1.5-ps FWHM trigger jitter and a phase-locked delay box to provide phase stability of {approx}1 ps over 10s of minutes. This allowed us to measure both the UV laser pulse train at 244 nm and the e-beam via optical transition radiation (OTR). Due to the low electron beam energies and OTR signals, we typically summed over 50 micropulses with 1 nC per micropulse. We also did electron beam bunch length vs. micropulse charge measurements to identify a significant e-beam micropulse elongation from 10 to 30 ps (FWHM) for charges from 1 to 4.6 nC. This effect is attributed to space-charge effects in the PC gun as reproduced by ASTRA calculations. Chromatic temporal dispersion effects in the optics were also characterized and will be reported.

Lumpkin, A.H.; Ruan, J.; /Fermilab

2008-04-01

221

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

222

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

223

Numerical Modelling of Vein Microstructures  

NASA Astrophysics Data System (ADS)

Mineral veins occur in a variety of forms (syntaxial, antitaxial, etc.), and with various microstructures (fibrous, stretched crystals, vuggy, etc.). These structures can, if correctly interpreted, provide useful insight into the geological and tectonic conditions at which the veins formed (Oliver and Bons 2001). Durney and Ramsay (1973) defined the base for the modern classification and interpretation of vein (micro-) structures. Numerical modelling, not available then, has since been added as a tool to better understand the formation of vein (micro-) structures, focussing on three aspects in particular: 1) What determines the habit of growing vein crystals? In particular, what determines the formation of a fibrous habit? (Bons 2001, Hilgers et al. 2001) 2) The formation of fibrous pressure fringes. The complex internal structures of the fringes appear mostly the result of the relative rotation of object and fringes (Koehn et al. 2001). 3) Competition between growing crystals, which for example explains the development of a conical c-axes CPO in zeolite films (Bons and Bons 2003). References: Bons, P.D. 2001. Development of crystal morphology during unitaxial growth in a progressively widening vein: I. The numerical model. Journal of Structural Geology 23, 865-872. Bons, A.J., Bons, P.D. 2003. The development of oblique preferred orientations in zeolite films and membranes. Microporous and Mesoporous Materials 62, 9-16. Durney DW, Ramsay JG (1973) Incremental strains measured by syntectonic crystal growths. In: Gravity and Tectonics (eds De Jong KA, Scholten K), John Wiley and Sons, New York, pp. 67-96. Hilgers, C., Koehn, D., Bons, P.D., Urai, J.L. 2001. Development of crystal morphology during unitaxial growth in a progressively widening vein: II. Numerical simulations of the evolution of antitaxial fibrous veins. Journal of Structural Geology 23, 873-885. Koehn, D., Aerden, D.G.A.M., Bons, P.D., Passchier, C.W. 2001. Computer experiments to investigate complex fibre patterns in natural antitaxial strain fringes. Journal of Metamorphic Geology 19, 217-232. Oliver, N.H.S., Bons, P.D. 2001. Mechanisms of fluid flow and fluid-rock interaction in fossil metamorphic-hydrothermal systems inferred from vein-wallrock patterns, geometry, and microstructure. Geofluids 1, 137-163.

Bons, P. D.

2005-12-01

224

Biodiesel from Yellow Mustard Oil.  

National Technical Information Service (NTIS)

The goals of this project were to evaluate locally developed yellow mustard cultivars, experiment with the biodiesel made from them through stationary engine and on-road testing and to sponsor and host the tenth biennial bioenergy conference. A 2001 Volks...

C. Peterson J. Thompson

2005-01-01

225

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

226

Abnormal continuation of umbilical vein into extra-hepatic portal vein: Report of three cases.  

PubMed

Anomalies of the umbilical venous system are perplexing essentially due to dissection errors and vascular connection delineation failure. Continuation of umbilical vein into the extra-hepatic portal vein is classified as group IV umbilical vein anomaly and involves the vitelline vein or its remnants. Despite this categorization most examiners ascribe fetal extra hepatic abdominal vascular abnormality as an umbilical vein anomaly. Since these anomalies involve vitelline vein, the term "umbilical vein anomaly" is inappropriate and should be referred to as "vitelline vein abnormalities". Vitelline vein abnormalities are exceedingly rare and to the best of our knowledge only three cases have been reported prenatally. We report three cases presenting with intrauterine fetal demise and on perinatal autopsy demonstrating aneurysmally dilated group IV umbilical vein anomaly. Review of the literature, embryological basis and clinical implications of persistent vitelline vein and its varix are discussed. PMID:24712478

Jaiman, Sunil; Nalluri, Hima Bindu

2013-12-01

227

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

228

Biventricular Pacemaker Implantation via the Femoral Vein  

PubMed Central

We report the case of biventricular pacemaker implantation via the femoral vein, in a patient with impossibility of using standard superior vein approach and a contraindication to epicardial lead placement.

Agosti, Sergio; Brunelli, Claudio; Bertero, Giovanni

2012-01-01

229

Minimally invasive saphenous vein harvesting  

Microsoft Academic Search

Background. Minimally invasive techniques to harvest the saphenous vein for coronary artery bypass grafting continue to improve and evolve. Smaller cutaneous incisions have been shown to decrease postoperative discomfort and improve healing. We describe a technique involving carbon dioxide insufflation and endoscopic dissection to allow easier and atraumatic dissection.Methods. The VasoView endoscope system (Origin Medsystems, Inc) was used to harvest

Rohinton J Morris; Michael T Butler; Louis E Samuels

1998-01-01

230

Vascular Remodeling in Varicose Veins  

Microsoft Academic Search

The present study describes the histopathologic aspects of varicose (n=29; mean age, 52 ± 12 years) and normal saphenous veins (n=17; mean age, 51 ± 12 years) of patients from a similar age group. We focused on the changes that occur in the circular layer of the venous wall. We examined the venous walls by light microscopy and transmission electronmicroscopy.

Mark M. Kockx; Michiel W. M. Knaapen; Hilde E. Bortier; Kristel M. Cromheeke; Odile Boutherin-Falson; Michel Finet

1998-01-01

231

Analysis of Yellow Sea circulation  

Microsoft Academic Search

Some features of the circulation in the Yellow Sea (hereafter referred to as YS) in the cold season (mid-November through\\u000a mid-April) are analyzed emphatically by using the observations of several large-scale surveys in recent years together with\\u000a historical data. Compared with the previous studies, a wealth of observed data have firstly been used in this study to further\\u000a discuss the

Jiayie Zang; Yuxiang Tang; Emei Zou; Heung-Jae Lie

2003-01-01

232

Surgical Access to Jejunal Veins for Local Thrombolysis and Stent Placement in Portal Vein Thrombosis  

SciTech Connect

Portal vein thrombosis is an infrequent entity, which may cause high morbidity and mortality. We report a case of portal vein thrombosis due to benign stenosis following partial pancreatoduodenectomy with segmental replacement of the portal vein by a Gore-tex graft. Using a surgical access to jenunal veins, local thrombolysis, mechanical fragmentation of thrombus, and stent placement were successfully performed.

Schellhammer, Frank, E-mail: frank.schellhammer@med.uni-duesseldorf.d [University Hospital Duesseldorf, Institute of Diagnostic Radiology (Germany); Esch, Jan Schulte am [University Hospital Duesseldorf, Department of General, Visceral and Pediatric Surgery (Germany); Hammerschlag, Sascha [University Hospital Duesseldorf, Institute of Diagnostic Radiology (Germany); Knoefel, Wolfram Trudo [University Hospital Duesseldorf, Department of General, Visceral and Pediatric Surgery (Germany); Fuerst, Guenter [University Hospital Duesseldorf, Institute of Diagnostic Radiology (Germany)

2008-07-15

233

What Are the Signs and Symptoms of Varicose Veins?  

MedlinePLUS

... Twitter. What Are the Signs and Symptoms of Varicose Veins? The signs and symptoms of varicose veins include: ... signs of other, more serious conditions. Complications of Varicose Veins Varicose veins can lead to dermatitis (der-ma- ...

234

Carbon dioxide embolism during endoscopic vein harvesting.  

PubMed

Endoscopic vein harvesting (EVH) is becoming common for the patients undergoing coronary artery bypass grafting. Using carbon dioxide insufflations during the vein harvest can produce rare but catastrophic CO(2) embolism. We report a case of massive right atrial CO(2) embolism due to femoral vein injury which occurred during the performance of a routine EVH procedure. PMID:18381362

Tamim, Muhammed; Omrani, Maher; Tash, Adel; El Watidy, Ahmed

2008-08-01

235

Prospective analysis of endoscopic vein harvesting  

Microsoft Academic Search

Background: Utilization of bridging vein harvesting (BVH) of saphenous vein grafts (SVG) for coronary artery bypass grafting (CABG) results in large wounds with great potential for pain and infection. Endoscopic vein harvesting (EVH) may significantly reduce the morbidity associated with SVG harvesting.Methods: A prospective database of 200 matched patients receiving EVH and BVH was compared. The patients all underwent CABG

Amit N Patel; Robert F Hebeler; Baron L Hamman; Carol Hunnicutt; Melody Williams; Lu Liu; Richard E Wood

2001-01-01

236

Endoscopic vein harvest: advantages and limitations  

Microsoft Academic Search

BackgroundAlthough long saphenous vein remains the most commonly used conduit in coronary revascularization, traditional open vein harvest (OVH) may lead to significantly impaired wound healing and postoperative pain. Endoscopic vein harvest (EVH) attempts to reduce this morbidity and improve patient satisfaction with no compromise in outcome.

Pramod Bonde; Alastair N. J Graham; Simon W MacGowan

2004-01-01

237

How Can Varicose Veins Be Prevented?  

MedlinePLUS

... from the NHLBI on Twitter. How Can Varicose Veins Be Prevented? You can't prevent varicose veins from forming. However, you can prevent the ones ... also can take steps to delay other varicose veins from forming. Avoid standing or sitting for long ...

238

Cephalic veins in coronary artery bypass surgery  

Microsoft Academic Search

Various alternative conduits for aortocoronary bypass grafting have been suggested when the saphenous vein quality is inadequate. During a 10-year period we have used the cephalic vein in 39 patients. Eighteen entered an angiographic follow-up study. A total of 31 arm vein grafts were used with 43 distal anastomoses. When calculating patency by number of patent distal anastomoses, this was

P. E. Andersen; E. Jacobsen; G. Lerbjerg

1996-01-01

239

Hemodilution therapy in central retinal vein occlusion  

Microsoft Academic Search

Systemic hemorheologic abnormalities may play a part in the pathogenesis of central retinal vein occlusions. A statistically significant elevation of plasma viscosity was found in patients with acute central retinal vein occlusion compared with control patients. Local retinal blood flow parameters including arteriovenous passage time and mean arterial dye bolus velocity were significantly altered in the central retinal vein occlusion

Sebastian Wolf; Oliver Arend; Bernd Bertram; Andreas Remky; Karin Schulte; Kenneth J. Wald; Martin Reim

1994-01-01

240

Optimization of subcutaneous vein contrast enhancement  

Microsoft Academic Search

A technique for enhancing the contrast of subcutaneous veins has been demonstrated. This techniques uses a near IR light source and one or more IR sensitive CCD TV cameras to produce a contrast enhanced image of the subcutaneous veins. This video image of the veins is projected back onto the patient's skin using a n LCD video projector. The use

Herbert D. Zeman; Gunnar Lovhoiden; Harshal Deshmukh

2000-01-01

241

Gradient Based Image Segmentation for Vein Pattern  

Microsoft Academic Search

The biometrics identification technology based on vein pattern has being developed rapidly in recent years. However, the vein image acquired by near-infrared (NIR) imaging device has low contrast and usually has a mount of noise which make an effective image segmentation be a great challenge. Thresholding is a popular vein image segmentation method, which is easy to calculate and can

Yiding Wang; Hai Wang

2009-01-01

242

A new approach for sclera vein recognition  

Microsoft Academic Search

The vein structure in the sclera is stable over time, unique to each person, and well suited for human identification. A few researchers have performed sclera vein pattern recognition and reported promising initial results. Sclera recognition poses several challenges: the vein structure moves and deforms with the movement of the eye; images of sclera patterns are often defocused and\\/or saturated;

N. L. Thomas; Yingzi Du; Zhi Zhou

2010-01-01

243

Automatic spatial characterization of low-speed streaks from thermal images  

NASA Astrophysics Data System (ADS)

Flow visualization is an important tool for investigating turbulent flow, and, specifically, for characterizing low-speed streaks in the boundary layer. The span-wise spatial characteristics of these streaks are commonly extracted by human visual inspection, which is time consuming and subject to human errors and biases. Attempts to develop automatic methods have relied exclusively on spectral techniques, using mostly the autocorrelation or its Fourier transform, the spatial spectrum. However, the autocorrelation tends to get flattened with the amount of data analyzed and has been reported to provide biased estimates. Furthermore, it estimates only the mean spacing and does not provide a direct measure of its distribution. In this paper, an alternative automatic method is developed based on edge detection, and is applied to thermal images obtained by infrared thermography of a heated wall exposed to a turbulent flow. The method presented yields not only the spacing between the low-speed streaks but also their width and separation. The analysis indicates that the spacing (120+/-52wall units) is divided almost evenly between the width (65+/-33wall units) and the separation (55+/-40wall units) between the streaks, and that the width and separation are statistically independent. We also present a statistical model for the data, and demonstrate that when the spatial parameters of the streaks are so widely distributed, the spectral methods are not reliable.

Zacksenhouse, M.; Abramovich, G.; Hetsroni, G.

244

Distinct Wnt-driven primitive streak-like populations reflect in vivo lineage precursors.  

PubMed

During gastrulation, epiblast cells are pluripotent and their fate is thought to be constrained principally by their position. Cell fate is progressively restricted by localised signalling cues from areas including the primitive streak. However, it is unknown whether this restriction accompanies, at the individual cell level, a reduction in potency. Investigation of these early transition events in vitro is possible via the use of epiblast stem cells (EpiSCs), self-renewing pluripotent cell lines equivalent to the postimplantation epiblast. Strikingly, mouse EpiSCs express gastrulation stage regional markers in self-renewing conditions. Here, we examined the differentiation potential of cells expressing such lineage markers. We show that undifferentiated EpiSC cultures contain a major subfraction of cells with reversible early primitive streak characteristics, which is mutually exclusive to a neural-like fraction. Using in vitro differentiation assays and embryo grafting we demonstrate that primitive streak-like EpiSCs are biased towards mesoderm and endoderm fates while retaining pluripotency. The acquisition of primitive streak characteristics by self-renewing EpiSCs is mediated by endogenous Wnt signalling. Elevation of Wnt activity promotes restriction towards primitive streak-associated lineages with mesendodermal and neuromesodermal characteristics. Collectively, our data suggest that EpiSC pluripotency encompasses a range of reversible lineage-biased states reflecting the birth of pioneer lineage precursors from a pool of uncommitted EpiSCs similar to the earliest cell fate restriction events taking place in the gastrula stage epiblast. PMID:24595287

Tsakiridis, Anestis; Huang, Yali; Blin, Guillaume; Skylaki, Stavroula; Wymeersch, Filip; Osorno, Rodrigo; Economou, Costas; Karagianni, Eleni; Zhao, Suling; Lowell, Sally; Wilson, Valerie

2014-03-01

245

Immunohistochemistry comparing endoscopic vein harvesting vs. open vein harvesting on saphenous vein endothelium  

PubMed Central

Objective The present study attempts to compare the immunohistochemistry (IHC) of von Willebrand factor (vWf) , endothelial cadherin, Caveolin and endothelial Nitric Oxide Synthase (eNOS) in VasoView Endoscopic Vein Harvesting (EVH) versus traditional Open Vein Harvesting (OVH) techniques for Coronary Artery Bypass Graft (CABG) Surgery performed in Javad al Aemeh Hospital of Mashhad, Iran in 2013,. Methods and materials Forty-seven patients were scheduled for CABG (30 EVH and 17 OVH) among whom patients with relatively same gender and similar age were selected. Three separate two cm vein samples were harvested from each patient’s saphenous vein. Each portion was collected from distal, middle and proximal zones of the saphenous vein. The tissues were deparaffinized, and antigen retrieval was done using EZ-retriever followed by an immunohistochemistry evaluation with vWf, e-cadherin, Caveolin and eNOS. In addition, demographic questioner as of Lipid profile, FBS, BMI, and cardiovascular risk factors were collected. Data analyses, including parametric and nonparametric tests were undertaken using the SPSS 16 software. A P value??0.05). Qualitative report of vWf, e-cadherin, Caveolin and eNOS reveals no significant difference between the EVH and OVH (P?>?0.05). Conclusion This study indicates that VasoView EVH technique causes no endothelial damage in comparison with OVH. This study could be a molecular confirmation for the innocuous of EVH technique.

2014-01-01

246

Image streak techniques: ISKRA-5 facility X-ray space-time and spectral characteristics recording  

SciTech Connect

Presented below are the X-ray image streak techniques used to study the spectral- and spectral-spatial time behavior of the ISKRA-5 facility laser-irradiated target X-ray radiation. For this purpose, we developed several 0.1-10 keV range X-ray slit streak cameras with 3x10{sup {minus}11}-s time resolution. Our X-ray imaging layout made it possible to simultaneously project several target images (in different spectral intervals) to the photocathode and streak them synchroniously. These techniques made it possible to: Study the microsphere target and plasma corona implosion dynamics; investigate the well-adjacent plasma electron temperature behavior; determine the compressed core lifetime; and monitor the state of the external (non-irradiated) target surface. 7 refs., 4 figs.

Lazarchuk, V.P.; Murugov, V.M.; Petrov, S.I.; Senik, A.V. [VNIIEF Russian Federal Nuclear Center, Novgorod (Russian Federation)

1994-12-31

247

Time-resolved photoemission by attosecond streaking: extraction of time information  

NASA Astrophysics Data System (ADS)

Attosecond streaking is one of the most fundamental processes in attosecond science allowing for a mapping of temporal information to the energy domain. We study attosecond streaking setups for measuring the release time of electrons in atomic photoemission [cf. M. Schultze et al, Science 328, 1658 (2010)]. We show that on the single-particle level, the extracted time delays (phase shifts) contain timing (or spectral phase) information associated with the Eisenbud-Wigner-Smith time delay matrix of quantum scattering. However, this is only accessible if distortion effects by the streaking infrared field on the emission process are properly accounted for. We show that the ``time shifts'' due to the interaction between the outgoing electron and the combined Coulomb and IR laser field can be described classically. By contrast, we also find a strong initial state dependence of the apparent time delay, which is of quantum mechanical origin.

Nagele, Stefan; Pazourek, Renate; Doblhoff-Dier, Katharina; Lemell, Christoph; Burgdörfer, Joachim; T?kési, Karoly; Feist, Johannes

2011-06-01

248

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

NASA Technical Reports Server (NTRS)

Higher temporal resolution data from NASA's fourth Atmospheric Variability Experiment (April 24-25, 1975) are used to study the role of diabatic heating within the convective region in altering the ageostrophic mass circulation in the entrance region of the jet streak. The modifying effect this diabatic heating in the mesoscale storm exerts on the synoptic-scale environmental flow through dynamical mechanisms which link the mass circulation of these two scales is examined. The effect of diabatic heating on the ageostrophic motion within the thermally direct circulation of the jet streak and the mesoscale convective complexes is investigated. Diabatic modes of ageostrophic motion that intensify the upper tropospheric jet streak downstream are identified.

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

1984-01-01

249

Development of streak cameras for time-resolved experiments at the advanced laser light source laboratory  

NASA Astrophysics Data System (ADS)

The Advanced Laser light Source (ALLS) infrastructure is a new state-of-the-art multi-beams femtosecond laser facility currently in operation at INRS near Montreal, Canada. Multi-beams experiments and pump-probe geometry lead to the need of synchronization instrumentation tools. The use of a wide range of energy radiation from hard x-ray up to infrared light on the ultrafast time scale requires the development of ultrafast detector diagnostics tools to study the emission spectrum of these sources. To fulfill these requirements, new streak cameras have been developed for ALLS facility. The SV streak camera is a simple and compact multi-purpose instrument that will be used for beams synchronization with picosecond time resolution and good spatial resolution. The FXR streak camera is dedicated to x-ray spectroscopy with sub-picosecond time resolution combined with a very high spatial resolution.

Martel, C.; Fourmaux, S.; Côté, C. Y.; Magnan, S.; Lecherbourg, L.; Kieffer, J. C.

2007-01-01

250

Variable features on Mars V - Evidence for crater streaks produced by wind erosion  

NASA Technical Reports Server (NTRS)

High-resolution television pictures obtained by Mariner 9 are presented as evidence to show that the ragged dark streaks which appeared behind many dark craters several months after the end of the 1971 global dust storm resulted from wind erosion of a thin surface veneer consisting of dust-storm fallout. The pictures were taken over an area near the border between Mare Serpentis and Pandorae Fretum (approximately 30 deg S, 335 deg W). The high-resolution pictures are compared with low-resolution views of the same area, and it is shown that one very long dark streak is interrupted by a rille. It is concluded that this interruption proves that the dark streaks were produced by the present erosional mechanism.

Veverka, J.

1975-01-01

251

Ever heard of the obturator vein?  

PubMed

We report a complication related to advancement of a large diameter long sheath in the obturator vein. In an adult with a previously thrombosed femoral vein, the obturator vein was inadvertently cannulated. During percutaneous pulmonary valve implantation, the Ensemble(R) delivery system could not be advanced after repositioning attempt. The obturator vein had been perforated and sheath was coiled up in the pelvis leading to a retroperitoneal pelvic hematoma. Continuity of the vein was established using two self-expanding covered stents. The obturator vein runs dorsally and joins the inferior caval vein at a very acute angle posterior in the pelvis, creating a corner in which stiff catheters or sheaths may get entrapped. PMID:19882714

Brown, Stephen C; Gewillig, Marc

2010-02-15

252

Leiomyosarcoma of the renal vein.  

