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Sample records for angioid streaks

  1. Angioid streaks. A case report

    Directory of Open Access Journals (Sweden)

    Aimé Broche Hernández

    2011-03-01

    Full Text Available Angioid streaks are breaks in Bruch's membrane displayed at the bottom of the eye as orange or gray bands around the optic disc, and from that point on they extend radially. There are a number of diseases associated with the development of angioid streaks such as the pseudoxanthoma elasticum, Paget's disease, senile elastosis and hyperplastic fibrous dysplasia or Ehlers-Danlos syndrome. A case of a patient with pseudoxanthoma elasticum who suffers from sudden loss of bilateral visual acuity after a facial trauma is presented.

  2. Angioid streaks, clinical course, complications, and current therapeutic management

    Directory of Open Access Journals (Sweden)

    Ilias Georgalas

    2008-12-01

    Full Text Available Ilias Georgalas1, Dimitris Papaconstantinou2, Chrysanthi Koutsandrea2, George Kalantzis2, Dimitris Karagiannis2, Gerasimos Georgopoulos2, Ioannis Ladas21Department of Ophthalmology, “G. Gennimatas” Hospital of Athens, NHS, Athens, Greece; 2Department of Ophthalmology, “G. Gennimatas” Hospital of Athens, University of Athens, Athens, GreeceAbstract: Angioid streaks are visible irregular crack-like dehiscences in Bruch’s membrane that are associated with atrophic degeneration of the overlying retinal pigmented epithelium. Angioid streaks may be associated with pseudoxanthoma elasticum, Paget’s disease, sickle-cell anemia, acromegaly, Ehlers–Danlos syndrome, and diabetes mellitus, but also appear in patients without any systemic disease. Patients with angioid streaks are generally asymptomatic, unless the lesions extend towards the foveola or develop complications such as traumatic Bruch’s membrane rupture or macular choroidal neovascularization (CNV. The visual prognosis in patients with CNV secondary to angioid streaks if untreated, is poor and most treatment modalities, until recently, have failed to limit the devastating impact of CNV in central vision. However, it is likely that treatment with antivascular endothelial growth factor, especially in treatment-naive eyes to yield favorable results in the future and this has to be investigated in future studies.Keywords: angioid streaks, pseudoxanthoma elasticum, choroidal neovascularization

  3. Silent polypoidal choroidal vasculopathy in a patient with angioid streaks

    Directory of Open Access Journals (Sweden)

    Zafer Cebeci

    2016-06-01

    Full Text Available ABSTRACT We present a case of silent polypoidal choroidal vasculopathy (PCV in a patient with angioid streaks. PCV was detected during a routine ophthalmic examination and confirmed by fluorescein angiography, indocyanine green angiography, and optical coherence tomography. After 2 years of follow-up, the PCV remained silent without any complications. We report this rare coexistence and review literature on this topic.

  4. Angioid streaks - a rare cause of neovascular glaucoma. Case report.

    Science.gov (United States)

    Ungureanu, E; Geamanu, A; Careba, I; Grecescu, M; Gradinaru, S

    2014-01-01

    Rationale. Neovascular glaucoma is the type of glaucoma most refractory to treatment. The most frequent causes are those associated with retinal hypoxia, such as proliferative diabetic retinopathy, central retinal vein occlusion, branch retinal vein occlusion, central retinal arterial occlusion, ischemic ocular syndrome etc. Rare causes of neovascular glaucoma are multiple and are due to VEGF synthesis associated with chorioretinal inflammations or degenerations. We present a case with neovascular glaucoma associated with an extremely rare cause, angioid streaks Objective. The objective of our prsentation was to asses efficacy of the 5-FU associated trabeculectomy following bevacizumab intravitreal administration Methods and results. Case report of a 48 years old female patient which presented at the emergency room with painful red left eye. At presentation best corrected left eye visual acuity was 1/10, intraocular pressure was 36 mm Hg. Examination established the diagnosis of Neovascular glaucoma associated with angioid streaks. After intravenous Manitol, oral Acetazolamide and topical treatment with fixed combination timolol-brinzolamide, topical steroid and mydriatic intraocular pressure decreased. Intravitreal bevacizumab injection was performed, followed after 3 weeks by trabeculectomy. Discussion. Angioid streaks are an extremely rare cause of neovascular glaucoma. The treatment is similar to the treatment for other causes of neovascular glaucoma. PMID:27057253

  5. Angioid streaks. A case report Estrías angioides. Presentación de un caso

    Directory of Open Access Journals (Sweden)

    Iusimí Guillén Brizuela.

    2011-03-01

    Full Text Available Angioid streaks are breaks in Bruch's membrane displayed at the bottom of the eye as orange or gray bands around the optic disc, and from that point on they extend radially. There are a number of diseases associated with the development of angioid streaks such as the pseudoxanthoma elasticum, Paget's disease, senile elastosis and hyperplastic fibrous dysplasia or Ehlers-Danlos syndrome. A case of a patient with pseudoxanthoma elasticum who suffers from sudden loss of bilateral visual acuity after a facial trauma is presented.Las estrías angioides son roturas en la membrana de Bruch que aparecen en el fondo del ojo como bandas anaranjadas o grisáceas alrededor del disco óptico, y desde allí tienen una extensión radial. Existe una serie de patologías que se asocian al desarrollo de estrías angioides como son: el pseudoxantoma elástico, la enfermedad de Paget, la elastosis senil cutánea y la fibrodisplasia hiperplástica o síndrome de Ehlers-Danlos. Se presenta el caso de una paciente con diagnóstico de pseudoxantoma elástico que sufrió una pérdida brusca de la agudeza visual bilateral luego de un trauma facial.

  6. Verteporfin photodynamic therapy combined with intravitreal triamcinolone for choroidal neovascularization due to angioid streaks

    Directory of Open Access Journals (Sweden)

    Alfredo Pece

    2010-05-01

    Full Text Available Alfredo Pece1, Gaetano Russo2, Federico Ricci3, Vincenzo Isola1, Ugo Introini4, Giuseppe Querques51Department of Ophthalmology, Melegnano Hospital, Milan, Italy; 2Fondazione Evangelica Betania, Napoli, Italy; 3University of Tor Vergata, Rome, Italy; 5University, Paris XII, France; 4San Raffaele University Hospital, Milan, ItalyPurpose: To report the visual outcome of photodynamic therapy (PDT combined with intravitreal triamcinolone acetonide (IVTA for choroidal neovascularization (CNV secondary to angioid streaks (AS.Methods: Five eyes of five consecutive patients (mean age 45 ± 10 years with CNV secondary to AS were treated by combination of PDT and IVTA. TA (4 mg/0.1 mL was injected 7 days before PDT.Results: All patients completed the 12-month follow-up. CNV was subfoveal in three cases and extrafoveal in two. Median best-corrected visual acuity (BCVA was 0.3 LogMAR (70 letters at baseline (range 1.3–0.1, and 0.5 LogMAR (60 letters at the final examination (range 1.0–0.1. At 12 months, one patient had severe visual deterioration, with a loss of seven lines of VA; Two patients lost up to three lines. One patient had no change in BCVA and the fifth gained nine lines of VA. Two patients received one further combination of PDT and IVTA after the first combination treatment. All eyes showed the CNV closure at the 12-month follow-up visit.Conclusions: Combination of PDT and IVTA may reduce the need for retreatment and could be potentially useful for preserving vision in some patients with CNV due to AS. Keywords: ocular corticosteroids

  7. Combination treatment of low fluence photodynamic therapy and intravitreal ranibizumab for choroidal neovascular membrane secondary to angioid streaks in Paget′s disease - 12 month results

    Directory of Open Access Journals (Sweden)

    Varsha V Prabhu

    2011-01-01

    Full Text Available Angioid streaks also called Knapp striae are small breaks in the Bruch′s membrane and have been reported with a host of systemic diseases. Rupture of streaks or development of secondary choroidal neovascular membrane (CNVM carries a dismal visual prognosis. We report the successful treatment of CNVM secondary to Paget′s disease using low fluence photodynamic therapy (PDT and intravitreal ranibizumab.

  8. Anti-vascular endothelial growth factor treatment for choroidal neovascularization secondary to angioid streaks in pseudoxanthoma elasticum:a case report and systemic review

    Institute of Scientific and Technical Information of China (English)

    Aiyi Zhou; Chenjing Zhou; Ziyao Liu; Yanlong Quan

    2016-01-01

    The present study reports a case of a patient with choroidal neovascularization (CNV) associated with pseudoxanthoma elasticum (PXE). We observed the functional and anatomical improvement of the patient treated with intravitreal vascular endothelial growth factor (VEGF) inhibitor bevacizumab. The study also systematically searched the database for similar cases to provide a literature review. Data concerning the clinical features, treatment strategies and outcomes were extracted and analyzed. Retrospective interventional case report and systematic literature review. A 56-year-old healthy Chinese woman with CNV secondary to PXE was reported. Examinations included best corrected visual acuity (BCVA), biomicroscopy, optical coherence tomography (OCT), lfuorescein and indocyanine green angiography and digital fundus photography. The patient managed with intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections (bevacizumab 1.25 mg/0.05 mL). The Cochrane Library, PubMed, OVID, and UpToDate databases were searched using the term pseudoxanthoma elasticum or Grönblad-Strandberg syndrome with the limits English. Articles that predated the databases were gathered from current references. Fundus examination revealed angioid streaks bilaterally and CNV in left eye (LE). After the patient underwent three intravitreal injections of bevacizumab, the LE showed absorption of the subretinal lfuid and shrinkage of the CNV. Visual acuity (VA) was improved in her treated LE. Bevacizumab treatment was well tolerated with no adverse events reported. Approximately ten articles about 45 patients (49 eyes) describing CNV secondary to angioid streaks in PXE treated with anti-VEGF were found in the literature search. In the present case, bevacizumab of an initial three injection loading dose, achieved maintenance of visual function in the treatment of CNV associated with angioid streaks in PXE. Literature articles concluded that the intravitreal application of anti-VEGF is

  9. Choroidal neovascularization and angioid streaks in pseudoxanthoma elasticum%弹性假黄瘤的脉络膜新生血管和血管样条纹症

    Institute of Scientific and Technical Information of China (English)

    Melisa Nika; Cagri G Besirli

    2011-01-01

    目的:报告1例表现为双眼视力模糊的48岁女子患弹性假黄瘤病(pseudoxanthoma elasticum,PXE)的病例.方法:病例报告.结果:患者,女,48岁,双眼视力模糊,右眼视物变形.10a前因左眼患血管样条纹症接受激光手术,残余视力较差.右眼视力为20/60,左眼6英尺数指.眼底检查可见视网膜下出血和右侧黄斑增厚及左侧椭圆形黄斑瘢痕伴病灶萎缩性色素上皮病变.双眼有血管样条纹和橙色视网膜色素图案.外部检查发现颈部侧面和后面有几处黄色皮肤丘疹和斑块,以及明显的颏皱褶.皮肤切片病理检查证实了PXE的诊断,显示有网状真皮层深层的钙沉积和成碎片的成丛的弹性纤维.患者对玻璃体内注射贝伐单抗反应良好,右眼视力提高到20/25.强调预防保健的重要性,建议患者求助于心脏病学、胃肠病学和人类遗传学咨询服务.结论:PXE是一个累及多系统的疾病,它影响着皮肤、眼和心血管系统.在固有的皮肤变化和明显的颏皱褶的存在下,血管样条纹症和脉络膜新生血管的眼科发现能提高PXE的评估.%AIM: To report a case of pseudoxanthoma elasticum (PXE) in a 48-year-old woman that presented with bilateral blurry vision.METHODS: A case report.RESULTS: A 48-year-old woman presented with bilateral blurry vision and right eye metamorphopsia. The patient had a history of angioid streaks in the left eye ten years ago for which she had received laser surgery and had poor residual vision. Visual acuity was 20/60 in the right eye and count fingers at 6 feet in the left. Fundus examination showed subretinal hemorrhage and macular thickening on the right and a disciform macular scar with focal atrophic pigment epithelial lesions on the left. Both eyes had angioid streaks and peau d'orange pigmentary pattern of the retina. External examination showed several, yellow skin papules and plaques on the lateral and posterior neck, as well as prominent mental

  10. Angioid streaks - a rare cause of neovascular glaucoma. Case report.

    OpenAIRE

    Ungureanu, E; Geamanu, A; Careba, I; Grecescu, M; Gradinaru, S

    2014-01-01

    Rationale. Neovascular glaucoma is the type of glaucoma most refractory to treatment. The most frequent causes are those associated with retinal hypoxia, such as proliferative diabetic retinopathy, central retinal vein occlusion, branch retinal vein occlusion, central retinal arterial occlusion, ischemic ocular syndrome etc. Rare causes of neovascular glaucoma are multiple and are due to VEGF synthesis associated with chorioretinal inflammations or degenerations. We present a case with neovas...

  11. Microchannel plate streak camera

    Science.gov (United States)

    Wang, Ching L.

    1989-01-01

    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.

  12. Streaking into middle school science: The Dell Streak pilot project

    Science.gov (United States)

    Austin, Susan Eudy

    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

  13. Slope Streaks in Terra Sabaea

    Science.gov (United States)

    2007-01-01

    [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

  14. Orbital objects detection algorithm using faint streaks

    Science.gov (United States)

    Tagawa, Makoto; Yanagisawa, Toshifumi; Kurosaki, Hirohisa; Oda, Hiroshi; Hanada, Toshiya

    2016-02-01

    This study proposes an algorithm to detect orbital objects that are small or moving at high apparent velocities from optical images by utilizing their faint streaks. In the conventional object-detection algorithm, a high signal-to-noise-ratio (e.g., 3 or more) is required, whereas in our proposed algorithm, the signals are summed along the streak direction to improve object-detection sensitivity. Lower signal-to-noise ratio objects were detected by applying the algorithm to a time series of images. The algorithm comprises the following steps: (1) image skewing, (2) image compression along the vertical axis, (3) detection and determination of streak position, (4) searching for object candidates using the time-series streak-position data, and (5) selecting the candidate with the best linearity and reliability. Our algorithm's ability to detect streaks with signals weaker than the background noise was confirmed using images from the Australia Remote Observatory.

  15. Streak Tubes for Diagnostics of Lasers and Plasmas

    Science.gov (United States)

    Sokolov, A. Yu; Konovalov, P. I.; Nurtdinov, R. I.; Vikulin, M. P.; Pryanishnikov, I. G.; Dolotov, A. S.; Krapiva, P. S.

    2016-09-01

    Designing a facility for laser fusion research requires sufficient advancement in diagnostics techniques for lasers and plasmas, including those involving streak camera imaging. Maximum specifications of streak cameras depend on the parameters of streak tubes. The paper illustrates how these devices function, and which of their parameters are limiting. The paper presents a novel technological platform designed at VNIIA, which was used to develop a new generation of streak tubes. Using these streak tubes in streak cameras, the efficiency of streak camera imaging techniques can be improved by several orders of magnitude, and new techniques can be designed.

  16. Time-resolved photoemission using attosecond streaking

    CERN Document Server

    Nagele, Stefan; Wais, Michael; Wachter, Georg; Burgdörfer, Joachim

    2014-01-01

    We theoretically study time-resolved photoemission in atoms as probed by attosecond streaking. We review recent advances in the study of the photoelectric effect in the time domain and show that the experimentally accessible time shifts can be decomposed into distinct contributions that stem from the field-free photoionization process itself and from probe-field induced corrections. We perform accurate quantum-mechanical as well as classical simulations of attosecond streaking for effective one-electron systems and determine all relevant contributions to the time delay with attosecond precision. In particular, we investigate the properties and limitations of attosecond streaking for the transition from short-ranged potentials (photodetachment) to long-ranged Coulomb potentials (photoionization). As an example for a more complex system, we study time-resolved photoionization for endohedral fullerenes $A$@$\\text{C}_{60}$ and discuss how streaking time shifts are modified due to the interaction of the $\\text{C}_...

  17. A solid state streak camera

    Science.gov (United States)

    Kleinfelder, Stuart; Kwiatkowski, Kris; Shah, Ashish

    2005-03-01

    A monolithic solid-state streak camera has been designed and fabricated in a standard 0.35 μm, 3.3V, thin-oxide digital CMOS process. It consists of a 1-D linear array of 150 integrated photodiodes, followed by fast analog buffers and on-chip, 150-deep analog frame storage. Each pixel's front-end consists of an n-diffusion / p-well photodiode, with fast complementary reset transistors, and a source-follower buffer. Each buffer drives a line of 150 sample circuits per pixel, with each sample circuit consisting of an n-channel sample switch, a 0.1 pF double-polysilicon sample capacitor, a reset switch to definitively clear the capacitor, and a multiplexed source-follower readout buffer. Fast on-chip sample clock generation was designed using a self-timed break-before-make operation that insures the maximum time for sample settling. The electrical analog bandwidth of each channels buffer and sampling circuits was designed to exceed 1 GHz. Sampling speeds of 400 M-frames/s have been achieved using electrical input signals. Operation with optical input signals has been demonstrated at 100 MHz sample rates. Sample output multiplexing allows the readout of all 22,500 samples (150 pixels times 150 samples per pixel) in about 3 ms. The chip"s output range was a maximum of 1.48 V on a 3.3V supply voltage, corresponding to a maximum 2.55 V swing at the photodiode. Time-varying output noise was measured to be 0.51 mV, rms, at 100 MHz, for a dynamic range of ~11.5 bits, rms. Circuit design details are presented, along with the results of electrical measurements and optical experiments with fast pulsed laser light sources at several wavelengths.

  18. ASTRiDE: Automated Streak Detection for Astronomical Images

    Science.gov (United States)

    Kim, Dae-Won

    2016-05-01

    ASTRiDE detects streaks in astronomical images using a "border" of each object (i.e. "boundary-tracing" or "contour-tracing") and their morphological parameters. Fast moving objects such as meteors, satellites, near-Earth objects (NEOs), or even cosmic rays can leave streak-like traces in the images; ASTRiDE can detect not only long streaks but also relatively short or curved streaks.

  19. Bichromatic particle streak velocimetry bPSV

    Science.gov (United States)

    Voss, Björn; Stapf, Julian; Berthe, André; Garbe, Christoph S.

    2012-11-01

    We propose a novel technique for three-dimensional three-component (3D3C) interfacial flow measurement. It is based on the particle streak velocimetry principle. A relatively long integration time of the camera is used for capturing the movement of tracer particles as streaks on the sensor. The velocity along these streaks is extracted by periodically changing the illumination using a known pattern. A dye with different absorption characteristics in two distinct wavelengths is used to color the fluid. The depth of particles relative to the fluid interface can then be computed from their intensities when illuminated with light sources at those two different wavelengths. Hence, from our approach, a bichromatic, periodical illumination together with an image processing routine for precisely extracting particle streak features is used for measuring 3D3C fluid flow with a single camera. The technique is applied to measuring turbulent Rayleigh-Bénard convection at the free air--water interface. Using Lagrangian statistics, we are able to demonstrate a clear transition from the Batchelor regime to the Richardson regime, both of which were postulated for isotropic turbulence. The relative error of the velocity extraction of our new technique was found to be below 0.5 %.

  20. Understanding baseball team standings and streaks

    Science.gov (United States)

    Sire, C.; Redner, S.

    2009-02-01

    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.

  1. Particle Streak Velocimetry of Supersonic Nozzle Flows

    Science.gov (United States)

    Willits, J. D.; Pourpoint, T. L.

    2016-01-01

    A novel velocimetry technique to probe the exhaust flow of a laboratory scale combustor is being developed. The technique combines the advantages of standard particle velocimetry techniques and the ultra-fast imaging capabilities of a streak camera to probe high speed flows near continuously with improved spatial and velocity resolution. This "Particle Streak Velocimetry" technique tracks laser illuminated seed particles at up to 236 picosecond temporal resolution allowing time-resolved measurement of one-dimensional flows exceeding 2000 m/s as are found in rocket nozzles and many other applications. Developmental tests with cold nitrogen have been performed to validate and troubleshoot the technique with supersonic flows of much lower velocity and without background noise due to combusting flow. Flow velocities on the order of 500 m/s have been probed with titanium dioxide particles and a continuous-wave laser diode. Single frame images containing multiple streaks are analyzed to find the average slope of all incident particles corresponding to the centerline axial flow velocity. Long term objectives for these tests are correlation of specific impulse to theoretical combustion predictions and direct comparisons between candidate green fuels and the industry standard, monomethylhydrazine, each tested under identical conditions.

  2. High throughput Single-cell Cultivation on Microfluidic Streak Plates

    OpenAIRE

    Jiang, Cheng-Ying; Dong, Libing; Zhao, Jian-Kang; Hu, Xiaofang; Shen, Chaohua; Qiao, Yuxin; Zhang, Xinyue; Wang, Yapei; Ismagilov, Rustem F.; Liu, Shuang-Jiang; Du, Wenbin

    2016-01-01

    This paper describes the microfluidic streak plate (MSP), a facile method for high-throughput microbial cell separation and cultivation in nanoliter sessile droplets. The MSP method builds upon the conventional streak plate technique by using microfluidic devices to generate nanoliter droplets that can be streaked manually or robotically onto petri dishes prefilled with carrier oil for cultivation of single cells. In addition, chemical gradients could be encoded in the droplet array for compr...

  3. Electron accelerating unit for streak image tubes

    Indian Academy of Sciences (India)

    Fangke Zong; Qinlao Yang; Houzhi Cai; Li Gu; Xiang Li; Jingjin Zhang

    2015-12-01

    An electron accelerating unit is proposed for use in streak image tubes (SITs). An SIT with this new accelerating unit was simulated using the Monte Carlo method. The simulation results show that the accelerating unit improves both the spatial and temporal resolution. Compared to a traditional SIT, the transit time spread for electrons in the cathode-to-mesh region is reduced from 247 to 162 fs, the line width of the electron beam on the image surface is reduced from 42.7 to 26.1 m, and the temporal resolution is improved from 515 to 395 fs.

  4. Streak tube photocathode development program. Phase 2, Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-20

    This report details the progress made toward developing a streak tube with greater than 1% quantum efficiency at a wavelength of 1300 nm. The achieved performance is the result of approximately three years of effort. The goal of Phase 2 of this contract was to seal a working 1.3 {mu}m streak tube. This effort was focused in two areas. First there was a continuing effort to further develop and demonstrate the cathodes ability to meet the stated requirements. The second effort was aimed at solving the mechanical and process related problems related to sealing this cathode onto a EG&G streak tube.

  5. Attosecond streaking of photoelectron emission from disordered solids

    CERN Document Server

    Okell, W A; Fabris, D; Arrell, C A; Hengster, J; Ibrahimkutty, S; Seiler, A; Barthelmess, M; Stankov, S; Lei, D Y; Sonnefraud, Y; Rahmani, M; Uphues, Th; Maier, S A; Marangos, J P; Tisch, J W G

    2014-01-01

    Attosecond streaking of photoelectrons emitted by extreme ultraviolet light has begun to reveal how electrons behave during their transport within simple crystalline solids. Many sample types within nanoplasmonics, thin-film physics, and semiconductor physics, however, do not have a simple single crystal structure. The electron dynamics which underpin the optical response of plasmonic nanostructures and wide-bandgap semiconductors happen on an attosecond timescale. Measuring these dynamics using attosecond streaking will enable such systems to be specially tailored for applications in areas such as ultrafast opto-electronics. We show that streaking can be extended to this very general type of sample by presenting streaking measurements on an amorphous film of the wide-bandgap semiconductor tungsten trioxide, and on polycrystalline gold, a material that forms the basis of many nanoplasmonic devices. Our measurements reveal the near-field temporal structure at the sample surface, and photoelectron wavepacket te...

  6. Semiclassical model for attosecond angular streaking.

    Science.gov (United States)

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

    2010-08-16

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

  7. Streak instability induced by bedload diffusion

    Science.gov (United States)

    Abramian, Anaïs; Seizilles, Grégoire; Devauchelle, Olivier; Lajeunesse, Eric

    2016-04-01

    The bed of an alluvial river is made of the sediment it transports. Its shape and size are controlled mostly by bedload transport which, at first order, entrains sediment grains along the flow. Gravity also pulls the moving grains towards the center of the channel, thus eroding the banks continually (Parker 1978). However, laboratory observations show that, due to the bed roughness, the trajectory of a transported grain fluctuates in the transverse direction (Seizilles et al. 2014). The bedload layer is therefore a collection of random walkers which diffuse towards the less active areas of the bed. In a river at equilibrium, bedload diffusion counteracts gravity to maintain the banks. If an initially flat bed of sediment is perturbed with longitudinal streaks, the flow-induced shear stress is weaker where the flow is shallower. Therefore, we expect bedload diffusion to induce a flux of sediment towards the crests of the perturbation. This positive feedback induces an instability which can generate new channels. We suggest that this mechanism could explain the transition from a single-thread river to a braided one.

  8. Ductile streaks in precision grinding of hard and brittle materials

    Indian Academy of Sciences (India)

    V C Venkatesh; S Izman; S Sharif; T T Mon; M Konneh

    2003-10-01

    Ductile streaks produced during diamond grinding of hard and brittle materials have aided the subsequent process of polishing. Two novel techniques were used to study the formation of ductile mode streaks during diamond grinding (primary process) of germanium, silicon, and glass. In the first technique, aspheric surfaces were generated on Ge and Si at conventional speeds (5000 rpm). In the second technique, diamond grinding of plano surfaces on glass and Si surfaces using high speed (100,000 rpm) was carried out. Form accuracy, surface finish and ductile mode grinding streaks are discussed in this paper. It was found that resinoid diamond wheels gave more ductile streaks than metal-bonded wheels but better form accuracy was obtained with the latter. Ductile streaks were obtained more easily with pyrex rather than with BK 7 glass thus necessitating very little time for polishing. Ductile streaks appeared in abundance on germanium rather than silicon. Both the novel grinding techniques were used on CNC machining centres.