PubMed

A 43-year-old woman was referred to our clinic for evaluation of a left retroperitoneal mass. She presented to our internal medicine department complaining of back pain. Computed tomography (CT) scan revealed a left retroperitoneal mass 55 mm in size in the hilum of the left kidney. Enhanced CT scan and magnetic resonance imaging (MRI) disclosed a poorly staining mass. Metaiodobenzylguanidine scintigraphy demonstrated no accumulation in the mass; moreover, endocrinologic examination was normal. Laparoscopic resection of the left retroperitoneal tumor was attempted; however, strong adhesion between the tumor and the left renal vein was encountered. Thus, left nephrectomy after open conversion was performed. Histological findings indicated leiomyosarcoma originating from the left renal vein. The postoperative course has been uneventful; neither recurrence nor metastasis is evident 2 years postsurgery. PMID:20694494

Imao, Tetsuya; Amano, Toshiyasu; Takemae, Katsurou

2011-02-01

253

Probing dielectric-response effects with attosecond time-resolved streaked photoelectron spectroscopy of metal surfaces  

NASA Astrophysics Data System (ADS)

The release of conduction-band electrons from a metal surface by a subfemtosecond extreme ultraviolet (XUV) pulse and their propagation through the solid provoke a dielectric response in the solid that acts back on the photoelectron wave packet. We calculated the (wake) potential associated with this photoelectron self-interaction in terms of bulk and surface plasmon excitations and show that it induces a considerable, XUV-frequency-dependent temporal shift in laser-streaked XUV photoemission spectra, suggesting the observation of the ultrafast solid-state dielectric response in contemporary streaked photoemission experiments.

Zhang, C.-H.; Thumm, U.

2011-12-01

254

Accurate and efficient characterization of streak camera using etalon and fitting method with constraints.  

PubMed

Streak camera is widely used in continuous time diagnostics in fast physical process. To produce accurate result, it requires delicate calibration and a reliable analysis method. High quality sweep-rate data with uncertainty smaller than 0.5% are obtained over the full record area by a constrained fitting method of peak position measurement, with a short pulse laser and an etalon as the fiducial source. The temporal response is linearized by this full-screen sweep-rate data, which eliminates errors in measurement due to nonlinearity and space-distortion inherent in streak camera. PMID:22128970

Yang, Dong; Wang, Zhebin; Jiang, Xiaohua; Liu, Yonggang; Peng, Xiaoshi; Zhu, Tuo; Zhang, Huan; Li, Zhichao; Li, Sanwei; Ding, Yongkun

2011-11-01

255

Effect of Yellow Filters on the Vision  

NASA Astrophysics Data System (ADS)

In the literature, controversial information could be found whether the yellow filters may improve the quality of vision. To find out what is the effect of yellow filters on the quality of vision, 27 individuals were examined for the contrast sensitivity using the Pelli-Robson chart, under normal (photopic) and reduced (mesopic) illumination. The measurements were carried out with and without yellow filters (light transmission 67%, measured with an Ocean Optic spectrometer). Also, the measurements were taken using a grey filter with transmission close to that of the yellow filter (73%). The results did not show statistically significant improvement when looking through yellow filters. However, 56% of the individuals asserted that under reduced illumination they found it more agreeable to look through yellow filters. Two persons were extra tested for low contrast visual acuity using a computerized test and objective measurements by the visual evoked potentials (VEP) method. These visual measurements also did not show statistically significant improvement of the visual contrast sensitivity when yellow filters were used. Our measurements do not confirm the data found in literature about the vision improvement owing to yellow filters. However, the mentioned above subjective improvement at using yellow filters in mesopic conditions shows that under very low illumination such filters may slightly increase the visual quality.

Slica, S.; Ikaunieks, G.; Rinkus, D.

2010-03-01

256

Everted cervical vein for carotid patch angioplasty.  

PubMed

Because of the theoretic benefits of autologous vein we undertook an investigation to evaluate cervical veins (facial, external jugular) as patch material after carotid endarterectomy. A device that stimulated both circumferential fixation by sutures and radial tension exerted on in vivo patches was constructed to measure burst strength of tissue. Mean bursting pressure for groin saphenous vein (n = 10) was 94.5 +/- 15.1 pounds per square inch (psi), 75.5 +/- 8.9 psi for ankle saphenous vein (n = 10), 83.3 +/- 14.5 psi for everted (double layer) cervical vein (n = 5) and 10 +/- 3.3 psi for single layer cervical vein (n = 5). No significant differences between saphenous vein at any level and everted (double layer) cervical vein, but all were significantly different from single layer cervical vein (p less than 0.05). From June 1987 through November 1989, 19 patients underwent 21 carotid endarterectomies complemented with adjunctive everted cervical vein patch angioplasty. Indications for surgery were asymptomatic stenosis (53%), transient ischemic attack (29%), and cerebrovascular accident with recovery (18%). All patients were studied after surgery with duplex scanning. Asymptomatic recurrent stenosis was observed in one patient. Transient hypoglossal nerve dysfunction occurred in one other patient. One postoperative death occurred as a result of massive aspiration. These results indicate that everted cervical vein is comparable to the saphenous vein in resistance to bursting and can yield similar results as patch material after carotid endarterectomy. Accordingly, saphenous vein can be spared and lower extremity incisions avoided.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2231962

Yu, A; Dardik, H; Wolodiger, F; Raccuia, J; Kapadia, I; Sussman, B; Kahn, M; Pecoraro, J P; Ibrahim, I M

1990-11-01

257

More great saphenous vein valves - less varicose veins?  

PubMed

Background: In patients with chronic venous disease (CVD) the number of venous valves and the degree of valve deterioration have not been extensively investigated and are poorly understood. The aim of this prospective study was to quantitatively and qualitatively investigate the venous valves in CVD patients in view of their clinical classification. Patients and methods: Within two years a consecutive series of 152 patients (223 limbs) undergoing primary surgery for great saphenous vein varicose veins was investigated. In all patients the ?C? class according to the basic CEAP-classification was registered preoperatively (C2 to C6) for each limb. Both the quantity and quality of venous valves were assessed in the GSV?s after removal. Qualitative evaluation of the valves was based on macroscopic appearance using a classification from 0 to 5 and described as ?valve disease class?. Results: A negative correlation between age and the number of valves was detected (p = 0.0035). There was an increase of C-class with increasing age. No significant correlation between the average number of valves per meter and the C-class was detected. For all C-classes an average of between four and five valves per meter was counted. Valve disease class was positively correlated with the C-class although the valve disease class was never higher than the C-class (p < 0.05). Conclusions: The valve disease class of the great saphenous vein correlates with the C-class of the CEAP-classification. The number of valves did not correlate with the ?C?-class. With each increase in the CEAP class the age increased as well. PMID:25007904

Gräub, Anna-Barbara; Naef, Markus; Wagner, Hans E; Mouton, Wolfgang G

2014-07-01

258

One and two-dimensional fast x-ray imaging of laser-driven implosion dynamics with x-ray streak cameras  

Microsoft Academic Search

One- (1D) and two-dimensional (2D) x-ray imaging techniques with x-ray streak cameras have been developed and utilized for investigating implosion dynamics of laser fusion targets. Conventional streaked 1D images of the shell motion of the imploding target was recorded together with the time-resolved 2D multi-imaging x-ray streak images of the core shapes on the same x-ray streak camera. Precise comparison

H. Shiraga; M. Heya; M. Nakasuji; N. Miyanaga; H. Azechi; H. Takabe; T. Yamanaka; K. Mima

1997-01-01

259

Squash Vein Yellowing Virus, Causal Agent of Watermelon Vine Decline in Florida1  

Microsoft Academic Search

INTRODUCTION: Plants from the cucurbit family (Cucurbitaceae) are grown throughout the world for their edible fruits. The family includes watermelons (Citrullus lanatus), cantaloupes (Cucumis melo), cucumbers (C. sativus), pumpkins (Cucurbita pepo) and numerous varieties of summer and winter squash (C. pepo, C. moschata and C. maxima). It also includes those grown as ornamental vines (Luffa spp.) and a few common

Carlye Baker; Susan Webb; Scott Adkins

260

Streak camera measurements of laser pulse temporal dispersion in short graded-index optical fibers  

SciTech Connect

Streak camera measurements were used to determine temporal dispersion in short (5 to 30 meter) graded-index optical fibers. Results show that 50-ps, 1.06-..mu..m and 0.53-..mu..m laser pulses can be propagated without significant dispersion when care is taken to prevent propagation of energy in fiber cladding modes.

Lerche, R.A.; Phillips, G.E.

1981-08-28

261

Architectures and signal reconstruction methods for nanosecond resolution Integrated Streak Camera in standard CMOS technology  

Microsoft Academic Search

This paper presents the state of the art of the Integrated Streak Camera (ISC) architectures in standard CMOS technology. It focuses on some of the methods required for reconstructing the luminous events profile from the chip raw data. Two main ISC architectures are presented. The first adopts the traditional for the most silicon imagers pixel array configuration, where the photocharges-induced

Martin Zlatanski; Wilfried Uhring; Virginie Zint; Jean-Pierre Le Normand; Daniel Mathiot

2010-01-01

262

Photoemissive materials for 0. 35. mu. m laser fiducials in x-ray streak cameras  

SciTech Connect

Using a soft x-ray streak camera, materials are tested for suitability as transmission photocathodes when irradiated by 0.35..mu..m laser pulses. Preliminary measurements of sensitivity, dynamic range and temporal resolution are reported. A practical fiber optic fiducial under development for laser fusion x-ray diagnostics on the LLNL Nova laser system is described.

Hale, C.P.; Medecki, H.; Lee, P.H.Y.

1984-01-01

263

Optical Comb Generation for Streak Camera Calibration for Inertial Confinement Fusion Experiments  

SciTech Connect

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) is coming on-line to support physics experimentation for the U.S. Department of Energy (DOE) programs in Inertial Confinement Fusion (ICF) and Stockpile Stewardship (SS). Optical streak cameras are an integral part of the experimental diagnostics instrumentation at NIF. To accurately reduce streak camera data a highly accurate temporal calibration is required. This article describes a technique for simultaneously generating a precise +/- 2 ps optical marker pulse (fiducial reference) and trains of precisely timed, short-duration optical pulses (so-called “comb” pulse trains) that are suitable for the timing calibrations. These optical pulse generators are used with the LLNL optical streak cameras. They are small, portable light sources that, in the comb mode, produce a series of temporally short, uniformly spaced optical pulses, using a laser diode source. Comb generators have been produced with pulse-train repetition rates up to 10 GHz at 780 nm, and somewhat lower frequencies at 664 nm. Individual pulses can be as short as 25-ps FWHM. Signal output is via a fiber-optic connector on the front panel of the generator box. The optical signal is transported from comb generator to streak camera through multi-mode, graded-index optical fiber.

Ronald Justin, Terence Davies, Frans Janson, Bruce Marshall, Perry Bell, Daniel Kalantar, Joseph Kimbrough, Stephen Vernon, Oliver Sweningsen

2008-09-18

264

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

265

Full waveform earthquake location: Application to seismic streaks on the Calaveras Fault, California  

Microsoft Academic Search

We use a novel technique based upon source array analysis to locate three moderate earthquakes that occur at the edge of previously identified streaks of seismicity on the Calaveras Fault, California. Our method determines centroid locations for earthquakes, in addition to the hypocenters previously determined using first-break picks. Application of the method to smaller earthquakes indicates that the errors associated

Justin L. Rubinstein; Gregory C. Beroza

2007-01-01

266

Analysis of the thermal equilibrium state of bunched beams with a streak camera  

NASA Astrophysics Data System (ADS)

The thermal equilibrium distribution of cooled bunched ion beams in the ESR storage ring is investigated in simultaneous longitudinal-transverse measurements by using a scintillator and streak camera in the extraction beam line. We have found a cylindrical bunch model with local Gaussian density profiles confirming the model of a Maxwell-Boltzmann distribution in six-dimensional phase space.

Hofmann, I.; Johnson, K. F.; Spiller, P.; Eickhoff, H.; Kalisch, G.; Laux, W.; Steck, M.

1995-11-01

267

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

268

Monoclonal antibodies against the aster yellows agent.  

PubMed

Hybridoma clones secreting specific monoclonal antibodies against the aster yellows agent, a mycoplasma-like organism, were produced by using partially purified salivary gland preparations from infected leafhopper vectors as the immunogen. After 3947 hybridomas from 20 independent fusions were screened for specific antibody against the aster yellows agent, two table clones were obtained. With these monoclonal antibodies the aster yellows agent in diseased lettuce, periwinkles, and inoculative insects was specifically identified by enzyme-linked immunosorbent assay. The aster yellows agent was serologically differentiated from the mycoplasma-like organisms associated with ash yellows, loofah witches'-broom, paulownia witches'-broom, sweet potato witches'-broom, peanut rosette, maize bushy stunt, and elm phloem necrosis. PMID:17757867

Lin, C P; An Chen, T

1985-03-01

269

Minimally invasive vein surgery: ambulatory phlebectomy.  

PubMed

Ambulatory phlebectomy has proven to be an effective treatment for varicose veins. Alone or complementing the treatment of incompetent long or short saphenous vein by high ligation, saphenectomy, or transcatheter occlusion, ambulatory phlebectomy not only adequately and satisfactorily removes the diseased veins but also results in a series of extremely small micro-incisions, which are cosmetically pleasing to the patient and the surgeon. Furthermore, the entire procedure can be performed under local anesthesia on an ambulatory basis. PMID:14614696

Olivencia, Jose Antonio

2003-09-01

270

Portal vein aneurysm in a dog.  

PubMed

Portal vein aneurysm (PVA) is a rare abnormal dilatation of the portal vein, which has not been reported in dogs. We describe the findings of ultrasound and computed tomography in a case of PVA in a young male toy poodle, with the final diagnosis established by explorative surgical observation. The dog had an aneurysmal fusiform dilatation in the extrahepatic portal vein with portal hypertension and multiple portsystemic shunts. This is the first report of canine PVA. PMID:22571895

Miyawaki, Shingo; Washizu, Makoto; Maeda, Sadatoshi; Shibata, Sanae; Watanabe, Kazuhiro; Yamazoe, Kazuaki

2012-09-01

271

Hemodialysis-associated subclavian vein stenosis  

Microsoft Academic Search

Hemodialysis-associated subclavian vein stenosis. This study was undertaken to evaluate hemodialysis-associated subclavian vein stenosis (SVS) and to clarify treatment of this condition. Forty-seven patients underwent upper arm venography to evaluate fistula dysfunction. Subclavian vein stenosis was documented in 12. Eleven of 12 had elevated venous dialysis pressure (196 ± 8.9 mm Hg), and six had arm edema. All 12 had

Steve J Schwab; L Darryl Quarles; John P Middleton; Richard H Cohan; Moshin Saeed; Vincent W Dennis

1988-01-01

272

Jugular vein thrombosis associated with distant malignancy.  

PubMed Central

We describe two patients who developed internal jugular vein thrombosis associated with primary malignant disease arising outside the neck, and in one patient it was the presenting feature. Computed tomography was performed and the findings characteristic of internal jugular vein thrombosis are illustrated. We conclude that malignant disease should be considered in patients presenting with spontaneous internal jugular vein thrombosis with no other predisposing factors and that computed tomography is of value in confirming the diagnosis. Images Figure 1 Figure 2

Carrington, B. M.; Adams, J. E.

1988-01-01

273

On the condition of streak formation in a bounded turbulent flow  

SciTech Connect

Flow between two surfaces at which no-slip and free-slip conditions can be imposed has been investigated numerically with a Fourier--Chebyshev pseudospectral method. Different mean shear rates have been applied to each boundary to study the effect of shear and boundary condition on the streaky structures that have been observed near walls in many previous investigations. In addition to the streaks found near the no-slip wall, the computations also reveal streaky structures when the free-slip surface is under a sufficiently high shear. The low-speed streaks observed near the free-slip surface, although appearing somewhat more pronounced, have much the same characteristics as the wall-layer streaks---e.g., the average spanwise spacing between the streaks both near the wall and the free surface is about 100 when normalized by the kinematic viscosity and the appropriate shear velocity (at the wall or at the free-slip surface). The results show that shear is much more important than the nature of the boundary in determining the dominant flow structure, rather unexpected since vortex lines can attach at a free-slip boundary whereas they cannot at a no-slip one. The formation of streaks appears to be governed by a local nondimensional shear parameter defined as {ital {tilde S}}{equivalent to}{ital S}{vert bar}{l angle}{ital u}{prime}{ital w}{prime}{r angle}{vert bar}/{epsilon}, where {ital S} is the mean shear rate, and {l angle}{ital u}{prime}{ital w}{prime}{r angle} and {epsilon} are the kinematic turbulent shear stress and rate of dissipation of turbulent kinetic energy, respectively. It is found that {ital {tilde S}}{congruent}1.0 is the condition at which the elongated low-speed streaky regions first appear.

Lam, K. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)); Banerjee, S. (Department of Chemical and Nuclear Engineering, University of California, Santa Barbara, California 93106 (United States))

1992-02-01

274

Below-the-Belt Dermatological Conditions: Spider Veins, Varicose Veins, Cellulite, Pedicures  

MedlinePLUS

... Psoriasis Skin cancer Prevention and care Cosmetic treatments Gold Triangle Awards Home Media resources Stats and facts ... not prevent spider veins. Sclerotherapy is considered the gold standard in treating people with spider veins. This ...

275

Small hepatic veins Budd-Chiari syndrome.  

PubMed

Budd-Chiari syndrome is a rare disorder characterized by hepatic venous outflow obstruction at any level from the small hepatic veins to the atrio-caval junction, in the absence of heart failure or constrictive pericarditis. Various imaging modalities are available for investigating the gross hepatic vascular anatomy but there are rare forms of this disease where the obstruction is limited to the small intrahepatic veins, with normal appearance of the large hepatic veins at imaging. In this cases only a liver biopsy can demonstrate the presence of a small vessels outflow block. We report two cases of small hepatic veins Budd-Chiari syndrome. PMID:23813023

Riggio, Oliviero; Marzano, Chiara; Papa, Alessia; Pasquale, Chiara; Gasperini, Maria Ludovica; Gigante, Antonietta; Valla, Dominique Charles; Plessier, Aurélie; Amoroso, Antonio

2014-05-01

276

Remodelling of the Superior Caval Vein After Angioplasty in an Infant with Superior Caval Vein Syndrome  

SciTech Connect

An 8-month old girl was presented with superior caval vein syndrome early after cardiac surgery. Angiography showed severe stenosis of the superior caval vein with 50 mmHg pressure gradient. Following balloon angioplasty, the pressure gradient was reduced to 7 mmHg with some residual stenosis of the superior caval vein. When the patient was reevaluated 5 months after the procedure, angiography revealed a normal diameter of the superior caval vein without a pressure gradient.

Mert, Murat [Istanbul University, Institute of Cardiology, Department of Cardiovascular Surgery (Turkey)], E-mail: mmert@superonline.com; Saltik, Levent [Istanbul University, Cerrahpasa Medical School, Department of Pediatric Cardiology (Turkey); Gunay, Ilhan [Istanbul University, Institute of Cardiology, Department of Cardiovascular Surgery (Turkey)

2004-08-15

277

Treatment of central retinal vein occlusion by injection of tissue plasminogen activator into a retinal vein  

Microsoft Academic Search

Purpose: To report the injection of tissue plasminogen activator into a retinal vein to treat central retinal vein occlusion.Methods: An 81-year-old woman with visual loss of the right eye secondary to central retinal vein occlusion developed central retinal vein occlusion and visual loss in her left eye. Treatment of her left eye with topical ocular hypotensive medications, pentoxifylline, and laser

Jeffrey N. Weiss

1998-01-01

278

Andreas Acrivos Dissertation Award Talk: Generation of near-wall streamwise vortices by transient growth of streak perturbations  

NASA Astrophysics Data System (ADS)

A new mechanism for generation of near-wall streamwise vortices is presented, based on linear perturbation analysis and direct numerical simulations of turbulent channel flow. Analysis of streaks extracted from fully developed near-wall turbulence indicates that roughly 20 percent of buffer layer streaks exceed the strength threshold for classical normal-mode instability. However, these unstable streaks exhibit only moderate (twofold) normal mode amplification, the growth arrested by viscous cross-diffusion of streak-flank vorticity. An alternative, streak transient growth (STG) mechanism is revealed, capable of producing much larger (tenfold) linear amplification of x-dependent disturbances. Streamwise vortices are generated from the more numerous normal-mode-stable streaks, via a new STG-based scenario: (i) formation of a sheet of streamwise vorticity, (ii) growth of sinuous streak waviness and hence partialu/partialx as STG reaches nonlinear amplitude, and (iii) collapse of the vorticity sheet via stretching by partialu/partialx into streamwise vortices. Notably, the three-dimensional features of the (instantaneous) streamwise vortices of x-alternating sign generated by STG agree well with the (ensemble-averaged) coherent structures educed from fully turbulent flow. The STG-induced formation of internal shear layers, quadrant Reynolds stresses, and other measures of 'bursting' also agree well with fully-developed turbulence, and suggest new possibilities for control of drag and heat transfer.

Schoppa, Wade; Hussain, Fazle

2002-11-01

279

The use of spliced vein bypasses for infrainguinal arterial reconstruction  

Microsoft Academic Search

Purpose: The use of autogenous vein, whether in situ or excised, for arterial bypass procedures is well accepted. However, this usually requires the presence of a length of good-quality vein of adequate diameter. In patients lacking sufficient length of vein, two or more pieces of vein may be spliced together to complete the reconstruction. The effect of vein splicing on

Benjamin B. Chang; R. Clement Darling; Devon E. M. Bock; Dhiraj M. Shah; Robert P. Leather

1995-01-01

280

A clinicopathological study of human yellow fever.  

PubMed

During an epidemic of yellow fever in the Jos Plateau area of Nigeria, 9 adult males with clinically diagnosed yellow fever were studied by haematological, biochemical, virological, serological, and liver biopsy methods. The ages of the patients ranged from 20 to 55 years and the duration of illness was 3-62 days. No virus was isolated from any patient but all patients should biochemical evidence of severe hepatocellular damage. Leucopenia was a feature of the late acute stage of the disease. Five sera had antibodies to yellow fever at titres greater than 1: 32, 3 of them being monospecific for yellow fever. The classical histological features of yellow fever were present only in the acute or late acute stages, when complement-fixation tests may be negative. With convalescence and the production of complement-fixing antibodies in high titres, the histological features resembled those of a persisting nonspecific hepatitis. In an endemic area, the histological features of yellow fever will depend on the stage of the disease and a picture of nonspecific hepatitis would not exclude yellow fever in the absence of confirmation from serological tests. PMID:4538039

Francis, T I; Moore, D L; Edington, G M; Smith, J A

1972-01-01

281

A clinicopathological study of human yellow fever*  

PubMed Central

During an epidemic of yellow fever in the Jos Plateau area of Nigeria, 9 adult males with clinically diagnosed yellow fever were studied by haematological, biochemical, virological, serological, and liver biopsy methods. The ages of the patients ranged from 20 to 55 years and the duration of illness was 3-62 days. No virus was isolated from any patient but all patients should biochemical evidence of severe hepatocellular damage. Leucopenia was a feature of the late acute stage of the disease. Five sera had antibodies to yellow fever at titres greater than 1: 32, 3 of them being monospecific for yellow fever. The classical histological features of yellow fever were present only in the acute or late acute stages, when complement-fixation tests may be negative. With convalescence and the production of complement-fixing antibodies in high titres, the histological features resembled those of a persisting nonspecific hepatitis. In an endemic area, the histological features of yellow fever will depend on the stage of the disease and a picture of nonspecific hepatitis would not exclude yellow fever in the absence of confirmation from serological tests. ImagesFig. 1Fig. 2AFig. 2BFig. 3Fig. 4Fig. 5Fig. 6

Francis, T. I.; Moore, D. L.; Edington, G. M.; Smith, J. A.