  9. Simulation of FEL pulse length calculation with THz streaking method

    Energy Technology Data Exchange (ETDEWEB)

    Gorgisyan, I., E-mail: ishkhan.gorgisyan@psi.ch [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); École Polytechnique Fédérale de Lausanne, Route Cantonale, 1015 Lausanne (Switzerland); Ischebeck, R.; Prat, E.; Reiche, S. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Rivkin, L. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); École Polytechnique Fédérale de Lausanne, Route Cantonale, 1015 Lausanne (Switzerland); Juranić, P., E-mail: ishkhan.gorgisyan@psi.ch [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland)

    2016-04-02

    Simulation of THz streaking of photoelectrons created by X-ray pulses from a free-electron laser and reconstruction of the free-electron laser pulse lengths. Having accurate and comprehensive photon diagnostics for the X-ray pulses delivered by free-electron laser (FEL) facilities is of utmost importance. Along with various parameters of the photon beam (such as photon energy, beam intensity, etc.), the pulse length measurements are particularly useful both for the machine operators to measure the beam parameters and monitor the stability of the machine performance, and for the users carrying out pump–probe experiments at such facilities to better understand their measurement results. One of the most promising pulse length measurement techniques used for photon diagnostics is the THz streak camera which is capable of simultaneously measuring the lengths of the photon pulses and their arrival times with respect to the pump laser. This work presents simulations of a THz streak camera performance. The simulation procedure utilizes FEL pulses with two different photon energies in hard and soft X-ray regions, respectively. It recreates the energy spectra of the photoelectrons produced by the photon pulses and streaks them by a single-cycle THz pulse. Following the pulse-retrieval procedure of the THz streak camera, the lengths were calculated from the streaked spectra. To validate the pulse length calculation procedure, the precision and the accuracy of the method were estimated for streaking configuration corresponding to previously performed experiments. The obtained results show that for the discussed setup the method is capable of measuring FEL pulses with about a femtosecond accuracy and precision.

  10. Attosecond streaking in a nano-plasmonic field

    Science.gov (United States)

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

    2012-09-01

    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.

  11. Mead Crater, Venus - Aerodynamic roughness of wind streaks

    Science.gov (United States)

    Williams, K. K.; Greeley, R.

    1997-03-01

    Radar backscatter images of Venus returned by the Magellan spacecraft revealed many aeolian features on the planet's surface. While much work has focused on terrestrial wind streaks, the harsh environment of Venus limits direct measurement of surface properties, such as aerodynamic roughness, that affect aeolian features on that planet. However, a correlation between radar backscatter and aerodynamic roughness (Z0) for the S-band radar system on Magellan can be used to study the aerodynamic roughnesses of areas in which Venusian wind streaks occur. The aerodynamic roughness of areas with both radar-bright and radar-dark wind streaks near Mead crater are calculated and compared to z0 values measured on Earth in order to compare the surface of Venus with known terrestrial surface textures.

  12. A new African streak virus species from Nigeria.

    Science.gov (United States)

    Oluwafemi, Sunday; Varsani, Arvind; Monjane, Adérito L; Shepherd, Dionne N; Owor, Betty E; Rybicki, Edward P; Martin, Darren P

    2008-01-01

    The African streak viruses (AfSVs) are a diverse group of mastrevirus species (family Geminiviridae) that infect a wide variety of annual and perennial grass species across the African continent and its nearby Indian Ocean islands. Six AfSV species (of which maize streak virus is the best known) have been described. Here we report the full genome sequences of eight isolates of a seventh AfSV species: Urochloa streak virus (USV), sampled from various locations in Nigeria. Despite there being good evidence of recombination in many other AfSV species, we found no convincing evidence that any of the USV sequences were either inter- or intra-species recombinants. The USV isolates, all of which appear to be variants of the same strain (their genome sequences are all more than 98% identical), share less than 69% nucleotide sequence identity with other currently described AfSV species. PMID:18521534

  13. Performance of Laser Megajoule's x-ray streak camera

    Science.gov (United States)

    Zuber, C.; Bazzoli, S.; Brunel, P.; Burillo, M.; Fronty, J. P.; Gontier, D.; Goulmy, C.; Moreau, I.; Oudot, G.; Rubbelynck, C.; Soullié, G.; Stemmler, P.; Trosseille, C.

    2016-11-01

    A prototype of a picosecond x-ray streak camera has been developed and tested by Commissariat à l'Énergie Atomique et aux Énergies Alternatives to provide plasma-diagnostic support for the Laser Megajoule. We report on the measured performance of this streak camera, which almost fulfills the requirements: 50-μm spatial resolution over a 15-mm field in the photocathode plane, 17-ps temporal resolution in a 2-ns timebase, a detection threshold lower than 625 nJ/cm2 in the 0.05-15 keV spectral range, and a dynamic range greater than 100.

  14. Hitting is contagious in baseball: evidence from long hitting streaks.

    Science.gov (United States)

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

    2012-01-01

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

  15. Hitting is contagious in baseball: evidence from long hitting streaks.

    Directory of Open Access Journals (Sweden)

    Joel R Bock

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

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

    Science.gov (United States)

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

  17. Monitoring Nonadiabatic Electron-Nuclear Dynamics in Molecules by Attosecond Streaking of Photoelectrons

    Science.gov (United States)

    Kowalewski, Markus; Bennett, Kochise; Rouxel, Jérémy R.; Mukamel, Shaul

    2016-07-01

    Streaking of photoelectrons has long been used for the temporal characterization of attosecond extreme ultraviolet pulses. When the time-resolved photoelectrons originate from a coherent superposition of electronic states, they carry additional phase information, which can be retrieved by the streaking technique. In this contribution we extend the streaking formalism to include coupled electron and nuclear dynamics in molecules as well as initial coherences. We demonstrate how streaked photoelectrons offer a novel tool for monitoring nonadiabatic dynamics as it occurs in the vicinity of conical intersections and avoided crossings. Streaking can provide high time resolution direct signatures of electronic coherences, which affect many primary photochemical and biological events.

  18. Observation of molecular dipole excitations by attosecond self-streaking

    CERN Document Server

    Wachter, Georg; Sato, Shunsuke A; Pazourek, Renate; Wais, Michael; Lemell, Christoph; Tong, Xiao-Min; Yabana, Kazuhiro; Burgdörfer, Joachim

    2015-01-01

    We propose a protocol to probe the ultrafast evolution and dephasing of coherent electronic excitation in molecules in the time domain by the intrinsic streaking field generated by the molecule itself. Coherent electronic motion in the endohedral fullerene \\Necsixty~is initiated by a moderately intense femtosecond UV-VIS pulse leading to coherent oscillations of the molecular dipole moment that persist after the end of the laser pulse. The resulting time-dependent molecular near-field is probed through the momentum modulation of photoemission from the central neon atom by a time-delayed attosecond XUV pulse. Our ab-initio time-dependent density functional theory and classical trajectory simulations predict that this self-streaking signal accurately traces the molecular dipole oscillations in real time. We discuss the underlying processes and give an analytical model that captures the essence of our ab-initio simulations.

  19. Streaked x-ray microscopy of laser-fusion targets

    International Nuclear Information System (INIS)

    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 μm and temporal resolution was 20 ps. Data is presented showing the ablative acceleration of foils to velocities near 107 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

  20. Energy Sharing in the 2-Electron Attosecond Streak Camera

    CERN Document Server

    Price, H; Emmanouilidou, A

    2011-01-01

    Using the recently developed concept of the 2-electron streak camera (see NJP 12, 103024 (2010)), we have studied the energy-sharing between the two ionizing electrons in single-photon double ionization of He(1s2s). We find that the most symmetric and asymmetric energy sharings correspond to different ionization dynamics with the ion's Coulomb potential significantly influencing the latter. This different dynamics for the two extreme energy sharings gives rise to different patterns in asymptotic observables and different time-delays between the emission of the two electrons. We show that the 2-electron streak camera resolves the time-delays between the emission of the two electrons for different energy sharings.

  1. A new design of filter system in streak camera

    Science.gov (United States)

    Zhou, Pengyu; Bai, Yonglin

    2015-10-01

    In order to reduce the frequency of researchers routing in and out of the testing site and ensure the fluency of the testing we design a new filter system applied to the streak cameras. This system promotes streak cameras' abilities on spatial discrimination and time resolution. This paper focuses on the instruction of the piezoelectric motor's principle based on field-effect tubes. Filter wheel is driven by piezoelectric motor. It can effectively avoid the influences of high field produced by streak tube. Finally we achieve auto regulation at different gears and promote the efficiency of operations and guarantee the safety of researchers. CD4046 introduces the driven clock of this system and we use an inverter to get two synchronous inverted signals. These signals are amplified by field-effect tubes to more than 300V. The amplified ones are integrated at the output terminals to generate sinusoidal signal. The test shows that in this filter system piezoelectric motor operates at its resonance frequency under a control signal of 62.5 KHz. Its working current is 1.9A and driving power is almost 10W. By adjusting the gears, the filter wheel costs less than 2 seconds to calibrate. We accomplish the test in respected results.

  2. Stabilization of boundary layer streaks by plasma actuators

    International Nuclear Information System (INIS)

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

  3. Stochastic Structural Stability Theory applied to roll/streak formation in boundary layer shear flow

    CERN Document Server

    Farrell, Brian F

    2010-01-01

    Stochastic Structural Stability Theory (SSST) provides an autonomous, deterministic, nonlinear dynamical system for evolving the statistical mean state of a turbulent system. In this work SSST is applied to the problem of understanding the formation of the roll/streak structures that arise from free-stream turbulence (FST) and are associated with bypass transition in boundary layers. Roll structures in the cross-stream/spanwise plane and associated streamwise streaks are shown to arise as a linear instability of interaction between the FST and the mean flow. In this interaction incoherent Reynolds stresses arising from FST are organized by perturbation streamwise streaks to coherently force perturbation rolls giving rise to an amplification of the streamwise streak perturbation and through this feedback to an instability of the combined roll/streak/turbulence complex. The dominant turbulent perturbation structures involved in supporting the roll/streak/turbulence complex instability are non-normal optimal per...

  4. Modeling gastrulation in the chick embryo: formation of the primitive streak.

    Directory of Open Access Journals (Sweden)

    Bakhtier Vasiev

    Full Text Available The body plan of all higher organisms develops during gastrulation. Gastrulation results from the integration of cell proliferation, differentiation and migration of thousands of cells. In the chick embryo gastrulation starts with the formation of the primitive streak, the site of invagination of mesoderm and endoderm cells, from cells overlaying Koller's Sickle. Streak formation is associated with large-scale cell flows that carry the mesoderm cells overlying Koller's sickle into the central midline region of the embryo. We use multi-cell computer simulations to investigate possible mechanisms underlying the formation of the primitive streak in the chick embryo. Our simulations suggest that the formation of the primitive streak employs chemotactic movement of a subpopulation of streak cells, as well as differential adhesion between the mesoderm cells and the other cells in the epiblast. Both chemo-attraction and chemo-repulsion between various combinations of cell types can create a streak. However, only one combination successfully reproduces experimental observations of the manner in which two streaks in the same embryo interact. This finding supports a mechanism in which streak tip cells produce a diffusible morphogen which repels cells in the surrounding epiblast. On the other hand, chemotactic interaction alone does not reproduce the experimental observation that the large-scale vortical cell flows develop simultaneously with streak initiation. In our model the formation of large scale cell flows requires an additional mechanism that coordinates and aligns the motion of neighboring cells.

  5. Monitoring Nonadiabatic Electron-Nuclear Dynamics in Molecules by Attosecond Streaking of Photoelectrons

    CERN Document Server

    Kowalewski, Markus; Rouxel, Jérémy R; Mukamel, Shaul

    2016-01-01

    Streaking of photoelectrons has long been used for the temporal characterization of attosecond extreme ultraviolet pulses. When the time-resolved photoelectrons originate from a coherent superposition of electronic states, they carry an additional phase information, which can be retrieved by the streaking technique. In this contribution we extend the streaking formalism to include coupled electron and nuclear dynamics in molecules as well as initial coherences and demonstrate how it offers a novel tool to monitor non-adiabatic dynamics as it occurs in the vicinity of conical intersections and avoided crossings. Streaking can enhance the time resolution and provide direct signatures of electronic coherences, which affect many primary photochemical and biological events.

  6. Characterization of Brown Streak Virus-Resistant Cassava.

    Science.gov (United States)

    Anjanappa, Ravi B; Mehta, Devang; Maruthi, M N; Kanju, Edward; Gruissem, Wilhelm; Vanderschuren, Hervé

    2016-07-01

    Cassava brown streak disease (CBSD) has become a major constraint to cassava production in East and Central Africa. The identification of new sources of CBSD resistance is essential to deploy CBSD mitigation strategies, as the disease is progressing westwards to new geographical areas. A stringent infection method based on top cleft-grafting combined with precise virus titer quantitation was utilized to screen 14 cassava cultivars and elite breeding lines. When inoculated with mixed infections of Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV), the scions of elite breeding lines KBH 2006/18 and KBH 2006/26 remained symptom-free during a 16-week period of virus graft inoculation, while susceptible varieties displayed typical CBSD infection symptoms at 4 weeks after grafting. The identified CBSD resistance was stable under the coinoculation of CBSV and UCBSV with cassava geminiviruses. Double-grafting experiments revealed that transmission of CBSV and UCBSV to CBSD-susceptible top scions was delayed when using intermediate scions of elite breeding lines KBH 2006/18 and KBH 2006/26. Nonetheless, comparison of virus systemic movement using scions from KBH2006/18 and a transgenic CBSD resistant 60444 line (60444-Hp9 line) showed that both CBSV and UCBSV move at undetectable levels through the stems. Further, protoplast-based assays of virus titers showed that the replication of CBSV is inhibited in the resistant line KBH2006/18, suggesting that the identified CBSD resistance is at least partially based on inhibition of virus replication. Our molecular characterization of CBSD resistance in cassava offers a robust virus-host system to further investigate the molecular determinants of CBSD resistance. PMID:27070326

  7. Characterization of Brown Streak Virus-Resistant Cassava.

    Science.gov (United States)

    Anjanappa, Ravi B; Mehta, Devang; Maruthi, M N; Kanju, Edward; Gruissem, Wilhelm; Vanderschuren, Hervé

    2016-07-01

    Cassava brown streak disease (CBSD) has become a major constraint to cassava production in East and Central Africa. The identification of new sources of CBSD resistance is essential to deploy CBSD mitigation strategies, as the disease is progressing westwards to new geographical areas. A stringent infection method based on top cleft-grafting combined with precise virus titer quantitation was utilized to screen 14 cassava cultivars and elite breeding lines. When inoculated with mixed infections of Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV), the scions of elite breeding lines KBH 2006/18 and KBH 2006/26 remained symptom-free during a 16-week period of virus graft inoculation, while susceptible varieties displayed typical CBSD infection symptoms at 4 weeks after grafting. The identified CBSD resistance was stable under the coinoculation of CBSV and UCBSV with cassava geminiviruses. Double-grafting experiments revealed that transmission of CBSV and UCBSV to CBSD-susceptible top scions was delayed when using intermediate scions of elite breeding lines KBH 2006/18 and KBH 2006/26. Nonetheless, comparison of virus systemic movement using scions from KBH2006/18 and a transgenic CBSD resistant 60444 line (60444-Hp9 line) showed that both CBSV and UCBSV move at undetectable levels through the stems. Further, protoplast-based assays of virus titers showed that the replication of CBSV is inhibited in the resistant line KBH2006/18, suggesting that the identified CBSD resistance is at least partially based on inhibition of virus replication. Our molecular characterization of CBSD resistance in cassava offers a robust virus-host system to further investigate the molecular determinants of CBSD resistance.

  8. Particle-streak-velocimetry for room air flows

    Energy Technology Data Exchange (ETDEWEB)

    Scholzen, F.; Moser, A.; Suter, P. [Swiss Federal Inst. of Technology, Zurich (Switzerland). Energy Systems Lab.

    1994-12-31

    This paper presents a measurement technique to perform quantitative visualization of room air flows. The visualization is done by discrete particles, namely helium-filled soap bubbles, illuminated in a plane light sheet generated by a point light source in combination with a special lens. The recording is done stereoscopically with 3 standard cameras by streak photography. The scanned negatives are analysed digitally. The method is able to give the three-dimensional instantaneous velocity field of room air movements, also in real-scale. (author)

  9. Analyses of Twelve New Whole Genome Sequences of Cassava Brown Streak Viruses and Ugandan Cassava Brown Streak Viruses from East Africa: Diversity, Supercomputing and Evidence for Further Speciation

    OpenAIRE

    Ndunguru, Joseph; Sseruwagi, Peter; Tairo, Fred; Stomeo, Francesca; Maina, Solomon; Djinkeng, Appolinaire; Kehoe, Monica; Boykin, Laura M

    2015-01-01

    Cassava brown streak disease is caused by two devastating viruses, Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV) which are frequently found infecting cassava, one of sub-Saharan Africa’s most important staple food crops. Each year these viruses cause losses of up to $100 million USD and can leave entire families without their primary food source, for an entire year. Twelve new whole genomes, including seven of CBSV and five of UCBSV were uncovered in this re...

  10. Range accuracy analysis of streak tube imaging lidar systems

    Science.gov (United States)

    Ye, Guangchao; Fan, Rongwei; Chen, Zhaodong; Yuan, Wei; Chen, Deying; He, Ping

    2016-02-01

    Streak tube imaging lidar (STIL) is an active imaging system that has a high range accuracy and a wide range gate with the use of a pulsed laser transmitter and streak tube receiver to produce 3D range images. This work investigates the range accuracy performance of STIL systems based on a peak detection algorithm, taking into account the effects of blurring of the image. A theoretical model of the time-resolved signal distribution, including the static blurring width in addition to the laser pulse width, is presented, resulting in a modified range accuracy analysis. The model indicates that the static blurring width has a significant effect on the range accuracy, which is validated by both the simulation and experimental results. By using the optimal static blurring width, the range accuracies are enhanced in both indoor and outdoor experiments, with a stand-off distance of 10 m and 1700 m, respectively, and corresponding, best range errors of 0.06 m and 0.25 m were achieved in a daylight environment.

  11. Microprocessor-controlled, wide-range streak camera

    International Nuclear Information System (INIS)

    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

  12. Microprocessor-controlled wide-range streak camera

    Science.gov (United States)

    Lewis, Amy E.; Hollabaugh, Craig

    2006-08-01

    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.

  13. Genome Sequence of Banana Streak MY Virus from the Pacific Ocean Island of Tonga

    OpenAIRE

    Stainton, Daisy; Halafihi, Mana’ia; Collings, David A.; Varsani, Arvind

    2015-01-01

    Banana streak disease is caused by a variety of banana-infecting badnaviruses. A genome of the episomal form of a banana streak MY virus was recovered from an infected banana plant sampled on Vava’u Island, Tonga, and shares >98% pairwise identity with the six other genomes available in public databases.

  14. Femtosecond streaking of electron diffraction patterns to study structural dynamics in crystalline matter

    NARCIS (Netherlands)

    Eichberger, M.; Erasmus, N.; Haupt, K.; Kassier, G.; von Flotow, A.; Demsar, J.; Schwoerer, H.

    2013-01-01

    A table-top femtosecond, non-relativistic, electron diffraction setup is combined with a low-jitter, photo-triggered streak camera to follow the optically induced structural dynamics in complex solids. A temporal resolution of 550 fs is experimentally demonstrated, while the route to streaking with

  15. Major QTL Conferring Resistance to Rice Bacterial Leaf Streak

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Bacterial leaf streak (BLS) is one of the important limiting factors to rice production in southern China and other tropical and sub-tropical areas in Asia. Resistance to BLS was found to be a quantitative trait and no major resistant gene was located in rice until date. In the present study, a new major quantitative trait locus (QTL) conferring resistance to BLS was identified from a highly resistant variety Dular by the employment of Dular/Balilla (DB) and Dular/IR24 (DI) segregation populations and was designated qBLSR-11-1. This QTL was located between the simple sequence repeat (SSR) markers RM120 and RM441 on chromosome 11 and could account for 18.1-21.7% and 36.3% of the variance in DB and DI populations, respectively. The genetic pattern of rice resistance to BLS was discussed.

  16. Steering continuum electron dynamics by low-energy attosecond streaking

    Science.gov (United States)

    Geng, Ji-Wei; Xiong, Wei-Hao; Xiao, Xiang-Ru; Gong, Qihuang; Peng, Liang-You

    2016-08-01

    A semiclassical model is developed to understand the electronic dynamics in the low-energy attosecond streaking. Under a relatively strong infrared (IR) pulse, the low-energy part of photoelectrons initialized by a single attosecond pulse (SAP) can either rescatter with the ionic core and induce interferences structures in the momentum spectra of the ionized electrons or be recaptured into the Rydberg states. The Coulomb potential plays essential roles in both the electron rescattering and recapturing processes. We find that by changing the time delay between the SAP and the IR pulse, the photoelectrons yield or the population of the Rydberg states can be effectively controlled. The present study demonstrates a fascinating way to steer the electron motion in the continuum.

  17. Particle streak velocimetry and its application to impinging laminar jets

    Science.gov (United States)

    Bergthorson, Jeff; Dimotakis, Paul

    2002-11-01

    The technique of Particle Streak Velocimetry (PSV) was improved to include digital imaging and image processing, allowing it to compete with PIV or LDV in terms of accuracy and ease of implementation. PSV provides advantages over other techniques, such as low particle mass loading, short run time experiments, and high accuracy velocity data through the direct measurement of Lagrangian trajectories. PSV, coupled with measurements of the static (Bernoulli) pressure drop across a well designed nozzle contraction, provided redundancy in the measurement of the axisymmetric impinging laminar jet. The impinging laminar jet was studied in the intermediate regime where the existence of a stagnation plate will affect the flow out of the nozzle. This nozzle separation to diameter ratio, L/d_j, regime has not been well characterized. The results indicate that a one-dimensional streamfunction formulation is not sufficient to characterize this flow.

  18. Illusory Streaks from Corners and Their Perceptual Integration.

    Science.gov (United States)

    Roncato, Sergio; Guidi, Stefano; Parlangeli, Oronzo; Battaglini, Luca

    2016-01-01

    Perceptual grouping appears both as organized forms of real figural units and as illusory or "phantom" figures. The phenomenon is visible in the Hermann grid and in configurations which generate color spreading, e.g., "neon effects." These configurations, generally regular repetitive patterns, appear to be crossed by illusory bands filled with a brighter shade or a colored tinge connecting the various loci of illusory effects. In this work, we explore a particular new illusion showing a grouping effect. It manifests as illusory streaks irradiating from the vertexes of angular contours and connecting pairs of figures nearby. It is only clearly visible when more than one figure is shown, and takes the shape of a net crossing their corners. Although the grouping effect is vivid, the local source of the illusion is completely hidden. Theories explaining this effect as due to the irradiation of illusory streaks (mainly that of Grossberg and Mingolla, 1985a,b) do not fully explain the figural patterns presented here. Illusory effects have already been documented at the angles of various figures, causing them to alter in amplitude and brightness; however, the figure illustrated here appears to have different features and location. Phenomenological observations and an experiment were conducted to assess the role played by geometric and photometric parameters in this illusion. Results showed that sharp angles, in low contrast with the surround, are the main source of the illusion which, however, only becomes visible when at least two figures are close together. These findings are discussed with respect to theories of contour processing and perceptual grouping, and in relation to other illusions.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-01-01

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

  20. Ultra Fast X-ray Streak Camera for TIM Based Platforms

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-05-02

    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.

  1. Attosecond streaking of Cohen-Fano interferences in the photoionization of H$_2^+$

    CERN Document Server

    Ning, Qi-Cheng; Song, Shu-Na; Jiang, Wei-Chao; Nagele, Stefan; Pazourek, Renate; Burgdörfer, Joachim; Gong, Qihuang

    2014-01-01

    We present the first numerical simulation of the time delay in the photoionization of the simplest diatomic molecule H$_2^+$ as observed by attosecond streaking. We show that the strong variation of the Eisenbud-Wigner-Smith time delay as a function of energy and emission angle becomes observable in the streaking time shift provided laser field-induced components are accounted for. The strongly enhanced photoemission time shifts are traced to destructive Cohen-Fano (or two-center) interferences. Signatures of these interferences in the streaking trace are shown to be enhanced when the ionic fragments are detected in coincidence.

  2. Analyses of Twelve New Whole Genome Sequences of Cassava Brown Streak Viruses and Ugandan Cassava Brown Streak Viruses from East Africa: Diversity, Supercomputing and Evidence for Further Speciation.

    Science.gov (United States)

    Ndunguru, Joseph; Sseruwagi, Peter; Tairo, Fred; Stomeo, Francesca; Maina, Solomon; Djikeng, Appolinaire; Djinkeng, Appolinaire; Kehoe, Monica; Boykin, Laura M

    2015-01-01

    Cassava brown streak disease is caused by two devastating viruses, Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV) which are frequently found infecting cassava, one of sub-Saharan Africa's most important staple food crops. Each year these viruses cause losses of up to $100 million USD and can leave entire families without their primary food source, for an entire year. Twelve new whole genomes, including seven of CBSV and five of UCBSV were uncovered in this research, doubling the genomic sequences available in the public domain for these viruses. These new sequences disprove the assumption that the viruses are limited by agro-ecological zones, show that current diagnostic primers are insufficient to provide confident diagnosis of these viruses and give rise to the possibility that there may be as many as four distinct species of virus. Utilizing NGS sequencing technologies and proper phylogenetic practices will rapidly increase the solution to sustainable cassava production. PMID:26439260

  3. Analyses of Twelve New Whole Genome Sequences of Cassava Brown Streak Viruses and Ugandan Cassava Brown Streak Viruses from East Africa: Diversity, Supercomputing and Evidence for Further Speciation.

    Directory of Open Access Journals (Sweden)

    Joseph Ndunguru

    Full Text Available Cassava brown streak disease is caused by two devastating viruses, Cassava brown streak virus (CBSV and Ugandan cassava brown streak virus (UCBSV which are frequently found infecting cassava, one of sub-Saharan Africa's most important staple food crops. Each year these viruses cause losses of up to $100 million USD and can leave entire families without their primary food source, for an entire year. Twelve new whole genomes, including seven of CBSV and five of UCBSV were uncovered in this research, doubling the genomic sequences available in the public domain for these viruses. These new sequences disprove the assumption that the viruses are limited by agro-ecological zones, show that current diagnostic primers are insufficient to provide confident diagnosis of these viruses and give rise to the possibility that there may be as many as four distinct species of virus. Utilizing NGS sequencing technologies and proper phylogenetic practices will rapidly increase the solution to sustainable cassava production.

  4. Willapa NWR: Initial Survey Instructions for Streaked Horned Lark Density and Reproductive Success

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The streaked horned lark subspecies represents a small endemic population that breeds and winters in only a few locations in Oregon and Washington. It is perhaps...

  5. Inventory and Monitoring of Streaked Horned Larks on Agricultural Lands: Willamette Valley National Wildlife Refuge Complex

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In an effort to refine knowledge of nest success of streaked horned larks in the southern Willamette Valley, field personnel found and monitored nests at William L....