1972-01-01

282

Clara Maass, yellow fever and human experimentation.  

PubMed

Clara Louise Maass, a 25-year-old American nurse, died of yellow fever on August 24, 1901, following experimental inoculation by infected mosquitoes in Havana, Cuba. The human yellow fever experiments were initially conducted by MAJ Walter Reed, who first used written informed consent and proved the validity of Finlay's mosquito-vector hypothesis. Despite informed consent form and an incentive of $100 in U.S. gold, human subjects were exposed to a deadly virus. The deaths of Clara Maass and two Spanish immigrants resulted in a public outcry and the immediate cessation of yellow fever human experiments in Cuba. PMID:23756016

Chaves-Carballo, Enrique

2013-05-01

283

[Arteriovenous dissection for branch retinal vein occlusion].  

PubMed

Arteriovenous dissection (AVD) is a surgical maneuver to separate the retinal artery and vein at the crossing site in patients with branch retinal vein occlusion (BRVO). The published studies showed an evidence level 3. AVD seems to be maintainable in patients with recent onset of BRVO and decimal visual acuity < or =0.4. PMID:18317778

Feltgen, N; Hattenbach, L-O; Mirshahi, A; Hansen, L

2008-04-01

284

Arteries and veins of the zebra fish  

NSDL National Science Digital Library

Arteries and veins are blood vessels and are part of the circulatory system. Arteries take oxygenated blood away from the heart and veins bring blood back to the heart after it has circulated through the body. The circulatory system distributes oxygen to the body and also moves around nutrients.

Katie Hale (CSUF;Biological Sciences)

2007-06-19

285

Improving the management of varicose veins.  

PubMed

Up to 30% of the UK population are affected by varicose veins. They are a manifestation of increased venous pressure in the lower limb caused by impaired venous return. Primary varicosities result from poor drainage from the superficial to the deep venous system. Secondary varicosities arise as a result of underlying pathology impeding venous drainage, such as deep venous thrombosis or increased intra-abdominal pressure caused by a mass, pregnancy or obesity. Patients with bleeding varicose veins should be referred to a vascular service immediately. Referral is also indicated in the following cases: symptomatic primary or recurrent varicose veins; lower limb skin changes thought to be caused by chronic venous insufficiency; superficial vein thrombosis and suspected venous incompetence; a venous leg ulcer or healed venous leg ulcer. Imaging is crucial in the assessment of the superficial and deep venous system to enable assessment of venous competence. The gold standard imaging technique is colour duplex ultrasonography. Duplex ultrasound should be used to confirm the diagnosis of varicose veins and the extent of truncal reflux, and to plan treatment for patients with suspected primary or recurrent varicose veins. Superficial vein ligation, phlebectomy and stripping have been the mainstay of treatment. In recent years, new techniques have been developed that are minimally invasive, enabling treatment of superficial venous incompetence with reduced morbidity. NICE recommends that endothermal ablation, in the form of radiofrequency or laser treatment, should be offered as treatment for patients with confirmed varicose veins and truncal reflux. PMID:24555256

Onida, Sarah; Lane, Tristan R A; Davies, Alun H

2013-01-01

286

The Superior Ophthalmic Vein in Carotid Angiograms  

Microsoft Academic Search

Examination of routine carotid angiograms from 1,000 patients gave 52 definite and 80 possible cases in which the superior ophthalmic vein was filled with contrast medium. Only one of these cases suffered from sinus thrombosis. In the other cases no certain correlation could be found between the angiographic or clinical diagnosis and the filling of the orbital vein. However, the

M. Brüderlin; R. Wüthrich

1973-01-01

287

Who Is at Risk for Varicose Veins?  

MedlinePLUS

... the heart, increasing the risk for varicose veins. Rate This Content: Varicose Veins Clinical Trials Clinical trials are research studies that explore whether a medical strategy, treatment, or device is safe and effective for humans. To find clinical trials that are currently underway ...

288

Recognizing and managing retinal vein occlusion.  

PubMed

Retinal vein occlusion is the second most common retinal vascular disease after diabetic retinopathy and represents a significant cause of irreversible sight loss and disability in persons over the age of 50 years (The Branch Vein Occlusion Study Group, 1984). PMID:24402030

Arunakirinathan, Meena; Aj Ting, Michelle; Crawley, Laura

2014-01-01

289

Treating Varicose Veins with Transilluminated Powered Phlebectomy  

Microsoft Academic Search

In the past, patients endured hours of surgery, many incisions, and multiple scars to manually remove painful, unsightly, swollen varicose veins. Patients now have a new treatment option. Endoscopic resection and ablation of superficial varicosities is possible using a powered vein resector, irrigated illuminator, and tumescent anesthesia. This article describes this new technique, called transilluminated powered phlebectomy, and explains how

Lisa M. Zotto

2002-01-01

290

Basilic vein transposition: review of different techniques.  

PubMed

This is a review of the basilic vein procedure and changes that have evolved to improve outcomes. This includes reviewing data on the one-stage vs. two-stage technique as well as elevation for the basilic vein. The review discusses data that help the surgeon decide which technique he should evaluate. PMID:24817461

Glickman, Marc

2014-01-01

291

What Are the Signs and Symptoms of Deep Vein Thrombosis?  

MedlinePLUS

... Are the Signs and Symptoms of Deep Vein Thrombosis? The signs and symptoms of deep vein thrombosis ( ... life-threatening problems if not treated. Deep Vein Thrombosis Only about half of the people who have ...

292

Enhancing the contrast of subcutaneous veins  

NASA Astrophysics Data System (ADS)

A technique for enhancing the contrast of subcutaneous veins has been demonstrated. This technique uses a near infrared light source and one or more infrared sensitive CCD TV cameras to produce a contrast enhanced image of the subcutaneous veins. This video image of the veins is projected back onto the patient's skin using an LCD vein projector. The use of an infrared transmitting filter in front of the video cameras prevents any positive feedback from the visible light from the video projector from causing instabilities in the projected image. The demonstration contrast enhancing illuminator has been tested on adults, both Caucasian and African-American, and it enhances veins quite well in most cases. Preliminary studies on a 9 month old girl indicate promise for pediatric use.

Zeman, Herbert D.; Lovhoiden, Gunnar

1999-07-01

293

Lost Trust: A Yellow Fever Patient Response  

PubMed Central

In the 19th century, yellow fever thrived in the tropical, urban trade centers along the American Gulf Coast. Industrializing and populated, New Orleans and Memphis made excellent habitats for the yellow fever-carrying Aedes aegypti mosquitoes and the virulence they imparted on their victims. Known for its jaundice and black, blood-filled vomit, the malady terrorized the region for decades, sometimes claiming tens of thousands of lives during the near annual summertime outbreaks. In response to the failing medical community, a small, pronounced population of sick and healthy laypeople openly criticized the efforts to rid the Gulf region of yellow jack. Utilizing newspapers and cartoons to vocalize their opinions, these critics doubted and mocked the medical community, contributing to the regional and seasonal dilemma yellow fever posed for the American South. These sentient expressions prove to be an early example of patient distrust toward caregivers, a current problem in clinical heath care.

Runge, John S.

2013-01-01

294

Lost trust: a yellow fever patient response.  

PubMed

In the 19th century, yellow fever thrived in the tropical, urban trade centers along the American Gulf Coast. Industrializing and populated, New Orleans and Memphis made excellent habitats for the yellow fever-carrying Aedes aegypti mosquitoes and the virulence they imparted on their victims. Known for its jaundice and black, blood-filled vomit, the malady terrorized the region for decades, sometimes claiming tens of thousands of lives during the near annual summertime outbreaks. In response to the failing medical community, a small, pronounced population of sick and healthy laypeople openly criticized the efforts to rid the Gulf region of yellow jack. Utilizing newspapers and cartoons to vocalize their opinions, these critics doubted and mocked the medical community, contributing to the regional and seasonal dilemma yellow fever posed for the American South. These sentient expressions prove to be an early example of patient distrust toward caregivers, a current problem in clinical heath care. PMID:24348220

Runge, John S

2013-12-01

295

Teachable Fiction Comes to Yellow Sky.  

ERIC Educational Resources Information Center

Proposes that teachable fiction is efficient, strategically sound, and very visual. Analyzes Stephen Crane's "The Bride Comes to Yellow Sky" to show it fulfills these three characteristics. Suggests the story should be taught later in the semester. (PM)

Tietz, Stephen

2001-01-01

296

Optical Memory Potential of Photoactive Yellow Protein.  

National Technical Information Service (NTIS)

This contract targeted improved growth of photoactive yellow protein (PYP) and evaluation of its optical signal processing capabilities. The growth experiments were highly successful. Ectothiorhodopsin halophila bacteria were grown and plenty of PYP isola...

H. Gibbs G. Khitrova T. Meyer G. Tollin M. Cusanovich

1997-01-01

297

Turnip Yellow Mosaic Virus Structure  

NASA Technical Reports Server (NTRS)

The bumpy exterior of the turnip yellow mosaic virus (TYMV) protein coat, or capsid, was defined in detail by Dr. Alexander McPherson of the University of California, Irvin using protein crystallized in space for analysis on Earth. TYMV is an icosahedral virus constructed from 180 copies of the same protein arranged into 12 clusters of five proteins (pentamers), and 20 clusters of six proteins (hexamers). The final TYMV structure led to the enexpected hypothesis that the virus release its RNA by essentially chemical-mechanical means. Most viruses have farly flat coats, but in TYMV, the fold in each protein, called the jellyroll, is clustered at the points where the protein pentamers and hexamers join. The jellyrolls are almost standing on end, producing a bumpy surface with knobs at all of the pentamers and hexamers. At the inside surface of the pentamers is a void that is not present at the hexamers. The coating had been seen in early studies of TYMV, but McPhereson's atomic structure shows much more detail. The inside surface is strikingly, and unexpectedly, different than the outside. While the pentamers contain a central viod on the inside, the hexameric units contain peptides liked to each other, forming a ring or, more accurately, rings to fill the voild. Credit: Dr. Alexander McPherson, University of California, Irvine.

2000-01-01

298

78 FR 24199 - Streak Products, Inc. v. UTi, United States, Inc.; Notice of Filing of Complaint and Assignment  

Federal Register 2010, 2011, 2012, 2013

...Docket No. 13--04] Streak Products, Inc. v. UTi, United States, Inc.; Notice of Filing of Complaint...hereinafter ``Complainant,'' against UTi, United States, Inc. (``UTi''), hereinafter ``Respondent.''...

2013-04-24

299

Analysis of Streak-Camera Measurement Errors Caused by Misorientation of the Camera Slit with Recording Direction.  

National Technical Information Service (NTIS)

Erroneous data are produced when we analyze streak or smear camera records in which the lack of perpendicularity between the camera slit and the recording direction is not considered. Generated velocity errors are either constant or variable, depending up...

E. A. Igel

1982-01-01

300

New ultra fast x-ray streak camera for the advanced laser light source facility  

NASA Astrophysics Data System (ADS)

The Advanced Laser Light Source (ALLS) infrastructure is a new state-of-the-art multi-beams femtosecond laser facility currently in operation at INRS near Montreal, Canada. The use of a wide range of energy radiation from hard x-ray up to infrared light on the ultrafast time scale requires the development of ultrafast detector diagnostics tools to study the emission spectrum of these sources. To fulfill these requirements, new streak cameras have been developed for ALLS facility. We present the new FXR streak camera which has been specifically developed for ALLS and which is dedicated to x-ray spectroscopy with sub-picosecond time resolution combined with a very high spatial resolution.

Martel, C.; Fourmaux, S.; Lecherbourg, L.; Bandulet, H.; Kieffer, J. C.

2007-09-01

301

Time-resolved spectra of dense plasma focus using spectrometer, streak camera, and CCD combination  

SciTech Connect

A time-resolving spectrographic instrument has been assembled with the primary components of a spectrometer, image-converting streak camera, and CCD recording camera, for the primary purpose of diagnosing highly dynamic plasmas. A collection lens defines the sampled region and couples light from the plasma into a step index, multimode fiber which leads to the spectrometer. The output spectrum is focused onto the photocathode of the streak camera, the output of which is proximity-coupled to the CCD. The spectrometer configuration is essentially Czerny-Turner, but off-the-shelf Nikon refraction lenses, rather than mirrors, are used for practicality and flexibility. Only recently assembled, the instrument requires significant refinement, but has now taken data on both bridge wire and dense plasma focus experiments.

Goldin, F. J. [Livermore Operations, National Security Technologies, LLC, Livermore, California 94550 (United States); Meehan, B. T.; Hagen, E. C. [North Las Vegas Facility, National Security Technologies, LLC, North Las Vegas, Nevada 89030 (United States); Wilkins, P. R. [Lawrence Livermore National Laboratories, Livermore, California 94550 (United States)

2010-10-15

302

Dynamical image-charge effects in attosecond time-resolved streaked photoelectron spectra of metal surfaces  

NASA Astrophysics Data System (ADS)

The release of conduction-band electrons from a metal surface by a sub-femtosecond extreme ultraviolet (XUV) pulse, and their propagation through and near the solid [1], provokes a dielectric response in the solid that acts back on the photoelectron wave packet. We calculated the (wake) potential associated with this photoelectron self-interaction in terms of bulk and surface plasmon excitations and show that it induces a considerable, XUV-frequency-dependent temporal shift in laser-streaked XUV-photoemission spectra [2], suggesting the observation of the ultrafast solid-state dielectric response in contemporary streaked photoemission experiments. [4pt] [1] C.-H. Zhang and U. Thumm, Phys. Rev. Lett. 102, 123601(2009); Phys. Rev. A 80, 032902 (2009).[0pt] [2] C.-H. Zhang and U. Thumm, Phys. Rev. A 82, 043405(2010).

Zhang, Chang-Hua; Thumm, Uwe

2011-06-01

303

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

304

A distinct tospovirus causing necrotic streak on Alstroemeria sp. in Colombia.  

PubMed

A tospovirus causing necrotic streaks on leaves was isolated from Alstroemeria sp. in Colombia. Infected samples reacted positively with tomato spotted wilt virus (TSWV) antiserum during preliminary serological tests. Further analysis revealed a close serological relationship to tomato chlorotic spot virus (TCSV) and groundnut ringspot virus (GRSV). A major part of the S-RNA segment, encompassing the nucleocapsid (N) protein gene, the 5' untranslated region and a part of the intergenic region 3' of the N gene, was cloned and sequenced. The deduced N protein sequence showed highest amino acid identity (82%) to that of TCSV, indicating that the virus represents a new tospovirus species, for which the name Alstroemeria necrotic streak virus (ANSV) is coined. Phylogenetic analysis based on the N protein sequence revealed that this Alstroemeria-infecting tospovirus clustered with tospoviruses from the American continent. Frankliniella occidentalis was identified as potential vector species for ANSV. PMID:20151164

Hassani-Mehraban, Afshin; Botermans, Marleen; Verhoeven, J Th J; Meekes, Ellis; Saaijer, Janneke; Peters, Dick; Goldbach, Rob; Kormelink, Richard

2010-03-01

305

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

306

Drag reduction of a 3D bluff body using coherent streamwise streaks  

NASA Astrophysics Data System (ADS)

Separation on the rear-end of an Ahmed body is suppressed by means of large-scale coherent streaks forced on the roof of the model. These streaks originate from an array of suitably shaped cylindrical roughness elements and are amplified by the mean shear through the lift-up effect. Interacting with the mean velocity field at leading order, they induce a strong controlled spanwise modulation. The resulting streaky base flow is observed to sustain the adverse pressure gradient since PIV measurements as well as static wall pressure distributions show that the re-circulation bubble completely vanishes. These modifications of the topology of the flow are associated with a substantial drag reduction, which can be of about 10% when the roughness array is optimally placed on the roof of the bluff body.

Pujals, G.; Depardon, S.; Cossu, C.

2010-11-01

307

Motion streaks do not influence the perceived position of stationary flashed objects.  

PubMed

In the present study, we investigated whether motion streaks, produced by fast moving dots Geisler 1999, distort the positional map of stationary flashed objects producing the well-known motion-induced position shift illusion (MIPS). The illusion relies on motion-processing mechanisms that induce local distortions in the positional map of the stimulus which is derived by shape-processing mechanisms. To measure the MIPS, two horizontally offset Gaussian blobs, placed above and below a central fixation point, were flashed over two fields of dots moving in opposite directions. Subjects judged the position of the top Gaussian blob relative to the bottom one. The results showed that neither fast (motion streaks) nor slow moving dots influenced the perceived spatial position of the stationary flashed objects, suggesting that background motion does not interact with the shape-processing mechanisms involved in MIPS. PMID:22645464

Pavan, Andrea; Bellacosa Marotti, Rosilari

2012-01-01

308

X-ray streak camera temporal resolution improvement using a longitudinal time-dependent field  

SciTech Connect

X-ray streak cameras (XSC) have been known to be one of the fastest detectors forultrafast X-ray science. A number of applications in material science, biochemistry, accelerator physics, require sub-picosecond resolution to study new phenomena. Inthis paper, we report on a new method which can potentially improve the temporal resolution of a streak camera down to 100 femtoseconds. This method uses a time-dependent acceleration field to lengthen the photoelectron bunch, significantlyimproving the time resolution as well as reducing the time dispersion caused byinitial energy spread and the effects fromthe space charge forces. A computer simulation of an XSC using this method shows significant improvement in the resolution.

Qiang, Ji; Qiang, J.; Byrd, J.M.; Feng, J.; Huang, G.

2008-05-09

309

Time-resolved spectra of dense plasma focus using spectrometer, streak camera, and CCD combination  

NASA Astrophysics Data System (ADS)

A time-resolving spectrographic instrument has been assembled with the primary components of a spectrometer, image-converting streak camera, and CCD recording camera, for the primary purpose of diagnosing highly dynamic plasmas. A collection lens defines the sampled region and couples light from the plasma into a step index, multimode fiber which leads to the spectrometer. The output spectrum is focused onto the photocathode of the streak camera, the output of which is proximity-coupled to the CCD. The spectrometer configuration is essentially Czerny-Turner, but off-the-shelf Nikon refraction lenses, rather than mirrors, are used for practicality and flexibility. Only recently assembled, the instrument requires significant refinement, but has now taken data on both bridge wire and dense plasma focus experiments.

Goldin, F. J.; Meehan, B. T.; Hagen, E. C.; Wilkins, P. R.

2010-10-01

310

Time-resolved spectra of dense plasma focus using spectrometer, streak camera, and CCD combination.  

PubMed

A time-resolving spectrographic instrument has been assembled with the primary components of a spectrometer, image-converting streak camera, and CCD recording camera, for the primary purpose of diagnosing highly dynamic plasmas. A collection lens defines the sampled region and couples light from the plasma into a step index, multimode fiber which leads to the spectrometer. The output spectrum is focused onto the photocathode of the streak camera, the output of which is proximity-coupled to the CCD. The spectrometer configuration is essentially Czerny-Turner, but off-the-shelf Nikon refraction lenses, rather than mirrors, are used for practicality and flexibility. Only recently assembled, the instrument requires significant refinement, but has now taken data on both bridge wire and dense plasma focus experiments. PMID:21034059

Goldin, F J; Meehan, B T; Hagen, E C; Wilkins, P R

2010-10-01

311

Redox alters yellow dragonflies into red  

PubMed Central

Body color change associated with sexual maturation—so-called nuptial coloration—is commonly found in diverse vertebrates and invertebrates, and plays important roles for their reproductive success. In some dragonflies, whereas females and young males are yellowish in color, aged males turn vivid red upon sexual maturation. The male-specific coloration plays pivotal roles in, for example, mating and territoriality, but molecular basis of the sex-related transition in body coloration of the dragonflies has been poorly understood. Here we demonstrate that yellow/red color changes in the dragonflies are regulated by redox states of epidermal ommochrome pigments. Ratios of reduced-form pigments to oxidized-form pigments were significantly higher in red mature males than yellow females and immature males. The ommochrome pigments extracted from the dragonflies changed color according to redox conditions in vitro: from red to yellow in the presence of oxidant and from yellow to red in the presence of reductant. By injecting the reductant solution into live insects, the yellow-to-red color change was experimentally reproduced in vivo in immature males and mature females. Discontinuous yellow/red mosaicism was observed in body coloration of gynandromorphic dragonflies, suggesting a cell-autonomous regulation over the redox states of the ommochrome pigments. Our finding extends the mechanical repertoire of pigment-based body color change in animals, and highlights an impressively simple molecular mechanism that regulates an ecologically important color trait.