  6. Structured photocathodes for improved high-energy x-ray efficiency in streak cameras

    Science.gov (United States)

    Opachich, Y. P.; Bell, P. M.; Bradley, D. K.; Chen, N.; Feng, J.; Gopal, A.; Hatch, B.; Hilsabeck, T. J.; Huffman, E.; Koch, J. A.; Landen, O. L.; MacPhee, A. G.; Nagel, S. R.; Udin, S.

    2016-11-01

    We have designed and fabricated a structured streak camera photocathode to provide enhanced efficiency for high energy X-rays (1-12 keV). This gold coated photocathode was tested in a streak camera and compared side by side against a conventional flat thin film photocathode. Results show that the measured electron yield enhancement at energies ranging from 1 to 10 keV scales well with predictions, and that the total enhancement can be more than 3×. The spatial resolution of the streak camera does not show degradation in the structured region. We predict that the temporal resolution of the detector will also not be affected as it is currently dominated by the slit width. This demonstration with Au motivates exploration of comparable enhancements with CsI and may revolutionize X-ray streak camera photocathode design.

  7. Laser-based terahertz-field-driven streak camera for the temporal characterization of ultrashort processes

    Energy Technology Data Exchange (ETDEWEB)

    Schuette, Bernd

    2011-09-15

    In this work, a novel laser-based terahertz-field-driven streak camera is presented. It allows for a pulse length characterization of femtosecond (fs) extreme ultraviolet (XUV) pulses by a cross-correlation with terahertz (THz) pulses generated with a Ti:sapphire laser. The XUV pulses are emitted by a source of high-order harmonic generation (HHG) in which an intense near-infrared (NIR) fs laser pulse is focused into a gaseous medium. The design and characterization of a high-intensity THz source needed for the streak camera is also part of this thesis. The source is based on optical rectification of the same NIR laser pulse in a lithium niobate crystal. For this purpose, the pulse front of the NIR beam is tilted via a diffraction grating to achieve velocity matching between NIR and THz beams within the crystal. For the temporal characterization of the XUV pulses, both HHG and THz beams are focused onto a gas target. The harmonic radiation creates photoelectron wavepackets which are then accelerated by the THz field depending on its phase at the time of ionization. This principle adopted from a conventional streak camera and now widely used in attosecond metrology. The streak camera presented here is an advancement of a terahertz-field-driven streak camera implemented at the Free Electron Laser in Hamburg (FLASH). The advantages of the laser-based streak camera lie in its compactness, cost efficiency and accessibility, while providing the same good quality of measurements as obtained at FLASH. In addition, its flexibility allows for a systematic investigation of streaked Auger spectra which is presented in this thesis. With its fs time resolution, the terahertz-field-driven streak camera thereby bridges the gap between attosecond and conventional cameras. (orig.)

  8. Streak detection and analysis pipeline for space-debris optical images

    Science.gov (United States)

    Virtanen, Jenni; Poikonen, Jonne; Säntti, Tero; Komulainen, Tuomo; Torppa, Johanna; Granvik, Mikael; Muinonen, Karri; Pentikäinen, Hanna; Martikainen, Julia; Näränen, Jyri; Lehti, Jussi; Flohrer, Tim

    2016-04-01

    We describe a novel data-processing and analysis pipeline for optical observations of moving objects, either of natural (asteroids, meteors) or artificial origin (satellites, space debris). The monitoring of the space object populations requires reliable acquisition of observational data, to support the development and validation of population models and to build and maintain catalogues of orbital elements. The orbital catalogues are, in turn, needed for the assessment of close approaches (for asteroids, with the Earth; for satellites, with each other) and for the support of contingency situations or launches. For both types of populations, there is also increasing interest to detect fainter objects corresponding to the small end of the size distribution. The ESA-funded StreakDet (streak detection and astrometric reduction) activity has aimed at formulating and discussing suitable approaches for the detection and astrometric reduction of object trails, or streaks, in optical observations. Our two main focuses are objects in lower altitudes and space-based observations (i.e., high angular velocities), resulting in long (potentially curved) and faint streaks in the optical images. In particular, we concentrate on single-image (as compared to consecutive frames of the same field) and low-SNR detection of objects. Particular attention has been paid to the process of extraction of all necessary information from one image (segmentation), and subsequently, to efficient reduction of the extracted data (classification). We have developed an automated streak detection and processing pipeline and demonstrated its performance with an extensive database of semisynthetic images simulating streak observations both from ground-based and space-based observing platforms. The average processing time per image is about 13 s for a typical 2k-by-2k image. For long streaks (length >100 pixels), primary targets of the pipeline, the detection sensitivity (true positives) is about 90% for

  9. Laser-based terahertz-field-driven streak camera for the temporal characterization of ultrashort processes

    International Nuclear Information System (INIS)

    In this work, a novel laser-based terahertz-field-driven streak camera is presented. It allows for a pulse length characterization of femtosecond (fs) extreme ultraviolet (XUV) pulses by a cross-correlation with terahertz (THz) pulses generated with a Ti:sapphire laser. The XUV pulses are emitted by a source of high-order harmonic generation (HHG) in which an intense near-infrared (NIR) fs laser pulse is focused into a gaseous medium. The design and characterization of a high-intensity THz source needed for the streak camera is also part of this thesis. The source is based on optical rectification of the same NIR laser pulse in a lithium niobate crystal. For this purpose, the pulse front of the NIR beam is tilted via a diffraction grating to achieve velocity matching between NIR and THz beams within the crystal. For the temporal characterization of the XUV pulses, both HHG and THz beams are focused onto a gas target. The harmonic radiation creates photoelectron wavepackets which are then accelerated by the THz field depending on its phase at the time of ionization. This principle adopted from a conventional streak camera and now widely used in attosecond metrology. The streak camera presented here is an advancement of a terahertz-field-driven streak camera implemented at the Free Electron Laser in Hamburg (FLASH). The advantages of the laser-based streak camera lie in its compactness, cost efficiency and accessibility, while providing the same good quality of measurements as obtained at FLASH. In addition, its flexibility allows for a systematic investigation of streaked Auger spectra which is presented in this thesis. With its fs time resolution, the terahertz-field-driven streak camera thereby bridges the gap between attosecond and conventional cameras. (orig.)

  10. Optical Transmission Line For Streak Camera Measurements at Pitz

    CERN Document Server

    Bähr, J; Lüdecke, H

    2003-01-01

    The photoinjector injector test facility at DESY Zeuthen (PITZ) [1] produces electrons with a momentum of about 4 MeV/c. It is the aim to measure the temporal characteristics of the electron bunch train and single bunches with high accuracy of the order of 1 ps and less. Several types of streak cameras will be used in combination with different radiators which transform particle energy in light. The problem to be solved is the light transport over a distance of about 27 m. Basic demands to the optical system and design principles will be explained. The optical and technical solutions will be presented. The strategy of adjustment and commissioning of the optical system will be described. The system contains switchable optics to use different radiators (OTR, Cherenkov radiators). Diagnostic tools are foreseen at different positions along the optical axis. The results of different measurements in the lab and using the original system will be presented. The problems on the minimalization of the time dipersion in ...

  11. Control of Vascular Streak Dieback Disease of Cocoa with Flutriafol Fungicides

    Directory of Open Access Journals (Sweden)

    Febrilia Nur'aini

    2014-12-01

    Full Text Available Vascular streak dieback caused by the fungus Oncobasidium theobromae is one of the important diseases in cocoa crop in Indonesia. One approach to control the disease is by using fungicides. The aim of this research was to determine the effect of class triazole fungicides to the intensity of the vascular streak dieback disease on cocoa seedling phase, immature and mature cocoa. Experiments were conducted in Kotta Blater, PTPN XII and Kaliwining, Indonesian  Coffee and Cocoa Research Institute. Flutriafol 250 g/l with a concentration 0,05%, 0,1% and 0,15% foliar sprayed on cocoa seedlings, immature and mature cocoa. Active compound combination of Azoxystrobin and Difenoconazole with 0,1% concentration used as a comparation fungicides. The result showed that Flutriafol with 0,05%, 0,1% and 0,15% concentration and Azoxystrobin & Difenoconazol with 0,1% concentration could suppress the vascular streak dieback disease on seedlings. On immature plants, the application of Flutriafol was not effectively suppress the vascular streak dieback disease whereas the fungicide comparison could suppress with the efficacy level of 46.22%. On mature plants,both of fungicides could not suppress the vascular streak dieback disease. Key words: Fungicide, cocoa, vascular streak dieback, triazole, flutriafol, azoxystrobin+difenoconazol

  12. Manifestation of attosecond XUV fields temporal structures in attosecond streaking spectrogram

    Institute of Scientific and Technical Information of China (English)

    Guanglong Chen; Yunjiu Cao; Dong Eon Kim

    2011-01-01

    @@ The features of an attosecond extreme ultraviolet (XUV) field are encoded in the attosecond XUV spectrogram.We investigate the effect of the temporal structures of attosecond XUV fields on the attosecond streaking spectrogram.Factors such as the number of attosecond XUV pulses and the temporal chirp of attosecond XUV pulses are considered.Results indicate that unlike the attosecond streaking spectrogram for an attosecond XUV field with two pulses of a half-cycle separation of streaking field, the spectrogram for the attosecond XUV field with three pulses demonstrates fine spectral fringes in separated traces.%The features of an attosecond extreme ultraviolet (XUV) field are encoded in the attosecond XUV spectrogram. We investigate the effect of the temporal structures of attosecond XUV fields on the attosecond streaking spectrogram. Factors such as the number of attosecond XUV pulses and the temporal chirp of attosecond XUV pulses are considered. Results indicate that unlike the attosecond streaking spectrogram for an attosecond XUV field with two pulses of a half-cycle separation of streaking field, the spectrogram for the attosecond XUV field with three pulses demonstrates fine spectral fringes in separated traces.

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

    Science.gov (United States)

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

    2010-01-01

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

  14. Absolute calibration method for fast-streaked, fiber optic light collection, spectroscopy systems.

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, Mark D.; Frogget, Brent (National Security Technologies, Las Vegas, NV); Oliver, Bryan Velten; Maron, Yitzhak (Weizmann Institute of Science, Rehovot, Israel); Droemer, Darryl W. (National Security Technologies, Las Vegas, NV); Crain, Marlon D. (National Security Technologies, Las Vegas, NV)

    2010-04-01

    This report outlines a convenient method to calibrate fast (<1ns resolution) streaked, fiber optic light collection, spectroscopy systems. Such a system is used to collect spectral data on plasmas generated in the A-K gap of electron beam diodes fielded on the RITS-6 accelerator (8-12MV, 140-200kA). On RITS, light is collected through a small diameter (200 micron) optical fiber and recorded on a fast streak camera at the output of 1 meter Czerny-Turner monochromator (F/7 optics). To calibrate such a system, it is necessary to efficiently couple light from a spectral lamp into a 200 micron diameter fiber, split it into its spectral components, with 10 Angstroms or less resolution, and record it on a streak camera with 1ns or less temporal resolution.

  15. Impact of laser phase and amplitude noises on streak camera temporal resolution

    Energy Technology Data Exchange (ETDEWEB)

    Wlotzko, V., E-mail: wlotzko@optronis.com [ICube, UMR 7357, University of Strasbourg and CNRS, 23 rue du Loess, 67037 Strasbourg (France); Optronis GmbH, Ludwigstrasse 2, 77694 Kehl (Germany); Uhring, W. [ICube, UMR 7357, University of Strasbourg and CNRS, 23 rue du Loess, 67037 Strasbourg (France); Summ, P. [Optronis GmbH, Ludwigstrasse 2, 77694 Kehl (Germany)

    2015-09-15

    Streak cameras are now reaching sub-picosecond temporal resolution. In cumulative acquisition mode, this resolution does not entirely rely on the electronic or the vacuum tube performances but also on the light source characteristics. The light source, usually an actively mode-locked laser, is affected by phase and amplitude noises. In this paper, the theoretical effects of such noises on the synchronization of the streak system are studied in synchroscan and triggered modes. More precisely, the contribution of band-pass filters, delays, and time walk is ascertained. Methods to compute the resulting synchronization jitter are depicted. The results are verified by measurement with a streak camera combined with a Ti:Al{sub 2}O{sub 3} solid state laser oscillator and also a fiber oscillator.

  16. Imaging plasmonic fields near gold nanospheres in attosecond time-resolved streaked photoelectron spectra

    Science.gov (United States)

    Li, Jianxiong; Thumm, Uwe

    2016-05-01

    To study time-resolved photoemission from gold nanospheres, we introduce a quantum-mechanical approach, including the plasmonic near-field-enhancement of the streaking field at the surface of the nanosphere. We use Mie theory to calculate the plasmonically enhanced fields near 10 to 200 nm gold nanospheres, driven by incident near infrared (NIR) or visible laser pulses. We model the gold conduction band in terms of a spherical square well potential. Our simulated streaked photoelectron spectra reveal a plasmonic amplitude enhancement and phase shift related to calculations that exclude the induced plasmonic field. The phase shift is due to the plasma resonance. This suggests the use of streaked photoelectron spectroscopy for imaging the dielectric response and plasmonic field near nanoparticles. Supported by the NSD-EPSCoR program, NSF, and the USDoE.

  17. Blind Detection of Ultra-faint Streaks with a Maximum Likelihood Method

    CERN Document Server

    Dawson, William A; Kamath, Chandrika

    2016-01-01

    We have developed a maximum likelihood source detection method capable of detecting ultra-faint streaks with surface brightnesses approximately an order of magnitude fainter than the pixel level noise. Our maximum likelihood detection method is a model based approach that requires no a priori knowledge about the streak location, orientation, length, or surface brightness. This method enables discovery of typically undiscovered objects, and enables the utilization of low-cost sensors (i.e., higher-noise data). The method also easily facilitates multi-epoch co-addition. We will present the results from the application of this method to simulations, as well as real low earth orbit observations.

  18. A Monte Carlo Approach to Joe DiMaggio and Streaks in Baseball

    CERN Document Server

    Arbesman, S

    2008-01-01

    We examine Joe DiMaggio's 56-game hitting streak and look at its likelihood, using a number of simple models. And it turns out that, contrary to many people's expectations, an extreme streak, while unlikely in any given year, is not unlikely to have occurred about once within the history of baseball. Surprisingly, however, such a record should have occurred far earlier in baseball history: back in the late 1800's or early 1900's. But not in 1941, when it actually happened.

  19. Linear stability of optimal streaks in the log-layer of turbulent channel flows

    Science.gov (United States)

    Alizard, Frédéric

    2015-10-01

    The importance of secondary instability of streaks for the generation of vortical structures attached to the wall in the logarithmic region of turbulent channels is studied. The streaks and their linear instability are computed by solving equations associated with the organized motion that include an eddy-viscosity modeling the effect of incoherent fluctuations. Three friction Reynolds numbers, Reτ = 2000, 3000, and 5000, are investigated. For all flow cases, optimal streamwise vortices (i.e., having the highest potential for linear transient energy amplification) are used as initial conditions. Due to the lift-up mechanism, these optimal perturbations lead to the nonlinear growth of streaks. Based on a Floquet theory along the spanwise direction, we observe the onset of streak secondary instability for a wide range of spanwise wavelengths when the streak amplitude exceeds a critical value. Under neutral conditions, it is shown that streak instability modes have their energy mainly concentrated in the overlap layer and propagate with a phase velocity equal to the mean streamwise velocity of the log-layer. These neutral log-layer modes exhibit a sinuous pattern and have characteristic sizes that are proportional to the wall distance in both streamwise and spanwise directions, in agreement with the Townsend's attached eddy hypothesis (A. Townsend, the structure of turbulent shear flow, Cambridge university press, 1976 2nd edition). In particular, for a distance from the wall varying from y+ ≈ 100 (in wall units) to y ≈ 0.3h, where h is half the height of the channel, the neutral log-layer modes are self-similar with a spanwise width of λz ≈ y/0.3 and a streamwise length of λx ≈ 3λz, independently of the Reynolds number. Based on this observation, it is suggested that compact vortical structures attached to the wall can be ascribed to streak secondary instabilities. In addition, spatial distributions of fluctuating vorticity components show that the onset

  20. Pedicle streaking: A novel and simple aid in pedicle positioning in free tissue transfer

    Directory of Open Access Journals (Sweden)

    Aditya Aggarwal

    2015-01-01

    Full Text Available Introduction: The pedicle positioning in free tissue transfer is critical to its success. Long thin pedicles are especially prone to this complication where even a slight twist in the perforator can result in flap loss. Pedicles passing through the long tunnels are similarly at risk. Streaking the pedicle with methylene blue is a simple and safe method which increases the safety of free tissue transfer. Materials and Methods: Once the flap is islanded on the pedicle and the vascularity of the flap is confirmed, the pedicle is streaked with methylene blue dye at a distance of 6-7 mm. The streaking starts from the origin of the vessels and continued distally on to the under surface of flap to mark the complete course of the pedicle in alignment. The presence of streaking in some parts and not in rest indicates twist in the pedicle. Observation and Results: Four hundred and sixty five free flaps have been done at our centre in the last 5 years. The overall success rate of free flaps is 95.3% (22 free flap failures. There has not been a single case of pedicle twist leading to flap congestion and failure. Conclusion: This simple and novel method is very reliable for pedicle positioning avoiding any twist necessary for successful free tissue transfer.

  1. Evaluation of banana hybrids for tolerance to black leaf streak (Mycosphaerella fijiensis Morelet) in Puerto Rico

    Science.gov (United States)

    In Puerto Rico, bananas (including plantains) are important agricultural commodities; their combined production totaled 133,500 tons in 2008. Black leaf streak (BLS) and Sigatoka leaf spot diseases, caused by Mycosphaerella fijiensis and M. musicola, respectively, are responsible for significant los...

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

    International Nuclear Information System (INIS)

    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-μm and 0.53-μm laser pulses can be propagated without significant dispersion when care is taken to prevent propagation of energy in fiber cladding modes

  3. Inheritance of resistance to bacterial streak and hacterial blight in rice

    Institute of Scientific and Technical Information of China (English)

    XUJianlong; WANGHanrong; LINYi; XIYongan

    1998-01-01

    Bacterial streak(BS) caused by Xanthomonas campesiris pv. oryzicola bas become one of the major diseases in southbern rice areas.Up to date, tbere are few reports on the inheritance of resistance to BS and its relationsbip with the resistance to bacterial blight(BB).

  4. Improving the off-axis spatial resolution and dynamic range of the NIF X-ray streak cameras (invited)

    Science.gov (United States)

    MacPhee, A. G.; Dymoke-Bradshaw, A. K. L.; Hares, J. D.; Hassett, J.; Hatch, B. W.; Meadowcroft, A. L.; Bell, P. M.; Bradley, D. K.; Datte, P. S.; Landen, O. L.; Palmer, N. E.; Piston, K. W.; Rekow, V. V.; Hilsabeck, T. J.; Kilkenny, J. D.

    2016-11-01

    We report simulations and experiments that demonstrate an increase in spatial resolution of the NIF core diagnostic x-ray streak cameras by at least a factor of two, especially off axis. A design was achieved by using a corrector electron optic to flatten the field curvature at the detector plane and corroborated by measurement. In addition, particle in cell simulations were performed to identify the regions in the streak camera that contribute the most to space charge blurring. These simulations provide a tool for convolving synthetic pre-shot spectra with the instrument function so signal levels can be set to maximize dynamic range for the relevant part of the streak record.

  5. Lewis and Clark NWR: Initial Survey Instructions for Streaked Horned Lark Occupancy and Abundance Survey Protocols and Strategies

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The streaked horned lark is a subspecies of horned lark that breeds on sparsely vegetated and transitional habitats in the Pacific Northwest. On the L&C many of...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  7. Time-Resolved Spectra of Dense Plasma Focus Using Spectrometer, Streak Camera, CCD Combination

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-10-01

    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.

  8. Route to One Atomic Unit of Time: Development of a Broadband Attosecond Streak Camera

    Science.gov (United States)

    Zhao, Kun; Zhang, Qi; Chini, Michael; Chang, Zenghu

    A new attosecond streak camera based on a three-meter-long magnetic-bottle time-of-flight electron spectrometer (MBES) is developed. The temporal resolution of the photoelectron detection system is measured to be better than 250 ps, which is sufficient to achieve an energy resolution of 0.5 eV at 150 eV photoelectron energy. In preliminary experiments, a 94-as isolated XUV pulse was generated and characterized. With a new algorithm to retrieve the amplitude and phase of XUV pulses (PROOF—phase retrieval by omega oscillation filtering), the attosecond streak camera will be able to characterize isolated attosecond pulses as short as one atomic unit of time (25 as).

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

    Science.gov (United States)

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

    2014-08-22

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

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

    Science.gov (United States)

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

    2010-03-01

    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

  11. A pulse-front-tilt-compensated streaked optical spectrometer with high throughput and picosecond time resolution

    Science.gov (United States)

    Katz, J.; Boni, R.; Rivlis, R.; Muir, C.; Froula, D. H.

    2016-11-01

    A high-throughput, broadband optical spectrometer coupled to the Rochester optical streak system equipped with a Photonis P820 streak tube was designed to record time-resolved spectra with 1-ps time resolution. Spectral resolution of 0.8 nm is achieved over a wavelength coverage range of 480 to 580 nm, using a 300-groove/mm diffraction grating in conjunction with a pair of 225-mm-focal-length doublets operating at an f/2.9 aperture. Overall pulse-front tilt across the beam diameter generated by the diffraction grating is reduced by preferentially delaying discrete segments of the collimated input beam using a 34-element reflective echelon optic. The introduced delay temporally aligns the beam segments and the net pulse-front tilt is limited to the accumulation across an individual sub-element. The resulting spectrometer design balances resolving power and pulse-front tilt while maintaining high throughput.

  12. Simultaneous streak and frame interferometry for electron density measurements of laser produced plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Quevedo, H. J., E-mail: hjquevedo@utexas.edu; McCormick, M.; Wisher, M.; Bengtson, Roger D.; Ditmire, T. [Center for High Energy Density Science, Department of Physics, University of Texas at Austin, Austin, Texas 78712 (United States)

    2016-01-15

    A system of two collinear probe beams with different wavelengths and pulse durations was used to capture simultaneously snapshot interferograms and streaked interferograms of laser produced plasmas. The snapshots measured the two dimensional, path-integrated, electron density on a charge-coupled device while the radial temporal evolution of a one dimensional plasma slice was recorded by a streak camera. This dual-probe combination allowed us to select plasmas that were uniform and axisymmetric along the laser direction suitable for retrieving the continuous evolution of the radial electron density of homogeneous plasmas. Demonstration of this double probe system was done by measuring rapidly evolving plasmas on time scales less than 1 ns produced by the interaction of femtosecond, high intensity, laser pulses with argon gas clusters. Experiments aimed at studying homogeneous plasmas from high intensity laser-gas or laser-cluster interaction could benefit from the use of this probing scheme.

  13. Temporal resolution limit estimation of x-ray streak cameras using a CsI photocathode

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiang; Gu, Li; Zong, Fangke; Zhang, Jingjin; Yang, Qinlao, E-mail: qlyang@szu.edu.cn [Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Institute of Optoelectronics, Shenzhen University, Shenzhen 518060 (China)

    2015-08-28

    A Monte Carlo model is developed and implemented to calculate the characteristics of x-ray induced secondary electron (SE) emission from a CsI photocathode used in an x-ray streak camera. Time distributions of emitted SEs are investigated with an incident x-ray energy range from 1 to 30 keV and a CsI thickness range from 100 to 1000 nm. Simulation results indicate that SE time distribution curves have little dependence on the incident x-ray energy and CsI thickness. The calculated time dispersion within the CsI photocathode is about 70 fs, which should be the temporal resolution limit of x-ray streak cameras that use CsI as the photocathode material.

  14. Mach-zehnder based optical marker/comb generator for streak camera calibration

    Science.gov (United States)

    Miller, Edward Kirk

    2015-03-03

    This disclosure is directed to a method and apparatus for generating marker and comb indicia in an optical environment using a Mach-Zehnder (M-Z) modulator. High speed recording devices are configured to record image or other data defining a high speed event. To calibrate and establish time reference, the markers or combs are indicia which serve as timing pulses (markers) or a constant-frequency train of optical pulses (comb) to be imaged on a streak camera for accurate time based calibration and time reference. The system includes a camera, an optic signal generator which provides an optic signal to an M-Z modulator and biasing and modulation signal generators configured to provide input to the M-Z modulator. An optical reference signal is provided to the M-Z modulator. The M-Z modulator modulates the reference signal to a higher frequency optical signal which is output through a fiber coupled link to the streak camera.

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

    Science.gov (United States)

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

    2001-01-01

    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.

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

    OpenAIRE

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

    2010-01-01

    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...

  17. Molecular Characterization of Banana streak virus Isolate from Musa Acuminata in China

    Institute of Scientific and Technical Information of China (English)

    Jun Zhuang; Jian-hua Wang; Xin Zhang; Zhi-xinLiu

    2011-01-01

    Banana streak virus (BSV),a member of genus Badnavirus,is a causal agent of banana streak disease throughout the world.The genetic diversity of BSVs from different regions of banana plantations has previously been investigated,but there are relatively few reports of the genetic characteristic of episomal (non-integrated)BSV genomes isolated from China.Here,the complete genome,a total of 7722bp (GenBank accession number DQ092436),of an isolate of Banana streak virus (BSV) on cultivar Cavendish (BSAcYNV) in Yunnan,China was determined.The genome organises in the typical manner of badnaviruses.The intergenic region of genomic DNA contains a large stem-loop,which may contribute to the ribosome shift into the following open reading frames (ORFs).The coding region of BSAcYNV consists of three overlapping ORFs,ORF 1 with a non-AUG start eodon and ORF2 encoding two small proteins are individually involved in viral movement and ORF3 encodes a polyprotein.Besides the complete genome,a defective genome lacking the whole RNA leader region and a majority of ORF1 and which encompasses 6525bp was also isolated and sequenced from this BSV DNA reservoir in infected banana plants.Sequence analyses showed that BSAcYNV has closest similarity in terms of genome organization and the coding assignments with an BSV isolate from Vientam (BSAcVNV).The corresponding coding regions shared identities of 88% and ~95% at nucleotide and amino acid levels,respectively.Phylogenetic analysis also indicated BSAcYNV shared the closest geographical evolutionary relationship to BSAcVNV among sequenced banana streak badnaviruses.