Futahashi, Ryo; Kurita, Ryoji; Mano, Hiroaki; Fukatsu, Takema

2012-01-01

312

Integration of Banana Streak Badnavirus into the MusaGenome: Molecular and Cytogenetic Evidence  

Microsoft Academic Search

Breeding and tissue culture of certain cultivars of bananas (Musa) have led to high levels of banana streak badnavirus (BSV) infection in progeny from symptomless parents. BSV DNA hybridized to genomic DNA of one such parent, Obino l'Ewai, suggesting integration of viral sequences. Sequencing of clones of Obino l'Ewai genomic DNA revealed an interface between BSV andMusasequences and a complex

Glyn Harper; Julian O. Osuji; Roger Hull

1999-01-01

313

Comparison of cesium iodide and gold photocathodes for x-ray streak cameras  

Microsoft Academic Search

X-ray streak cameras at Lawrence Livermore Laboratory use gold transmission photocathodes for x-ray detection. Other photocathode materials which might provide improved sensitivity without loss of temporal resolution are of interest. Of particular interest are dielectrics such as cesium iodide. Simultaneous measurements of the sensitivity to 500 eV x-rays of both gold and cesium iodide photocathodes in the LLL Soft X-ray

G. L. Stradling; H. Medecki; D. T. Attwood; R. L. Kauffman; B. L. Henke

1979-01-01

314

Isolation of polymorphic tetranucleotide microsatellite markers for the streak-necked flycatcher Mionectes striaticollis  

Microsoft Academic Search

We have isolated 11 polymorphic microsatellite markers for the streak-necked flycatcher Mionectes striaticollis from genomic libraries enriched for either (AACC) n , (AAGG) n or (AAAG) n repetitive elements. The number of alleles ranged from four to 14 per locus with the observed heterozygosity ranging from 0.38 to 1.00. These markers will be useful for analysis of questions concerning population

CAROLYNE BARDELEBEN; MELISSA M. GRAY

2005-01-01

315

Structure and Temporal Dynamics of Populations within Wheat Streak Mosaic Virus Isolates  

Microsoft Academic Search

Variation within the Type and Sidney 81 strains of wheat streak mosaic virus was assessed by single-strand conformation polymorphism (SSCP) analysis and confirmed by nucleotide sequencing. Limiting-dilution subisolates (LDSIs) of each strain were evaluated for polymorphism in the P1, P3, NIa, and CP cistrons. Different SSCP patterns among LDSIs of a strain were associated with single-nucleotide substitutions. Sidney 81 LDSI-S10

JEFFREY S. HALL; ROY FRENCH; T. JACK MORRIS; DRAKE C. STENGER

2001-01-01

316

Streak camera technique to measure plastic plate velocities as a continuum  

Microsoft Academic Search

A technique was developed to measure velocities of thin plastic plates as a continuum with a streak camera at 20 mm\\/..mu.. s and 8.4X magnification. The plastic plates are bonded to an exploding foil with a transparent cylindrical barrel located over the exploding foil\\/plastic plate laminate on the side of the plastic plate. When the foil is exploded, a plastic

Paisley

1976-01-01

317

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

318

Note: A technique to capture and compose streak images of explosive events with unpredictable timing  

Microsoft Academic Search

The authors describe a method to capture optical data and construct digitized streak images for analysis of high-speed phenomena with unpredictable timing by using a high-speed video camera and software routines. Advances in high-speed video camera technology have led to development of cameras with frame rates (1×106 frames per second) and spatial resolution (1280×800 pixels) suitable to capture fast phenomena,

Gary R. Parker; Blaine W. Asay; Peter M. Dickson

2010-01-01

319

Optical laser-based THz streaking for full FEL pulse characterization  

NASA Astrophysics Data System (ADS)

Full temporal characterization of ultrashort, high brilliance x-ray pulses at Free Electron Laser (FEL) facilities, while elusive, will underpin their future use in experiments ranging from single-molecule imaging to extreme timescale x-ray science. This issue is especially acute when confronted with the characteristics of current generation FELs operating on the principle of self-amplified spontaneous emission, as most parameters fluctuate from pulse to pulse. We have achieved this crucial characterization by extending the techniques of photoelectron streaking originally developed for attosecond spectroscopy. In our experiments, high-intensity, optical laser generated single-cycle THz pulses were used to broaden and shift -- or streak -- the photoelectron spectrum of a noble gas target ionized by the incident FEL pulse. Due to the relatively long rise time of the THz streaking field (˜600 fs), these measurements allow for the arrival-time and temporal profile of femtosecond to hundred-femtosecond FEL pulses to be determined simultaneously and on a single-shot basis. Optical laser-based THz streaking is suited for use over the full range of photon energies and pulse durations produced at FELs, from XUV to the hard x-ray regime. Experiments have now been performed at the hard x-ray Linac-Coherent Light Source at the SLAC National Accelerator Laboratory as well as at the XUV Free Electron Laser in Hamburg. Distinct temporal features as short as 50 fs FWHM have been observed in the raw pulse profile prior to any correction for instrument resolution. While these first measurements have been resolution-limited, the potential for improvement to access the sub 10-fs range has also been demonstrated, which would allow for characterization and effective application of the shortest predicted, few-femtosecond x-ray pulses in the near future.

Cavalieri, Adrian

2012-06-01

320

Molecular organization of the cholesteryl ester droplets in the fatty streaks of human aorta.  

PubMed Central

X-ray diffraction patterns from human arterial specimens containing atherosclerotic fatty streak lesions exhibited a single sharp reflection, corresponding to a structural spacing of about 35 A. Specimens without lesions did not. When specimens with fatty streaks were heated, an order-to-disorder phase transition was revealed by the disappearance of the sharp reflection. The transition was thermally reversible and its temperature varied from aorta to aorta over a range from 28 degrees to 42 degrees C. Since cholesteryl ester droplets are a major component of fatty streaks, comparison studies were made of the diffraction behavior from pure cholesteryl esters. We found that the diffraction patterns of the fatty streak material could be accounted for by the organization of the cholesteryl esters into a liquid-crystalline smectic phase that melts from the smectic to a less ordered phase upon heating. When combined with the conclusions of others from polarized light microscopy, our study shows that a droplet in the smectic phase has well-defined concentric layers of lipid molecules. In each layer, the long axes of the molecules have a net radial orientation with respect to the droplet, but the side-to-side organization is disordered. We suggest that the accessibility of portions of the lipids for specific binding to enzymes or transport proteins may be restricted when they are in the smectic state, and that exchange of lipids with surrounding membranes or other potential binding sites may likewise be inhibited. The restriction in the smectic phase should be greater than in the less ordered phases that exist at higher temperatures. Images

Engelman, D M; Hillman, G M

1976-01-01

321

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

PubMed

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. PMID:19498569

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

2005-07-25

322

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

323

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

324

Cheap streak camera based on the LD-S-10 intensifier tube  

Microsoft Academic Search

Basic properties of a new streak camera and its test results are reported. To intensify images on its screen, we employed modular G1 tubes, the LD-A-1.0 and LD-A-0.33, enabling magnification of 1.0 and 0.33, respectively. If necessary, the LD-A-0.33 tube may be substituted by any other image intensifier of the LDA series, the choice to be determined by the size

Boris E. Dashevsky; Mikhail I. Krutik; Alexander L. Surovegin

1992-01-01

325

High temporal resolution and streak-free four-dimensional cone-beam computed tomography  

PubMed Central

Cone-beam computed tomography (CBCT) has been clinically used to verify patient position and to localize the target of treatment in image-guided radiation therapy (IGRT). However, when the chest and the upper abdomen are scanned, respiratory-induced motion blurring limits the utility of CBCT. In order to mitigate this blurring, respiratory-gated CBCT, i.e. 4D CBCT, was introduced. In 4D CBCT, the cone-beam projection data sets acquired during a gantry rotation are sorted into several respiratory phases. In these gated reconstructions, the number of projections for each respiratory phase is significantly reduced. Consequently, undersampling streaking artifacts are present in the reconstructed images, and the image contrast resolution is also significantly compromised. In this paper, we present a new method to simultaneously achieve both high temporal resolution (~100 ms) and streaking artifact-free image volumes in 4D CBCT. The enabling technique is a newly proposed image reconstruction method, i.e. prior image constrained compressed sensing (PICCS), which enables accurate image reconstruction using vastly undersampled cone-beam projections and a fully sampled prior image. Using PICCS, a streak-free image can be reconstructed from 10–20 cone-beam projections while the signal-to-noise ratio is determined by a denoising feature of the selected objective function and by the prior image, which is reconstructed using all of the acquired cone-beam projections. This feature of PICCS breaks the connection between the temporal resolution and streaking artifacts’ level in 4D CBCT. Numerical simulations and experimental phantom studies have been conducted to validate the method.

Leng, Shuai; Tang, Jie; Zambelli, Joseph; Nett, Brian; Tolakanahalli, Ranjini; Chen, Guang-Hong

2009-01-01

326

2-ps Hard X-Ray Streak Camera Measurements at Sector 7 Beamline of the Advanced Photon Source  

SciTech Connect

A hard X-ray streak camera capable of 2-ps time resolution is in operation at the Sector 7 beamline of the Advanced Photon Source. It is used for laser-pump, X-ray probe experiments using the Ti:Sapphire femtosecond laser system installed on the beamline. This streak camera, combined with standardized and prealigned experimental setups, can perform time-resolved liquid-phase absorption spectroscopy, reflectivity, and diffraction experiments.

Chollet, M.; Ahr, B.; Walko, D.A.; Rose-Petruck, C.; Adams, B.

2011-08-02

327

Ultrafast two-dimensional x-ray imaging with x-ray streak cameras for laser fusion research (invited)  

Microsoft Academic Search

Ultrafast two-dimensional x-ray imaging is required for diagnosing laser-driven inertial confinement fusion plasmas. Image sampling technique with x-ray streak cameras can meet this requirement. Multi-imaging x-ray streak camera method (MIXS) with temporal and spatial resolutions of 10 ps and 15 ?m, respectively, has been developed and successfully utilized for diagnosing the uniformity and heating process of the imploded core plasmas.

H. Shiraga; N. Miyanaga; M. Heya; M. Nakasuji; Y. Aoki; H. Azechi; T. Yamanaka; K. Mima

1997-01-01

328

Grazing-incidence mirror streak camera diagnostic for emission measurements of imploding z pinches on the Sandia Z-machine  

Microsoft Academic Search

A soft x-ray (0.1-1 keV) streak camera using a grazing-incidence mirror has been developed for the Sandia Z facility, a 20 MA, 100 ns rise-time accelerator that can generate >200 TW,2 MJ, x-ray pulses. The streak camera is used to measure with one dimension of spatial resolution the continuous time history of sub-kilo-electron-volts emission from z-pinch and radiation flow experiments.

D. F. Wenger; D. B. Sinars; K. L. Keller; R. A. Aragon; L. E. Ruggles; W. W. Simpson; P. H. Primm; J. L. Porter

2004-01-01

329

A Case of Intravitreal Bevacizumab Injection for the Treatment of Choroidal Neovascularization in Angioid Streaks  

PubMed Central

A 56-year-old Korean woman presented with decreased visual acuity of the right eye. She had a history of two photodynamic therapy treatments for choroidal neovascularization (CNV) due to angioid streaks in her left eye with central scarring and low visual acuity. She was diagnosed with subfoveal CNV due to angioid streaks in her right eye and treated with six intravitreal bevacizumab (1.25 mg / 0.05 mL) injections over one year. Best corrected visual acuity improved from 20 / 125 at baseline to 20 / 50 at the final visit. The area of CNV had changed into a fibrotic scar by the final visit, and fluorescein angiography and indocyanine green angiography revealed no evidence of leakage. Optical coherence tomography showed that central macular thickness decreased from 311 µm at baseline to 203 µm with complete resolution of subretinal and intraretinal fluid at the final visit. Intravitreal bevacizumab for CNV associated with angioid streaks prevented the progression of disease and resulted in the improvement of visual acuity after one year of follow-up in our patient.

Lee, Ji Woong; Shin, Jae Pil

2011-01-01

330

A possible scenario for the evolution of Banana streak virus in banana.  

PubMed

Outbreaks of Banana streak virus (BSV) have been recorded worldwide where Musa spp. is grown during the last 20 years with no convincing evidence of epidemics. Epidemics were previously reported in Uganda where BSV is currently endemic. BSV is a plant pararetrovirus of the family Caulimoviridae, genus Badnavirus it causes chlorosis leaf streak disease. The information currently available on banana streak disease makes it possible to identify a complex of distinct BSV species each causing the same disease. BSV exists in two states: one as an episomal form, infecting plant cells; the other as viral DNA integrated within the B genome of banana (endogenous BSV-eBSV) forming a viral genome for de novo viral particles. Both forms can be infectious in banana plants. The BSV phylogeny is polyphyletic with BSV distributed in two clades. Clade 1 clusters BSV species that occur worldwide and may have an eBSV counterpart, whereas Clade 3 only comprises BSV species from Uganda. Clearly, two distinct origins explain such BSV diversity. However, the epidemiology/outbreaks of BSV remains unclear and the role of eBSV needs to be clarified. In this review, the biodiversity of BSV is explained and discussed in the light of field and molecular epidemiology data. A scheme is proposed for the co-evolution of BSV and banana based on old or recent infection hypotheses related to African domestication sites and banana dissemination to explain the disease context. PMID:24457073

Iskra-Caruana, Marie-Line; Chabannes, Matthieu; Duroy, Pierre-Olivier; Muller, Emmanuelle

2014-06-24

331

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

332

Retention of stem cell plasticity in avian primitive streak cells and the effects of local microenvironment.  

PubMed

Primitive streak (PS) is the first structure occurring in embryonic gastrulation, in which the epiblast cells undergo the epithelial-mesenchymal transition to become the loose mesoderm cells subsequently. Because the mesoderm cells departing from different portions of PS are blessed with disparate migration trajectory and differentiation fate, one question is when the cell fate is determinated. To understand whether the cell fate and cell migration pattern will be alternated along with the microenvironment transformation, the traditional transplantation technology was used to replace the anterior PS cells in HH4 host embryo using posterior PS tissue labeled by green fluorescent protein (GFP) in the same stage donor embryo, and then, we tracked the migration trajectory of the GFP-positive cells with fluorescence stereomicroscope after incubation, and eventually verified the cell contribution from the transplants with in situ hybridization and immunocytochemistry. The same experimental strategy applied for posterior PS site replacement in host embryo. We found that the transplanted posterior PS cells to anterior part of streak followed the anterior PS cell migration pattern rather than kept its posterior streak cell migration trajectory, and so did vice versa. In addition, the transplants were involved in the contribution to the subsequent organogenesis as the local PS tissues affirmed by specific expression of myocardial or hematopoietic markers. Therefore, our data strongly suggest that the PS cells still keep stem cell plasticity during gastrulation and the eventual cell fate will depend on the spatial gene expression within local microenvironment along with development. PMID:23382139

Wang, Xiao-Yu; Li, Yan; Ma, Zheng-Lai; Wang, Li-Jing; Chuai, Manli; Münsterberg, Andrea; Geng, Jian-Guo; Yang, Xuesong

2013-03-01

333

RNAi-derived field resistance to Cassava brown streak disease persists across the vegetative cropping cycle.  

PubMed

A confined field trial was established to determine durability of RNAi-mediated resistance to Cassava brown streak disease (CBSD). Stem cuttings were obtained from field-grown cassava plants of cv 60444 transgenic for construct p718, consisting of an 894 bp inverted repeat sequence from the Ugandan Cassava brown streak virus (UCBSV) coat protein. Plants were established from three transgenic lines previously shown to provide complete resistance to UCBSV and differing levels of protection to the non-homologous virus species Cassava brown streak virus (CBSV), and grown for 11 months. CBSD symptoms were observed on shoots and storage roots of all non-transgenic cv 60444 control plants and transgenic lines p718-002 and p718-005, but not on p718-001. RT-PCR diagnostic showed tissues of plant lines p718-002 and p718-005 to be infected with CBSV, but free of UCBSV. All leaves and roots of p718-001 plants were to carry no detectable levels of either pathogen. Plants of cv 60444 in this field trial showed severe cassava mosaic disease symptoms, indicating that presence of replicating geminiviruses did not cause significant suppression of RNAi-mediated resistance to CBSD. Resistance to CBSD across a vegetative cropping cycle confirms earlier field data, and provides an important step in proof of concept for application of RNAi technology to control of CBSD under conditions encountered in farmers' fields. PMID:24296511

Odipio, John; Ogwok, Emmanuel; Taylor, Nigel J; Halsey, Mark; Bua, Anton; Fauquet, Claude M; Alicai, Titus

2014-01-01

334

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.

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

335

Portal vein gas in emergency surgery  

PubMed Central

Background Portal vein gas is an ominous radiological sign, which indicates a serious gastrointestinal problem in the majority of patients. Many causes have been identified and the most important was bowel ischemia and mesenteric vascular accident. The presentation of patients is varied and the diagnosis of the underlying problem depends mainly on the radiological findings and clinical signs. The aim of this article is to show the clinical importance of portal vein gas and its management in emergency surgery. Methods A computerised search was made of the Medline for publications discussing portal vein gas through March 2008. Sixty articles were identified and selected for this review because of their relevance. These articles cover a period from 1975–2008. Results Two hundreds and seventy-five patients with gas in the portal venous system were reported. The commonest cause for portal vein gas was bowel ischemia and mesenteric vascular pathology (61.44%). This was followed by inflammation of the gastrointestinal tract (16.26%), obstruction and dilatation (9.03%), sepsis (6.6%), iatrogenic injury and trauma (3.01%) and cancer (1.8%). Idiopathic portal vein gas was also reported (1.8%). Conclusion Portal vein gas is a diagnostic sign, which indicates a serious intra-abdominal pathology requiring emergency surgery in the majority of patients. Portal vein gas due to simple and benign cause can be treated conservatively. Correlation between clinical and diagnostic findings is important to set the management plan.

Hussain, Abdulzahra; Mahmood, Hind; El-Hasani, Shamsi

2008-01-01

336

Application of the continuous wavelet transform for analysis of formation and streaks in fibrous web structures  

NASA Astrophysics Data System (ADS)

The purpose of this research was to develop a method to characterize the distribution of material in paper and other fibrous webs using a method based on the continuous wavelet transform. While investigating this subject, two major advantages of the method were discovered. The first is the ability of the method to accommodate stochastic, non-stationary data sets by spatial localization of the spectral analysis. The second is its ability to distinguish flocs and lightweight region in the spectral analysis. The impetus for using continuous wavelet transform to analyze the structure of webs, and especially machine made papers, was the need to relate the final structure of the product to the forming processes. Given that objective, an existing method that separates the static and the stochastic components of the wavelet based energy spectrum of the cross machine profile was enhanced to account for additional characteristics of machine direction streaks. These included streak intermittency, off axis orientation and oscillation of the streak position in the cross machine direction. The method was validated using simulated and measured images of the paper formation (distribution of mass). This permitted the existing problem of separating different types of streaks from the wavelet energy spectra. The potential for application of the wavelet algorithm for online processing of webs was also examined. The zone-variance effect on the quality of separation of various streaks was studied. Descriptive parameters that can simplify and effectively represent the energy spectra were described and demonstrated. Machine direction variability that was not identified in the simultaneous space-scale analysis can now be incorporated in the analysis by using the spottiness parameter. The continuous wavelet transform was also used to delineate between heavy weight (floc) and lightweight zones to provide separate spectra for each. The manner in which these spectra change with floc geometry and density was tested by using simulated and actual formation images. Significant difference in the spectra reflected the manner in which the flocs were formed. This will find significant use for characterizing differences in processes that influence the uniformity of the structure and will allow the identification of process improvements.

Hasan, Asif

337

How Can Deep Vein Thrombosis Be Prevented?  

MedlinePLUS

... prevent deep vein thrombosis (DVT) and pulmonary embolism (PE). If you're at risk for these conditions: ... from forming. If you've had DVT or PE before, you can help prevent future blood clots. ...

338

Evaluating Diagnostic Decisions for Deep Vein Thrombosis.  

National Technical Information Service (NTIS)

Prompt diagnosis of proximal lower extremity deep vein thrombosis (PDVT) in outpatients is critical because of the risk of pulmonary embolism. Our primary purpose was to determine the accuracy of orthopaedists' and orthopaedic physical therapists' estimat...

D. L. Riddle B. Hillner P. Wells W. Zuelzer

2004-01-01

339

Intravenous pyogenic granuloma of the angular vein.  

PubMed

A 47-year-old woman presented with a painful mass below her left medial canthus. Examination revealed a 1-cm tender, smooth, pulseless, mobile mass inferior to the level of the anterior lacrimal crest. CT imaging was performed. Excision of the involved angular vein revealed a smooth, intralumenal lesion. Histopathologic examination demonstrated intravenous pyogenic granuloma (IVPG). There are approximately 30 reported cases of IVPG in the English literature, 2 of which arise in the periocular angular vein. The ultrasound and MRI characteristics of IVPG have been previously described. We describe the CT profile of this rare, benign tumor as a mildly heterogeneic, contrast-enhancing cylindrical lesion within, and conforming to the shape of, the angular vein. There is dilatation of the vein proximal to the lesion with marked narrowing distal to it secondary to obstruction of flow. On noncontrast imaging, the lesion is isodense with nasal mucosa and without calcifications. PMID:19617809

Winn, Bryan J; Herreid, Peter A; Sires, Bryan S

2009-01-01

340

Anatomy of the crocodilian spinal vein.  

PubMed

The crocodilian spinal vein is remarkably robust yet historically overlooked. Using corrosion casting, we describe the anatomy of this vessel and its connections with the caval and hepatic venous systems in representatives from four crocodilian genera. The spinal vein arises from an enlarged occipital sinus over the medulla and extends the entire length of the vertebral column. Unlike in squamate reptiles, the spinal vein is single (nonplexiform), voluminous, and situated dorsal to the spinal cord, and plexi lateral to the cord span between emerging intercostal veins. The connections with the other venous systems are otherwise similar to those in other tetrapods. The overall anatomy of this vessel and its abundant connections with the other venous systems indicate it likely plays a primary role in returning blood to the heart from all parts of the body. Preliminary studies of function suggest that this vessel could also play an adaptive role during basking and diving. PMID:14584034

Zippel, Kevin C; Lillywhite, Harvey B; Mladinich, Christopher R J

2003-12-01

341

Personal authentication using hand vein triangulation  

NASA Astrophysics Data System (ADS)

This paper presents a new approach to authenticate individuals using triangulation of hand vein images. The proposed method is fully automated and employs palm dorsal hand vein images acquired from the low-cost, near infrared, contactless imaging. The knuckle tips are used as key points for image normalization and the extraction of region of interest. The matching scores are generated in two parallel stages; (i) hierarchical matching score from the four topologies of triangulation in binarized vein structures and (ii) from the geometrical features consisting of knuckle point perimeter distances in the acquired images. The weighted score level combination from these two matching scores are used to authenticate the individuals. The achieved experimental results from the proposed system using contactless, palm dorsal hand vein images are promising and suggest more user friendly alternative for user identification.

Kumar, Ajay; Prathyusha, K. Venkata

2008-03-01

342

Nomadic Enhancers: Tissue-Specific cis-Regulatory Elements of yellow Have Divergent Genomic Positions among Drosophila Species  

PubMed Central

cis-regulatory DNA sequences known as enhancers control gene expression in space and time. They are central to metazoan development and are often responsible for changes in gene regulation that contribute to phenotypic evolution. Here, we examine the sequence, function, and genomic location of enhancers controlling tissue- and cell-type specific expression of the yellow gene in six Drosophila species. yellow is required for the production of dark pigment, and its expression has evolved largely in concert with divergent pigment patterns. Using Drosophila melanogaster as a transgenic host, we examined the expression of reporter genes in which either 5? intergenic or intronic sequences of yellow from each species controlled the expression of Green Fluorescent Protein. Surprisingly, we found that sequences controlling expression in the wing veins, as well as sequences controlling expression in epidermal cells of the abdomen, thorax, and wing, were located in different genomic regions in different species. By contrast, sequences controlling expression in bristle-associated cells were located in the intron of all species. Differences in the precise pattern of spatial expression within the developing epidermis of D. melanogaster transformants usually correlated with adult pigmentation in the species from which the cis-regulatory sequences were derived, which is consistent with cis-regulatory evolution affecting yellow expression playing a central role in Drosophila pigmentation divergence. Sequence comparisons among species favored a model in which sequential nucleotide substitutions were responsible for the observed changes in cis-regulatory architecture. Taken together, these data demonstrate frequent changes in yellow cis-regulatory architecture among Drosophila species. Similar analyses of other genes, combining in vivo functional tests of enhancer activity with in silico comparative genomics, are needed to determine whether the pattern of regulatory evolution we observed for yellow is characteristic of genes with rapidly evolving expression patterns.

Kalay, Gizem; Wittkopp, Patricia J.

2010-01-01

343

Endoscopic Saphenous Vein Harvesting: Minimally Invasive Video-Assisted Saphenectomy  

Microsoft Academic Search

A technique of greater saphenous vein harvesting for coronary artery revascularization using an endoscopic approach is herein detailed. The saphenous vein is directly identified at the knee through a single incision. An endoscopic dissector is advanced proximally and distally along the course of the vein, ligating side-branches with clips. The vein is divided at the ends of dissection, dependent on

David G Cable; Joseph A Dearani

1997-01-01

344

The Anti-spoofing Study of Vein Identification System  

Microsoft Academic Search

The vein identification systems identify a certain person by acquiring the local infrared image of hand (dorsa, palm and finger) and extracting vein pattern. The vein identification systems are widely used in security and surveillance field, but most of them ignore the liveness detection requirement or only check the temperature to prevent spoofing. After studying the spoofing method for vein

Bin Qin; Jian-fei Pan; Guang-zhong Cao; Ge-guo Du

2009-01-01

345

Biometric identification through palm and dorsal hand vein patterns  

Microsoft Academic Search

Hand vein patterns are among the biometric traits being investigated today for identification purposes, attracting interest from both the research community and industry. This paper presents a multimodal system that combines hand-palm vein and hand-dorsal vein biometrics information at the score level. The palm and dorsal veins are considered as texture samples being automatically extracted from the user's hand image.

Sanchit; Mauricio Ramalho; Paulo Lobato Correia; Luis Ducla Soares

2011-01-01

346

Finger vein extraction using gradient normalization and principal curvature  

Microsoft Academic Search

Finger vein authentication is a personal identification technology using finger vein images acquired by infrared imaging. It is one of the newest technologies in biometrics. Its main advantage over other biometrics is the low risk of forgery or theft, due to the fact that finger veins are not normally visible to others. Extracting finger vein patterns from infrared images is

Joon Hwan Choi; Wonseok Song; Taejeong Kim; Seung-Rae Lee; Hee Chan Kim

2009-01-01

347

Facial Vein Catheterization for Transvenous Embolization of the Cavernous Sinus  

PubMed Central

Summary We describe three cases of transvenous embolization of arteriovenous fistulas of the cavernous sinus, achieved through the facial vein approach. The facial vein was catheterized from a jugular vein access. This cervical approach offered good stability to the guiding catheter that permitted us to negotiate difficult curves of the facial vein and to recanalize venous thrombosis in one case.

Karygiannis, M.N.; Szatmary, Z.; Claudino, P.A.; Houdart, E.

2006-01-01

348

Epithelioid hemangioendothelioma encasing the left brachiocephalic vein  

PubMed Central

Epithelioid hemangioendotheliomas are rare vascular tumors, often arising from medium to large veins in the extremities. Symptoms of these tumors vary depending upon location. Rarely, tumors may arise in chest and involve large vessels in the mediastinum. We present a case of a 17-year-old male presenting with compressive symptoms of the left upper extremity who was found to have a large epithelioid hemangioendothelioma encasing the left brachiocephalic vein.

Long, Kristin; Skinner, Sean; Martin, Jeremiah

2014-01-01

349

Primary leiomyosarcoma of the innominate vein.  

PubMed

Primary venous leiomyosarcoma is rare. We report the case of a primary leiomyosarcoma of the left innominate vein, with neoplastic thrombus extending into the left jugular and subclavian veins. The tumor was curatively resected en bloc with anterior mediastinal and laterocervical lymphatics, through a median sternotomy prolonged into left cervicotomy. Primary venous sarcomas may be associated with prolonged survival in individual cases, with curative resection recommended as the standard treatment, in the absence of distant spread. PMID:17349340

Illuminati, Giulio; Miraldi, Fabio; Mazzesi, Giuseppe; D'urso, Antonio; Ceccanei, Gianluca; Bezzi, Marcello

2007-01-01

350

Human Identification Using Palm-Vein Images  

Microsoft Academic Search

This paper presents two new approaches to improve the performance of palm-vein-based identification systems pre- sented in the literature. The proposed approach attempts to more effectively accommodate the potential deformations, rotational and translational changes by encoding the orientation preserving features and utilizing a novel region-based matching scheme. We systematically compare the previously proposed palm-vein identification approaches with our proposed ones

Yingbo Zhou; Ajay Kumar

2011-01-01

351

Low contrast hand vein image enhancement  

Microsoft Academic Search

An image of hand vein acquired by near-infrared (NIR) imaging device usually suffers from low contrast and noise due to non-illumination and thickness of the hand skin. This makes subsequent processing such as segmentation difficult. In this work, combination of histogram-based and fuzzy-based contrast enhancement algorithms are applied on hand vein images. Comparative analysis on a test image using different

M. Yakno; J. Mohamad Saleh; B. Affendi Rosdi

2011-01-01

352

Iliocaval reconstruction in chronic deep vein thrombosis.  

PubMed

Chronic occlusion of the iliac veins and the inferior vena cava is a source of significant morbidity to often otherwise healthy patients, but it can be successfully managed with percutaneous recanalization and stenting. In this article, I summarize our current approach to patients with chronic occlusion of the iliac veins: patient selection, timing of intervention, commonly needed equipment, procedure, difficulties encountered, complications, clinical follow-up, and outcomes. An ideal patient is the one who is physically active (or was so before iliocaval occlusion), is at least 6 months past acute iliocaval thrombosis, has a patent common femoral vein and hepatic vein or caval confluence, and has no thrombophilic state. The duration of the occlusion has not affected our technical success of recanalization but may, by predisposing the patient to recurrent deep vein thrombosis, affect long-term patency by degrading the size and number of inflow vessels. Secondary patency rates at 4 years can be as high as 70%-90%. We anticipate that even higher success rates will follow with ongoing evolutions in device design (stents with appropriate diameter, length, radial conformity to conduits of varying diameter, and resistance to compression); better understanding of the biological interaction of the stent, the veins, and the coagulation system; and improved navigation systems to cross longer, occluded segments that are resistant to guidewire passage. PMID:24840966

Williams, David M

2014-06-01

353

Veins Improve Fracture Toughness of Insect Wings  

PubMed Central

During the lifetime of a flying insect, its wings are subjected to mechanical forces and deformations for millions of cycles. Defects in the micrometre thin membranes or veins may reduce the insect’s flight performance. How do insects prevent crack related material failure in their wings and what role does the characteristic vein pattern play? Fracture toughness is a parameter, which characterises a material’s resistance to crack propagation. Our results show that, compared to other body parts, the hind wing membrane of the migratory locust S. gregaria itself is not exceptionally tough (1.04±0.25 MPa?m). However, the cross veins increase the wing’s toughness by 50% by acting as barriers to crack propagation. Using fracture mechanics, we show that the morphological spacing of most wing veins matches the critical crack length of the material (1132 µm). This finding directly demonstrates how the biomechanical properties and the morphology of locust wings are functionally correlated in locusts, providing a mechanically ‘optimal’ solution with high toughness and low weight. The vein pattern found in insect wings thus might inspire the design of more durable and lightweight artificial ‘venous’ wings for micro-air-vehicles. Using the vein spacing as indicator, our approach might also provide a basis to estimate the wing properties of endangered or extinct insect species.

Dirks, Jan-Henning; Taylor, David

2012-01-01

354

Simultaneous detection and differentiation of Rice black streaked dwarf virus (RBSDV) and Southern rice black streaked dwarf virus (SRBSDV) by duplex real time RT-PCR  

PubMed Central

Background The diseases caused by Rice black streaked dwarf virus (RBSDV) and Southern rice black streaked dwarf virus (SRBSDV) have been occurring epidemically in China and southeastern Asia in recent years. A sensitive, reliable and quantitative method is required to detect and distinguish for RBSDV and SRBSDV in rice and vector insects. Results We developed a sensitive and lineage-specific duplex real time RT-qPCR for detection of RBSDV and SRBSDV in a single or/and double infection in rice samples. The duplex RT-qPCR was optimized using standard samples transcribed by T7 Large Scale RNA Production System in vitro. We developed a reliable system for duplex RT-qPCR, in which its co-efficiency of RBSDV and SRBSDV, were 91.6% and 90.7%, respectively. The coefficient of determination was more than 0.990; the slope of linear equation was ?3.542, and ?3.567, respectively. Out of 30 samples collected in North and Central China, which were suspected to be infected with these two viruses, 10 samples were detected RBSDV positive by RT-PCR and 12 samples by RT-qPCR. No mixed infections were found. Simultaneously, out of total 60 samples collected from Southern China, which were also suspected to be infected with these two viruses, 41 samples were determined SRBSDV positive by RT-PCR and 47 samples by RT-qPCR. Also in this case no mixed infections were found. The rice genes eEF-1a and UBQ5 were selected as internal controls for quantification assay also performed as good expression stability. Conclusion The duplex RT-qPCR assay provided as a sufficiently sensitive, specific, accurate, reproducible and rapid tool for the detection and differentiation of RBSDV and SRBSDV. The RT-qPCR assay can be used in routine diagnostic of these two viruses in order to study the disease epidemiology in rice crops.

2013-01-01

355

Complete genome sequence of a new begomovirus associated with yellow mosaic disease of Hemidesmus indicus in India.  

PubMed

The complete DNA A genome of a virus isolate associated with yellow mosaic disease of a medicinal plant, Hemidesmus indicus, from India was cloned and sequenced. The length of DNA A was 2825 nucleotides, 35 nucleotides longer than the unit genome of monopartite begomoviruses. Comparison of the nucleotide sequence of DNA A of the virus isolate with those of other begomoviruses showed maximum sequence identity of 69 % to DNA A of ageratum yellow vein China virus (AYVCNV; AJ558120) and 68 % with tomato yellow leaf curl virus- LBa4 (TYLCV; EF185318), and it formed a distinct clade in phylogenetic analysis. The genome organization of the present virus isolate was found to be similar to that of Old World monopartite begomoviruses. The genome was considered to be monopartite, because association of DNA B and ? satellite DNA components was not detected. Based on its sequence identity (<70 %) to all other begomoviruses known to date and ICTV (International Committee on Taxonomy of Viruses) species demarcating criteria (<89 % identity), it is considered a member of a novel begomovirus species, and the tentative name "Hemidesmus yellow mosaic virus" (HeYMV) is proposed. PMID:24276235

Reddy, M Sreekanth; Kanakala, S; Srinivas, K P; Hema, M; Malathi, V G; Sreenivasulu, P

2014-05-01

356

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

NASA Astrophysics Data System (ADS)

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.

2013-07-01

357

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

358

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

PubMed

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. PMID:23902041

Qiao, J; Jaanimagi, P A; Boni, R; Bromage, J; Hill, E

2013-07-01

359

Barley yellow rust in North America.  

PubMed

Yellow rust of barley is an invasive disease that was found in the past 10 years in North America. The causal agent, Puccinia striiformis f. sp. hordei, was introduced into Colombia, South America, from Europe in 1975. It spread to all major barley-producing areas in South America by 1982. In 1988 it was found in Mexico and in 1991 in Texas. Since then it has been found in all major barley-producing areas of the American West. Originally described as race (R) 24, barley yellow rust in North America is now known to be a very heterogeneous population. Resistance has been identified, evaluated, and is being introduced into commercial malting and other barley cultivars. Cultural and chemical controls are effective and available. An integrated approach using general field resistance and other tactics is described for sustainable management of barley yellow rust. PMID:11701870

Brown, W M; Hill, J P; Velasco, V R

2001-01-01

360

Nutcracker syndrome complicated by left renal vein thrombosis.  

PubMed

Isolated renal vein thrombosis is a rare entity. We present a patient whose complaint of flank pain led to the diagnosis of a renal vein thrombosis. In this case, abdominal computed tomography angiography was helpful in diagnosing the nutcracker syndrome complicated by the renal vein thrombosis. Anticoagulation was started and three weeks later, CTA showed complete disappearance of the renal vein thrombosis. To treat the Nutcracker syndrome, we proposed left renal vein transposition that the patient consented to. PMID:24349817

Mallat, Faouzi; Hmida, Wissem; Jaidane, Mehdi; Mama, Nadia; Mosbah, Faouzi

2013-01-01

361

Nutcracker Syndrome Complicated by Left Renal Vein Thrombosis  

PubMed Central

Isolated renal vein thrombosis is a rare entity. We present a patient whose complaint of flank pain led to the diagnosis of a renal vein thrombosis. In this case, abdominal computed tomography angiography was helpful in diagnosing the nutcracker syndrome complicated by the renal vein thrombosis. Anticoagulation was started and three weeks later, CTA showed complete disappearance of the renal vein thrombosis. To treat the Nutcracker syndrome, we proposed left renal vein transposition that the patient consented to.

Mallat, Faouzi; Hmida, Wissem; Jaidane, Mehdi; Mama, Nadia; Mosbah, Faouzi

2013-01-01

362

Minor vein structure and sugar transport in Arabidopsis thaliana  

Microsoft Academic Search

.   Leaf and minor vein structure were studied in Arabidopsis thaliana (L.) Heynh. to gain insight into the mechanism(s) of phloem loading. Vein density (length of veins per unit leaf area) is\\u000a extremely low. Almost all veins are intimately associated with the mesophyll and are probably involved in loading. In transverse\\u000a sections of veins there are, on average, two companion

Edith Haritatos; Richard Medville; Robert Turgeon

2000-01-01

363

Symplastic Transfer of Fluorescent Dyes from Mesophyll to Sieve Tube in Stripped Leaf Tissue and Partly Isolated Minor Veins of Commelina benghalensis.  

PubMed

We have stripped small (3 x 3 mm) fields of the upper and the opposite lower epidermis of Commelina benghalensis leaves. Pectinase treatment of the resulting chlorenchyma windows produced free-lying viable minor veins with small lumps of mesophyll cells attached. These veins were still connected with the intact remainder of the leaf. Fluorescent dyes were injected into mesophyll cells or mestome sheath cells. Continuous following of the dye from the moment of injection and use of the simple vein system allowed an unhindered and precise assessment of the cell-to-cell route of dye transfer. Disodium fluorescein and Lucifer Yellow CH injected into mesophyll or mestome sheath cells readily moved to the sieve tube. This symplastic dye transfer from mesophyll to sieve tube was also observed after injection into unmacerated stripped leaf tissue. The displacement of fluorescent dyes substantiates a symplastic continuity between mesophyll and sieve tube and therefore supports the possibility of symplastic phloem loading. PMID:16666366

van Kesteren, W J; van der Schoot, C; van Bel, A J

1988-11-01

364

Yellow fever vaccine-associated viscerotropic disease.  

PubMed

Yellow fever is a mosquito-transmitted hemorrhagic viral disease that is endemic to tropical regions in South America and Africa. It remains a significant health concern for deploying military personnel, accordingly vaccination is frequently performed on troops. Although the vaccine is generally administered with only minor complications, rare severe complications are also reported. Herein, we report a mild case of yellow fever vaccine-associated viscerotropic disease 4 days after administration of the vaccine. The various complications of the vaccine and their pathogenesis are also reviewed. PMID:22594140

Rowland, Michael; Plackett, Timothy P; Smith, Richard

2012-04-01

365

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

SciTech Connect

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 {mu}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{sup 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.

Johnston, Mark D.; Oliver, Bryan V. [Advanced Radiographic Technologies, Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185-1195 (United States); Droemer, Darryl W.; Frogget, Brent; Crain, Marlon D. [National Security Technologies, LLC, P.O. Box 98521, Las Vegas, Nevada 89193 (United States); Maron, Yitzhak [Weizmann Institute of Science, Rehovot, Israel 76100 (Israel)

2012-08-15

366

Transgenic RNA interference (RNAi)-derived field resistance to cassava brown streak disease.  

PubMed

Cassava brown streak disease (CBSD), caused by the Ipomoviruses Cassava brown streak virus (CBSV) and Ugandan Cassava brown streak virus (UCBSV), is considered to be an imminent threat to food security in tropical Africa. Cassava plants were transgenically modified to generate small interfering RNAs (siRNAs) from truncated full-length (894-bp) and N-terminal (402-bp) portions of the UCBSV coat protein (?CP) sequence. Seven siRNA-producing lines from each gene construct were tested under confined field trials at Namulonge, Uganda. All nontransgenic control plants (n = 60) developed CBSD symptoms on aerial tissues by 6 months after planting, whereas plants transgenic for the full-length ?CP sequence showed a 3-month delay in disease development, with 98% of clonal replicates within line 718-001 remaining symptom free over the 11-month trial. Reverse transcriptase-polymerase chain reaction (RT-PCR) diagnostics indicated the presence of UCBSV within the leaves of 57% of the nontransgenic controls, but in only two of 413 plants tested (0.5%) across the 14 transgenic lines. All transgenic plants showing CBSD were PCR positive for the presence of CBSV, except for line 781-001, in which 93% of plants were confirmed to be free of both pathogens. At harvest, 90% of storage roots from nontransgenic plants were severely affected by CBSD-induced necrosis. However, transgenic lines 718-005 and 718-001 showed significant suppression of disease, with 95% of roots from the latter line remaining free from necrosis and RT-PCR negative for the presence of both viral pathogens. Cross-protection against CBSV by siRNAs generated from the full-length UCBSV ?CP confirms a previous report in tobacco. The information presented provides proof of principle for the control of CBSD by RNA interference-mediated technology, and progress towards the potential control of this damaging disease. PMID:22845735

Ogwok, Emmanuel; Odipio, John; Halsey, Mark; Gaitán-Solís, Eliana; Bua, Anton; Taylor, Nigel J; Fauquet, Claude M; Alicai, Titus

2012-12-01

367

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.

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

2012-01-01

368

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

369

Deep vein thrombosis: a clinical review  

PubMed Central

Background: Deep vein thrombosis (DVT) is the formation of blood clots (thrombi) in the deep veins. It commonly affects the deep leg veins (such as the calf veins, femoral vein, or popliteal vein) or the deep veins of the pelvis. It is a potentially dangerous condition that can lead to preventable morbidity and mortality. Aim: To present an update on the causes and management of DVT. Methods: A review of publications obtained from Medline search, medical libraries, and Google. Results: DVT affects 0.1% of persons per year. It is predominantly a disease of the elderly and has a slight male preponderance. The approach to making a diagnosis currently involves an algorithm combining pretest probability, D-dimer testing, and compression ultrasonography. This will guide further investigations if necessary. Prophylaxis is both mechanical and pharmacological. The goals of treatment are to prevent extension of thrombi, pulmonary embolism, recurrence of thrombi, and the development of complications such as pulmonary hypertension and post-thrombotic syndrome. Conclusion: DVT is a potentially dangerous condition with a myriad of risk factors. Prophylaxis is very important and can be mechanical and pharmacological. The mainstay of treatment is anticoagulant therapy. Low-molecular-weight heparin, unfractionated heparin, and vitamin K antagonists have been the treatment of choice. Currently anticoagulants specifically targeting components of the common pathway have been recommended for prophylaxis. These include fondaparinux, a selective indirect factor Xa inhibitor and the new oral selective direct thrombin inhibitors (dabigatran) and selective factor Xa inhibitors (rivaroxaban and apixaban). Others are currently undergoing trials. Thrombolytics and vena caval filters are very rarely indicated in special circumstances.

Kesieme, Emeka; Kesieme, Chinenye; Jebbin, Nze; Irekpita, Eshiobo; Dongo, Andrew

2011-01-01

370

Human umbilical veins and autogenous veins as canine arterial bypass grafts.  

PubMed Central

Glutaraldehyde treated human umbilical veins (Dardik Biograft) were used to bypass short segments of the femoral artery in 15 dogs and were compared to autogenous jugular veins placed in the contralateral femoral artery of each animal. All 15 autogenous jugular veins remained patent for the four month period of observation whereas thrombosis occurred in seven of 15 umbilical vein grafts. This patency rate of 53% was significantly lower than that observed for autogenous jugular veins (p less than 0.01). Neointimal Fibrous Hyperplasia (NFH) a the proximal anastomosis was responsible for six of the seven umbilical vein graft occlusions. Of the eight patent umbilical veins, five had varying degrees of proximal anastomotic stenosis secondary to NFH. Histological examination of each graft revealed significant fibroblastic proliferation and collagen deposition within the lumen of stenosed and thrombosed grafts. Although human umbilical veins have distinct advantages over other prosthetics, such as availability and flexibility, the incidence of experimental neointimal fibrous hyperplasia causing anastomotic stenosis and thrombosis is prohibitively high. Images Fig. 1. Fig. 2.

Oblath, R W; Buckley, F O; Donnelly, W A; Green, R M; Deweese, J A

1978-01-01

371

Human umbilical veins and autogenous veins as canine arterial bypass grafts.  