  18. New Experimental Hosts of Tobacco streak virus and Absence of True Seed Transmission in Leguminous Hosts

    OpenAIRE

    Vemana, K.; Jain, R K

    2010-01-01

    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 off...

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

    OpenAIRE

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

    2012-01-01

    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 int...

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

    Science.gov (United States)

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

    2012-12-20

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

  1. Laser Activated Streak Camera for Measurement of Electron Pulses with Femtosecond Resolution

    Science.gov (United States)

    Zandi, Omid; Desimone, Alice; Wilkin, Kyle; Yang, Jie; Centurion, Martin

    2015-05-01

    The duration of femtosecond electron pulses used in time-resolved diffraction and microscopy experiments is challenging to measure in-situ. To overcome this problem, we have fabricated a streak camera that uses the time-varying electric field of a discharging parallel plate capacitor. The capacitor is discharged using a laser-activated GaAs photoswitch, resulting in a damped oscillation of the electric field. The delay time between the laser pulse and electron pulse is set so that the front and back halves of the bunch encounter opposite electric fields of the capacitor and are deflected in opposite directions. Thus, the electron bunch appears streaked on the detector with a length proportional to its duration. The temporal resolution of the streak camera is proportional to the maximum value of the electric field and the frequency of the discharge oscillation. The capacitor is charged by high voltage short pulses to achieve a high electric field and prevent breakdown. We have achieved an oscillation frequency in the GHz range by reducing the circuit size and hence its inductance. The camera was used to measure 100 keV electron pulses with up to a million electrons that are compressed transversely by magnetic lenses and longitudinally by an RF cavity. This work was supported mainly by the Air Force Office of Scientific Research, Ultrashort Pulse Laser Matter Interaction program, under grant # FA9550-12-1-0149.

  2. High-Throughput Single-Cell Cultivation on Microfluidic Streak Plates.

    Science.gov (United States)

    Jiang, Cheng-Ying; Dong, Libing; Zhao, Jian-Kang; Hu, Xiaofang; Shen, Chaohua; Qiao, Yuxin; Zhang, Xinyue; Wang, Yapei; Ismagilov, Rustem F; Liu, Shuang-Jiang; Du, Wenbin

    2016-04-01

    This paper describes the microfluidic streak plate (MSP), a facile method for high-throughput microbial cell separation and cultivation in nanoliter sessile droplets. The MSP method builds upon the conventional streak plate technique by using microfluidic devices to generate nanoliter droplets that can be streaked manually or robotically onto petri dishes prefilled with carrier oil for cultivation of single cells. In addition, chemical gradients could be encoded in the droplet array for comprehensive dose-response analysis. The MSP method was validated by using single-cell isolation of Escherichia coli and antimicrobial susceptibility testing of Pseudomonas aeruginosa PAO1. The robustness of the MSP work flow was demonstrated by cultivating a soil community that degrades polycyclic aromatic hydrocarbons. Cultivation in droplets enabled detection of the richest species diversity with better coverage of rare species. Moreover, isolation and cultivation of bacterial strains by MSP led to the discovery of several species with high degradation efficiency, including four Mycobacterium isolates and a previously unknown fluoranthene-degrading Blastococcus species. PMID:26850294

  3. Development of intelligent control system for X-ray streak camera in diagnostic instrument manipulator

    International Nuclear Information System (INIS)

    An intelligent control system for an X ray streak camera in a diagnostic instrument manipulator (DIM) is proposed and implemented, which can control time delay, electric focusing, image gain adjustment, switch of sweep voltage, acquiring environment parameters etc. The system consists of 16 A/D converters and 16 D/A converters, a 32-channel general purpose input/output (GPIO) and two sensors. An isolated DC/DC converter with multi-outputs and a single mode fiber were adopted to reduce the interference generated by the common ground among the A/D, D/A and I/O. The software was designed using graphical programming language and can remotely access the corresponding instrument from a website. The entire intelligent control system can acquire the desirable data at a speed of 30 Mb/s and store it for later analysis. The intelligent system was implemented on a streak camera in a DIM and it shows a temporal resolution of 11.25 ps, spatial distortion of less than 10% and dynamic range of 279:1. The intelligent control system has been successfully used in a streak camera to verify the synchronization of multi-channel laser on the Inertial Confinement Fusion Facility

  4. A new streaked soft x-ray imager for the National Ignition Facility.

    Science.gov (United States)

    Benstead, J; Moore, A S; Ahmed, M F; Morton, J; Guymer, T M; Soufli, R; Pardini, T; Hibbard, R L; Bailey, C G; Bell, P M; Hau-Riege, S; Bedzyk, M; Shoup, M J; Reagan, S; Agliata, T; Jungquist, R; Schmidt, D W; Kot, L B; Garbett, W J; Rubery, M S; Skidmore, J W; Gullikson, E; Salmassi, F

    2016-05-01

    A new streaked soft x-ray imager has been designed for use on high energy-density (HED) physics experiments at the National Ignition Facility based at the Lawrence Livermore National Laboratory. This streaked imager uses a slit aperture, single shallow angle reflection from a nickel mirror, and soft x-ray filtering to, when coupled to one of the NIF's x-ray streak cameras, record a 4× magnification, one-dimensional image of an x-ray source with a spatial resolution of less than 90 μm. The energy band pass produced depends upon the filter material used; for the first qualification shots, vanadium and silver-on-titanium filters were used to gate on photon energy ranges of approximately 300-510 eV and 200-400 eV, respectively. A two-channel version of the snout is available for x-ray sources up to 1 mm and a single-channel is available for larger sources up to 3 mm. Both the one and two-channel variants have been qualified on quartz wire and HED physics target shots.

  5. Development of intelligent control system for X-ray streak camera in diagnostic instrument manipulator

    Energy Technology Data Exchange (ETDEWEB)

    Pei, Chengquan [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi' an Jiaotong University, Xi' an 710049 (China); Wu, Shengli, E-mail: slwu@mail.xjtu.edu.cn [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi' an Jiaotong University, Xi' an 710049 (China); Tian, Jinshou [Xi' an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an 710119 (China); Liu, Zhen [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi' an Jiaotong University, Xi' an 710049 (China); Fang, Yuman [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi' an Jiaotong University, Xi' an 710049 (China); University of the Chinese Academy of Sciences, Beijing 100039 (China); Gao, Guilong; Liang, Lingliang [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi' an Jiaotong University, Xi' an 710049 (China); Xi' an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an 710119 (China); University of the Chinese Academy of Sciences, Beijing 100039 (China); Wen, Wenlong [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi' an Jiaotong University, Xi' an 710049 (China)

    2015-11-01

    An intelligent control system for an X ray streak camera in a diagnostic instrument manipulator (DIM) is proposed and implemented, which can control time delay, electric focusing, image gain adjustment, switch of sweep voltage, acquiring environment parameters etc. The system consists of 16 A/D converters and 16 D/A converters, a 32-channel general purpose input/output (GPIO) and two sensors. An isolated DC/DC converter with multi-outputs and a single mode fiber were adopted to reduce the interference generated by the common ground among the A/D, D/A and I/O. The software was designed using graphical programming language and can remotely access the corresponding instrument from a website. The entire intelligent control system can acquire the desirable data at a speed of 30 Mb/s and store it for later analysis. The intelligent system was implemented on a streak camera in a DIM and it shows a temporal resolution of 11.25 ps, spatial distortion of less than 10% and dynamic range of 279:1. The intelligent control system has been successfully used in a streak camera to verify the synchronization of multi-channel laser on the Inertial Confinement Fusion Facility.

  6. RNAi-mediated resistance to Cassava brown streak Uganda virus in transgenic cassava.

    Science.gov (United States)

    Yadav, Jitender S; Ogwok, Emmanuel; Wagaba, Henry; Patil, Basavaprabhu L; Bagewadi, Basavaraj; Alicai, Titus; Gaitan-Solis, Eliana; Taylor, Nigel J; Fauquet, Claude M

    2011-09-01

    Cassava brown streak disease (CBSD), caused by Cassava brown streak Uganda virus (CBSUV) and Cassava brown streak virus (CBSV), is of new epidemic importance to cassava (Manihot esculenta Crantz) production in East Africa, and an emerging threat to the crop in Central and West Africa. This study demonstrates that at least one of these two ipomoviruses, CBSUV, can be efficiently controlled using RNA interference (RNAi) technology in cassava. An RNAi construct targeting the near full-length coat protein (FL-CP) of CBSUV was expressed constitutively as a hairpin construct in cassava. Transgenic cassava lines expressing small interfering RNAs (siRNAs) against this sequence showed 100% resistance to CBSUV across replicated graft inoculation experiments. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis showed the presence of CBSUV in leaves and some tuberous roots from challenged controls, but not in the same tissues from transgenic plants. This is the first demonstration of RNAi-mediated resistance to the ipomovirus CBSUV in cassava.

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

    Science.gov (United States)

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

    2014-01-01

    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.

  8. Artificial microRNA-derived resistance to Cassava brown streak disease.

    Science.gov (United States)

    Wagaba, Henry; Patil, Basavaprabhu L; Mukasa, Settumba; Alicai, Titus; Fauquet, Claude M; Taylor, Nigel J

    2016-05-01

    Artificial miRNAs (amiRNA) were generated targeting conserved sequences within the genomes of the two causal agents of Cassava brown streak disease (CBSD): Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV). Transient expression studies on ten amiRNAs targeting 21nt conserved sequences of P1(CBSV and UCBSV), P3(CBSV and UCBSV), CI(UCBSV), NIb(CBSV and UCBSV), CP(UCBSV) and the un-translated region (3'-UTR) were tested in Nicotiana benthamiana. Four out of the ten amiRNAs expressed the corresponding amiRNA at high levels. Transgenic N. benthamiana plants were developed for the four amiRNAs targeting the P1 and NIb genes of CBSV and the P1 and CP genes of UCBSV and shown to accumulate miRNA products. Transgenic plants challenged with CBSV and UCBSV isolates showed resistance levels that ranged between ∼20-60% against CBSV and UCBSV and correlated with expression levels of the transgenically derived miRNAs. MicroRNAs targeting P1 and NIb of CBSV showed protection against CBSV and UCBSV, while amiRNAs targeting the P1 and CP of UCBSV showed protection against UCBSV but were less efficient against CBSV. These results indicate a potential application of amiRNAs for engineering resistance to CBSD-causing viruses in cassava. PMID:26912232

  9. Investigation of influencing factors of hot streaks migration in high pressure stage of a vaneless counter-rotating turbine

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Three-dimensional,viscous,and unsteady CFD simulations have been performed in order to reveal the influencing factors of hot streaks migration in high pressure stage of a vaneless counter-rotating turbine. Based on the numerical results,the comparison between the case with inlet hot streaks and case without inlet hot streaks is carried out,which shows that the effect of inlet hot streaks on the load distributions of high pressure turbine airfoils is not notable and the airfoil load distributions are directly related to the inlet pressure distributions. The predicted results also indicate that the circumferential and radial movements of the hot streaks were not observed in the high pressure turbine stator. This means that the combined effects of secondary flow and buoyancy are very weak in the high pres-sure turbine stator. The numerical results also prove that the circumferential flow angle effect at the inlet of the high pressure turbine rotor,secondary flow effect and buoyancy effect are the mainly influencing factors to directly affect the migration characteristics of the hot streaks in the high pressure turbine rotor.

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

    OpenAIRE

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

    2012-01-01

    Cassava brown streak disease (CBSD) and cassava mosaic disease (CMD) are currently two major viral diseases that severely reduce cassava production in large areas of Sub-Saharan Africa. Natural resistance has so far only been reported for CMD in cassava. CBSD is caused by two virus species, Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV). A sequence of the CBSV coat protein (CP) highly conserved between the two virus species was used to demonstrate that a CBSV...

  11. Electronic Image Readout Devices Used In Conjunction With Picosecond Streak Cameras

    Science.gov (United States)

    Cavailler, C.; Genoud, M.; Fleurot, N.; Launspach, J.; Mazataud, D.; Mens, A.

    1985-02-01

    Understanding the laser-matter interaction experiments require a dynamic recording of the phenomena as well as a good knowledge of the laser pulse occuring during the irradiation of the target ; those measurements are made with streak cameras the increasing number of which leads to processing problems when the results are recorded on films. Furthermore, since physicists wish to have those temporal information immediatly, we unfolded automatic image readout devices fitted specially to streak cameras. The first one used an ISOCON tube operating with a slow sweep (0.5 s frame)1-2. The sensitivity of the tube was very good but its dynamic range was too limited when seeing pulsed images at low light level. So we developped two electronic readout chains with solid state devices which behave better for that kind of light. The first one was designed to get the most information along the temporal axis of the camera sweep (1024 points) in one or two spatial channels ; this device operates a linear 1024 photodiodes array the signal of which is digitized on 12 bits. We have obtained a temporal resolution better than 15 ps and a dynamic range over 500 ; this system is mainly useful to study laser pulses (rise time, temporal profile...)3. For applications requiring two dimension images, we studied and realized a device operating a CCD array and a fiber optics reducer (40-18 mm) adapting the image of the streak camera screen to the dimensions of the input fiber optics of the CCD. A comparison has been made on different CCD cameras on a test setup which simulates the experimental conditions, in order to choose the CCD which would fit the best for that purpose ; we present these results here, as well as those of the associated readout chains.

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

    Directory of Open Access Journals (Sweden)

    Nasim Dana

    2012-01-01

    Full Text Available 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.

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

    Science.gov (United States)

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

    2012-12-01

    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 (ΔCP) 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 ΔCP 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 ΔCP 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.

  14. Study of the Performance of a Streaked Optical Pyrometer System for Temperature Measurement of Shocked Materials

    International Nuclear Information System (INIS)

    A streaked optical pyrometer (SOP) is developed and calibrated for the measurement of the temperature of shocked materials. In order to achieve a higher relative sensitivity, a one-channel scheme is adopted for the system. The system is calibrated with a shocked step-shaped aluminum sample in the SG-III prototype laser facility. The relation between the count number in the detection system and the sample temperature is thus obtained, which can be adopted to infer the temperature of any shocked materials in future experiments

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

    International Nuclear Information System (INIS)

    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

  16. Vertical Beam Size Measurement by Streak Camera under Colliding and Single Beam Conditions in KEKB

    CERN Document Server

    Ikeda, Hitomi; Fukuma, Hitoshi; Funakoshi, Yoshihiro; Hiramatsu, Shigenori; Mitsuhashi, Toshiyuki; Ohmi, Kazuhito; Uehara, Sadaharu

    2005-01-01

    Beam behavior of KEKB was studied by measurement of the beam size using a streak camera. Effect of the electron-cloud and the parasitic collision on the vertical beam size was examined in beam collision. We intentionally injected a test bunch of positrons after 2 rf buckets of a bunch to enhance the electron cloud effect and changed electron beam conditions to see the beam-beam effect. The beam size was also measured with a single positron beam and compared with that during collision. The result of the measurement is reported in this paper.

  17. Temporal Characterization of individual Harmonics of an attosecond pulse train by THz Streaking

    CERN Document Server

    Ardana-Lamas, F; Stepanov, A; Gorgisyan, I; Juranic, P; Abela, R; Hauri, C P

    2015-01-01

    We report on the global temporal pulse characteristics of individual harmonics in an attosecond pulse train by means of photo-electron streaking in a strong low-frequency transient. The scheme allows direct retrieval of pulse durations and first order chirp of individual harmonics without the need of temporal scanning. The measurements were performed using an intense THz field generated by tilted phase front technique in LiNbO_3 . Pulse properties for harmonics of order 23, 25 and 27 show that the individual pulse durations and linear chirp are decreasing by the harmonic order.

  18. A sub-picosecond accumulating streak camera for x-rays

    OpenAIRE

    G A Naylor; Scheidt, K; Larsson, Jörgen; Wulff, M.; J. M. Filhol

    2001-01-01

    An x-ray streak camera system uses a laser triggered photo-conductive switch to synchronize the high voltage ramp applied to its sweep plates to the photo-excitation of a sample. This technique allows the jitter. between successive sweeps to be kept below 100 fs compared to over 1 ps:using classical methods. By accumulating a stable pulsed x-ray signal over many sweeps, a very high dynamic range can be achieved whilst maintaining a sub-picosecond time resolution. The ultimate time resolution ...

  19. Loop-mediated Isothermal Amplification Assay to Rapidly Detect Wheat Streak Mosaic Virus in Quarantined Plants

    Directory of Open Access Journals (Sweden)

    Siwon Lee

    2015-12-01

    Full Text Available We developed a loop-mediated isothermal amplification (LAMP method to rapidly diagnose Wheat streak mosaic virus (WSMV during quarantine inspections of imported wheat, corn, oats, and millet. The LAMP method was developed as a plant quarantine inspection method for the first time, and its simplicity, quickness, specificity and sensitivity were verified compared to current reverse transcription-polymerase chain reaction (RT-PCR and nested PCR quarantine methods. We were able to quickly screen for WSMV at quarantine sites with many test samples; thus, this method is expected to contribute to plant quarantine inspections.

  20. Phenotypic and biochemical characterisation of the causal agent of bacterial leaf streak of maize / Nienaber

    OpenAIRE

    Nienaber, Jesse Jay

    2015-01-01

    Maize is the staple food for a majority of people in Southern Africa, but plant diseases are responsible for at least 10% of crop production losses. Bacterial leaf streak (BLS) of maize was first reported in South Africa in 1949 and has not been reported elsewhere. Very little is known about the pathogen involved and therefore it is deemed necessary to compile a characteristic profile for the pathogen to prevent the possibility of major crop losses as a result of this disease. This study a...

  1. Physics and roller coasters-The Blue Streak at Cedar Point

    Science.gov (United States)

    Speers, Robert R.

    1991-06-01

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

  2. Capsule Ablator Inflight Performance Measurements Via Streaked Radiography Of ICF Implosions On The NIF*

    Science.gov (United States)

    Dewald, E. L.; Tommasini, R.; Mackinnon, A.; MacPhee, A.; Meezan, N.; Olson, R.; Hicks, D.; LePape, S.; Izumi, N.; Fournier, K.; Barrios, M. A.; Ross, S.; Pak, A.; Döppner, T.; Kalantar, D.; Opachich, K.; Rygg, R.; Bradley, D.; Bell, P.; Hamza, A.; Dzenitis, B.; Landen, O. L.; MacGowan, B.; LaFortune, K.; Widmayer, C.; Van Wonterghem, B.; Kilkenny, J.; Edwards, M. J.; Atherton, J.; Moses, E. I.

    2016-03-01

    Streaked 1-dimensional (slit imaging) radiography of 1.1 mm radius capsules in ignition hohlraums was recently introduced on the National Ignition Facility (NIF) and gives an inflight continuous record of capsule ablator implosion velocities, shell thickness and remaining mass in the last 3-5 ns before peak implosion time. The high quality data delivers good accuracy in implosion metrics that meets our requirements for ignition and agrees with recently introduced 2-dimensional pinhole radiography. Calculations match measured trajectory across various capsule designs and laser drives when the peak laser power is reduced by 20%. Furthermore, calculations matching measured trajectories give also good agreement in ablator shell thickness and remaining mass.

  3. Instability of the roll/streak structure induced by free-stream turbulence in pre-transitional Couette flow

    CERN Document Server

    Farrell, Brian F; Nikolaidis, Marios-Andreas

    2016-01-01

    Although the roll/streak structure is ubiquitous in pre-transitional wall-bounded shear flow, this structure is linearly stable if the idealization of laminar flow is made. Lacking an instability, the large transient growth of the roll/streak structure has been invoked to explain its appearance as resulting from chance occurrence in the free-stream turbulence (FST) of perturbations configured to optimally excite it. However, there is an alternative interpretation which is that FST interacts with the roll/streak structure to destabilize it. Statistical state dynamics (SSD) provides analysis methods for studying instabilities of this type which arise from interaction between the coherent and incoherent components of turbulence. Stochastic structural stability theory (S3T), which implements SSD in the form of a closure at second order, is used to analyze the SSD modes arising from interaction between the coherent streamwise invariant component and the incoherent FST component of turbulence. The least stable S3T ...

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

    Directory of Open Access Journals (Sweden)

    I. U. Mohammed

    2012-01-01

    Full Text Available 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.

  5. Genetic variation of wheat streak mosaic virus in the United States Pacific Northwest.

    Science.gov (United States)

    Robinson, Megan D; Murray, Timothy D

    2013-01-01

    Wheat streak mosaic virus (WSMV), the cause of wheat streak mosaic, is a widespread and damaging pathogen of wheat. WSMV is not a chronic problem of annual wheat in the United States Pacific Northwest but could negatively affect the establishment of perennial wheat, which is being developed as an alternative to annual wheat to prevent soil erosion. Fifty local isolates of WSMV were collected from 2008 to 2010 near Lewiston, ID, Pullman, WA, and the United States Department of Agriculture Central Ferry Research Station, near Pomeroy, WA to determine the amount of genetic variation present in the region. The coat protein gene from each isolate was sequenced and the data subjected to four different methods of phylogenetic analyses. Two well-supported clades of WSMV were identified. Isolates in clade I share sequence similarity with isolates from Central Europe; this is the first report of isolates from Central Europe being reported in the United States. Isolates in clade II are similar to isolates originating from Australia, Argentina, and the American Pacific Northwest. Nine isolates showed evidence of recombination and the same two well-supported clades were observed when recombinant isolates were omitted from the analysis. More polymorphic sites, parsimony informative sites, and increased diversity were observed in clade II than clade I, suggesting more recent establishment of the virus in the latter. The observed diversity within both clades could make breeding for durable disease resistance in perennial wheat difficult if there is a differential response of WSMV resistance genes to isolates from different clades.

  6. PARTIAL CHARACTERIZATION OF REPLICASE GENE OF TOBACCO STREAK ILARVIRUS IN ONION (ALLIUM CEPA.L

    Directory of Open Access Journals (Sweden)

    Sujitha A

    2015-07-01

    Full Text Available Tobacco streak virus (TSV is an important emerging virus belongs to the genus Ilarvirus and family Bromovidae. The Onion crop is infected by Tobacco streak ilar virus and it is major problem in different places of Andhra Pradesh in South India and also transmitted by thrips vector. TSV suspecting onion samples were identified by direct antigen coating enzyme linked immunosorbent assay using TSV polyclonal antiserum. The Replicase gene from each isolate was amplified using TSV replicase gene specific primers by using the RT-PCR. The ~530 bp product was amplified, cloned, sequenced and determined its length as 534 nucleotides and codes for 178 amino acids. The partial sequence of TSV-Rep shared identity of 87.6 -99.8% at nucleotide levels and 67.8- 99.4% at amino acid levels respectively with other reported TSV isolates. The phylogenetic tree relationship based on the nucleotide sequence of present study isolate (AP-Onion-Chittoor from different geographical regions was also analyzed in this study.

  7. Immunodiagnosis of episomal Banana streak MY virus using polyclonal antibodies to an expressed putative coat protein.

    Science.gov (United States)

    Sharma, Susheel Kumar; Kumar, P Vignesh; Baranwal, Virendra Kumar

    2014-10-01

    A cryptic Badnavirus species complex, known as banana streak viruses (BSV) poses a serious threat to banana production and genetic improvement worldwide. Due to the presence of integrated BSV sequences in the banana genome, routine detection is largely based on serological and nucleo-serological diagnostic methods which require high titre specific polyclonal antiserum. Viral structural proteins like coat protein (CP) are the best target for in vitro expression, to be used as antigen for antiserum production. However, in badnaviruses precise CP sequences are not known. In this study, two putative CP coding regions (p48 and p37) of Banana streak MY virus (BSMYV) were identified in silico by comparison with caulimoviruses, retroviruses and Rice tungro bacilliform virus. The putative CP coding region (p37) was in vitro expressed in pMAL system and affinity purified. The purified fusion protein was used as antigen for raising polyclonal antiserum in rabbit. The specificity of antiserum was confirmed in Western blots, immunosorbent electron microscopy (ISEM) and antigen coated plate-enzyme linked immunosorbent assay (ACP-ELISA). The antiserum (1:2000) was successfully used in ACP-ELISA for specific detection of BSMYV infection in field and tissue culture raised banana plants. The antiserum was also utilized in immuno-capture PCR (IC-PCR) based indexing of episomal BSMYV infection. This is the first report of in silico identification of putative CP region of BSMYV, production of polyclonal antiserum against recombinant p37 and its successful use in immunodetection.

  8. Paracoccus burnerae (HOMOPTERA; PLANOCOCCIDAE AS A VECTOR OF Banana streak virus

    Directory of Open Access Journals (Sweden)

    Muturi S M

    2013-11-01

    Full Text Available The Banana streak virus ( BSV is a causative agent of the banana streak disease (BSD which causes considerable damage to banana production in tropical countries. The virus is vectored by several mealy bug species. However, the competence of the oleander mealy bug ( Paracoccus burnerae , in the transmission of BSV is unknown. Rolling Circle Amplification (RCA technique was used to select both diseased and healthy plantlets fo r transmission experiments. RCA was conducted on viruliferous instars of P . burnerae and virus - inoculated plantlet DNA samples. The results revealed that P . burnerae is a vector of BSV . However, during hot conditions (24 - 30ºC, the insect was unable to acq uire and transmit BSV . Under cool conditions (9 - 20ºC, a minimum of 6 h of feeding time was necessary for P . burnerae instars to become viruliferous. These results indicate that P . burnerae is a vector of BSV and transmission efficiency depends on the ambi ent temperature and the feeding time.

  9. Crowd Motion Analysis Based on Social Force Graph with Streak Flow Attribute

    Directory of Open Access Journals (Sweden)

    Shaonian Huang

    2015-01-01

    Full Text Available Over the past decades, crowd management has attracted a great deal of attention in the area of video surveillance. Among various tasks of video surveillance analysis, crowd motion analysis is the basis of numerous subsequent applications of surveillance video. In this paper, a novel social force graph with streak flow attribute is proposed to capture the global spatiotemporal changes and the local motion of crowd video. Crowd motion analysis is hereby implemented based on the characteristics of social force graph. First, the streak flow of crowd sequence is extracted to represent the global crowd motion; after that, spatiotemporal analogous patches are obtained based on the crowd visual features. A weighted social force graph is then constructed based on multiple social properties of crowd video. The graph is segmented into particle groups to represent the similar motion patterns of crowd video. A codebook is then constructed by clustering all local particle groups, and consequently crowd abnormal behaviors are detected by using the Latent Dirichlet Allocation model. Extensive experiments on challenging datasets show that the proposed method achieves preferable results in the application of crowd motion segmentation and abnormal behavior detection.