PubMed

Glutaraldehyde treated human umbilical veins (Dardik Biograft) were used to bypass short segments of the femoral artery in 15 dogs and were compared to autogenous jugular veins placed in the contralateral femoral artery of each animal. All 15 autogenous jugular veins remained patent for the four month period of observation whereas thrombosis occurred in seven of 15 umbilical vein grafts. This patency rate of 53% was significantly lower than that observed for autogenous jugular veins (p less than 0.01). Neointimal Fibrous Hyperplasia (NFH) a the proximal anastomosis was responsible for six of the seven umbilical vein graft occlusions. Of the eight patent umbilical veins, five had varying degrees of proximal anastomotic stenosis secondary to NFH. Histological examination of each graft revealed significant fibroblastic proliferation and collagen deposition within the lumen of stenosed and thrombosed grafts. Although human umbilical veins have distinct advantages over other prosthetics, such as availability and flexibility, the incidence of experimental neointimal fibrous hyperplasia causing anastomotic stenosis and thrombosis is prohibitively high. PMID:686880

Oblath, R W; Buckley, F O; Donnelly, W A; Green, R M; Deweese, J A

1978-08-01

372

Varicose Veins, Deep Vein Thrombosis, and Haemorrhoids: Epidemiology and Suggested Aetiology  

Microsoft Academic Search

Current concepts on the aetiology of varicose veins, deep vein thrombosis, and haemorrhoids have been examined and, in the light of epidemiological evidence, found wanting.It is suggested that the fundamental cause of these disorders is faecal arrest which is the result of a low-residue diet.

Denis P. Burkitt

1972-01-01

373

[Calcified deep vein thrombosis in a patient with recurrent deep vein thrombosis and sarcoidosis].  

PubMed

In this article, we present a rare case of calcified deep vein thrombosis in a 42-year-old female patient with frequent relapses of pulmonary sarcoidosis since 1995, for which she was on maintenance therapy with corticosteroids and with consequential secondary diabetes. Recent femoral vein thrombosis was diagnosed with color Doppler in 2012. At the same time, calcified occlusive thrombus in vena cava inferior from the level of renal vein to the confluence of hepatic veins was diagnosed on abdominal multi-slice computed tomography (MSCT). Digital subtraction venography (DSV) revealed a well-developed collateral circulation through the paravertebral veins, azygos and hemiazygos vein. There were no risk factors for thrombosis other than sarcoidosis and diabetes. Deep vein thrombosis is rarely described with sarcoidosis, but according to literature reports, it usually appears as a recurrence and simultaneously at multiple locations. According to the current knowledge, we cannot say for sure whether it is a disease with an increased risk of deep vein thrombosis or there is a combination of multiple risk factors present simultaneously. PMID:24979886

Krmek, Dubravka Zupani?; Brajkovi?, Ivana; Beki?, Dinko; Krni?, Antun; Jurkovi?, Petar; Pavlovi?, Tomislav

2013-12-01

374

Varicose Veins, Deep Vein Thrombosis, and Haemorrhoids: Epidemiology and Suggested Aetiology  

PubMed Central

Current concepts on the aetiology of varicose veins, deep vein thrombosis, and haemorrhoids have been examined and, in the light of epidemiological evidence, found wanting. It is suggested that the fundamental cause of these disorders is faecal arrest which is the result of a low-residue diet.

Burkitt, Denis P.

1972-01-01

375

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

376

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

377

Picosecond fluorescence spectroscopy of purple membrane in Halobacterium halobium with a photon-counting streak camera  

NASA Astrophysics Data System (ADS)

Fluorescence lifetimes and spectra of native and deionized purple membranes of Halobacterium halobium at 22°C were measured to be <3 and 12±4 ps, respectively, with a photon-counting streak camera system. The results confirmed that the blue-shifted transient previously found by absorption spectroscopy is attributed to bacteriorhodopsin in the lowest excited-singlet state. Ultraweak fluorescence of the light-adapted purple membrane with 2.5 × 10 -4 quantum yield could be detected even though the excitation pulse energy at 570 nm was reduced to 0.88 pJ (72 ?W average power).

Ohtani, Hiroyuki; Ishikawa, Mitsuru; Itoh, Hiroyasu; Takiguchi, Yoshihiro; Urakami, Tsuneyuki; Tsuchiya, Yutaka

1990-05-01

378

Streaked optical pyrometer system for laser-driven shock-wave experiments on OMEGA.  

PubMed

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 approximately megabar 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. PMID:17411209

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

2007-03-01

379

Transient electric fields in laser plasmas observed by proton streak deflectometry  

SciTech Connect

A novel proton imaging technique was applied which allows a continuous temporal record of electric fields within a time window of several nanoseconds. This 'proton streak deflectometry' was used to investigate transient electric fields of intense ({approx}10{sup 17} W/cm{sup 2}) laser irradiated foils. We found out that these fields with an absolute peak of up to 10{sup 8} V/m extend over millimeter lateral extension and decay at nanosecond duration. Hence, they last much longer than the (approximately picosecond) laser excitation and extend much beyond the laser irradiation focus.

Sokollik, T.; Schnuerer, M.; Ter-Avetisyan, S.; Nickles, P. V.; Risse, E.; Kalashnikov, M.; Sandner, W. [Max Born Institut, Max Born Str. 2a, D-12489 Berlin (Germany); Priebe, G. [STFC Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Amin, M.; Toncian, T.; Willi, O. [Heinrich Heine Universitaet Duesseldorf, D-40225 Duesseldorf (Germany); Andreev, A. A. [Vavilov State Optical Institute, St. Petersburg (Russian Federation)

2008-03-03

380

Resolving the shape of a sonoluminescence pulse in sulfuric acid by the use of streak camera.  

PubMed

A streak camera is used to measure the shape of sonoluminescence pulses from a cavitation bubble levitated stably in a sulfuric acid solution. The shape and response to an acoustic pressure field of the sonoluminescence pulse in 85% by weight sulfuric acid are qualitatively similar to those in water. However, the pulse width in sulfuric acid is wider than that in water by over one order of magnitude. The width of the sonoluminescence pulse is strongly dependent on the concentration of the sulfuric acid solution, while the skewed distribution of the shape remains unchanged. PMID:19507941

Huang, Wei; Chen, Weizhong; Cui, Weicheng

2009-06-01

381

High resolution vidicon-based readout system for photon-counting streak camera applications  

NASA Technical Reports Server (NTRS)

The design, implementation, and evaluation of a high-resolution vidicon-based reconfigurable imaging system for integration into a photon-counting streak camera that can be readily coupled to a standard interface and computer have been achieved. Experimental results are reported which demonstrate that the design goals are met, providing the capability to measure differential time to better than 3 picosecond accuracy. Augmented by real-time calibration, the accuracy, linearity, noise levels, and stability of the system are adequate to support dual wavelength laser ranging.

Varghese, Thomas K.; Steggerda, Charles; Selden, Mike; Oldham, Thomas; Degnan, John J.

1992-01-01

382

21 CFR 137.275 - Yellow corn meal.  

Code of Federal Regulations, 2013 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION CEREAL FLOURS AND RELATED PRODUCTS Requirements for Specific Standardized Cereal Flours and Related Products § 137.275 Yellow corn meal. Yellow corn meal...

2013-04-01

383

21 CFR 137.280 - Bolted yellow corn meal.  

Code of Federal Regulations, 2013 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION CEREAL FLOURS AND RELATED PRODUCTS Requirements for Specific Standardized Cereal Flours and Related Products § 137.280 Bolted yellow corn meal. Bolted yellow...

2013-04-01

384

Dietary treatment of chylous ascites in yellow nail syndrome  

Microsoft Academic Search

Chylous ascites has rarely been reported in yellow nail syndrome. A case of chylous ascites in yellow nail syndrome is described which was treated successfully with dietary restriction of fat and supplements of medium chained triglycerides.

W C Tan

1989-01-01

385

Endovascular Radiofrequency Ablation for Varicose Veins  

PubMed Central

Executive Summary Objective The objective of the MAS evidence review was to conduct a systematic review of the available evidence on the safety, effectiveness, durability and cost–effectiveness of endovascular radiofrequency ablation (RFA) for the treatment of primary symptomatic varicose veins. Background The Ontario Health Technology Advisory Committee (OHTAC) met on August 26th, 2010 to review the safety, effectiveness, durability, and cost-effectiveness of RFA for the treatment of primary symptomatic varicose veins based on an evidence-based review by the Medical Advisory Secretariat (MAS). Clinical Condition Varicose veins (VV) are tortuous, twisted, or elongated veins. This can be due to existing (inherited) valve dysfunction or decreased vein elasticity (primary venous reflux) or valve damage from prior thrombotic events (secondary venous reflux). The end result is pooling of blood in the veins, increased venous pressure and subsequent vein enlargement. As a result of high venous pressure, branch vessels balloon out leading to varicosities (varicose veins). Symptoms typically affect the lower extremities and include (but are not limited to): aching, swelling, throbbing, night cramps, restless legs, leg fatigue, itching and burning. Left untreated, venous reflux tends to be progressive, often leading to chronic venous insufficiency (CVI). A number of complications are associated with untreated venous reflux: including superficial thrombophlebitis as well as variceal rupture and haemorrhage. CVI often results in chronic skin changes referred to as stasis dermatitis. Stasis dermatitis is comprised of a spectrum of cutaneous abnormalities including edema, hyperpigmentation, eczema, lipodermatosclerosis and stasis ulceration. Ulceration represents the disease end point for severe CVI. CVI is associated with a reduced quality of life particularly in relation to pain, physical function and mobility. In severe cases, VV with ulcers, QOL has been rated to be as bad or worse as other chronic diseases such as back pain and arthritis. Lower limb VV is a very common disease affecting adults – estimated to be the 7th most common reason for physician referral in the US. There is a very strong familial predisposition to VV. The risk in offspring is 90% if both parents affected, 20% when neither affected and 45% (25% boys, 62% girls) if one parent affected. The prevalence of VV worldwide ranges from 5% to 15% among men and 3% to 29% among women varying by the age, gender and ethnicity of the study population, survey methods and disease definition and measurement. The annual incidence of VV estimated from the Framingham Study was reported to be 2.6% among women and 1.9% among men and did not vary within the age range (40-89 years) studied. Approximately 1% of the adult population has a stasis ulcer of venous origin at any one time with 4% at risk. The majority of leg ulcer patients are elderly with simple superficial vein reflux. Stasis ulcers are often lengthy medical problems and can last for several years and, despite effective compression therapy and multilayer bandaging are associated with high recurrence rates. Recent trials involving surgical treatment of superficial vein reflux have resulted in healing and significantly reduced recurrence rates. Endovascular Radiofrequency Ablation for Varicose Veins RFA is an image-guided minimally invasive treatment alternative to surgical stripping of superficial venous reflux. RFA does not require an operating room or general anaesthesia and has been performed in an outpatient setting by a variety of medical specialties including surgeons and interventional radiologists. Rather than surgically removing the vein, RFA works by destroying or ablating the refluxing vein segment using thermal energy delivered through a radiofrequency catheter. Prior to performing RFA, color-flow Doppler ultrasonography is used to confirm and map all areas of venous reflux to devise a safe and effective treatment plan. The RFA procedure involves the introduction of a guide wire into the target v

2011-01-01

386

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

387

A new approach for sclera vein recognition  

NASA Astrophysics Data System (ADS)

The vein structure in the sclera is stable over time, unique to each person, and well suited for human identification. A few researchers have performed sclera vein pattern recognition and reported promising initial results. Sclera recognition poses several challenges: the vein structure moves and deforms with the movement of the eye; images of sclera patterns are often defocused and/or saturated; and, most importantly, the vein structure in the sclera is multi-layered and has complex non-linear deformation. In this paper, we proposed a new method for sclera recognition: First, we developed a color-based sclera region estimation scheme for sclera segmentation. Second, we designed a Gabor wavelet-based sclera pattern enhancement method, and an adaptive thresholding method to emphasize and binarize the sclera vein patterns. Third, we proposed a line descriptor-based feature extraction, registration, and matching method that is illumination-, scale-, orientation-, and deformation-invariant, and can mitigate the multi-layered deformation effects exhibited in the sclera and tolerate segmentation error. It is empirically verified using the UBIRIS database that the proposed method can perform accurate sclera recognition.

Thomas, N. L.; Du, Yingzi; Zhou, Zhi

2010-04-01

388

Optimization of subcutaneous vein contrast enhancement  

NASA Astrophysics Data System (ADS)

A technique for enhancing the contrast of subcutaneous veins has been demonstrated. This techniques uses a near IR light source and one or more IR sensitive CCD TV cameras to produce a contrast enhanced image of the subcutaneous veins. This video image of the veins is projected back onto the patient's skin using a n LCD video projector. The use of an IR transmitting filter in front of the video cameras prevents any positive feedback from the visible light from the video projector from causing instabilities in the projected image. The demonstration contrast enhancing illuminator has been tested on adults and children, both Caucasian and African-American, and it enhances veins quite well in all cases. The most difficult cases are those where significant deposits of subcutaneous fat are present which make the veins invisible under normal room illumination. Recent attempts to see through fat using different IR wavelength bands and both linearly and circularly polarized light were unsuccessful. The key to seeing through fat turns out to be a very diffuse source of RI light. Results on adult and pediatric subjects are shown with this new IR light source.

Zeman, Herbert D.; Lovhoiden, Gunnar; Deshmukh, Harshal

2000-05-01

389

Replacement of the yellow dixie cup  

Microsoft Academic Search

The upgrade and improvement of life support systems has always been a priority for the United States Air Force. A study is currently underway to determine the feasibility of replacing the emergency passenger protective breathing device used on USAF transport aircraft. The present system, the “yellow dixie cup”, provides supplemental oxygen in the event of a rapid decompression. The system

E. Ancman; C. Poprik

1994-01-01

390

Adverse event reports following yellow fever vaccination  

Microsoft Academic Search

Yellow fever (YF) vaccine has been used for prevention of YF since 1937 with over 500 million doses administered. However, rare reports of severe adverse events following vaccination have raised concerns about the vaccine’s safety. We reviewed reports of adverse events following YF vaccination reported to the U.S. Vaccine Adverse Event Reporting System (VAERS) from 2000 to 2006. We used

Nicole P. Lindsey; Betsy A. Schroeder; Elaine R. Miller; M. Miles Braun; Alison F. Hinckley; Nina Marano; Barbara A. Slade; Elizabeth D. Barnett; Gary W. Brunette; Katherine Horan; J. Erin Staples; Phyllis E. Kozarsky; Edward B. Hayes

2008-01-01

391

Optical anisotropy in photoactive yellow protein film  

NASA Astrophysics Data System (ADS)

Photoinduced anisotropy of photoactive yellow protein film in polyvinyl alcohol matrix was investigated. Studies were done for wavelengths longer than 446 nm, the location of the absorption maximum. Dicroism and birefringence of the sample were found to be wavelength dependent but intensity independent.

Vanhanen, J.; Leppanen, V. P.; Jaaskelainen, T.; Parkkinen, S.; Parkkinen, J. P. S.

2001-01-01

392

Phytoplankton and sediments in Yellow Sea  

NASA Technical Reports Server (NTRS)

Sediment and phytoplankton cloud the waters of the Yellow Sea in this true-color MODIS image acquired March 18, 2002. The swirls of sediment appear as a murky brownish blue color, while the phytoplankton are purely blue green and are concentrated around the small island in the lower right corner of the image.

2002-01-01

393

Oversized vein grafts develop advanced atherosclerosis in hypercholesterolemic minipigs  

PubMed Central

Background Accelerated atherosclerosis is the main cause of late aortocoronary vein graft failure. We aimed to develop a large animal model for the study of pathogenesis and treatment of vein graft atherosclerosis. Methods An autologous reversed jugular vein graft was inserted end-to-end into the transected common carotid artery of ten hypercholesteroemic minipigs. The vein grafts were investigated 12-14 weeks later with ultrasound and angiograpy in vivo and microscopy post mortem. Results One minipig died during follow up (patent vein graft at autopsy), and one vein graft thrombosed early. In the remaining eight patent vein grafts, the mean (standard deviation) intima-media thickness was 712 ?m (276 ?m) versus 204 ?m (74 ?m) in the contralateral control internal jugular veins (P < .01). Advanced atherosclerotic plaques were found in three of four oversized vein grafts (diameter of graft > diameter of artery). No plaques were found in four non-oversized vein grafts (P < .05). Conclusions Our model of jugular vein graft in the common carotid artery of hypercholesterolemic minipigs displayed the components of human vein graft disease, i.e. thrombosis, intimal hyperplasia, and atherosclerosis. Advanced atherosclerosis, the main cause of late failure of human aortocoronary vein grafts was only seen in oversized grafts. This finding suggests that oversized vein grafts may have detrimental effects on patient outcome.

2012-01-01

394

Unusual manifestation of the yellow nail syndrome - Case report.  

PubMed

The yellow nail syndrome is a rare disorder characterized by the classic triad of yellow and dystrophic nails, lymphedema and pleural effusion. We report in this paper a case of yellow nail syndrome, presenting the classic triad of the disease, associated with an unusual lymph accumulation in the abdomen region. PMID:24937826

Papaiordanou, Francine; Epstein, Marina Gabrielle; Miyaoka, Mariana Yumi; Yang, Jeane Jeong Hoon; Pires, Mario Cezar

2014-06-01

395

Wind-driven effects on the Yellow Sea Warm Current  

Microsoft Academic Search

The Yellow Sea is a shallow basin with an average depth of 44 m located between China and the Korean Peninsula. One of the dominant ocean circulation features of the Yellow Sea is a warm water intrusion known as the Yellow Sea Warm Current. This feature is present throughout the year but reaches its farthest northward extension in winter. The

Andrea C. Mask; James J. O'Brien; Ruth Preller

1998-01-01

396

Is it time for a new yellow fever vaccine?  

Microsoft Academic Search

An inexpensive live attenuated vaccine (the 17D vaccine) against yellow fever has been effectively used to prevent yellow fever for more than 70 years. Interest in developing new inactivated vaccines has been spurred by recognition of rare but serious, sometimes fatal adverse events following live virus vaccination. A safer inactivated yellow fever vaccine could be useful for vaccinating people at

Edward B. Hayes

2010-01-01

397

Nutritional properties of yellow mombin ( Spondias mombin L.) pulp  

Microsoft Academic Search

Yellow mombin (Spondias mombin L.) is a tropical fruit with increasing acceptance in both national and international fruit markets. The aim of this work was to evaluate the centesimal composition, mineral content, total phenolics, antioxidant activity, and characterize the carotenoids of frozen yellow mombin pulp. Results indicated that the yellow mombin pulp contained an important amount of potassium and copper.

Júlia Hauck Tiburski; Amauri Rosenthal; Rosires Deliza; Ronoel L. de Oliveira Godoy; Sidney Pacheco

2011-01-01

398

49 CFR 173.188 - White or yellow phosphorus.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false White or yellow phosphorus. 173.188 Section 173.188 Transportation...Class 1 and Class 7 § 173.188 White or yellow phosphorus. Phosphorus, white or yellow, when offered for...

2013-10-01

399

Unusual manifestation of the yellow nail syndrome - Case report*  

PubMed Central

The yellow nail syndrome is a rare disorder characterized by the classic triad of yellow and dystrophic nails, lymphedema and pleural effusion. We report in this paper a case of yellow nail syndrome, presenting the classic triad of the disease, associated with an unusual lymph accumulation in the abdomen region.

Papaiordanou, Francine; Epstein, Marina Gabrielle; Miyaoka, Mariana Yumi; Yang, Jeane Jeong Hoon; Pires, Mario Cezar

2014-01-01

400

Wind-driven effects on the Yellow Sea Warm Current  

Microsoft Academic Search

The Yellow Sea is a shallow basin with an average depth of 44 m located between China_and the Korean Peninsula. One of the dominant ocean circulation features of the Yellow Sea is a warm water intrusion known as the Yellow Sea Warm Current. This feature is present throughout the year but reaches its farthest northward extension in winter. The circulation

Andrea C. Mask; James J. O'Brien; Ruth Preller

1998-01-01

401

Differences in Apparent Contrast in Yellow and White Light.  

National Technical Information Service (NTIS)

The purpose of this study was to investigate suprathreshold contrast perception in white and yellow light. The contrast of black-on-white letters was adjusted to match the perceived contrast of yellow-on-yellow letters presented simultaneously on a video ...

J. C. Rabin R. Wiley

1996-01-01

402

Induction of pluripotency in human somatic cells via a transient state resembling primitive streak-like mesendoderm.  

PubMed

During mammalian embryonic development, the primitive streak initiates the differentiation of pluripotent epiblast cells into germ layers. Pluripotency can be reacquired in committed somatic cells using a combination of a handful of transcription factors, such as OCT3/4, SOX2, KLF4 and c-MYC (hereafter referred to as OSKM), albeit with low efficiency. Here we show that during OSKM-induced reprogramming towards pluripotency in human cells, intermediate cells transiently show gene expression profiles resembling mesendoderm, which is a major component of the primitive streak. Based on these findings, we discover that forkhead box H1 (FOXH1), a transcription factor required for anterior primitive streak specification during early development, significantly enhances the reprogramming efficiency of human fibroblasts by promoting their maturation, including mesenchymal to epithelial transition and the activation of late pluripotency markers. These results demonstrate that during the reprogramming process, human somatic cells go through a transient state that resembles mesendoderm. PMID:24759836

Takahashi, Kazutoshi; Tanabe, Koji; Ohnuki, Mari; Narita, Megumi; Sasaki, Aki; Yamamoto, Masamichi; Nakamura, Michiko; Sutou, Kenta; Osafune, Kenji; Yamanaka, Shinya

2014-01-01

403

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

SciTech Connect

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. [Department of Physics, University of Texas at Austin, Austin, TX, 78712 (United States)

2010-11-04

404

Holocene development of the Yellow River's subaqueous delta, North Yellow Sea  

Microsoft Academic Search

High-resolution seismic profiles from the North Yellow Sea reveal a 20–40-m-thick subaqueous clinoform delta that wraps around the eastern end of the Shandong Peninsula, extending into the South Yellow Sea. This complex sigmoidal-oblique clinoform, containing an estimated 400 km3 of sediment, overlies prominent relict transgressive surfaces. The nearshore topset of the clinoform, <30-m water depth, has a ?1:1000 gradient, with

J. Paul Liu; John D. Milliman; Shu Gao; Peng Cheng

2004-01-01

405

First streaked radiography experiments of indirect drive ICF capsule implosions on the National Ignition Facility  

NASA Astrophysics Data System (ADS)

1-dimensional (slit imaging) time resolved radiography of capsule implosions in ignition hohlraums on the National Ignition Facility (NIF) is used to measure the time history of implosion velocities, ablator shell thickness and remaining ablator mass in the last 5 ns before peak implosion time [1]. While first experiments on the NIF performed with gated imagers recorded these quantities at four adjustable times, streaked radiography [2] adds the tremendous benefit of recording the full implosion evolution through capsule stagnation and explosion phase. First streaked radiography experiments of Si doped indirect drive ignition capsule surrogates with an initial radius of 1.1 mm successfully measured implosion performance with required accuracies at radii in the 0.9 to 0.2 mm range. These experiments were performed in Au and Au/DU gas filled ignition hohlraums driven by laser pulses with a peak power in the 330-420 TW range and total laser energy up to 1.8 MJ. Data quality and inferred statistical uncertainties in implosion velocity, remaining mass and capsule thickness will be discussed. [1] O.L. Landen et al, Phys. Plasmas 18, 051002 (2011). [2] D.G. Hicks et al, Phys. Plasmas 17, 102703 (2010).