  10. Role of heparanase on hepatic uptake of intestinal derived lipoprotein and fatty streak formation in mice.

    Directory of Open Access Journals (Sweden)

    David Planer

    Full Text Available BACKGROUND: Heparanase modulates the level of heparan sulfate proteoglycans (HSPGs which have an important role in multiple cellular processes. Recent studies indicate that HSPGs have an important function in hepatic lipoprotein handling and processes involving removal of lipoprotein particles. PRINCIPAL FINDINGS: To determine the effects of decreased HSPGs chain length on lipoprotein metabolism and atherosclerosis, transgenic mice over-expressing the human heparanase gene were studied. Hepatic lipid uptake in hpa-Tg mice were evaluated by giving transgenic mice oral fat loads and labeled retinol. Sections of aorta from mice over-expressing heparanase (hpa-Tg and controls (C57/BL6 fed an atherogenic diet were examined for evidence of atherosclerosis. Heparanase over-expression results in reduced hepatic clearance of postprandial lipoproteins and higher levels of fasting and postprandial serum triglycerides. Heparanase over-expression also induces formation of fatty streaks in the aorta. The mean lesion cross-sectional area in heparanase over-expressing mice was almost 6 times higher when compared to control mice (23,984 µm(2±5,922 vs. 4,189 µm(2±1,130, p<0.001. CONCLUSIONS: Over-expression of heparanase demonstrates the importance of HSPGs for the uptake of intestinal derived lipoproteins and its role in the formation of fatty streaks.

  11. Inactivation of the Huntington's disease gene (Hdh impairs anterior streak formation and early patterning of the mouse embryo

    Directory of Open Access Journals (Sweden)

    Conlon Ronald A

    2005-08-01

    Full Text Available Abstract Background Huntingtin, the HD gene encoded protein mutated by polyglutamine expansion in Huntington's disease, is required in extraembryonic tissues for proper gastrulation, implicating its activities in nutrition or patterning of the developing embryo. To test these possibilities, we have used whole mount in situ hybridization to examine embryonic patterning and morphogenesis in homozygous Hdhex4/5 huntingtin deficient embryos. Results In the absence of huntingtin, expression of nutritive genes appears normal but E7.0–7.5 embryos exhibit a unique combination of patterning defects. Notable are a shortened primitive streak, absence of a proper node and diminished production of anterior streak derivatives. Reduced Wnt3a, Tbx6 and Dll1 expression signify decreased paraxial mesoderm and reduced Otx2 expression and lack of headfolds denote a failure of head development. In addition, genes initially broadly expressed are not properly restricted to the posterior, as evidenced by the ectopic expression of Nodal, Fgf8 and Gsc in the epiblast and T (Brachyury and Evx1 in proximal mesoderm derivatives. Despite impaired posterior restriction and anterior streak deficits, overall anterior/posterior polarity is established. A single primitive streak forms and marker expression shows that the anterior epiblast and anterior visceral endoderm (AVE are specified. Conclusion Huntingtin is essential in the early patterning of the embryo for formation of the anterior region of the primitive streak, and for down-regulation of a subset of dynamic growth and transcription factor genes. These findings provide fundamental starting points for identifying the novel cellular and molecular activities of huntingtin in the extraembryonic tissues that govern normal anterior streak development. This knowledge may prove to be important for understanding the mechanism by which the dominant polyglutamine expansion in huntingtin determines the loss of neurons in

  12. Numerical Investigation on the Influence of Hot Streak Temperature Ratio in a High-Pressure Stage of Vaneless Counter-Rotating Turbine

    Directory of Open Access Journals (Sweden)

    Zhao Qingjun

    2007-01-01

    Full Text Available The results of recent studies have shown that combustor exit temperature distortion can cause excessive heat load of high-pressure turbine (HPT rotor blades. The heating of HPT rotor blades can lead to thermal fatigue and degrade turbine performance. In order to explore the influence of hot streak temperature ratio on the temperature distributions of HPT airfoil surface, three-dimensional multiblade row unsteady Navier-Stokes simulations have been performed in a vaneless counter-rotating turbine (VCRT. The hot streak temperature ratios from 1.0 (without hot streak to 2.4 were used in these numerical simulations, including 1.0, 1.2, 1.6, 2.0, and 2.4 temperature ratios. The hot streak is circular in shape with a diameter equal to 25% of the span. The center of the hot streak is located at 50% of span and 0% of pitch (the leading edge of the HPT stator vane. The predicted results show that the hot streak is relatively unaffected as it migrates through the HPT stator. The hot streak mixes with the vane wake and convects towards the pressure surface (PS of the HPT rotor when it moves over the vane surface of the HPT stator. The heat load of the HPT rotor increases with the increase of the hot streak temperature ratio. The existence of the inlet temperature distortion induces a thin layer of cooler air in the HPT rotor, which separates the PS of the HPT rotor from the hotter fluid. The numerical results also indicating the migration characteristics of the hot streak in the HPT rotor are predominated by the combined effects of secondary flow and buoyancy. The combined effects that induce the high-temperature fluid migrate towards the hub on the HPT rotor. The effect of the secondary flow on the hotter fluid increases as the hot streak temperature ratio is increased. The influence of buoyancy is directly proportional to the hot streak temperature ratio. The predicted results show that the increase of the hot streak temperature ratio trends to increase

  13. Efficient transmission of Cassava brown streak disease viral pathogens by chip bud grafting

    Science.gov (United States)

    2013-01-01

    Background Techniques to study plant viral diseases under controlled growth conditions are required to fully understand their biology and investigate host resistance. Cassava brown streak disease (CBSD) presents a major threat to cassava production in East Africa. No infectious clones of the causal viruses, Cassava brown streak virus (CBSV) or Ugandan cassava brown streak virus (UCBSV) are available, and mechanical transmission to cassava is not effective. An improved method for transmission of the viruses, both singly and as co-infections has been developed using bud grafts. Findings Axillary buds from CBSD symptomatic plants infected with virulent isolates of CBSV and UCBSV were excised and grafted onto 6–8 week old greenhouse-grown, disease-free cassava plants of cultivars Ebwanateraka, TME204 and 60444. Plants were assessed visually for development of CBSD symptoms and by RT-PCR for presence of the viruses in leaf and storage root tissues. Across replicated experiments, 70-100% of plants inoculated with CBSV developed CBSD leaf and stem symptoms 2–6 weeks after bud grafting. Infected plants showed typical, severe necrotic lesions in storage roots at harvest 12–14 weeks after graft inoculation. Sequential grafting of buds from plants infected with UCBSV followed 10–14 days later by buds carrying CBSV, onto the same test plant, resulted in 100% of the rootstocks becoming co-infected with both pathogens. This dual transmission rate was greater than that achieved by simultaneous grafting with UCBSV and CBSV (67%), or when grafting first with CBSV followed by UCBSV (17%). Conclusions The bud grafting method described presents an improved tool for screening cassava germplasm for resistance to CBSD causal viruses, and for studying pathogenicity of this important disease. Bud grafting provides new opportunities compared to previously reported top and side grafting systems. Test plants can be inoculated as young, uniform plants of a size easily handled in a

  14. Analysis of Dark Slope Streaks on Mars based on Multitemporal HRSC Data

    Science.gov (United States)

    Schreiner, Björn; van Gasselt, Stephan; Jan-Peter, Muller

    2016-04-01

    Recurring slope lineae (RSL) on Mars are dark and narrow downhill oriented surface features found in equatorial regions (1) associated with water or hydrated salt flows (2). On the other hand there are Dark Slope Streaks which seem to be dry avalanches on dust covered slopes (3). The origin of both ist still under discussion. We found linear features in eastern Noctis Labyrinthus region (6°S, 265°E) with lengths of up to several kilometres and lateral extensions of 20-30 metres. As described by (4), RSL fade and recur in the same location over multiple Mars years. Similarily, Dark Slope Streaks form on at least annual to decade-long timescales (5). During 10 years of HRSC observation time (2005-2015) several linear features in Noctis Labyrinthus changed in visibility. Slope parameters and seasonal illumination conditions are investigated based on a digital elevation model derived from HRSC data. For large datasets a feature identification is presented which involves spatial filtering in conjunction with elevation data analysis. The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under iMars grant agreement n° 607379. (1) McEwen, A.S., et al. (2014): Recurring slope lineae in equatorial regions of Mars. Nat. Geosci 7: 53-58. (2) Ojha, L. et al. (2015): Spectral evidence for hydrated salts in recurring slope linear on Mars. Nat. Geosci, DOI:10.1038/NGEO2546. (3) Sullivan, R. et al. (2001). Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607-23,633. (4) McEwen, A.S., et al. (2011): Seasonal Flows on Warm Martian Slopes. Science, Vol. 333, Issue 6043, pp. 740-743. (5) Malin, M.C.; Edgett, K.S. (2001). Mars Global Surveyor Mars Orbiter Camera: Interplanetary cruise through primary mission. J. Geophys. Res., 106(E10), 23,429-23,570.

  15. Particle streak velocimetry-optical coherence tomography: a novel method for multidimensional imaging of microscale fluid flows.

    Science.gov (United States)

    Zhou, Kevin C; Huang, Brendan K; Gamm, Ute A; Bhandari, Vineet; Khokha, Mustafa K; Choma, Michael A

    2016-04-01

    We present a new OCT method for flow speed quantification and directional velocimetry: particle streak velocimetry-OCT (PSV-OCT). PSV-OCT generates two-dimensional, 2.5-vector component (vx ,|vy |,vz ) maps of microscale flow velocity fields. Knowledge of 2.5-vector components also enables the estimation of total flow speed. The enabling insight behind PSV-OCT is that tracer particles in sparsely-seeded fluid flow trace out streaks in (x,z,t)-space. The streak orientations in x-t and z-t yield vx and vz , respectively. The in-plane (x-z plane) residence time yields the out-of-plane speed |vy |. Vector component values are generated by fitting streaks to a model of image formation that incorporates equations of motion in 3D space. We demonstrate cross-sectional estimation of (vx ,|vy |,vz ) in two important animal models in ciliary biology: Xenopus embryos (tadpoles) and mouse trachea.

  16. Resistance to wheat streak mosaic virus and Triticum mosaic virus in wheat lines carrying Wsm1 and Wsm3

    Science.gov (United States)

    Wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV) are important viruses of wheat (Triticum aestivum L.) in the Great Plains of United States. In addition to agronomic practices to prevent damage from these viruses, temperature sensitive resistance genes Wsm1, Wsm2 and Wsm3, have bee...

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

    Science.gov (United States)

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

  18. Environmental factors influencing the development of black leaf streak (Mycosphaerella fijiensis Morelet) on bananas in Puerto Rico.

    Science.gov (United States)

    The effects of environmental factors on the development of black leaf streak (BLS) were studied in Puerto Rico under field conditions. Environmental factors evaluated included temperature, relative humidity, rainfall and solar radiation. Their effect on BLS was determined by recording the youngest...

  19. Introgression of chromosome segments from multiple alien species in wheat breeding lines with wheat streak mosaic virus resistance

    Science.gov (United States)

    Pyramiding of alien-derived Wheat streak mosaic virus (WSMV) resistance and resistance enhancing genes in wheat is a costeffective and environmentally safe strategy for disease control. PCR-based markers and cytogenetic analysis with genomic in situ hybridisation were applied to identify alien chrom...

  20. Transcriptome of the plant virus vector Graminella nigrifrons, and the molecular interactions of Maize fine streak rhabdovirus transmission

    Science.gov (United States)

    Background: Leafhoppers (Hemiptera:Cicadellidae) are plant-phloem feeders that are known for their ability to vector plant pathogens. The black-faced leafhopper (Graminella nigrifrons) has been identified as the only known vector for the Maize fine streak virus (MFSV), an emerging plant pathogen in...

  1. Photoemissive materials for 0.35μm laser fiducials in x-ray streak cameras

    International Nuclear Information System (INIS)

    Using a soft x-ray streak camera, materials are tested for suitability as transmission photocathodes when irradiated by 0.35μm 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

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

    CERN Document Server

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

    2015-01-01

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

  3. Lasers and laser applications. Imaging implosion dynamics: The x-ray pinhole/streak camera

    International Nuclear Information System (INIS)

    A Livermore-developed x-ray-sensitive streak camera was combined with a unique x-ray pinhole camera to make dynamic photographs of laser-irradiated fusion target implosions. These photographs show x radiation emitted from the imploding shell during its 100-ps implosion; they are the first continuous observations of an imploding laser-driven fusion capsule. The diagnostic system has a time resolution of 15 ps and a spatial resolution of about 6 μm. Results agree very well with those predicted by our LASNEX calculations, confirming that the essential physics are correctly described in the code and providing further confidence in the soundness of this approach to inertial confinement fusion

  4. Investigation of thin laser-driven flyer plates using streak imaging and stop motion microphotography

    Energy Technology Data Exchange (ETDEWEB)

    Frank, A.M. [Lawrence Livermore National Lab., CA (United States); Trott, W.M. [Sandia National Labs., Albuquerque, NM (United States)

    1995-09-01

    The dynamic behavior of laser-accelerator flyers has been studied using high-speed streak imaging in combination with stop motion microphotography. With very thin targets, melting and plasma penetration of the flyer material occur in rapid sequence. The time delay from the onset of motion to flyer breakup increases with flyer thickness and decreasing incident energy. Flyer materials examined include pure aluminum (0.25-2.6 {mu}m thick) and composite targets (0.5-2.0 {mu}m thick) containing an insulating layer of aluminum oxide. While flyer breakup is observed in both types of material, the Al{sub 2}O{sub 3} barrier significantly delays the deleterious effects of deep thermal diffusion.

  5. Time-resolved measure technique for electron beam envelope basing on synchronous framing and streaking principle

    CERN Document Server

    Xiaoguo, Jiang; Zhiyong, Yang; Huang, Zhang; Yi, Wang; Tao, Wei

    2015-01-01

    The time-resolved electron beam envelope parameters including sectional distribution and position are important and necessary for the study of beam transmission characteristics in the magnetic field and verifying the magnetic field setup rationality. One kind of high time-resolved beam envelope measurement system has developed recently. It is mainly constituted of high framing camera and streak camera. It can obtain 3 panoramic images of the beam and the time continuous information of the given beam cross section at one time. The recently obtained data has proved that several fast vibration of beam envelope along the diameter direction occur during the rising edge and the falling edge of the electron beam. The vibration period is about several nanoseconds. The effect of magnetic field on the electron beam is also observed and verified. The beam debug experiments have proved that the existing beam transmission design is reasonable and viable. The beam envelope measurement system will establish a good foundatio...

  6. Time-resolved measurements with streaked diffraction patterns from electrons generated in laser plasma wakefield

    Science.gov (United States)

    He, Zhaohan; Nees, John; Hou, Bixue; Krushelnick, Karl; Thomas, Alec; Beaurepaire, Benoît; Malka, Victor; Faure, Jérôme

    2013-10-01

    Femtosecond bunches of electrons with relativistic to ultra-relativistic energies can be robustly produced in laser plasma wakefield accelerators (LWFA). Scaling the electron energy down to sub-relativistic and MeV level using a millijoule laser system will make such electron source a promising candidate for ultrafast electron diffraction (UED) applications due to the intrinsic short bunch duration and perfect synchronization with the optical pump. Recent results of electron diffraction from a single crystal gold foil, using LWFA electrons driven by 8-mJ, 35-fs laser pulses at 500 Hz, will be presented. The accelerated electrons were collimated with a solenoid magnetic lens. By applying a small-angle tilt to the magnetic lens, the diffraction pattern can be streaked such that the temporal evolution is separated spatially on the detector screen after propagation. The observable time window and achievable temporal resolution are studied in pump-probe measurements of photo-induced heating on the gold foil.

  7. Host range and transmission of Tobacco streak virus (TSV causing cotton mosaic disease

    Directory of Open Access Journals (Sweden)

    D. Utpal

    2012-07-01

    Full Text Available Tobacco streak virus (TSV causing cotton mosaic disease was found to be transmissible by mechanical means specially when extracts were made in neutral phosphate buffer 0.02M containing reducing agent like 2-Mercaptoethanol.The disease was found to be transmitted by Thrips palmi (cotton thrips and Thrips tobacci (onion thrips. TSV was detected in sample showing mosaic symptoms.TSV was readily graft transmissible but not transmissible by mechanical means, no evidence of its transmission through seed or by thrips was obtained. About 19 plant species belonging to five different families viz.malvaceae, chenopodiaceae, compositeae, leguminoceae and solanaceae were tested for host range and virus isolate causing cotton mosaic disease.

  8. Tracing dynamics of laser-induced fields on ultrathin foils using complementary imaging with streak deflectometry

    Science.gov (United States)

    Abicht, F.; Braenzel, J.; Priebe, G.; Koschitzki, Ch.; Andreev, A. A.; Nickles, P. V.; Sander, W.; Schnürer, M.

    2016-09-01

    We present a detailed study of the electric and magnetic fields, which are created on plasma vacuum interfaces as a result of highly intense laser-matter interactions. For the field generation ultrathin polymer foils (30-50 nm) were irradiated with high intensity femtosecond (1019 - 1020 W /cm2 ) and picosecond (˜1017 W /cm2 ) laser pulses with ultrahigh contrast (1010 - 1011 ). To determine the temporal evolution and the spatial distribution of these fields the proton streak deflectometry method has been developed further and applied in two different imaging configurations. It enabled us to gather complementary information about the investigated field structure, in particular about the influence of different field components (parallel and normal to the target surface) and the impact of a moving ion front. The applied ultrahigh laser contrast significantly increased the reproducibility of the experiment and improved the accuracy of the imaging method. In order to explain the experimental observations, which were obtained by applying ultrashort laser pulses, two different analytical models have been studied in detail. Their ability to reproduce the streak deflectometry measurements was tested on the basis of three-dimensional particle simulations. A modification and combination of the two models allowed for an extensive and accurate reproduction of the experimental results in both imaging configurations. The controlled change of the laser pulse duration from 50 femtoseconds to 2.7 picoseconds led to a transition of the dominating force acting on the probing proton beam at the rear side of the polymer foil. In the picosecond case the (v ⇀ x B ⇀ ) -term of the Lorentz force dominated over the counteracting E ⇀-field and was responsible for the direction of the net force. The applied proton deflectometry method allowed for an unambiguous determination of the magnetic field polarity at the rear side of the ultrathin foil.

  9. Southern rice black-streaked dwarf virus: A new proposed Fijivirus species in the family Reoviridae

    Institute of Scientific and Technical Information of China (English)

    ZHOU GuoHui; WEN JingJung; CAI DeJiang; LI Peng; XU DongLin; ZHANG ShuGuang

    2008-01-01

    For the past several years, a novel dwarf disease has been observed on rice (Oryza sativa) in some regions of Guangdong Province and Hainan Province, southern China. Infected plants showed stunting,dark leaf and small enations on stem and leaf back. Typical Fijivirus viroplasma containing crystalline arrayed spherical virons approximately 70-75 nm in diameter and tubular structures were detected in ultrathin sections by an electron microscope in parenchyma phloem cells of the infected plants. The virus was transmitted to rice seedlings by white-backed planthoppers, Sogatella furcifera (Hemiptera:Delphacidae), collected in the diseased fields. Analysis of dsRNA extracts from infected plants revealed ten linear segments, which were similar to the electrophoretic profile of Rice black-streaked dwarf virus (RBSDV). RT-PCR with a single primer which matched to a linker sequence ligated to both 3' ends of the viral genomic dsRNAs resulted in amplification of genome segments 9 (S9) and 10 (S10) cDNA products. The complete nucleotide sequences of S9 and S10 were obtained from clones of the RT-PCR amplicon exhibited characteristic properties of Fijivirus including low GC content (34.5% and 35.6%), genus conserved 5' and 3' termini sequences and similar genome organization. Blast searches indicated that the sequences of S9 and S10 shared 68.8%-74.9% and 67.1 %-77.4% nucleotide identities with those of viruses in the Fijivirus group 2, respectively. These values were similar to those among other viruses in the Fijivirus group 2 and considerably lower than those among RBSDV isolates. Phylogenetic trees based on S9 and S10 nucleotide sequences and their putative amino acid sequences showed that this virus represented a separate branch among other Fijiviruses. The virus was also detected by a nested RT-PCR assay in corn (Zea mays), barnyard grass (Echinochloa crusgalli), Juncellus serotinus and flaccidgrass (Pennisetum flaccidum) in and/or adjacent to the infected rice fields

  10. Transmission of Rice Black-Streaked Dwarf Virus from Frozen Infected Leaves to Healthy Rice Plants by Small Brown Planthopper (Laodelphax striatellus)

    Institute of Scientific and Technical Information of China (English)

    ZHOU Tong; WU Li-juan; WANG Ying; CHENG Zhao-bang; JI Ying-hua; FAN Yong-jian; ZHOU Yi-jun

    2011-01-01

    In order to preserve virus for identifying the resistance of rice varieties against rice black-streaked dwarf disease,a simple and reliable method was developed,through which virus-free small brown planthopper (SBPH) acquired rice black-streaked dwarf virus (RBSDV) from frozen infected leaves and the virus was transmitted to healthy rice plants.The experimental results showed that SBPH could obtain RBSDV from frozen infected rice leaves and the virus could be transmitted to a susceptible rice variety.For the ability to acquire RBSDV and transmit the virus to healthy plants by SBPH,there was no significant difference between frozen infected leaves and in vitro infected leaves.The novel method could be applied to identification of rice variety resistance to rice black-streaked dwarf disease,facilitating the breeding process for rice black-streaked dwarf disease resistance.

  11. Streak instability and generation of hairpin-vortices by a slotted jet in channel crossflow: Experiments and linear stability analysis

    Science.gov (United States)

    Philip, Jimmy; Karp, Michael; Cohen, Jacob

    2016-01-01

    Streaks and hairpin-vortices are experimentally generated in a laminar plane Poiseuille crossflow by injecting a continuous jet through a streamwise slot normal to the crossflow, with air as the working media. Small disturbances form stable streaks, however, higher disturbances cause the formation of streaks which undergo instability leading to the generation of hairpin vortices. Particular emphasis is placed on the flow conditions close to the generation of hairpin-vortices. Measurements are carried out in the cases of natural and phase-locked disturbance employing smoke visualisation, particle image velocimetry, and hot-wire anemometry, which include, the dominant frequency, wavelength, and the disturbance shape (or eigenfunctions) associated with the coherent part of the velocity field. A linear stability analysis for both one- and two-dimensional base-flows is carried out to understand the mechanism of instability and good agreement of wavelength and eigenfunctions are obtained when compared to the experimental data, and a slight under-prediction of the growth-rates by the linear stability analysis consistent with the final nonlinear stages in transitional flows. Furthermore, an energy analysis for both the temporal and spatial stability analysis revels the dominance of the symmetric varicose mode, again, in agreement with the experiments, which is found to be governed by the balance of the wallnormal shear and dissipative effects rather than the spanwise shear. In all cases the anti-symmetric sinuous modes governed by the spanwise shear are found to be damped both in analysis and in our experiments.

  12. Measurement of longitudinal electron beam parameters using indigenously developed streak camera system at Indus-1 synchrotron radiation source

    International Nuclear Information System (INIS)

    Indus-1 is a 450 MeV synchrotron radiation source (SRS) operational at RRCAT, Indore. A diagnostic beamline utilizing visible portion of wide synchrotron radiation spectrum is used for the measurement of electron beam parameters. Its RF frequency and harmonic number are 31.6 MHz and 2 respectively. Among the five operational user beamlines at Indus-1 SRS visible diagnostic beamline (V-DBL, BL-5) is used for the measurement and study of electron beam parameters at dipole magnet DP-3 in Indus-1 .The bunch length represents the extent of longitudinal distribution of electrons inside the bunch, and bunch centroid position is the temporal position or phase of bunch with respect to accelerating voltage inside RF cavity which are important beam dynamics parameters in an accelerator. For measuring the longitudinal beam profile, bunch length, bunch centroid position (of the order of few tens of picoseconds) etc. of the electron beam, a very high temporal resolution device such as streak camera is required to capture the images of the beam in the time domain. For this purpose, an indigenously developed single shot S-20 streak camera has been developed to capture longitudinal profile of electrons bunches in Indus-1 and installed at V-DBL (BL-5). In this paper various measurements carried out using this indigenously developed streak camera system at Indus-1 SRS are discussed

  13. A Robust In-Situ Warp-Correction Algorithm For VISAR Streak Camera Data at the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Labaria, George R. [Univ. of California, Santa Cruz, CA (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Warrick, Abbie L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Celliers, Peter M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kalantar, Daniel H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-01-12

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a 192-beam pulsed laser system for high-energy-density physics experiments. Sophisticated diagnostics have been designed around key performance metrics to achieve ignition. The Velocity Interferometer System for Any Reflector (VISAR) is the primary diagnostic for measuring the timing of shocks induced into an ignition capsule. The VISAR system utilizes three streak cameras; these streak cameras are inherently nonlinear and require warp corrections to remove these nonlinear effects. A detailed calibration procedure has been developed with National Security Technologies (NSTec) and applied to the camera correction analysis in production. However, the camera nonlinearities drift over time, affecting the performance of this method. An in-situ fiber array is used to inject a comb of pulses to generate a calibration correction in order to meet the timing accuracy requirements of VISAR. We develop a robust algorithm for the analysis of the comb calibration images to generate the warp correction that is then applied to the data images. Our algorithm utilizes the method of thin-plate splines (TPS) to model the complex nonlinear distortions in the streak camera data. In this paper, we focus on the theory and implementation of the TPS warp-correction algorithm for the use in a production environment.

  14. Laser Timing Jitter Measurements using a Dual-Sweep Streak Camera at the A0 Photoinjector

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-04-30

    Excellent phase stability of the drive laser is a critical performance specification of photoinjectors such as Fermilab's A0 photoinjector (A0PI). Previous efforts based on the measurement of the power spectrum of the signal of a fast photodiode illuminated by the mode locked infrared laser pulse component indicated a phase jitter of less than 1.4 ps (technique limited). A recently procured dual sweep plugin unit and existing Hamamatsu C5680 streak camera were used to study the phase stability of the UV laser pulse component. Initial measurements with the synchroscan vertical sweep unit locked to 81.25 MHz showed that the phase slew through the micropulse train and the phase jitter micropulse to micropulse were two key aspects that could be evaluated. The phase slew was much less than 100 fs per micropulse, and the total phase jitter (camera, trigger, and laser) was approximately 300 fs RMS for measurements of 50-micropulse trains. Data on the macropulse phase stability were also obtained. A possible upgrade to achieve better phase stability will be also discussed.

  15. A simple, novel and high efficiency sap inoculation method to screen for tobacco streak virus.

    Science.gov (United States)

    Sundaresha, S; Sreevathsa, Rohini; Balol, Gurupada B; Keshavareddy, G; Rangaswamy, K T; Udayakumar, M

    2012-10-01

    A rapid and efficient sap inoculation method for tobacco streak virus (TSV) was developed in sunflower. Sap from TSV-infected sunflower plants was freshly extracted in phosphate buffer and diluted serially from 10(-1) to 10(-8). Two-day old seedlings of sunflower were injured at the meristem and immersed in the sap for 10 min, maintained at 20 °C for 2-3 days and shifted to greenhouse. The surviving seedlings in the respective sap dilution were scored for symptoms of sunflower necrosis disease (SND). SND symptoms were seen in 80 % of the seedlings inoculated with a sap dilution of 10(-5). ELISA and RT-PCR analysis of coat protein and movement protein of TSV confirmed SND symptoms. The methodology was also found to be reproducible when the sap from the infected plants was inoculated onto healthy plants. The main aim of the study was to develop a primary screening strategy for the selection of transgenics developed for SND resistance. This methodology can also be extended for the analysis of resistance against other viruses.

  16. Screening of Rice Genes Interacting with p5b of Rice Black-Streaked Dwarf Virus

    Institute of Scientific and Technical Information of China (English)

    LU Ying; YANG Jian; ZHANG Heng-mu; CHEN Jian-ping

    2013-01-01

    Rice black-streaked dwarf virus (RBSDV) is a recognized member of the genus Fijivirus,family Reoviridae.Its genome has ten double-stranded RNA (dsRNA) segments (S1-S10),in which the fifth genome segment (S5) contains two open reading frames (ORFs) with a partially overlapping region.The second ORF of RBSDV S5 encodes a viral nonstructural protein named p5b with unknown function.To reveal the function of p5b,its gene was ligated into the bait plasmid pGBKT7 and an expression library containing rice cDNAs was constructed using plasmid pGADT7 for yeast two-hybrid assay.The bait protein p5b was detected in yeast by western blot,and the result of an auto-activation test showed that p5b could not autonomously activate the expression of reporter genes in yeast.Then the bait protein p5b was used for screening the cDNA expression libraries of rice.Gene fragments of some pivotal enzymes involved in photosynthesis,respiration and other important metabolic processes,were identified to interact with p5b in yeast,suggesting that these interactions may play roles in symptom development in infected plants.

  17. Streak-camera measurements of the PEP-II high-energy ring

    International Nuclear Information System (INIS)

    The third commissioning run of the PEP-II High-Energy Ring (HER, the 9 GeV electron ring), in January 1998, included extensive measurements of single-bunch and multibunch fills using LBNL close-quote s dual-axis streak camera combined with Argonne close-quote s 119.0 MHz synchroscan plug-in. For single bunches, the dependence of bunch length on charge and rf voltage was studied from 0.5 to 2.5 mA and from 9.5 to 15 MV; the measured values ranged from 38 to 49 ps rms. The multibunch work focused on longitudinal instabilities as the current in the ring was raised to 500 mA, and the length of the bunch train was varied from 100 bunches (with 4.2 ns spacing) to a full ring. Large oscillations of up to 180 ps peak to peak were observed for bunches half a ring turn away from the start of the train, especially at higher currents and for trains filling roughly half the ring. These observations led to a new fill pattern with more gaps that allowed us to raise the current to 750 mA by the end of the run. copyright 1998 American Institute of Physics

  18. Hairpin RNA Targeting Multiple Viral Genes Confers Strong Resistance to Rice Black-Streaked Dwarf Virus

    Directory of Open Access Journals (Sweden)

    Fangquan Wang

    2016-05-01

    Full Text Available Rice black-streaked dwarf virus (RBSDV belongs to the genus Fijivirus in the family of Reoviridae and causes severe yield loss in rice-producing areas in Asia. RNA silencing, as a natural defence mechanism against plant viruses, has been successfully exploited for engineering virus resistance in plants, including rice. In this study, we generated transgenic rice lines harbouring a hairpin RNA (hpRNA construct targeting four RBSDV genes, S1, S2, S6 and S10, encoding the RNA-dependent RNA polymerase, the putative core protein, the RNA silencing suppressor and the outer capsid protein, respectively. Both field nursery and artificial inoculation assays of three generations of the transgenic lines showed that they had strong resistance to RBSDV infection. The RBSDV resistance in the segregating transgenic populations correlated perfectly with the presence of the hpRNA transgene. Furthermore, the hpRNA transgene was expressed in the highly resistant transgenic lines, giving rise to abundant levels of 21–24 nt small interfering RNA (siRNA. By small RNA deep sequencing, the RBSDV-resistant transgenic lines detected siRNAs from all four viral gene sequences in the hpRNA transgene, indicating that the whole chimeric fusion sequence can be efficiently processed by Dicer into siRNAs. Taken together, our results suggest that long hpRNA targeting multiple viral genes can be used to generate stable and durable virus resistance in rice, as well as other plant species.

  19. Effect of rosella extract on development of fatty streaks lesions in female rats

    Directory of Open Access Journals (Sweden)

    E. R. Al-Kennany

    2010-01-01

    Full Text Available This research was conducted to explore the effect of rosella (Hibiscus sabdariffa on female rats on oxidative stress which induced by 0.5% H2O2. Oxidative stress has been investigated via tissue (aorta and heart malonadyaldehyde (MDA as indirect lipid peroxidation index. For atherosclerotic lesions follow up light microscopical technique has been applied. The result elucidate significant reduction in lipid profit parameters namely: low density lipoprotein (LDL-c, triglycerides, very low density lipoprotein (vLDL-c, atherogenic index and significant elevation in high density lipoprotein (HDL-c in few animals treated with H2O2 and rosella extract, parallely, this research illustrate reduction in aorta and heart MDA concentration, concomitant with significant rising in glutathione (GSH level. Histopathologically, this study revealed fatty streaks associated with infiltration of mononuclear inflammatory cells have been detected after 60 days, in animal treated with rosella revealed reduction in lipid vacuoles and proliferation in vascular smooth muscle cells (VSMcs in media toward intimal layers after 40 days from treatment.

  20. Attosecond streaking measurement of extreme ultraviolet pulses using a long-wavelength electric field

    Science.gov (United States)

    Saito, Nariyuki; Ishii, Nobuhisa; Kanai, Teruto; Watanabe, Shuntaro; Itatani, Jiro

    2016-01-01

    Long-wavelength lasers have great potential to become a new-generation drive laser for tabletop coherent light sources in the soft X-ray region. Because of the significantly low conversion efficiency from a long-wavelength light field to high-order harmonics, their pulse characterization has been carried out by measuring the carrier-envelope phase and/or spatial dependences of high harmonic spectra. However, these photon detection schemes, in general, have difficulty in obtaining information on the spectral phases, which is crucial to determine the temporal structures of high-order harmonics. Here, we report the first attosecond streaking measurement of high harmonics generated by few-cycle optical pulses at 1.7 μm from a BiB3O6–based optical parametric chirped-pulse amplifier. This is also the first demonstration of time-resolved photoelectron spectroscopy using high harmonics from a long-wavelength drive laser other than Ti:sapphire lasers, which paves the way towards ultrafast soft X-ray photoelectron spectroscopy. PMID:27752115

  1. Streaked optical pyrometer for measuring surface temperature of ion heated plasma

    Science.gov (United States)

    Roycroft, R.; Dyer, G. M.; Wagner, C.; Bernstein, A.; Ditmire, T.; Hegelich, B. M.; Albright, B. J.; Fernandez, J. C.; Bang, W.; Bradley, P. A.; Gautier, D. C.; Hamilton, C. E.; Palaniyappan, S.; Santiago Cordoba, M. A.; Vold, E. L.; Yin, L.

    2015-11-01

    The evolution of the interface between a light and heavy material isochorically heated to warm dense matter conditions is important to the understanding of electrostatic effects on the usual hydrodynamic understanding of fluid mixing. In recent experiments at the Trident laser facility in Los Alamos National Laboratory, the target, containing a high Z and a low Z material, is heated to several eV by laser accelerated aluminum ions. We fielded a streaked optical pyrometer to measure surface temperature. The pyrometer images the back surface of a heated target on a sub-nanosecond timescale with 400nm light from the plasma. This poster presents the details of the experimental setup and pyrometer design, as well as initial results of ion heating of aluminum targets. The interface between heated diamond and gold is also observed. Work supported by NNSA cooperative agreement DE-NA0002008 and the Los Alamos National Laboratory Directed Research and Development Program under the auspices of the U.S. DOE NNSAS, LLC, Los Alamos National Laboratory under Contract No. DE-AC52-06NA25396.

  2. New Experimental Hosts of Tobacco streak virus and Absence of True Seed Transmission in Leguminous Hosts.

    Science.gov (United States)

    Vemana, K; Jain, R K

    2010-10-01

    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

  3. Improving the diffraction of full-length human selenomethionyl metavinculin crystals by streak-seeding

    Energy Technology Data Exchange (ETDEWEB)

    Rangarajan, Erumbi S.; Izard, Tina (Scripps)

    2012-06-28

    Metavinculin is an alternatively spliced isoform of vinculin that has a 68-residue insert in its tail domain (1134 total residues) and is exclusively expressed in cardiac and smooth muscle tissue, where it plays important roles in myocyte adhesion complexes. Mutations in the metavinculin-specific insert are associated with dilated cardiomyopathy (DCM) in man. Crystals of a DCM-associated mutant of full-length selenomethionine-labeled metavinculin grown by hanging-drop vapor diffusion diffracted poorly and were highly sensitive to radiation, preventing the collection of a complete X-ray diffraction data set at the highest possible resolution. Streak-seeding markedly improved the stability, crystal-growth rate and diffraction quality of DCM-associated mutant metavinculin crystals, allowing complete data collection to 3.9 {angstrom} resolution. These crystals belonged to space group P4{sub 3}2{sub 1}2, with two molecules in the asymmetric unit and unit-cell parameters a = b = 170, c = 211 {angstrom}, {alpha} = {beta} = {gamma} = 90{sup o}.

  4. Closed-loop control of boundary layer streaks induced by free-stream turbulence

    Science.gov (United States)

    Papadakis, George; Lu, Liang; Ricco, Pierre

    2016-08-01

    The central aim of the paper is to carry out a theoretical and numerical study of active wall transpiration control of streaks generated within an incompressible boundary layer by free-stream turbulence. The disturbance flow model is based on the linearized unsteady boundary-region (LUBR) equations, studied by Leib, Wundrow, and Goldstein [J. Fluid Mech. 380, 169 (1999), 10.1017/S0022112098003504], which are the rigorous asymptotic limit of the Navier-Stokes equations for low-frequency and long-streamwise wavelength. The mathematical formulation of the problem directly incorporates the random forcing into the equations in a consistent way. Due to linearity, this forcing is factored out and appears as a multiplicative factor. It is shown that the cost function (integral of kinetic energy in the domain) is properly defined as the expectation of a random quadratic function only after integration in wave number space. This operation naturally introduces the free-stream turbulence spectral tensor into the cost function. The controller gains for each wave number are independent of the spectral tensor and, in that sense, universal. Asymptotic matching of the LUBR equations with the free-stream conditions results in an additional forcing term in the state-space system whose presence necessitates the reformulation of the control problem and the rederivation of its solution. It is proved that the solution can be obtained analytically using an extension of the sweep method used in control theory to obtain the standard Riccati equation. The control signal consists of two components, a feedback part and a feed-forward part (that depends explicitly on the forcing term). Explicit recursive equations that provide these two components are derived. It is shown that the feed-forward part makes a negligible contribution to the control signal. We also derive an explicit expression that a priori (i.e., before solving the control problem) leads to the minimum of the objective cost

  5. Structural studies on tobacco streak virus coat protein: Insights into the pleomorphic nature of ilarviruses.

    Science.gov (United States)

    Gulati, Ashutosh; Alapati, Kavitha; Murthy, Abhinandan; Savithri, H S; Murthy, M R N

    2016-02-01

    Tobacco streak virus (TSV), the type member of Ilarvirus genus, is a major plant pathogen. TSV purified from infected plants consists of a ss-RNA genome encapsidated in spheroidal particles with diameters of 27, 30 and 33nm constructed from multiple copies of a single species of coat protein (CP) subunits. Apart from protecting the viral genome, CPs of ilarviruses play several key roles in the life cycle of these viruses. Unlike the related bromo and cucumoviruses, ilarvirus particles are labile and pleomorphic, which has posed difficulties in their crystallization and structure determination. In the current study, a truncated TSV-CP was crystallized in two distinct forms and their structures were determined at resolutions of 2.4Å and 2.1Å, respectively. The core of TSV CP was found to possess the canonical β-barrel jelly roll tertiary structure observed in several other viruses. Dimers of CP with swapped C-terminal arms (C-arm) were observed in both the crystal forms. The C-arm was found to be flexible and is likely to be responsible for the polymorphic and pleomorphic nature of TSV capsids. Consistent with this observation, mutations in the hinge region of the C-arm that reduce the flexibility resulted in the formation of more uniform particles. TSV CP was found to be structurally similar to that of Alfalfa mosaic virus (AMV) accounting for similar mechanism of genome activation in alfamo and ilar viruses. This communication represents the first report on the structure of the CP from an ilarvirus. PMID:26706030

  6. Neutron Radiation Shielding For The NIF Streaked X-Ray Detector (SXD) Diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Song, P; Holder, J; Young, B; Kalantar, D; Eder, D; Kimbrough, J

    2006-11-02

    The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) is preparing for the National Ignition Campaign (NIC) scheduled in 2010. The NIC is comprised of several ''tuning'' physics subcampaigns leading up to a demonstration of Inertial Confinement Fusion (ICF) ignition. In some of these experiments, time-resolved x-ray imaging of the imploding capsule may be required to measure capsule trajectory (shock timing) or x-ray ''bang-time''. A capsule fueled with pure tritium (T) instead of a deutriun-tritium (DT) mixture is thought to offer useful physics surrogacy, with reduced yields of up to 5e14 neutrons. These measurements will require the use of the NIF streak x-ray detector (SXD). The resulting prompt neutron fluence at the planned SXD location ({approx}1.7 m from the target) would be {approx}1.4e9/cm{sup 2}. Previous measurements suggest the onset of significant background at a neutron fluence of {approx} 1e8/cm{sup 2}. The radiation damage and operational upsets which starts at {approx}1e8 rad-Si/sec must be factored into an integrated experimental campaign plan. Monte Carlo analyses were performed to predict the neutron and gamma/x-ray fluences and radiation doses for the proposed diagnostic configuration. A possible shielding configuration is proposed to mitigate radiation effects. The primary component of this shielding is an 80 cm thickness of Polyethylene (PE) between target chamber center (TCC) and the SXD diagnostic. Additionally, 6-8 cm of PE around the detector provide from the large number of neutrons that scatter off the inside of the target chamber. This proposed shielding configuration reduces the high-energy neutron fluence at the SXD by approximately a factor {approx}50.

  7. Comparative analysis of virus-derived small RNAs within cassava (Manihot esculenta Crantz) infected with cassava brown streak viruses.

    Science.gov (United States)

    Ogwok, Emmanuel; Ilyas, Muhammad; Alicai, Titus; Rey, Marie E C; Taylor, Nigel J

    2016-04-01

    Infection of plant cells by viral pathogens triggers RNA silencing, an innate antiviral defense mechanism. In response to infection, small RNAs (sRNAs) are produced that associate with Argonaute (AGO)-containing silencing complexes which act to inactivate viral genomes by posttranscriptional gene silencing (PTGS). Deep sequencing was used to compare virus-derived small RNAs (vsRNAs) in cassava genotypes NASE 3, TME 204 and 60444 infected with the positive sense single-stranded RNA (+ssRNA) viruses cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV), the causal agents of cassava brown streak disease (CBSD). An abundance of 21-24nt vsRNAs was detected and mapped, covering the entire CBSV and UCBSV genomes. The 21nt vsRNAs were most predominant, followed by the 22 nt class with a slight bias toward sense compared to antisense polarity, and a bias for adenine and uracil bases present at the 5'-terminus. Distribution and frequency of vsRNAs differed between cassava genotypes and viral genomes. In susceptible genotypes TME 204 and 60444, CBSV-derived sRNAs were seen in greater abundance than UCBSV-derived sRNAs. NASE 3, known to be resistant to UCBSV, accumulated negligible UCBSV-derived sRNAs but high populations of CBSV-derived sRNAs. Transcript levels of cassava homologues of AGO2, DCL2 and DCL4, which are central to the gene-silencing complex, were found to be differentially regulated in CBSV- and UCBSV-infected plants across genotypes, suggesting these proteins play a role in antiviral defense. Irrespective of genotype or viral pathogen, maximum populations of vsRNAs mapped to the cytoplasmic inclusion, P1 and P3 protein-encoding regions. Our results indicate disparity between CBSV and UCBSV host-virus interaction mechanisms, and provide insight into the role of virus-induced gene silencing as a mechanism of resistance to CBSD.

  8. Comparative analysis of virus-derived small RNAs within cassava (Manihot esculenta Crantz) infected with cassava brown streak viruses.

    Science.gov (United States)

    Ogwok, Emmanuel; Ilyas, Muhammad; Alicai, Titus; Rey, Marie E C; Taylor, Nigel J

    2016-04-01

    Infection of plant cells by viral pathogens triggers RNA silencing, an innate antiviral defense mechanism. In response to infection, small RNAs (sRNAs) are produced that associate with Argonaute (AGO)-containing silencing complexes which act to inactivate viral genomes by posttranscriptional gene silencing (PTGS). Deep sequencing was used to compare virus-derived small RNAs (vsRNAs) in cassava genotypes NASE 3, TME 204 and 60444 infected with the positive sense single-stranded RNA (+ssRNA) viruses cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV), the causal agents of cassava brown streak disease (CBSD). An abundance of 21-24nt vsRNAs was detected and mapped, covering the entire CBSV and UCBSV genomes. The 21nt vsRNAs were most predominant, followed by the 22 nt class with a slight bias toward sense compared to antisense polarity, and a bias for adenine and uracil bases present at the 5'-terminus. Distribution and frequency of vsRNAs differed between cassava genotypes and viral genomes. In susceptible genotypes TME 204 and 60444, CBSV-derived sRNAs were seen in greater abundance than UCBSV-derived sRNAs. NASE 3, known to be resistant to UCBSV, accumulated negligible UCBSV-derived sRNAs but high populations of CBSV-derived sRNAs. Transcript levels of cassava homologues of AGO2, DCL2 and DCL4, which are central to the gene-silencing complex, were found to be differentially regulated in CBSV- and UCBSV-infected plants across genotypes, suggesting these proteins play a role in antiviral defense. Irrespective of genotype or viral pathogen, maximum populations of vsRNAs mapped to the cytoplasmic inclusion, P1 and P3 protein-encoding regions. Our results indicate disparity between CBSV and UCBSV host-virus interaction mechanisms, and provide insight into the role of virus-induced gene silencing as a mechanism of resistance to CBSD. PMID:26811902

  9. Identifying and discriminating phase transitions along decaying shocks with line imaging Doppler interferometric velocimetry and streaked optical pyrometry

    Energy Technology Data Exchange (ETDEWEB)

    Millot, Marius, E-mail: millot1@llnl.gov [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2016-01-15

    Ultrafast line-imaging velocity interferometer system for any reflector and streaked optical pyrometry are now commonly used to obtain high precision equation of state and electronic transport data under dynamic compression at major high energy density science facilities. We describe a simple way to improve distinguishing phase transformation signatures from other signals when monitoring decaying shock waves. The line-imaging capability of these optical diagnostics offers additional supporting evidence to the assignment of particular anomalies—such as plateaus or reversals—to the occurrence of a phase transition along the Hugoniot. We illustrate the discussion with two example datasets collected during laser driven shock compression of quartz and stishovite.

  10. Analysis of Dark Slope Streaks on Mars based on Multitemporal Imagery and Digital Elevation Model derived from HRSC Data

    Science.gov (United States)

    Schreiner, Bjoern Peter; Walter, Sebastian; Muller, Jan-Peter; Sidiropoulos, Panagiotis

    2016-10-01

    Recurring slope lineae (RSL) on Mars are dark and narrow downhill oriented surface features found in equatorial regions (1) associated with water or hydrated salt flows (2). On the other hand there are Dark Slope Streaks which seem to be dry avalanches on dust covered slopes (3). The origin of both ist still under discussion. We found linear features in eastern Noctis Labyrinthus region (6°S, 265°E) with lengths of up to several kilometres and lateral extensions of 20-30 metres. RSL fade andrecur in the same location over multiple Mars years (4). Similarily, Dark Slope Streaks form on at least annual to decade-long timescales (5). During 10 years of HRSC observation time (2005-2015) several linear features in Noctis Labyrinthus changed in visibility. Slopeparameters and seasonal illumination conditions are investigated based ona DTM derived from HRSC data. Also particle flow along streaks has been modelled. Feature and change identification is presented involving spatial filtering and DTM analysis.The research leading to these results has received funding from theEuropean Union's Seventh Framework Programme (FP7/2007-2013) under iMars grant agreement n° 607379.(1) McEwen, A.S., et al. (2014): Recurring slope lineae in equatorialregions of Mars. Nat. Geosci 7: 53-58.(2) Ojha, L. et al. (2015): Spectral evidence for hydrated salts inrecurring slope linear on Mars. Nat. Geosci, DOI:10.1038/NGEO2 546.(3) Sullivan, R. et al. (2001). Mass Movement Slope Streaks Imaged by theMars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.(4) McEwen, A.S., et al. (2011): Seasonal Flows on Warm Martian Slopes.Science, Vol. 333, Issue 6043, pp. 740-743.(5) Malin, M.C.; Edgett, K.S. (2001). Mars Global Surveyor Mars OrbiterCamera: Interplanetary cruise through primary mission. J. Geophys. Res., 106(E10), 23,429–23,570.

  11. Time-resolved two-photon excitation fluorescence spectroscopy and microscopy using a high repetition rate streak camera

    Institute of Scientific and Technical Information of China (English)

    LIU Li-xin; QU Ju-le; LIN Zi-yang; WANG Lei; FU Zhe; GUO Bao-ping; NIU Han-ben

    2007-01-01

    We present a time-resolved two-photon excitation fluorescence spectroscopy and a simultaneous time- and spectrumresolved multifocal multiphoton microscopy system that is based on a high repetition rate picosecond streak camera for providing time- and spectrum- resolved measurement and imaging in biomedicine. The performance of the system is tested and characterized by the fluorescence spectrum and lifetime analysis of several standard fluorescent dyes and their mixtures.Spectrum-resolved fluorescence lifetime images of fluorescence beads are obtained. Potential applications of the system include clinical diagnostics and cell biology etc.