Dewald, E.; MacKinnon, A.; Tommasini, R.; Meezan, N.; Hicks, D.; Olson, R.; Prisbey, S.; Opachich, Y. P.; Kalantar, D.; Macphee, A.; Khan, S.; Hatch, B.; Bailey, C.; Ehrlich, B.; Bradley, D.; Bell, P.; Glenzer, S.; Landen, O.; MacGowan, B.; Kilkenny, J.; Edwards, J.; van Wonterghem, B.; Moses, E.

2012-10-01

406

Nonlinear response of the photocathode of an x-ray streak camera to UV light  

SciTech Connect

We have found that a potassium-iodide photocathode of an x-ray streak camera responds to UV light at {lambda}=308 nm. The photocathode surface work function, 6.5 eV, is larger than the 4 eV energy of the UV photon, hence the source of the response is interesting. We will present results on the response of a transmission type potassium-iodide photocathode to the UV light from a {lambda}308 nm, subpicosecond XeCl laser and from a {lambda}=326 nm HeCd laser. We will test for the nonlinearity of the yield to measure of the number of photons that are needed to be absorbed before a signal is recorded. We will present data on the effect of the UV irradiance on the yield, as well as on the temporal width of the recorded signal. We will give an explanation of the observation and its effect on the dynamic-range response of the streak-camera. We will show that the response is linear with the incident irradiance, up to an incident irradiance of 10{sup 8} W/cm{sup 2} and we will explain the observation.

Kyrala, G.A.; Oro, D.M.; Studebaker, J.K.; Wood, W.M.; Schappert, G.T.; Watts, S.; Fulton, R.D.

1994-09-01

407

On the origin of the streak spacing in turbulent shear flows  

NASA Technical Reports Server (NTRS)

It is shown that the ideas of selective amplification and direct resonance, based on linear theory, can not provide an explanation for the well-defined streak spacing of about 100 wall units (referred to as 100(+) hereafter) in wall-bounded turbulent shear flows. In addition, for the direct resonance theory, the streaks are created by the non-linear self-interaction of the vertical velocity rather than of the directly forced vertical vorticity. In view of the failure of these approaches, it is then proposed that the selection mechanism must be inherently non-linear and correspond to a self-sustaining mechanism. The 100(+) value should thus be considered as a critical Reynolds number for that mechanism. Indeed, in the case of Poiseuille flow, this 100(+) criterion for transition to turbulence corresponds to the usually quoted value of 1000 based on the half-width and the centerline velocity. In Couette flow, it corresponds to a critical Reynolds number of about 400 based on the half width and half velocity difference.

Waleffe, Fabian A.

1991-01-01

408

Synchroscan streak camera imaging at a 15-MeV photoinjector with emittance exchange  

NASA Astrophysics Data System (ADS)

At the Fermilab A0 photoinjector facility, bunch-length measurements of the laser micropulse and the e-beam micropulse have been done in the past with a fast single-sweep module of the Hamamatsu C5680 streak camera with an intrinsic shot-to-shot trigger jitter of 10-20 ps. We have upgraded the camera system with the synchroscan module tuned to 81.25 MHz to provide synchronous summing capability with less than 1.5 ps FWHM trigger jitter and a phase-locked delay box to provide phase stability of ˜1 ps over 10 s of minutes. These steps allowed us to measure both the UV laser pulse train at 263 nm and the e-beam via optical transition radiation (OTR). Due to the low electron beam energies and OTR signals, we typically summed over 50 micropulses with 0.25-1 nC per micropulse. The phase-locked delay box allowed us to assess chromatic temporal effects and instigated another upgrade to an all-mirror input optics barrel. In addition, we added a slow sweep horizontal deflection plug-in unit to provide dual-sweep capability for the streak camera. We report on a series of measurements made during the commissioning of these upgrades including bunch-length and phase effects using the emittance exchange beamline and simultaneous imaging of a UV drive laser component, OTR, and the 800 nm diagnostics laser.

Lumpkin, A. H.; Ruan, J.; Thurman-Keup, R.

2012-09-01

409

The Symptom and Genetic Diversity of Cassava Brown Streak Viruses Infecting Cassava in East Africa  

PubMed Central

The genetic and symptom diversity of six virus isolates causing cassava brown streak disease (CBSD) in the endemic (Kenya, Mozambique, and Tanzania) and the recently affected epidemic areas (Uganda) of eastern Africa was studied. Five cassava varieties; Albert, Colombian, Ebwanateraka, TMS60444 (all susceptible) and Kiroba (tolerant) were graft inoculated with each isolate. Based on a number of parameters including the severity of leaf and root symptoms, and the extent of virus transmission by grafting, the viruses were classified as either severe or relatively mild. These results were further confirmed by the mechanical inoculation of 13 herbaceous hosts in which the virulent isolates caused plant death in Nicotiana clevelandii and N. benthamiana whereas the milder isolates did not. Phylogenetic analysis of complete coat protein gene sequences of these isolates together with sequences obtained from 14 other field-collected samples from Kenya and Zanzibar, and reference sequences grouped them into two distinct clusters, representing the two species of cassava brown streak viruses. Put together, these results did not suggest the association of a hypervirulent form of the virus with the current CBSD epidemic in Uganda. Identification of the severe and milder isolates, however, has further implications for disease management and quarantine requirements.

Mohammed, I. U.; Abarshi, M. M.; Muli, B.; Hillocks, R. J.; Maruthi, M. N.

2012-01-01

410

Pathogenesis of varicose veins - lessons from biomechanics.  

PubMed

The development of varicose veins or chronic venous insufficiency is preceded by and associated with the pathophysiological remodelling of the venous wall. Recent work suggests that an increase in venous filling pressure is sufficient to promote varicose remodelling of veins by augmenting wall stress and activating venous endothelial and smooth muscle cells. In line with this, known risk factors such as prolonged standing or an obesity-induced increase in venous filling pressure may contribute to varicosis. This review focuses on biomechanically mediated mechanisms such as an increase in wall stress caused by venous hypertension or alterations in blood flow, which may be involved in the onset of varicose vein development. Finally, possible therapeutic options to counteract or delay the progress of this venous disease are discussed. PMID:24627315

Pfisterer, Larissa; König, Gerd; Hecker, Markus; Korff, Thomas

2014-03-01

411

Phasic activity of human dorsal foot veins.  

PubMed

Phasic contractions of the dorsal foot veins were detected in 7 male subjects, aged 23 to 49 years, by means of a linear variable differential transformer (LVDT) after congesting the veins by a pressure of 6.7 kPa (50 torr). This phasic activity (PA) had a frequency of 3 to 7 contractions per minute and led to a periodic diminution of the diameter of the distended veins by 12 to 44%. Using a double LVDT, the PA was shown to represent peristaltic waves travelling along the vessel wall concomitantly with the venous return. Determined in 3 out of the 7 subjects, the velocity of the waves amounted to 3.6 to 6.1 mm per second. A rheological significance of the peristaltic waves is assumed. PMID:3178793

Barthel, W; Koth, W

1988-01-01

412

Can tuffisite veins help dictate eruption styles?  

NASA Astrophysics Data System (ADS)

The ability of magmas to degas during ascent may affect eruption style. The permeability of the magma and/or the conduit wall rocks may therefore dictate whether an eruption will be explosive or effusive. Fractures increase permeability. Fractures filled by veins of autoclastic, cataclastic and tuffisitic glass shards and crystal fragments are common in shallow conduit systems. These veins have the potential to dramatically increase permeability and provide pathways for gas loss. Here we present the first study on the porosity, permeability, strength, P-and S-wave and dynamic elastic moduli of andesite containing tuffisite veins at Volcán de Colima, Mexico. Porosity was measured via pycnometry. The strength and mechanisms of deformation were investigated on tuffisite-bearing and tuffisite-free samples in a uniaxial press at 940°C by loading at 2 MPa/min until failure. The permeability, P- and S-wave velocity, and dynamic elastic moduli were measured in a high-pressure permeameter/pore volumometer up to effective confining pressures of 50 MPa (ca. 2km depth). Measurements were made on cylindrical samples prepared as: (1) without tuffisite veins and with tuffisite veins (2) perpendicular and (3) sub-parallel to flow (i.e., the samples’ axial direction). Petrographic analysis reveals that the tuffisites are comprised almost exclusively of micron-size crystal fragments. Dilatometric measurements of tuffisite (10°C/min up to 1000°C), failed to reveal a Tg, indicating the absence of interstitial glass. In contrast, the dome rocks exhibits viscous relaxation between 770 and 885 °C, indicating glass. The high-temperature (940°C) deformation experiments on samples containing tuffisite veins showed an absence of ductile deformation and a uniaxial strength of 116 MPa; i.e, slightly weaker than tuffisite-free rock (~130 MPa) and stronger than erupted dome lavas (~30 MPa). The presence of tuffisite increases the porosity. Permeability measurements show that tuffisite veins perpendicular to the direction of fluid flow do not increase permeability; however, those sub-parallel double the permeability (from about 5 x 10-14 m2 to 1 x 10-13 m2). With an increase in confining pressure, the efficiency of the tuffisites as an effective degassing pathway decreases. At a depth of just less than one kilometre the effective pressure was sufficient to compress the veins so that the permeability dropped to that of the host rock. These results suggest that tuffisite veins have important mechanical consequences for magma ascent at Volcán de Colima. The presence of tuffisite veins may focus/localize deformation within the host magma and wall rock. At depths greater that 1 km tuffisite veins will have little affect on conduit permeability. However, depressurization during ascent will dramatically increase the permeability of the tuffisite veins relative to the host magma, and thus reduce the potential of explosive eruptions.

Kolzenburg, S.; Heap, M. J.; Lavallee, Y.; Russell, J. K.; Meredith, P. G.; Dingwell, D. B.

2010-12-01

413

Hepatic fat accumulation with sparing associated with portal vein duplication.  

PubMed

Duplication of the portal vein is a rare congenital anomaly. We experienced a case of duplication of the portal vein associated with hepatic fat accumulation with sparing. Fat accumulation was seen in the central portion of the liver, which was supplied by the portal vein coursing upward to the porta hepatis (Portal Vein 2), and sparing of fatty liver was seen in the peripheral portion of the liver, which was supplied by the portal vein entering the liver inferiorly (Portal Vein 1). PMID:24679652

Yang, Dal Mo; Kim, Hyun Cheol; Kim, Sang Won

2014-01-01

414

Number of valves in superficial veins of the leg.  

PubMed

Study was performed on 83 great and 64 small saphenous veins obtained from human adults males and females, aged 26 to 85 years. The number of valves in the great saphenous veins varies from 3 to l3, and in the small saphenous veins the number of valves varies from 1 to 8. The mean number of valves in the femoral part of the great saphenous veins is 5 and in the crural part of this vein is 3. The number of valves is not related to the length of vein. PMID:14663766

M, C G; M, B

1999-01-01

415

Arteries and veins desensitize differently to endothelin.  

PubMed

Hypertension is accompanied by increased arterial endothelin-1 (ET-1) and decreased arterial contraction to ET-1. By contrast, veins remain responsive to ET-1 in hypertension. Isometric contraction was used to test the hypothesis that veins do not desensitize to ET-1 to the extent of arteries, possibly because of the presence of functional ETA and ETB receptors on veins and only functional ETA receptors on arteries. Contraction to ET-1 after exposure to ET-1 (100 nmol/L) was abolished in aortae, while in veins 36.3 +/- 0.2% of maximal contraction to ET-1 remained. Aortae were unresponsive to the ETA receptor agonist ET-1(1-31) (100 nmol/L) after ET-1 exposure, while 21.9 +/- 0.6% of maximum venous contraction to ET-1 (1-31) remained. In a similar manner, the venous ETB receptor did not lose responsiveness to the ETB receptor agonist sarafotoxin 6c (S6c, 100 nmol/L); aortae did not contract to S6c. In ET-1-desensitized veins, the ETB receptor antagonist BQ-788 (100 nmol/L) decreased maximum contraction to ET-1, but did not alter potency (-log EC50 control = 8.14 +/- 0.01 mol/L; BQ-788 = 8.13 +/- 0.04 mol/L). The ETA receptor antagonist atrasentan (100 nmol/L) blocked remaining venous contraction to ET-1 (control = 8.05 +/- 0.05 mol/L; atrasentan = unmeasurable). Maintained responsiveness to ET-1 in veins occurs primarily via the ETA receptor, while in arteries the ETA receptor is responsible for desensitization to ET-1. PMID:15076222

Thakali, Keshari; Fink, Gregory D; Watts, Stephanie W

2004-03-01

416

Characterisation of Banana streak Mysore virus and evidence that its DNA is integrated in the B genome of cultivated Musa.  

PubMed

We have sequenced the complete genome of an isolate of Banana streak virus from banana cv. 'Mysore' and show that it is sufficiently different from a previously characterised isolate from cv. 'Obino l'Ewai' to warrant recognition as a distinct species, for which the name Banana streak Mysore virus (BSMysV) is proposed. The structure of the BSMysV genome was typical of badnaviruses in general, although ORF I had a non-conventional start codon. Evidence that at least part of the BSMysV genome is integrated in the B genome of cultivated Musa is presented and transmissibility by the mealybug Planococcus citri also demonstrated. PMID:15785970

Geering, A D W; Pooggin, M M; Olszewski, N E; Lockhart, B E L; Thomas, J E

2005-04-01

417

Conduits for Coronary Bypass: Vein Grafts  

PubMed Central

The saphenous vein has been the principal conduit for coronary bypass grafting from the beginning, circa 1970. This report briefly traces this history and concomitantly presents one surgeons experience and personal views on use of the vein graft. As such it is not exhaustive but meant to be practical with a modest number of references. The focus is that of providing guidance and perspective which may be at variance with that of others and recognizing that there may be many ways to accomplish the task at hand. Hopefully the surgeon in training/early career may find this instructive on the journey to surgical maturity.

Farkas, Emily A

2012-01-01

418

Streak formation as side effect of optical breakdown during processing the bulk of transparent Kerr media with ultra-short laser pulses  

Microsoft Academic Search

Femtosecond lasers have been successfully used to perform refractive surgery, by cutting within the bulk of the corneal tissue. As a side effect to the laser cutting there, a streak-like discoloration is observed in histological sections above and below the cutting plane, incident with the direction of laser propagation. These streak-shaped alterations of tissue are believed to originate from low

C. L. Arnold; A. Heisterkamp; W. Ertmer; H. Lubatschowski

2005-01-01

419

Imported yellow fever in a United States citizen.  

PubMed

The last imported case of yellow fever seen in this country was in 1924. We report a case of yellow fever acquired by an American tourist who visited the jungles of Brazil along the Rio Negro and Amazon Rivers. The patient died 6 days after hospital admission and 10 days after his first symptoms appeared. Yellow fever virus was recovered from clinical specimens, and the isolate was genetically similar to the E genotype IIB of South American yellow fever viruses. This patient's illness represents a case of vaccine-preventable death since he failed to be immunized with a recommended preexposure yellow fever vaccine. PMID:9402373

McFarland, J M; Baddour, L M; Nelson, J E; Elkins, S K; Craven, R B; Cropp, B C; Chang, G J; Grindstaff, A D; Craig, A S; Smith, R J

1997-11-01

420

Characterization of complete genome and small RNA profile of pagoda yellow mosaic associated virus, a novel badnavirus in China.  

PubMed

A new badnavirus was discovered from pagoda trees showing yellow mosaic symptoms on the leaves by high throughput sequencing of small RNAs. The complete genome of this virus was determined to comprise 7424 nucleotides, and the virus shared 40.4-45.1% identity with that of other badnaviruses. The genome encodes five open reading frames (ORFs) on the plus strand, which includes three conserved badnaviral ORFs. These results suggest that this virus is a new member of the genus Badnavirus in the family Caulimoviridae. The virus is tentatively named pagoda yellow mosaic associated virus (PYMAV). Phylogenetic analysis suggested that this virus together with gooseberry vein banding virus (GVBV) and grapevine vein-clearing virus (GVCV) forms a separate group that is distinct two other well characterized badnaviral groups. Additionally, the viral derived small RNA (vsRNA) profile of PYMAV was analyzed and compared with that of viruses within the same family. Results showed that the most abundant PYMAV vsRNAs were 21-nt, whereas other viruses in the same family have a predominance of 22- or 24-nt vsRNA. The percentage of sense PYMAV vsRNA was almost equal to that of antisense vsRNA, whereas vsRNAs of other viruses in the family display preferences toward the sense strand of their genome. Furthermore, PYMAV vsRNAs were symmetrically distributed along the genome with no obvious vsRNA generating hotspots. PMID:24751798

Wang, Yilun; Cheng, Xiaofei; Wu, Xiaoxia; Wang, Aiming; Wu, Xiaoyun

2014-08-01

421

Differences in apparent contrast in yellow and white light.  

PubMed

The purpose of this study was to investigate suprathreshold contrast perception in white and yellow light. The contrast of black-on-white letters was adjusted to match the perceived contrast of yellow-on-yellow letters presented simultaneously on a video display. At lower contrasts (7-15%), the apparent contrast of yellow letters was slightly enhanced compared to black-on-white letters (mean enhancement = 23%), but this effect diminished with increasing contrast. The slight enhancement in yellow light was independent of letter size, and could not be explained by luminance differences between yellow and white displays. This effect may relate to the subjective improvement often reported when wearing yellow (blue-blocking) lenses. PMID:8729569

Rabin, J; Wiley, R

1996-01-01

422

The double retro-aortic left renal vein  

PubMed Central

The renal veins drain the kidney into the inferior vena cava and unite in a variable fashion to form the renal vein. The left renal vein is normally located in front of the aorta. However, the retro-aortic renal vein may course posterior to the aorta due to embryological developmental anomalies. During educational dissection, a rare variation of the left renal vein was found in a 66-year old male cadaver. The double retro-aortic renal veins coursed behind the aorta to drain into the inferior vena cava. The superior retro-aortic renal vein drained into the inferior vena cava at the lower border of the L2 vertebra, and the inferior retro-aortic renal vein drained into the inferior vena cava at the upper border of the L4 vertebra. Such a variant is rare, and is a clinically important observation which should be noted by vascular surgeons, oncologists, and traumatologists.

Kyung, Dong-Soo; Lee, Jae-Ho; Shin, Deuk-Yong; Kim, Dae-Kwang

2012-01-01

423

Vascular access outcomes using the transposed basilic vein arteriovenous fistula  

Microsoft Academic Search

Background:Although the transposed basilic vein arteriovenous fistula (TBAVF) is increasingly performed for hemodialysis vascular access in patients lacking adequate superficial veins, little is known about the long-term patency or risk factors for failure.

Jonathan H. Segal; Liise K. Kayler; Peter Henke; Robert M. Merion; Sean Leavey; Darrell A. Campbell

2003-01-01

424

Varicose and other vein problems - self-care  

MedlinePLUS

... you stand. As a result, you may have: Varicose veins Swelling in your legs Skin changes or even ... at home to: Slow down the development of varicose veins Decrease any discomfort Prevent skin ulcers

425

21 CFR 880.6970 - Liquid crystal vein locator.  

Code of Federal Regulations, 2010 CFR

...crystal vein locator. (a) Identification. A liquid crystal vein locator is a device used to indicate the...displaying the color changes of heat sensitive liquid crystals (cholesteric esters). (b) Classification....

2010-04-01

426

21 CFR 880.6970 - Liquid crystal vein locator.  

Code of Federal Regulations, 2010 CFR

...crystal vein locator. (a) Identification. A liquid crystal vein locator is a device used to indicate the...displaying the color changes of heat sensitive liquid crystals (cholesteric esters). (b) Classification....

2009-04-01

427

Deep Vein Thrombosis - Multiple Languages: MedlinePlus  

MedlinePLUS

... features on this page, please enable JavaScript. Deep Vein Thrombosis - Multiple Languages Arabic (???????) ASL (American Sign ... Somali (af Soomaali) Spanish (español) Arabic (???????) Deep Vein Thrombosis (DVT) (Arabic) ??????? Bilingual PDF Health Information ...

428

Modified incision for long saphenous vein harvest.  

PubMed

We describe a modification of the standard open technique of long saphenous vein harvesting that, by avoiding dissection in the region of the medial malleolus, can reduce the incidence of leg wound related complications after coronary artery bypass grafting. PMID:9692491

Chukwuemeka, A; John, L

1998-07-01

429

A secure cryptosystem from palm vein biometrics  

Microsoft Academic Search

This paper proposes a novel technique to generate an irrevocable cryptographic key from the biometric template. The biometric trait considered here is the palm vein. The technique proposed here utilises the minutiae features extracted from the pattern generated. The features include bifurcation points and ending points. Since other cryptographic keys are probable to theft or guess, keys generated from the

B. Prasanalakshmi; A. Kannammal

2009-01-01

430

Endoscopic vein harvesting: technique, outcomes, concerns & controversies  

PubMed Central

The choice of the graft conduit for coronary artery bypass grafting (CABG) has significant implications both in the short- and long-term. The patency of a coronary conduit is closely associated with an uneventful postoperative course, better long-term patient survival and superior freedom from re-intervention. The internal mammary artery is regarded as the primary conduit for CABG patients, given its association with long-term patency and survival. However, long saphenous vein (LSV) continues to be utilized universally as patients presenting for CABG often have multiple coronary territories requiring revascularization. Traditionally, the LSV has been harvested by creating incisions from the ankle up to the groin termed open vein harvesting (OVH). However, such harvesting methods are associated with incisional pain and leg wound infections. In addition, patients find such large incisions to be cosmetically unappealing. These concerns regarding wound morbidity and patient satisfaction led to the emergence of endoscopic vein harvesting (EVH). Published experience comparing OVH with EVH suggests decreased wound related complications, improved patient satisfaction, shorter hospital stay, and reduced postoperative pain at the harvest site following EVH. Despite these reported advantages concerns regarding risk of injury at the time of harvest with its potential detrimental effect on vein graft patency and clinical outcomes have prevented universal adoption of EVH. This review article provides a detailed insight into the technical aspects, outcomes, concerns, and controversies associated with EVH.