  12. Genomic variability and molecular evolution of Asian isolates of sugarcane streak mosaic virus.

    Science.gov (United States)

    Liang, Shan-Shan; Alabi, Olufemi J; Damaj, Mona B; Fu, Wei-Lin; Sun, Sheng-Ren; Fu, Hua-Ying; Chen, Ru-Kai; Mirkov, T Erik; Gao, San-Ji

    2016-06-01

    Sugarcane streak mosaic virus (SCSMV), an economically important causal agent of mosaic disease of sugarcane, is a member of the newly created genus Poacevirus in the family Potyviridae. In this study, we report the molecular characterization of three new SCSMV isolates from China (YN-YZ211 and HN-YZ49) and Myanmar (MYA-Formosa) and their genetic variation and phylogenetic relationship to SCSMV isolates from Asia and the type members of the family Potyviridae. The complete genome of each of the three isolates was determined to be 9781 nucleotides (nt) in size, excluding the 3' poly(A) tail. Phylogenetic analysis of the complete polyprotein amino acid (aa) sequences (3130 aa) revealed that all SCSMV isolates clustered into a phylogroup specific to the genus Poacevirus and formed two distinct clades designated as group I and group II. Isolates YN-YZ211, HN-YZ49 and MYA-Formosa clustered into group I, sharing 96.8-99.5 % and 98.9-99.6 % nt (at the complete genomic level) and aa (at the polyprotein level) identity, respectively, among themselves and 81.2-98.8 % and 94.0-99.6 % nt (at the complete genomic level) and aa (at the polyprotein level) identity, respectively, with the corresponding sequences of seven Asian SCSMV isolates. Population genetic analysis revealed greater between-group (0.190 ± 0.004) than within-group (group I = 0.025 ± 0.001 and group II = 0.071 ± 0.003) evolutionary divergence values, further supporting the results of the phylogenetic analysis. Further analysis indicated that natural selection might have contributed to the evolution of isolates belonging to the two identified SCSMV clades, with infrequent genetic exchanges occurring between them over time. These findings provide a comprehensive analysis of the population genetic structure and driving forces for the evolution of SCSMV with implications for global exchange of sugarcane germplasm. PMID:26973230

  13. Hairless Streaks in Cattle Implicate TSR2 in Early Hair Follicle Formation.

    Directory of Open Access Journals (Sweden)

    Leonardo Murgiano

    2015-07-01

    Full Text Available Four related cows showed hairless streaks on various parts of the body with no correlation to the pigmentation pattern. The stripes occurred in a consistent pattern resembling the lines of Blaschko. The non-syndromic hairlessness phenotype observed occurred across three generations of a single family and was compatible with an X-linked mode of inheritance. Linkage analysis and subsequent whole genome sequencing of one affected female identified two perfectly associated non-synonymous sequence variants in the critical interval on bovine chromosome X. Both variants occurred in complete linkage disequilibrium and were absent in more than 3900 controls. An ERCC6L missense mutation was predicted to cause an amino acid substitution of a non-conserved residue. Analysis in mice showed no specific Ercc6l expression pattern related to hair follicle development and therefore ERCC6L was not considered as causative gene. A point mutation at the 5'-splice junction of exon 5 of the TSR2, 20S rRNA accumulation, homolog (S. cerevisiae, gene led to the production of two mutant transcripts, both of which contain a frameshift and generate a premature stop codon predicted to truncate approximately 25% of the protein. Interestingly, in addition to the presence of both physiological TSR2 transcripts, the two mutant transcripts were predominantly detected in the hairless skin of the affected cows. Immunohistochemistry, using an antibody against the N-terminal part of the bovine protein demonstrated the specific expression of the TSR2 protein in the skin and the hair of the affected and the control cows as well as in bovine fetal skin and hair. The RNA hybridization in situ showed that Tsr2 was expressed in pre- and post-natal phases of hair follicle development in mice. Mammalian TSR2 proteins are highly conserved and are known to be broadly expressed, but their precise in vivo functions are poorly understood. Thus, by dissecting a naturally occurring mutation in a

  14. Hairless Streaks in Cattle Implicate TSR2 in Early Hair Follicle Formation

    Science.gov (United States)

    Murgiano, Leonardo; Shirokova, Vera; Welle, Monika Maria; Jagannathan, Vidhya; Plattet, Philippe; Oevermann, Anna; Pienkowska-Schelling, Aldona; Gallo, Daniele; Gentile, Arcangelo; Mikkola, Marja; Drögemüller, Cord

    2015-01-01

    Four related cows showed hairless streaks on various parts of the body with no correlation to the pigmentation pattern. The stripes occurred in a consistent pattern resembling the lines of Blaschko. The non-syndromic hairlessness phenotype observed occurred across three generations of a single family and was compatible with an X-linked mode of inheritance. Linkage analysis and subsequent whole genome sequencing of one affected female identified two perfectly associated non-synonymous sequence variants in the critical interval on bovine chromosome X. Both variants occurred in complete linkage disequilibrium and were absent in more than 3900 controls. An ERCC6L missense mutation was predicted to cause an amino acid substitution of a non-conserved residue. Analysis in mice showed no specific Ercc6l expression pattern related to hair follicle development and therefore ERCC6L was not considered as causative gene. A point mutation at the 5'-splice junction of exon 5 of the TSR2, 20S rRNA accumulation, homolog (S. cerevisiae), gene led to the production of two mutant transcripts, both of which contain a frameshift and generate a premature stop codon predicted to truncate approximately 25% of the protein. Interestingly, in addition to the presence of both physiological TSR2 transcripts, the two mutant transcripts were predominantly detected in the hairless skin of the affected cows. Immunohistochemistry, using an antibody against the N-terminal part of the bovine protein demonstrated the specific expression of the TSR2 protein in the skin and the hair of the affected and the control cows as well as in bovine fetal skin and hair. The RNA hybridization in situ showed that Tsr2 was expressed in pre- and post-natal phases of hair follicle development in mice. Mammalian TSR2 proteins are highly conserved and are known to be broadly expressed, but their precise in vivo functions are poorly understood. Thus, by dissecting a naturally occurring mutation in a domestic animal

  15. Method: a single nucleotide polymorphism genotyping method for Wheat streak mosaic virus

    Directory of Open Access Journals (Sweden)

    Rogers Stephanie M

    2012-05-01

    Full Text Available Abstract Background The September 11, 2001 attacks on the World Trade Center and the Pentagon increased the concern about the potential for terrorist attacks on many vulnerable sectors of the US, including agriculture. The concentrated nature of crops, easily obtainable biological agents, and highly detrimental impacts make agroterrorism a potential threat. Although procedures for an effective criminal investigation and attribution following such an attack are available, important enhancements are still needed, one of which is the capability for fine discrimination among pathogen strains. The purpose of this study was to develop a molecular typing assay for use in a forensic investigation, using Wheat streak mosaic virus (WSMV as a model plant virus. Method This genotyping technique utilizes single base primer extension to generate a genetic fingerprint. Fifteen single nucleotide polymorphisms (SNPs within the coat protein and helper component-protease genes were selected as the genetic markers for this assay. Assay optimization and sensitivity testing was conducted using synthetic targets. WSMV strains and field isolates were collected from regions around the world and used to evaluate the assay for discrimination. The assay specificity was tested against a panel of near-neighbors consisting of genetic and environmental near-neighbors. Result Each WSMV strain or field isolate tested produced a unique SNP fingerprint, with the exception of three isolates collected within the same geographic location that produced indistinguishable fingerprints. The results were consistent among replicates, demonstrating the reproducibility of the assay. No SNP fingerprints were generated from organisms included in the near-neighbor panel, suggesting the assay is specific for WSMV. Using synthetic targets, a complete profile could be generated from as low as 7.15 fmoles of cDNA. Conclusion The molecular typing method presented is one tool that could be

  16. Small near-Earth asteroids in the Palomar Transient Factory survey: A real-time streak-detection system

    CERN Document Server

    Waszczak, Adam; Laher, Russ; Masci, Frank; Bue, Brian; Rebbapragada, Umaa; Barlow, Tom; Surace, Jason; Helou, George; Kulkarni, Shrinivas

    2016-01-01

    Near-Earth asteroids (NEAs) in the 1-100 meter size range are estimated to be $\\sim$1,000 times more numerous than the $\\sim$15,000 currently-catalogued NEAs, most of which are in the 0.5-10 kilometer size range. Impacts from 10-100 meter size NEAs are not statistically life-threatening but may cause significant regional damage, while 1-10 meter size NEAs with low velocities relative to Earth are compelling targets for space missions. We describe the implementation and initial results of a real-time NEA-discovery system specialized for the detection of small, high angular rate (visually-streaked) NEAs in Palomar Transient Factory (PTF) images. PTF is a 1.2-m aperture, 7.3-deg$^2$ field-of-view optical survey designed primarily for the discovery of extragalactic transients (e.g., supernovae) in 60-second exposures reaching $\\sim$20.5 visual magnitude. Our real-time NEA discovery pipeline uses a machine-learned classifier to filter a large number of false-positive streak detections, permitting a human scanner t...

  17. Signal-to-noise performance analysis of streak tube imaging lidar systems. II. Theoretical analysis and discussion.

    Science.gov (United States)

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

    2012-12-20

    In the preceding paper (referred to here as paper I), we presented a general signal-to-noise performance analysis of a streak tube imaging lidar (STIL) system within the framework of linear cascaded systems theory. A cascaded model is proposed for characterizing the signal-to-noise performance of a STIL system with an internal or external intensified streak tube receiver. The STIL system can be decomposed into a series of cascaded imaging chains whose signal and noise transfer properties are described by the general (or the spatial-frequency dependent) noise factors (NFs). Equations for the general NFs of the cascaded chains (or the main components) in the STIL system are derived. This work investigates the signal-to-noise performance of an external intensified STIL system. The implementation of the cascaded model for predicting and evaluating the signal-to-noise performance of the external intensified STIL system is described. Some factors that limit the signal-to-noise performance of the external intensified STIL system are analyzed and discussed. PMID:23262623

  18. Transcriptional response of virus-infected cassava and identification of putative sources of resistance for cassava brown streak disease.

    Science.gov (United States)

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

    2014-01-01

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

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

    Indian Academy of Sciences (India)

    Arnab Roy; Umesh Varshney; Debnath Pal

    2014-09-01

    Acidic region streaking (ARS) is one of the lacunae in two-dimensional gel electrophoresis (2DE) of bacterial proteome. This streaking is primarily caused by nucleic acid (NuA) contamination and poses major problem in the downstream processes like image analysis and protein identification. Although cleanup and nuclease digestion are practiced as remedial options, these strategies may incur loss in protein recovery and perform incomplete removal of NuA. As a result, ARS has remained a common observation across publications, including the recent ones. In this work, we demonstrate how ultrasound wave can be used to shear NuA in plain ice-cooled water, facilitating the elimination of ARS in the 2DE gels without the need for any additional sample cleanup tasks. In combination with a suitable buffer recipe, IEF program and frequent paper-wick changing approach, we are able to reproducibly demonstrate the production of clean 2DE gels with improved protein recovery and negligible or no ARS. We illustrate our procedure using whole cell protein extracts from two diverse organisms, Escherichia coli and Mycobacterium smegmatis. Our designed protocols are straightforward and expected to provide good 2DE gels without ARS, with comparable times and significantly lower cost.

  20. Effects of Hot Streak and Phantom Cooling on Heat Transfer in a Cooled Turbine Stage Including Particulate Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Bons, Jeffrey [The Ohio State Univ., Columbus, OH (United States); Ameri, Ali [The Ohio State Univ., Columbus, OH (United States)

    2016-01-08

    The objective of this research effort was to develop a validated computational modeling capability for the characterization of the effects of hot streaks and particulate deposition on the heat load of modern gas turbines. This was accomplished with a multi-faceted approach including analytical, experimental, and computational components. A 1-year no cost extension request was approved for this effort, so the total duration was 4 years. The research effort succeeded in its ultimate objective by leveraging extensive experimental deposition studies complemented by computational modeling. Experiments were conducted with hot streaks, vane cooling, and combinations of hot streaks with vane cooling. These studies contributed to a significant body of corporate knowledge of deposition, in combination with particle rebound and deposition studies funded by other agencies, to provide suitable conditions for the development of a new model. The model includes the following physical phenomena: elastic deformation, plastic deformation, adhesion, and shear removal. It also incorporates material property sensitivity to temperature and tangential-normal velocity rebound cross-dependencies observed in experiments. The model is well-suited for incorporation in CFD simulations of complex gas turbine flows due to its algebraic (explicit) formulation. This report contains model predictions compared to coefficient of restitution data available in the open literature as well as deposition results from two different high temperature turbine deposition facilities. While the model comparisons with experiments are in many cases promising, several key aspects of particle deposition remain elusive. The simple phenomenological nature of the model allows for parametric dependencies to be evaluated in a straightforward manner. This effort also included the first-ever full turbine stage deposition model published in the open literature. The simulations included hot streaks and simulated vane cooling

  1. Clonagem e purificação de fragmento da proteína capsidial de Banana streak OL virus Cloning and purification of Banana streak OL virus coat protein fragment

    OpenAIRE

    Ricardo Lombardi; Ricardo Harakava; Addolorata Colariccio

    2010-01-01

    O objetivo deste trabalho foi clonar e induzir a expressão de fragmento da proteína capsidial de Banana streak OL virus (BSOLV-CP) em Escherichia coli, bem como purificar a proteína recombinante obtida. Empregou-se um par de iniciadores específicos para amplificar, em PCR, um fragmento de aproximadamente 390 pb, da região codificadora da porção central da BSOLV-CP. O fragmento obtido foi clonado em vetor pGEM-T Easy, subclonado em vetor pQE-30 e transformado em células de E. coli M15 (pREP4) ...

  2. Amino acid substitutions of cysteine residues near the amino terminus of Wheat streak mosaic virus HC-Pro abolishes virus transmission by the wheat curl mite

    Science.gov (United States)

    The amino-terminal half of HC-Pro of Wheat streak mosaic virus (WSMV) is required for semi-persistent transmission by the wheat curl mite (Aceria tosichella Keifer). The amino-proximal region of WSMV HC-Pro is cysteine-rich with a zinc finger-like motif. Amino acid substitutions were made in this re...

  3. Isolation and characterization of the mating type locus of Mycosphaerella fijiensis, the causal agent of black leaf streak disease of banana

    NARCIS (Netherlands)

    Conde-Ferráez, L.; Waalwijk, C.; Canto-Canché, B.B.; Kema, G.H.J.; Crous, P.W.; James, A.C.; Abeln, E.C.A.

    2007-01-01

    Idiomorphs mat1-1 and mat1-2 from Mycosphaerella fijiensis, the causal agent of black leaf streak disease of banana, were isolated. Degenerate oligos were used to amplify the HMG box of the mat1-2 idiomorph from M. fijiensis, showing homology with the HMG box of Mycosphaerella graminicola. Using a D

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

    NARCIS (Netherlands)

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

    2010-01-01

    ABSTRACT. We searched the genome of Mycosphaerella fijiensis for molecular markers that would allow population genetics analysis of this plant pathogen. M. fijiensis, the causal agent of banana leaf streak disease, also known as black Sigatoka, is the most devastating pathogen attacking bananas (Mus

  5. Variable Number of Tandem Repeat Markers in the Genome Sequence of Mycosphaerella Fijiensis, the Causal Agent of Black Leaf Streak Disease of Banana (Musa spp.)

    Science.gov (United States)

    Mycosphaerella fijiensis, the causal agent of banana leaf streak disease (commonly known as black Sigatoka), is the most devastating pathogen attacking bananas (Musa spp). Recently the whole genome sequence of M. fijiensis became available. This sequence was screened for the presence of Variable Num...

  6. Molecular interactions and immune responses between maize fine streak virus and the leafhopper vector G. nigrifrons through differential expression and RNA interference

    Science.gov (United States)

    Maize fine streak virus (MFSV) is an emerging virus of maize that is transmitted by an insect vector, the leafhopper called Graminella nigrifrons. Virus transmission by the leafhopper requires that the virus enter into and multiply in insect cells, tissues and organs before being transmitted to a ne...

  7. Realization of an optical multi and mono-channel analyzer, associated to a streak camera. Application to metrology of picosecond low intensity luminous pulses

    International Nuclear Information System (INIS)

    An electronic system including a low light level television tube (Nocticon) to digitize images from streak cameras is studied and realized. Performances (sensibility, signal-to-noise ratio) are studied and compared with a multi-channel analyzer using a linear network of photodiodes. It is applied to duration and amplitude measurement of short luminous pulses

  8. Particle streak velocimetry-OCT (PSV-OCT): a novel method for multi-vector component velocimetry of microscale flow physiology (Conference Presentation)

    Science.gov (United States)

    Zhou, Kevin C.; Huang, Brendan K.; Gamm, Ute A.; Bhandari, Vineet; Khokha, Mustafa K.; Choma, Michael A.

    2016-03-01

    We present a new method for 2.5 and 3 vector component velocimetry. We call this method particle streak velocimetry OCT (PSV-OCT). PSV-OCT generates two-dimensional, 2.5 vector component (v_x,|v_y|,v_z) cross-sectional maps of microscale flow velocity (e.g. biological cilia-driven fluid flow). The enabling insight is that a tracer particle in sparsely-seeded fluid flow traces out streaks in (x,z,t)-space. The streak orientations in x-t and z-t yield v_x and v_z, respectively. The in-plane (x-z plane) residence time yields the out-of-plane speed |v_y|. Vector component values are generated by fitting streaks to a model of image formation. We demonstrate cross-sectional estimation of (v_x,|v_y|,v_z) in two important animal models in ciliary biology: Xenopus embryos (tadpoles) and mouse trachea. Further, by incorporation the assumption of incompressible flow into the estimation process, we are able to generate 3 vector component (v_x,v_y,v_z) estimates in three spatial dimensions from 2.5 vector component measurements taken in parallel OCT planes in 3D space.

  9. cDNA cloning and sequence analysis of genome segments S8 from rice black-streaked dwarf virus

    Institute of Scientific and Technical Information of China (English)

    张恒木; 陈剑平; 薛庆中; 雷娟利

    2002-01-01

    Genome segments S8 of two Chinese isolates of rice black-streaked dwarf virus (RBSDV), one from Zhejiang Province and another from Hebei Province, were amplified by RT-PCR and sequenced. Both segments consisted of 1936 nts in full length (EMBL accession numbers were AJ297431 and AJ297432, respectively) and contained only one big open reading frame which encoded a polypeptide with molecular weight of 68kD. The two Chinese isolates shared 94.0% and 96.5% identity at nucleotide and amino acid level, respectively. They shared 94.5-94.9% and 92.5-92.9% homology with S8 of RBSDV Japanese isolate at nucleotide and amino acid level, respectively; shared 85.1-87.6% and 91.7-91.9% homology with S7 of Italian MRDV (maize rough dwarf virus).

  10. Tracing dynamics of laser-induced fields on ultra-thin foils using complementary imaging with streak deflectometry

    CERN Document Server

    Abicht, Florian; Priebe, Gerd; Koschitzki, Christian; Andreev, Alexander; Nickles, Peter; Sander, Wolfgang; Schnürer, Matthias

    2016-01-01

    We present a detailed study of the electric and magnetic fields, which are created on plasma vacuum interfaces as a result of highly intense laser-matter-interactions. For the field generation ultra-thin polymer foils were irradiated with high intensity femtosecond and picosecond laser pulses with ultra-high contrast. To determine the temporal evolution and the spatial distribution of these fields the proton streak deflectometry method has been developed further and applied in two different imaging configurations. It enabled us to gather complementary information about the investigated field structure, in particular about the influence of different field components (parallel and normal to the target surface) and the impact of a moving ion front. The applied ultra-high laser contrast significantly increased the reproducibility of the experiment and improved the accuracy of the imaging method. In order to explain the experimental observations, which were obtained by applying ultra-short laser pulses, two differ...

  11. Ecological Fitness of Non-vector Planthopper Sogatella furcifera on Rice Plants Infected with Rice Black Streaked Dwarf Virus

    Institute of Scientific and Technical Information of China (English)

    HE Xiao-chan; XU Hong-xing; ZHENG Xu-song; YANG Ya-jun; GAO Guang-chun; PAN Jian-hong; LU Zhong-xian

    2012-01-01

    We evaluated the effects of rice black streak dwarf virus (RBSDV)-infested rice plants on the ecological parameters and its relevant defensive and detoxification enzymes of white-backed planthopper (WBPH) in laboratory for exploring the relationship between RBSDV and the non-vector planthopper.The results showed that nymph survival rate,female adult weight and fecundity,and egg hatchability of WBPH fed on RBSDV-infested rice plants did not markedly differ from those on healthy plants,whereas the female adult longevity and egg duration significantly shortened on diseased plants.Furthermore,significantly higher activities of defensive enzymes (dismutase,catalase and peroxidase) and detoxification enzymes (acetylcholinesterase,carboxylesterase and glutathione S-transferase) were found in WBPH adults fed on infected plants.Results implied that infestation by RBSDV increased the ecological fitness of non-vector planlhopper population.

  12. Terpene Profile, Leaf Anatomy, and Enzyme Activity of Resistant and Susceptible Cocoa Clonesto Vascular Streak Dieback Disease

    Directory of Open Access Journals (Sweden)

    Adi Prawoto

    2014-10-01

    Full Text Available Vascular-streak dieback (VSD, Oncobasidium theobromae is the most prevalent disease of Theobroma cacao L. in Indonesia. This study aims to analyze resistance mechanism to VSD based on terpene profile, leaf anatomy, chitinase, and peroxidase study. Resistant clones of Sulawesi 1 and Sca 6 and susceptible clones of ICS 60 and TSH 858 were used for terpene profile, leaf anatomy analysis, chitinase, peroxides, polyphenol, lignin, and cellulose analysis. Those clones and KEE 2, KKM 22 and ICS 13 were used for peroxides analysis. For trichome study, the resistant clones of Sulawesi 1, Sca 6, KEE 2, and KKM 22, and susceptible clones of ICS 60 and TSH 858 were used. GCMS analysis showed that chromatogram pattern of resistant and susceptible groups were quite similar, but resistant clones contained 22% more components than the susceptible ones. Resistant clones contained groups of pinene, decane, myrcene, and octadecanoic acid, while those substances on usceptible clones were absent. Trichome was thicker on younger leaf, and its density on the basal was higher than that on the middle and tip leaf parts. Trichome density of resistant clone was not always thicker than that of susceptible ones. On resistant clones, stomatal density was lower and width of stomate pits was narrower, while thickness of epidermis layer and pallisade parenchym were higher. Polyphenol content of resistant clones were higher but lignin and cellulose of both groups were similar. Chitinase activity which has a role in hydrolysis of mycelia cell wall was higher on the resistant clones, but peroxides which has a role in polymeration of lignin biosynthesis was similar between both groups. It is concluded that groups of terpene pinene, decane, myrcene, and octadecanoic acid, thickness of leaf epidermis, density and width of stomata pit, and chitinase activity plays important role in cocoa resistance to VSD. Key words: Theobroma cacaoL., clone, vascular-streak dieback, resistance, leaf

  13. Yield performance of the cocoa clones of Sca 6 and DRC 15 resistant to vascular-streak dieback

    Directory of Open Access Journals (Sweden)

    Agung Wahyu Susilo

    2009-08-01

    Full Text Available Selection on cocoa resistance to vascular-streak dieback (VSD has identified some resistant clones for breeding purposes. Of the resistant clones, it was selected Sca 6 and DRC 15 which performing good potential for yield. This paper reports results on testing yield potential of the clones in separate trials. Sca 6 was tested in Kottablater Estate (dry climate in the altitude of ± 25 m asl. and DRC 15 was tested in Mumbulsari Estate (dry climate in the altitude of ± 45 m asl. both are in Jember. Trials were arranged in the randomized complete block design with 4 blocks. Evaluation for yield performance was conducted during 6 years of harvest and stability performance was analyzed in regression term using year of harvest as the index. The results indicate the yield potential of the clones was quite similar in the level of 1.4 kg/plant and performing stability during evaluation and good adaptability in the location. The yield potential was lower than the high yielding clones but use of Sca 6 and DRC 15 in heavily infasted VSD area should be considered than using of the susceptible clones. Sca 6 performed low potential on a dry-weight bean in the range of 0.65—0.86 g (class C of quality standard but better performance could be found in the wet area. DRC 15 performed good potential on a dryweight bean of 1.16 g (class AA of quality standard. Fat content analysis of Sca 6 indicate a better performance of beans which grown up in the wet area (58.2% than in the dry area (49.6%. It was reported the fat content potential of DRC 15 in the level of 50.4%. Key words: Yield performance, vascular-streak dieback, resistant clone, Theobroma cacao L.

  14. Identification and Removal of High Frequency Temporal Noise in a Nd:YAG Macro-Pulse Laser Assisted with a Diagnostic Streak Camera

    Energy Technology Data Exchange (ETDEWEB)

    Kent Marlett, Bechtel Nevada; Ke-Xun Sun Bechtel Nevada

    2004-09-23

    This paper discusses the use of a reference streak camera (SC) to diagnose laser performance and guide modifications to remove high frequency noise from Bechtel Nevada's long-pulse laser. The upgraded laser exhibits less than 0.1% high frequency noise in cumulative spectra, exceeding National Ignition Facility (NIF) calibration specifications. Inertial Confinement Fusion (ICF) experiments require full characterization of streak cameras over a wide range of sweep speeds (10 ns to 480 ns). This paradigm of metrology poses stringent spectral requirements on the laser source for streak camera calibration. Recently, Bechtel Nevada worked with a laser vendor to develop a high performance, multi-wavelength Nd:YAG laser to meet NIF calibration requirements. For a typical NIF streak camera with a 4096 x 4096 pixel CCD, the flat field calibration at 30 ns requires a smooth laser spectrum over 33 MHz to 68 GHz. Streak cameras are the appropriate instrumentation for measuring laser amplitude noise at these very high frequencies since the upper end spectral content is beyond the frequency response of typical optoelectronic detectors for a single shot pulse. The SC was used to measure a similar laser at its second harmonic wavelength (532 nm), to establish baseline spectra for testing signal analysis algorithms. The SC was then used to measure the new custom calibration laser. In both spatial-temporal measurements and cumulative spectra, 6-8 GHz oscillations were identified. The oscillations were found to be caused by inter-surface reflections between amplifiers. Additional variations in the SC spectral data were found to result from temperature instabilities in the seeding laser. Based on these findings, laser upgrades were made to remove the high frequency noise from the laser output.

  15. Clonagem e purificação de fragmento da proteína capsidial de Banana streak OL virus Cloning and purification of Banana streak OL virus coat protein fragment

    Directory of Open Access Journals (Sweden)

    Ricardo Lombardi

    2010-08-01

    Full Text Available O objetivo deste trabalho foi clonar e induzir a expressão de fragmento da proteína capsidial de Banana streak OL virus (BSOLV-CP em Escherichia coli, bem como purificar a proteína recombinante obtida. Empregou-se um par de iniciadores específicos para amplificar, em PCR, um fragmento de aproximadamente 390 pb, da região codificadora da porção central da BSOLV-CP. O fragmento obtido foi clonado em vetor pGEM-T Easy, subclonado em vetor pQE-30 e transformado em células de E. coli M15 (pREP4 por choque térmico. A expressão da proteína foi induzida por tiogalactopiranosídeo de isopropila (IPTG, e a proteína recombinante BSOLV-rcCP de 14 kDa foi detectada em Western blot e Dot blot. A expressão da proteína BSOLV-rcCP abre novas possibilidades para a obtenção de antígenos para a produção de antissoros contra o BSOLV.The objective of this work was to clone and to induce the expression of a fragment of Banana streak OL virus coat protein (BSOLV-CP in Escherichia coli, as well as to purify the obtained recombinant protein. Two specific primers were used for the PCR-amplification of approximately 390-bp fragment of the codifying region of the BSOLV-CP central portion. The obtained fragment was cloned in pGEM-T Easy vector, subcloned in pQE-30 expression vector and transformed into competent E. coli M15 (pREP4 cells by heat shock. The protein expression was induced by isopropyl thiogalactopyranoside (IPTG and the 14-kDa BSOLV-rcCP recombinant protein was detected in Western and Dot blotting. The expression of the BSOLV-rcCP protein enables new approaches to the obtention of antigens for the antisera production against BSOLV.

  16. Dynamic prop erties of a small-size streak tube%超小型条纹管的动态特性研究

    Institute of Scientific and Technical Information of China (English)

    惠丹丹; 田进寿; 王俊锋; 卢裕; 温文龙; 徐向晏

    2016-01-01

    Scannerless (flash) lidar system based on streak camera is able to realize three-dimensional (3D) multi-spectral fluorescence imaging and 3D imaging polarimetry. Compared with conventional lidar system, the flash lidar system overcomes image distortions caused by the motion between the target and the sensor platform. Other advantages of the flash lidar system are higher image update rates and the potential for creating a miniaturized lidar system. To meet the requirements for developing this new technology, a super small-sized, large photocathode area and meshless streak tube with spherical cathode and screen is designed with the aid of computer simulation technology (CST) software. The tube with nearly 28 mm wide photocathode work area contains two electrostatic focusing lens, a pair of deflection plates, and a 50 mm diameter output screen. The external dimension of the tube is merely 50 mm × 100 mm. And its electromagnetic fields are calculated in the CST Particle Studio based on the finite integration theory. Some dynamic properties of the tube are analyzed via observing different electron trajectories launched from a number of different points on the cathode. The influences of the deflector position on deflection sensitivity and spatial resolution are analyzed. Increasing the distance between the deflector and the anode pin hole leads to a worse deflection sensitivity but a better spatial resolution. As for the temporal resolution, three electron pulses separated by 30 ps can be well resolved by the streak tube in the dynamic mode. Thus, the dynamic temporal resolution of the streak tube is better than 30 ps. And a 10 lp/mm spatial resolution across the 28 mm long slit on the photocathode can be obtained by estimating modulation transfer functions of the electron trajectories. Temporal distortions at the entire photocathode working area are evaluated, and the data reveal that the larger the photocathode working area, the bigger the temporal distortions are

  17. A multi-wavelength streak-optical-pyrometer for warm-dense matter experiments at NDCX-I and NDCX-II

    International Nuclear Information System (INIS)

    We report on a multi-wavelength streak-optical-pyrometer (SOP) developed the for warm-dense-matter (WDM) experiments at the existing NDCX-I facility and the NDCX-II facility currently being commissioned at LBNL. The SOP served as the primary temperature diagnostic in the recent NDCX-I experiments, in which an intense K+ beam was used to heat different metal samples into WDM states. The SOP consists of a spectral grating (visible and near-infrared spectral range) and a fast, high-dynamic-range optical streak camera. The instrument is calibrated absolutely with a NIST-traceable tungsten ribbon lamp and can itself be considered as an absolutely calibrated, time-resolving spectrometer. The sample temperature is determined from fitting the recorded thermal spectrum into the Planck formula multiplied by a model of emissivity

  18. Tobacco streak virus (strain dahlia) suppresses post-transcriptional gene silencing of flavone synthase II in black dahlia cultivars and causes a drastic flower color change.