Sarang, Zubair

2013-01-01

431

The ophthalmic vein in the carotid angiogram  

Microsoft Academic Search

The appearance of the superior ophthalmic vein following the different methods of cerebral angiography is described in normal and pathological cases. The appearance of the SOV is usually closely related to the filling of the external carotid artery. In the presence of anatomical variations, or in cases of, intracranial lesions with unusual drainage behaviour, the SOV may also appear following

G. B. Bradac; R. S. Simon; W. Leonhardt

1974-01-01

432

Nitroprusside modulates pulmonary vein arrhythmogenic activity  

Microsoft Academic Search

BACKGROUND: Pulmonary veins (PVs) are the most important sources of ectopic beats with the initiation of paroxysmal atrial fibrillation, or the foci of ectopic atrial tachycardia and focal atrial fibrillation. Elimination of nitric oxide (NO) enhances cardiac triggered activity, and NO can decrease PV arrhythmogensis through mechano-electrical feedback. However, it is not clear whether NO may have direct electrophysiological effects

Yung-Kuo Lin; Yen-Yu Lu; Yao-Chang Chen; Yi-Jen Chen; Shih-Ann Chen

2010-01-01

433

Portal vein complications after pediatric liver transplantation.  

PubMed

Relatively few pediatric donors are available in relation to the number of children waiting for a liver transplant. This limited number of pediatric donor livers leads to the use of adult livers, usually requiring more complex portal vein (PV) anastomoses. These anastomoses are complicated by differences in PV caliber between donors and recipients, as well as by limitations of PV length, which may be inadequate to reach the recipient spleno-mesenteric junction. Three types of post-transplant complications result from these complexities: 1) anomalies of the portal flow; 2) stenosis of the PV anastomosis; and 3) PV thrombosis. Abnormal portal flow may rarely need a specific intervention, but persistent stenosis or appearance of signs of portal hypertension need to be corrected. Balloon dilatation and placement of a stent are usually successful to repair stenosis. Portal vein thromboses are in general diagnosed in the immediate post-operative period and frequently lead to re-transplantation; however, thrombolytic therapy should be attempted in children without major signs of liver necrosis. When intra-hepatic portal vein(s) are permeable, despite extrahepatic PV thrombosis, a Meso-Rex shunt may be the indicated therapy. PMID:22434261

Alvarez, Fernando

2012-06-01

434

Management of Central Retinal Vein Occlusion  

Microsoft Academic Search

The management of central retinal vein occlusion (CRVO) is discussed briefly. Since the prognosis, complications, visual outcome and management of nonischemic and ischemic CRVO are very different, the first essential step in the management of CRVO is to determine which type of CRVO one is dealing with. The various parameters which help to differentiate the two types reliably are described

Sohan Singh Hayreh

2003-01-01

435

Central retinal vein occlusion and thrombophilia  

Microsoft Academic Search

Central retinal vein occlusion is one of the commonest vascular diseases of the eye. The pathogenesis is multifactorial with both local factors and systemic diseases being aetiologically important. Many thrombophilic conditions have recently been identified and studies looking at their potential role in CRVO have been undertaken. The aim of this review is to critically appraise these studies as to

C D Fegan

2002-01-01

436

Central retinal vein occlusion in young people  

Microsoft Academic Search

In a study performed on 20 subjects with central retinal vein occlusion (CRVO) aged 40 years or less we found the ischemic form in 20%. Disc edema was a common finding at the onset, while macular edema was less frequently seen. Systemic or ocular disorders that could be related with the development of the CRVO were often found; a patient

Giuseppe Giuffré; Gaetano Randazzo-Papa; Carlo Palumbo

1992-01-01

437

Ultrafast Electron-Optical X-Ray Streak and Framing Cameras.  

NASA Astrophysics Data System (ADS)

Available from UMI in association with The British Library. In this thesis the development of ultrafast electron -optical streak and framing cameras having radiation sensitivities ranging from the visible to soft X-ray are discussed. A framing camera incorporating a vacuum demountable image tube with ultraviolet/soft X-ray sensitivity has been demonstrated to be capable of providing multiple, temporally separated, two-dimensional images with picosecond image exposure times under various operating conditions. Experimental evidence has been presented to show that this camera system can provide up to four high quality temporally separated images with an exposure time of 230 ps (FWHM) and inter-frame times of ~1 ns under UV illumination. In the two-frame operation with soft X-ray illumination (generated using a laser produced plasma) image exposure times of as short as 100 ps (FWHM) and inter-frame times of 400 ps have been achieved. The dynamic spatial resolution of the camera has been shown to be ~8 lp/mm and ~5 lp/mm for the UV and soft X-ray sensitive devices respectively. A visible-sensitivity electron-optical single -shot streak camera possessing a novel travelling-wave deflection structure has been experimentally evaluated using a mode -locked cw ring dye laser. The limiting temporal resolution for this has been measured to be 300 fs and the merits of the travelling-wave deflection structure have been discussed. The implementation of this type of deflector geometry has also been demonstrated in conjunction with the vacuum demountable framing camera system. Computer aided design techniques have been utilised to further optimise the electron-optical framing tube configuration, and modifications have been proposed to enable shorter frame periods to be obtained while maintaining the dynamic spatial resolution. Results from preliminary evaluations of this design using a vacuum demountable UV-sensitive system are included. A novel streak camera design has also been proposed in which very high electrostatic photocathode extraction fields (up to 12 kV/mm) may be employed without danger of structural damage arising from electrostatic breakdown. This has been achieved by the removal of the usual mesh electrode placed in close proximity to the photocathode. Preliminary evaluations of a vacuum demountable UV-sensitive version of this camera geometry have been achieved which demonstrate a static spatial resolution of 80 lp/mm (when referred to the photocathode).

Walker, David R.

438

High-efficiency 20 W yellow VECSEL.  

PubMed

A high-efficiency optically pumped vertical-external-cavity surface-emitting laser emitting 20 W at a wavelength around 588 nm is demonstrated. The semiconductor gain chip emitted at a fundamental wavelength around 1170-1180 nm and the laser employed a V-shaped cavity. The yellow spectral range was achieved by intra-cavity frequency doubling using a LBO crystal. The laser could be tuned over a bandwidth of ~26 nm while exhibiting watt-level output powers. The maximum conversion efficiency from absorbed pump power to yellow output was 28% for continuous wave operation. The VECSEL's output could be modulated to generate optical pulses with duration down to 570 ns by directly modulating the pump laser. The high-power pulse operation is a key feature for astrophysics and medical applications while at the same time enables higher slope efficiency than continuous wave operation owing to decreased heating. PMID:24663985

Kantola, Emmi; Leinonen, Tomi; Ranta, Sanna; Tavast, Miki; Guina, Mircea

2014-03-24

439

An improved method for finger-vein image enhancement  

Microsoft Academic Search

Finger vein, as a biological characteristic of individual, has been increasingly utilized for personal identification in advanced security applications. Nonetheless, the finger-vein images always are low in quality, which seriously affect the vein-feature extraction and classification. Hence, establishing a reasonable finger-vein enhancement strategy is indispensable in reality. In this paper, an improved approach, incorporating directional decomposition and Frangi filtering, is

Jinfeng Yang; Minfu Yan

2010-01-01

440

Marylanders defeat Philadelphia: yellow fever updated.  

PubMed Central

Those strategic points which influence this amateur historian to declare a victory for Baltimore and Maryland over Philadelphia are: I. Based upon clinical and epidemiological data, two Marylanders, Potter and Davidge, were among the first to contest Rush and his contagion theory; they told him so and published their views. To prove this point, Potter went to the extreme of inoculating himself with presumedly infected material. Stubbins Ffirth, a young University of Pennsylvania medical student, did the same four years later. To Rush's credit was ultimate abandonment of his originally held views. II. John Crawford, of Baltimore, although not the originator of the insect concept of transmission of infectious agents, published his concepts in 1811. III. Henry Rose Carter, a Maryland graduate, clearly delineated, in 1898, that after identification of an index case of yellow fever an extrinsic incubation period was necessary before the evolution of secondary cases. IV. James Carroll, another University of Maryland graduate, who worked as Deputy under Walter Reed with Lazear and Agramonte, helped prove Finlay's original concept that the Aedes aegypti mosquito was the natural vector of yellow fever. Carroll himself was the first experimentally induced case. V. Studies in primates provide new approaches for management of yellow fever. Nutritional support and treatment with specific anti-viral agents may be useful for therapy of human yellow fever. Maryland members of the Climatological are mindful of Philadelphia's rich medical heritage and of the many battles won in the City of Brotherly Love. Physicians in colonial and early America experienced The best and worst of times, theirs was an age of foolishness and belief, of incredulity and light, of darkness, despair and hope. This tale of two cities ends in peace. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 10 Fig. 11

Woodward, T. E.; Beisel, W. R.; Faulkner, R. D.

1976-01-01

441

Structure of Turnip Yellow Mosaic Virus  

Microsoft Academic Search

IN this communication we report some of the results of the early stages of an X-ray diffraction study of crystals of turnip yellow mosaic virus1,2. The two most important conclusions from the interpretation of the X-ray diagrams concern: (a) the packing of the virus particles in the crystal; and (b) the arrangement of protein sub-units in the individual virus particle.

A. Klug; J. T. Finch; Rosalind E. Franklin

1957-01-01

442

Saponins and flavonoid glycosides from yellow sweetclover  

Microsoft Academic Search

A new saponin, 3-O-[a-L-rhamnopyranosyl(1?2)-?-D-glucopyranosyl(1?2)-?-D-glucuronopyranosyl]soyasapogenol B carboxylate (6) has been isolated from the medicinal plant yellow sweetclover together with azukisaponin II(7), robinin(8), and clovin(9). 7, 8, and9 are reported for the first time from this plant. The new saponin(6) exhibited inhibitory action on leucocyte migration in inflammation.

Sam Sik Kang; Young Soon Lee; Eun Bang Lee

1988-01-01

443

Reconstruction of portal vein and superior mesenteric vein after extensive resection for pancreatic cancer  

PubMed Central

Purpose Tumor invasion to the portal vein (PV) or superior mesenteric vein (SMV) can be encountered during the surgery for pancreatic cancer. Venous reconstruction is required, but the optimal surgical methods and conduits remain in controversies. Methods From January 2007 to July 2012, 16 venous reconstructions were performed during surgery for pancreatic cancer in 14 patients. We analyzed the methods, conduits, graft patency, and patient survival. Results The involved veins were 14 SMVs and 2 PVs. The operative methods included resection and end-to-end anastomosis in 7 patients, wedge resection with venoplasty in 2 patients, bovine patch repair in 3 patients, and interposition graft with bovine patch in 1 patient. In one patient with a failed interposition graft with great saphenous vein (GSV), the SMV was reconstructed with a prosthetic interposition graft, which was revised with a spiral graft of GSV. Vascular morbidity occurred in 4 cases; occlusion of an interposition graft with GSV or polytetrafluoroethylene, segmental thrombosis and stenosis of the SMV after end-to-end anastomosis. Patency was maintained in patients with bovine patch angioplasty and spiral vein grafts. With mean follow-up of 9.8 months, the 6- and 12-month death-censored graft survival rates were both 81.3%. Conclusion Many of the involved vein segments were repaired primarily. When tension-free anastomosis is impossible, the spiral grafts with GSV or bovine patch grafts are good options to overcome the size mismatch between autologous vein graft and portomesenteric veins. Further follow-up of these patients is needed to demonstrate long-term patency.

Kim, Suh Min; Park, Daedo; Min, Sang-Il; Jang, Jin-Young; Kim, Sun-Whe; Ha, Jongwon; Kim, Sang Joon

2013-01-01

444

Inferior vena cava hypoplasia with right hepatic vein and accessory inferior hepatic vein shunt.  

PubMed

Inferior vena cava (IVC) hypoplasia is a rare condition. Venous blood flow is usually provided through collaterals in the azygos or hemiazygos venous systems. However, portosystemic shunts with intrahepatic venous collateral are extremely rare. The case is presented here of a large shunt between the right hepatic vein, accessory inferior hepatic vein, and inferior vena cava in a 37-year-old female patient with IVC hypoplasia. PMID:24590531

Cullu, N; Yeniçeri, O; Deveer, M; Tetiker, H

2014-01-01

445

Hepatocellular Carcinoma Invading the Main Portal Vein: Treatment with Transcatheter Arterial Chemoembolization and Portal Vein Stenting  

Microsoft Academic Search

To retrospectively analyze the therapeutic results of percutaneous transhepatic portal vein stenting (PTPVS) and transcatheter\\u000a arterial chemoembolization (TACE) treatment in 58 patients with hepatocellular carcinoma (HCC) invading the main portal vein\\u000a (MPV). A total of 58 procedures of PTPVS were performed, immediately after which TACE was undertaken to control HCC. The clinical\\u000a effects, complications, digital subtraction angiographic appearance, stent patency

Xue-Bin Zhang; Jian-Hua Wang; Zhi-Ping Yan; Sheng Qian; Rong Liu

2009-01-01

446

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

447

Viral Coat Protein Peptides with Limited Sequence Homology Bind Similar Domains of Alfalfa Mosaic Virus and Tobacco Streak Virus RNAs  

Microsoft Academic Search

An unusual and distinguishing feature of alfalfa mosaic virus (AMV) and ilarviruses such as tobacco streak virus (TSV) is that the viral coat protein is required to activate the early stages of viral RNA replication, a phenomenon known as genome activation. AMV-TSV coat protein homology is limited; however, they are functionally interchangeable in activating virus replication. For example, TSV coat

MAUD M. SWANSON; PATRICIA ANSEL-MCKINNEY; FELICIA HOUSER-SCOTT; VIDADI YUSIBOV; L. SUE LOESCH-FRIES; LEE GEHRKE

1998-01-01

448

Analysis of the diversity of African streak mastreviruses using PCR-generated RFLPs and partial sequence data  

Microsoft Academic Search

Maize streak virus (MSV) is the most economically significant member of a diverse group of African grass-infecting Mastrevirus species in the family Geminiviridae. We designed a single set of degenerate primers which enables the PCR amplification of an approximately 1300 bp DNA fragment spanning both conserved (the RepA gene) and variable (the long intergenic region and MP gene) portions of

J. A Willment; D. P Martin; E. P Rybicki

2001-01-01

449

TRANSMISSION, ELISA AND SDS-PAGE RESULTS OF SOME MAIZE STREAK VIRUS ISOLATES FROM DIFFERENT PARTS OF NIGERIA  

Microsoft Academic Search

Field surveys were undertaken in 1997-1999 across five ecological zones in Nigeria to collect isolates of Maize streak virus (MSV), genus Mastrevirus. Apart from maize (Zea mays L.), 15 other grass species were found with MSV symptoms in Nigeria. These hosts showed two types of symptoms viz: mild (with or without mottle) or severe (typical symptoms in maize). When Cicadulina

Sunday Oluwafemi; G. Thottappilly; Matthew D. Alegbejo

450

C.C.D. Readout of a Picosecond Streak Camera with an Intensified C.C.D.  

National Technical Information Service (NTIS)

This paper deals with a digital streak camera readout device. The device consists in a low light level television camera made of a solid state C.C.D. array coupled to an image intensifier associated to a video-digitizer coupled to a micro-computer system....

M. Lemonier J. C. Richard C. Cavailler A. Mens G. Raze

1984-01-01

451

Multiplex real-time RT-PCR for detection of Wheat streak mosaic virus and Tritcum mosaic virus  

Microsoft Academic Search

Wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV) are widespread throughout the southwestern Great Plains states. When using conventional diagnostics such as enzyme-linked immunosorbent assays (ELISA), these two viruses are commonly found together in infected wheat samples. Methods for molecular detection have been developed for wheat viral pathogens, but until recently no multiplex method for detection of both

J. A. Price; J. Smith; A. Simmons; J. Fellers; C. M. Rush

2010-01-01

452

Endoscopic saphenous vein harvest in infrainguinal bypass surgery  

Microsoft Academic Search

Background: Autologous greater saphenous vein is considered to be the optimal material for peripheral arterial reconstruction and coronary artery revascularization. We describe a new endoscopic technique of saphenous vein harvest in infrainguinal arterial bypass surgery.Methods: A retrospective analysis of 64 infrainguinal bypass procedures was performed comparing the standard open technique of saphenous vein harvesting with a new less invasive endoscopic

Mark R Robbins; Steven A Hutchinson; Stephen D Helmer

1998-01-01

453

Negative results - Coronary Carbon dioxide embolism during endoscopic vein harvesting  

Microsoft Academic Search

Endoscopic vein harvesting (EVH) is becoming common for the patients undergoing coronary artery bypass grafting. Using carbon dioxide insufflations during the vein harvest can produce rare but catastrophic CO embolism. We report a case of massive right atrial CO embolism 2 2 due to femoral vein injury which occurred during the performance of a routine EVH procedure. 2008 Published by

Muhammed Tamim; Maher Omrani; Adel Tash; Ahmed El Watidy

2010-01-01

454

Who Is at Risk for Deep Vein Thrombosis?  

MedlinePLUS

... Twitter. Who Is at Risk for Deep Vein Thrombosis? The risk factors for deep vein thrombosis (DVT) include: A history of DVT. Conditions or ... factors listed above. Rate This Content: Deep Vein Thrombosis Clinical Trials Clinical trials are research studies that ...

455

Portal Vein Measurements by Real-Time Sonography  

Microsoft Academic Search

Real-time sonography affords a simple and reliable definition of the portal veins. A standard chart of normal portal vein measurements is presented. The mean diameter of the portal vein in 107 patients aged 21 -40 years was 1 1 ± 2 mm. This information can be useful in evaluating portal hypertension in a variety of clinical situations. Sonognaphy has been

Jeffrey Weinreb; Sheila Kumari; Gail Phillips; Rubem Pochaczevsky

456

Neovascularization and recurrent varicose veins: more histologic and ultrasound evidence  

Microsoft Academic Search

BackgroundThe recurrence of varicose veins is a common and costly consequence of varicose vein surgery. Despite the long history and vast experience of varicose vein surgery, the exact cause of recurrence is still unknown. This study aims to investigate the cause of recurrence further by correlating findings from duplex ultrasound scans, resin casts, and histologic investigation at the recurrence of

André M van Rij; Gregory T Jones; Gerry B Hill; Ping Jiang

2004-01-01

457

Prevalence and Risk Factors of Varicose Veins in Japanese Women  

Microsoft Academic Search

The prevalence and risk factors of varicose veins in Japan were investigated in 541 Japanese women. Varicose veins were defined as any dilated, tortuous, and elongated veins of the lower extremity and classified into four types. The total prevalence rate was 45%. Saphenous type was observed in 22%, segment type in 35%, reticular type in 28%, and web type in

Masafumi Hirai; Kenichi Naiki; Ryu Nakayama

1990-01-01

458

Systemic diseases associated with various types of retinal vein occlusion  

Microsoft Academic Search

PURPOSE: To investigate systemic diseases associated with various types of retinal vein occlusion.METHODS: We investigated prospectively in 1090 consecutive patients with retinal vein occlusion, almost all Caucasian (consistent with the racial pattern here), the prevalence of associated systemic disorders before or at the onset of various types of retinal vein occlusion. The patients were categorized into six types of retinal

Sohan Singh Hayreh; Bridget Zimmerman; Mark J. McCarthy; Patricia Podhajsky

2001-01-01

459

Hand veins segmentation and matching under adverse conditions  

Microsoft Academic Search

Biometric identification based on hand veins subcutaneous network structure appears as a promising technique for personal recognition due to its robustness, low cost implementation and high users acceptability. Two of the most critical stages in these vein check identification systems are the vein pattern segmentation and matching, which extremely depend on the image acquisition process. The acquisition becomes a bottleneck

Sebastian Lopez; Albano González

2003-01-01

460

Non-contact finger vein acquisition system using NIR laser  

Microsoft Academic Search

Authentication using finger vein pattern has substantial advantage than other biometrics. Because human vein patterns are hidden inside the skin and tissue, it is hard to forge vein structure. But conventional system using NIR LED array has two drawbacks. First, direct contact with LED array raise sanitary problem. Second, because of discreteness of LEDs, non-uniform illumination exists. We propose non-contact

Jiman Kim; Hyoun-Joong Kong; Seungwoo Noh; Seung-Rae Lee; Taejeong Kim; Hee Chan Kim

2009-01-01

461

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

462

Pulsed versus direct current calibration of a proximity focused x-ray streak camera  

SciTech Connect

The absolute sensitivity of a proximity focused x-ray streak tube was measured with dc Henke tube x-ray line sources. Calibration covered the photon energy range from 0.930 to 8.05 keV at five points. These data were compared to a model of sensitivity based on photocathode response and matched the model well on a relative scale. A pulsed comparison was performed using a laser-plasma x-ray source. The calculated camera sensitivity was folded with the measured spectrum and compared to measured film exposures. The predicted exposures were 6.5 times less than the measured exposures, verifying concerns that the proximity focused tube response is nonlinear with flux at low, dc flux levels. Results of dc recalibrations that varied flux levels determined the extent of this phenomenon.

Rockett, P.D.; McGurn, J.S.

1981-02-01

463

Understanding the role of phase in chemical bond breaking with coincidence angular streaking.  

PubMed

Electron motion in chemical bonds occurs on an attosecond timescale. This ultrafast motion can be driven by strong laser fields. Ultrashort asymmetric laser pulses are known to direct electrons to a certain direction. But do symmetric laser pulses destroy symmetry in breaking chemical bonds? Here we answer this question in the affirmative by employing a two-particle coincidence technique to investigate the ionization and fragmentation of H? by a long circularly polarized multicycle femtosecond laser pulse. Angular streaking and the coincidence detection of electrons and ions are employed to recover the phase of the electric field, at the instant of ionization and in the molecular frame, revealing a phase-dependent anisotropy in the angular distribution of H? fragments. Our results show that electron localization and asymmetrical breaking of molecular bonds are ubiquitous, even in symmetric laser pulses. The technique we describe is robust and provides a powerful tool for ultrafast science. PMID:23867800

Wu, J; Magrakvelidze, M; Schmidt, L P H; Kunitski, M; Pfeifer, T; Schöffler, M; Pitzer, M; Richter, M; Voss, S; Sann, H; Kim, H; Lower, J; Jahnke, T; Czasch, A; Thumm, U; Dörner, R

2013-01-01

464

Improving the diffraction of full-length human selenomethionyl metavinculin crystals by streak-seeding  

PubMed Central

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?Å resolution. These crystals belonged to space group P43212, with two molecules in the asymmetric unit and unit-cell parameters a = b = 170, c = 211?Å, ? = ? = ? = 90°.

Rangarajan, Er