    OpenAIRE

    Deguchi, Ayumi; Tatsuzawa, Fumi; Hosokawa, Munetaka; Doi, Motoaki; Ohno, Sho

    2015-01-01

    Tobacco streak virus suppressed post-transcriptional gene silencing and caused a flower color change in black dahlias, which supported the role of cyanidin-based anthocyanins for black flower appearance. Black flower color of dahlia (Dahlia variabilis) has been attributed, in part, to the high accumulation of cyanidin-based anthocyanins that occurs when flavone synthesis is reduced because of post-transcriptional gene silencing (PTGS) of flavone synthase II (DvFNS). There are also purple-flow...

  19. GFP is Efficiently Expressed by Wheat Streak Mosaic Virus Using a Range of Tritimovirus NIa Cleavage Sites and Forms Dense Aggregates in Cereal Hosts

    Science.gov (United States)

    Wheat streak mosaic virus (WSMV)-based transient expression vector was developed to express GFP as a marker protein. The GFP cistron was engineered between the P1 and HC-Pro cistrons in an infectious cDNA clone of WSMV. The cleavage sites, P3/6KI, 6KI/CI, NIa/NIb, or NIb/CP, from WSMV were fused to ...

  20. The use and calibration of read-out streaks to increase the dynamic range of the Swift Ultraviolet/Optical Telescope

    CERN Document Server

    Page, M J; Breeveld, A A; Hancock, B; Holland, S T; Marshall, F E; Oates, S; Roming, P W A; Siegel, M H; Smith, P J; Carter, M; De Pasquale, M; Symeonidis, M; Yershov, V; Beardmore, A P

    2013-01-01

    The dynamic range of photon counting micro-channel-plate (MCP) intensified charged-coupled device (CCD) instruments such as the Swift Ultraviolet/Optical Telescope (UVOT) and the XMM-Newton Optical Monitor (XMM-OM) is limited at the bright end by coincidence loss, the superposition of multiple photons in the individual frames recorded by the CCD. Photons which arrive during the brief period in which the image frame is transferred for read out of the CCD are displaced in the transfer direction in the recorded images. For sufficiently bright sources, these displaced counts form read-out streaks. Using UVOT observations of Tycho-2 stars, we investigate the use of these read-out streaks to obtain photometry for sources which are too bright (and hence have too much coincidence loss) for normal aperture photometry to be reliable. For read-out-streak photometry, the bright-source limiting factor is coincidence loss within the MCPs rather than the CCD. We find that photometric measurements can be obtained for stars u...

  1. Dot Immunobinding Assay Method with Chlorophyll Removal for the Detection of Southern Rice Black-Streaked Dwarf Virus

    Directory of Open Access Journals (Sweden)

    Linhong Jin

    2012-06-01

    Full Text Available Southern rice black-streaked dwarf virus (SRBSDV, a new virus from Fiji, has seriously damaged rice crops in southern China and northern Vietnam in recent years. This virus is difficult to diagnose in the early stages of infection, and is very destructive at the late stage. In the present study, a dot immunobinding assay (DIBA that has a high sensitivity for diagnosing SRBSDV was developed. Two kinds of treatment for the DIBA were evaluated to determine the most effective one for removing chlorophyll interferences via rice extraction. The first included several reagents to remove chlorophyll, namely, the alkaline reagents like magnesium oxide and alumina oxide, the adsorbent reagents like activated carbon and bentonite, as well as the extraction agent acetone. The second and third treatments, which were used to remove chlorophyll in blot membrane-nitrocellulose and polyvinylidene fluoride (PVDF, included several organic solvents containing methanol, ethanol, acetone, ethyl acetate, and diethyl ether. The results showed that activated carbon and methanol yielded the best contrasting purple color for the infected samples by decreasing the chlorophyll content.

  2. Novel insights into the historical biogeography of the streak-breasted scimitar babbler complex (Aves:Timaliidae:Pomatorhinus ruficollis complex)

    Institute of Scientific and Technical Information of China (English)

    Sushma REDDY; rpd S NYRI

    2015-01-01

    The Streak-breasted Scimitar Babblers of thePomatorhinus ruficollis species complex are found in most of the fo-rested habitats across southern and eastern Asia. The diversification history of this group is obscured by high plumage variation across populations and conflicting genetic signal across loci. We combined genetic and geographic data from several recent stu-dies to investigate how these species diversified across China using both phylogenetic and ecological niche modeling analyses. These two lines of evidence are consistent in showing that two well-sampled species,P. reconditus andP. nigrostellatus,in cen-tral and southern China respectively, likely experienced a history of isolation and expansion as suitable habitat contracted during the last interglacial and expanded in patchy extent during the glacial maximum. The genetic analysis showed that populations ofP. nigrostellatus on Hainan Island are very similar to the ones in nearby mainland southern China. We recovered two well-supported clades withinP. reconditus that were not geographically structured with both containing individuals from the same localities across central China. This phylogenetic result corresponded to the ecological niche models that showed expansion from refugia since the last interglacial. This study illustrates the value of using an integrative approach and detailed geographic sampling to help understand the recent diversification of birds in China [Current Zoology 61 (5): 910–921, 2015].

  3. Streaked optical pyrometry of ion heated compound targets in the study of plasma mix at high density interfaces

    Science.gov (United States)

    Dyer, Gilliss; Roycroft, Rebecca; Wagner, Craig; Bernstein, Aaron; Ditmire, Todd; Hegelich, B. Manuel; Albright, Brian; Fernández, Juan; Bang, Woosuk; Bradley, Paul; Gautier, D. Cort; Hamilton, Christopher; Palaniyappan, Sasi; Santiago Cordoba, Miguel; Vold, Erik; Lin, Yin

    2015-11-01

    The interaction and mixing of different species of plasma at high energy density is of fundamental interest for HED physics and relevant to inertial confinement fusion. An ongoing campaign is underway at the Trident laser facility to study the dynamics at the interface of high and low atomic number materials under warm dense matter conditions. The experiments utilize laser-accelerated ions, such as aluminum, to flash heat solid targets to temperatures >1 eV. We report on streaked pyrometry measurements made in a recent experimental run, which shed light on the dynamics of heating induced in various target materials by these ion sources. Timescale as well as spatial extent of the heating can vary greatly depending on the dominant ion species and spectra. This work was supported by NNSA cooperative agreement DE-NA0002008 and the Los Alamos National Laboratory Directed Research and Development Program under the auspices of the U.S. DOE NNSAS, LLC, Los Alamos National Laboratory under Contract No. DE-AC52-06.

  4. Light field driven streak-camera for single-shot measurements of the temporal profile of XUV-pulses from a free-electron laser; Lichtfeld getriebene Streak-Kamera zur Einzelschuss Zeitstrukturmessung der XUV-Pulse eines Freie-Elektronen Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Fruehling, Ulrike

    2009-10-15

    The Free Electron Laser in Hamburg (FLASH) is a source for highly intense ultra short extreme ultraviolet (XUV) light pulses with pulse durations of a few femtoseconds. Due to the stochastic nature of the light generation scheme based on self amplified spontaneous emission (SASE), the duration and temporal profile of the XUV pulses fluctuate from shot to shot. In this thesis, a THz-field driven streak-camera capable of single pulse measurements of the XUV pulse-profile has been realized. In a first XUV-THz pump-probe experiment at FLASH, the XUV-pulses are overlapped in a gas target with synchronized THz-pulses generated by a new THz-undulator. The electromagnetic field of the THz light accelerates photoelectrons produced by the XUV-pulses with the resulting change of the photoelectron momenta depending on the phase of the THz field at the time of ionisation. This technique is intensively used in attosecond metrology where near infrared streaking fields are employed for the temporal characterisation of attosecond XUV-Pulses. Here, it is adapted for the analysis of pulse durations in the few femtosecond range by choosing a hundred times longer far infrared streaking wavelengths. Thus, the gap between conventional streak cameras with typical resolutions of hundreds of femtoseconds and techniques with attosecond resolution is filled. Using the THz-streak camera, the time dependent electric field of the THz-pulses was sampled in great detail while on the other hand the duration and even details of the time structure of the XUV-pulses were characterized. (orig.)

  5. Tomato yellow vein streak virus: relationship with Bemisia tabaci biotype B and host range Tomato yellow vein streak virus: interação com a Bemisia tabaci biótipo B e gama de hospedeiros

    Directory of Open Access Journals (Sweden)

    Ana Carolina Firmino

    2009-12-01

    Full Text Available The Tomato yellow vein streak virus (ToYVSV is a putative species of begomovirus, which was prevalent on tomato crops in São Paulo State, Brazil, until 2005. The objectives of this study were to evaluate the interaction between ToYVSV and its vector Bemisia tabaci biotype B and to identify alternative hosts for the virus. The minimum acquisition and inoculation access periods of ToYVSV by B. tabaci were 30 min and 10 min, respectively. Seventy five percent of tomato-test plants were infected when the acquisition and inoculation access periods were 24 h. The latent period of the virus in the insect was 16 h. The ToYVSV was retained by B. tabaci until 20 days after acquisition. First generation of adult whiteflies obtained from viruliferous females were virus free as shown by PCR analysis and did not transmit the virus to tomato plants. Out of 34 species of test-plants inoculated with ToYVSV only Capsicum annuum, Chenopodium amaranticolor, C. quinoa, Datura stramonium, Gomphrena globosa, Nicotiana clevelandii and N. tabacum cv. TNN were susceptible to infection. B. tabaci biotype B was able to acquire the virus from all these susceptible species, transmitting it to tomato plants.O Tomato yellow vein streak virus (ToYVSV é uma espécie putativa de begomovirus que infecta o tomateiro (Solanum lycopersicon em diversas regiões do Brasil onde se cultiva essa solanácea, sendo a espécie prevalente no estado de São Paulo até 2005. Estudou-se a interação do ToYVSV com a Bemisia tabaci biótipo B e identificaram-se hospedeiras alternativas deste vírus. Os períodos de acesso mínimo de aquisição (PAA e de inoculação (PAI foram de 30 min e 10 min, respectivamente. A porcentagem de plantas infectadas chegou até cerca de 75% após um PAA e PAI de 24 h. O período de latência do vírus no vetor foi de 16 horas. O ToYVSV foi retido pela B. tabaci até 20 dias após a aquisição do vírus. Não foi detectada transmissão do vírus para prog

  6. Dual transcriptome analysis reveals insights into the response to Rice black-streaked dwarf virus in maize

    Science.gov (United States)

    Zhou, Yu; Xu, Zhennan; Duan, Canxing; Chen, Yanping; Meng, Qingchang; Wu, Jirong; Hao, Zhuanfang; Wang, Zhenhua; Li, Mingshun; Yong, Hongjun; Zhang, Degui; Zhang, Shihuang; Weng, Jianfeng; Li, Xinhai

    2016-01-01

    Maize rough dwarf disease (MRDD) is a viral infection that results in heavy yield losses in maize worldwide, particularly in the summer maize-growing regions of China. MRDD is caused by the Rice black-streaked dwarf virus (RBSDV). In the present study, analyses of microRNAs (miRNAs), the degradome, and transcriptome sequences were used to elucidate the RBSDV-responsive pathway(s) in maize. Genomic analysis indicated that the expression of three non-conserved and 28 conserved miRNAs, representing 17 known miRNA families and 14 novel miRNAs, were significantly altered in response to RBSDV when maize was inoculated at the V3 (third leaf) stage. A total of 99 target transcripts from 48 genes of 10 known miRNAs were found to be responsive to RBSDV infection. The annotations of these target genes include a SQUAMOSA promoter binding (SPB) protein, a P450 reductase, an oxidoreductase, and a ubiquitin-related gene, among others. Characterization of the entire transcriptome suggested that a total of 28 and 1085 differentially expressed genes (DEGs) were detected at 1.5 and 3.0 d, respectively, after artificial inoculation with RBSDV. The expression patterns of cell wall- and chloroplast-related genes, and disease resistance- and stress-related genes changed significantly in response to RBSDV infection. The negatively regulated genes GRMZM2G069316 and GRMZM2G031169, which are the target genes for miR169i-p5 and miR8155, were identified as a nucleolin and a NAD(P)-binding Rossmann-fold superfamily protein in maize, respectively. The gene ontology term GO:0003824, including GRMZM2G031169 and other 51 DEGs, was designated as responsive to RBSDV. PMID:27493226

  7. Introgression of chromosome segments from multiple alien species in wheat breeding lines with wheat streak mosaic virus resistance.

    Science.gov (United States)

    Ali, N; Heslop-Harrison, Js Pat; Ahmad, H; Graybosch, R A; Hein, G L; Schwarzacher, T

    2016-08-01

    Pyramiding of alien-derived Wheat streak mosaic virus (WSMV) resistance and resistance enhancing genes in wheat is a cost-effective and environmentally safe strategy for disease control. PCR-based markers and cytogenetic analysis with genomic in situ hybridisation were applied to identify alien chromatin in four genetically diverse populations of wheat (Triticum aestivum) lines incorporating chromosome segments from Thinopyrum intermedium and Secale cereale (rye). Out of 20 experimental lines, 10 carried Th. intermedium chromatin as T4DL*4Ai#2S translocations, while, unexpectedly, 7 lines were positive for alien chromatin (Th. intermedium or rye) on chromosome 1B. The newly described rye 1RS chromatin, transmitted from early in the pedigree, was associated with enhanced WSMV resistance. Under field conditions, the 1RS chromatin alone showed some resistance, while together with the Th. intermedium 4Ai#2S offered superior resistance to that demonstrated by the known resistant cultivar Mace. Most alien wheat lines carry whole chromosome arms, and it is notable that these lines showed intra-arm recombination within the 1BS arm. The translocation breakpoints between 1BS and alien chromatin fell in three categories: (i) at or near to the centromere, (ii) intercalary between markers UL-Thin5 and Xgwm1130 and (iii) towards the telomere between Xgwm0911 and Xbarc194. Labelled genomic Th. intermedium DNA hybridised to the rye 1RS chromatin under high stringency conditions, indicating the presence of shared tandem repeats among the cereals. The novel small alien fragments may explain the difficulty in developing well-adapted lines carrying Wsm1 despite improved tolerance to the virus. The results will facilitate directed chromosome engineering producing agronomically desirable WSMV-resistant germplasm.

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

    Science.gov (United States)

    Swanson, Maud M.; Ansel-McKinney, Patricia; Houser-Scott, Felicia; Yusibov, Vidadi; Loesch-Fries, L. Sue; Gehrke, Lee

    1998-01-01

    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 protein will activate AMV RNA replication and vice versa. Although AMV and TSV coat proteins have little obvious amino acid homology, we recently reported that they share an N-terminal RNA binding consensus sequence (Ansel-McKinney et al., EMBO J. 15:5077–5084, 1996). Here, we biochemically compare the binding of chemically synthesized peptides that include the consensus RNA binding sequence and lysine-rich (AMV) or arginine-rich (TSV) environment to 3′-terminal TSV and AMV RNA fragments. The arginine-rich TSV coat protein peptide binds viral RNA with lower affinity than the lysine-rich AMV coat protein peptides; however, the ribose moieties protected from hydroxyl radical attack by the two different peptides are localized in the same area of the predicted RNA structures. When included in an infectious inoculum, both AMV and TSV 3′-terminal RNA fragments inhibited AMV RNA replication, while variant RNAs unable to bind coat protein did not affect replication significantly. The data suggest that RNA binding and genome activation functions may reside in the consensus RNA binding sequence that is apparently unique to AMV and ilarvirus coat proteins. PMID:9525649

  9. Foraging spots of streaked shearwaters in relation to ocean surface currents as identified using their drift movements

    Science.gov (United States)

    Yoda, Ken; Shiomi, Kozue; Sato, Katsufumi

    2014-03-01

    Ocean currents are in continuous motion and strongly influence oceanic ecosystems. In situ observation of currents is of primary importance for understanding how marine animals respond to ocean surface currents at various scales and for realizing effective ecosystem-based management and realistic oceanographic modelling. We developed a new method for obtaining in situ current measurements by using seabirds as Lagrangian current sensors akin to drifting buoys. We deployed high-resolution global positioning system (GPS) loggers on streaked shearwaters (Calonectris leucomelas) foraging in the Oyashio-Tsugaru Warm Current confluence in Japan, which is one of the most productive oceans in the world. The seabirds repeatedly performed foraging trips, including searching for prey and resting on the sea surface, over several hundred kilometres. The seabirds spent half of their time resting on the water surface and tended to be passive drifters. We inferred that the drift movements of C. leucomelas provided a direct and detailed description of the ocean surface currents, because currents deduced from their drift movements were in good agreement with ocean surface currents derived from in situ and satellite data. In addition, we extracted details of shearwaters’ intense searching flights associated with feeding (i.e. foraging spots) from GPS tracks. C. leucomelas did not forage at the core of anticyclonic eddies; rather, they used the boundary areas between eddies and the edge of eddies where primary productivity and prey density are thought to be high. Our study demonstrated that animal-borne GPS data can provide a detailed and cost-efficient tool for observing ocean surface currents and can reveal the ways in which marine animals respond to these currents at a fine scale.

  10. Development of a novel cross-streaking method for isolation, confirmation, and enumeration of Salmonella from irrigation ponds.

    Science.gov (United States)

    Luo, Zhiyao; Gu, Ganyu; Giurcanu, Mihai C; Adams, Paige; Vellidis, George; van Bruggen, Ariena H C; Wright, Anita C

    2014-06-01

    The 2013 Produce Safety Rules in Food Safety Modernization Act (FSMA) require regular testing for generic Escherichia coli in agricultural water intended for pre-harvest contact with the edible portion of fresh produce. However, the use of fecal contamination indicators frequently does not correctly reflect distribution of foodborne pathogens such as Salmonella enterica, and ensuring food safety may require direct detection and enumeration of pathogens in agricultural settings. Herein we report the evaluation of different cost-effective methods for quantification, isolation, and confirmation of Salmonella in irrigation pond water and sediment samples. A most probably number (MPN) dual enrichment culture method was used in combination with differential and selective agars, XLT4 and CHROMagar™ Salmonella plus (CSP). The necessity for PCR confirmation was evaluated, and methods were compared by cost and performance measures (i.e., sensitivity, specificity, positive predictive value, and negative predictive value). Statistical analyses showed that using XLT4 as the initial selective agar to isolate Salmonella colonies improved recovery compared to CSP agar; however, PCR confirmation was required to avoid false positive results on either agar. Therefore, a novel cross-streaking method utilizing CHROMagar™ agar for individual colony confirmation of Salmonella presence/absence on XLT4 was developed. This method classifies the colony as positive if typical Salmonella appearance is observed on both agars. Statistical analysis showed that this method was as effective as PCR for species confirmation of pure individual strains isolated from enrichment cultures (sensitivity=0.99, specificity=1.00, relative to PCR). This method offers a cost-effective alternative to PCR that would increase the capacity and sensitivity of Salmonella evaluation. PMID:24732066

  11. Evidence of ice crystal growth within mixed phase clouds along fall streaks - a radar observation case study

    Science.gov (United States)

    Pfitzenmaier, Lukas; Dufournet, Yann; Unal, Christine; Russchenberg, Herman

    2016-04-01

    Mixed phase clouds contain both ice particles and super-cooled cloud water droplets in the same volume of air. Currently, one of the main challenges is to observe and understand how ice particles grow by interacting with liquid water within the mixed-phase clouds. In the mid latitudes this process is one of the most efficient processes for precipitation formation. The case study presented here is based on observations obtained with the Transportable Atmospheric RAdar (TARA), S-band precipitation radar profiler, from Delft University of Technology during the Analysis of the Composition of mixed-phase Clouds with Extended Polarization Techniques campaign (ACCEPT) at Cabauw The Netherlands, autumn 2014. The high temporal (3 seconds) and spatial resolutions (21 m) as well as the Doppler and polarimetric capabilities of TARA are used to estimate size and shape information of the measured hydrometeors. In addition, the unique 3 beam configuration of TARA provides 3-D dynamical information within the cloud system. Based on the dynamical information it is possible to retrieve the fall steak signatures of falling ice particles within radar measurements. Those signatures allow to follow particle population from their generation (at cloud top) to their disintegration. So this technique offers a new perspective for cloud microphysical evolution studies. Using retrieved profiles of radar moments and spectral information along the fall streaks, microphysical information are estimated leading to a better understanding of the influence of super-cooled liquid layer on ice crystals growth under ambient conditions. A synergetic setup of instruments during the ACCEPT campaign was used to liquid layers within the cloud system. So several type of ice crystal growth processes could be detected and will be presented and discussed.

  12. The effect of strong pitch angle scattering on the use of artificial auroral streaks for echo detection - Echo 5

    Science.gov (United States)

    Swanson, R. L.; Steffen, J. E.; Winckler, J. R.

    1986-05-01

    During the Echo 5 experiment, launched November 13, 1979 from the Poker Flat Research Range (Fairbanks, AK), a 0.75 A, 37 keV electron beam was injected both up and down the field line. The objective of the experiment was to test the use of optical and X-ray methods to detect the beam as it interacted with the atmosphere below the rocket for both the downward injections (markers) and the upward injected electrons which mirrored at the Southern Hemisphere and returned echoes. A ground-based TV system, rocket-borne photometers, and X-ray detectors viewed the interaction region. The artificial auroral streaks created by the markers were easily visible on the ground TV system but the large intensity of photons produced around the rocket masked any response to the markers by the on-board photometers and X-ray detectors. No echoes were detected with any of the detection systems although the power in some of the upward injections was 7.6 times the power in a detected downward injection, thus setting an upper limit on the loss-cone echo flux. The magnitude of the bounce averaged pitch-angle-diffusion coefficient necessary to explain the lack of observable echoes was found to be 0.0004/s. Comparison with calculations done by Lyons (1974) for the pitch angle diffusion of electrons by electrostatic waves revealed that an equatorial wave electric field of 11 mV/m would account for the lack of echoes. Such fields should cause strong pitch angle scattering of up to 10 keV natural electrons and thus be consistent with the presence of diffuse aurora on the Echo 5 trajectory. Direct measurements have also revealed such fields in equatorial regions.

  13. Dual transcriptome analysis reveals insights into the response to Rice black-streaked dwarf virus in maize.

    Science.gov (United States)

    Zhou, Yu; Xu, Zhennan; Duan, Canxing; Chen, Yanping; Meng, Qingchang; Wu, Jirong; Hao, Zhuanfang; Wang, Zhenhua; Li, Mingshun; Yong, Hongjun; Zhang, Degui; Zhang, Shihuang; Weng, Jianfeng; Li, Xinhai

    2016-08-01

    Maize rough dwarf disease (MRDD) is a viral infection that results in heavy yield losses in maize worldwide, particularly in the summer maize-growing regions of China. MRDD is caused by the Rice black-streaked dwarf virus (RBSDV). In the present study, analyses of microRNAs (miRNAs), the degradome, and transcriptome sequences were used to elucidate the RBSDV-responsive pathway(s) in maize. Genomic analysis indicated that the expression of three non-conserved and 28 conserved miRNAs, representing 17 known miRNA families and 14 novel miRNAs, were significantly altered in response to RBSDV when maize was inoculated at the V3 (third leaf) stage. A total of 99 target transcripts from 48 genes of 10 known miRNAs were found to be responsive to RBSDV infection. The annotations of these target genes include a SQUAMOSA promoter binding (SPB) protein, a P450 reductase, an oxidoreductase, and a ubiquitin-related gene, among others. Characterization of the entire transcriptome suggested that a total of 28 and 1085 differentially expressed genes (DEGs) were detected at 1.5 and 3.0 d, respectively, after artificial inoculation with RBSDV. The expression patterns of cell wall- and chloroplast-related genes, and disease resistance- and stress-related genes changed significantly in response to RBSDV infection. The negatively regulated genes GRMZM2G069316 and GRMZM2G031169, which are the target genes for miR169i-p5 and miR8155, were identified as a nucleolin and a NAD(P)-binding Rossmann-fold superfamily protein in maize, respectively. The gene ontology term GO:0003824, including GRMZM2G031169 and other 51 DEGs, was designated as responsive to RBSDV. PMID:27493226

  14. Introgression of chromosome segments from multiple alien species in wheat breeding lines with wheat streak mosaic virus resistance.

    Science.gov (United States)

    Ali, N; Heslop-Harrison, Js Pat; Ahmad, H; Graybosch, R A; Hein, G L; Schwarzacher, T

    2016-08-01

    Pyramiding of alien-derived Wheat streak mosaic virus (WSMV) resistance and resistance enhancing genes in wheat is a cost-effective and environmentally safe strategy for disease control. PCR-based markers and cytogenetic analysis with genomic in situ hybridisation were applied to identify alien chromatin in four genetically diverse populations of wheat (Triticum aestivum) lines incorporating chromosome segments from Thinopyrum intermedium and Secale cereale (rye). Out of 20 experimental lines, 10 carried Th. intermedium chromatin as T4DL*4Ai#2S translocations, while, unexpectedly, 7 lines were positive for alien chromatin (Th. intermedium or rye) on chromosome 1B. The newly described rye 1RS chromatin, transmitted from early in the pedigree, was associated with enhanced WSMV resistance. Under field conditions, the 1RS chromatin alone showed some resistance, while together with the Th. intermedium 4Ai#2S offered superior resistance to that demonstrated by the known resistant cultivar Mace. Most alien wheat lines carry whole chromosome arms, and it is notable that these lines showed intra-arm recombination within the 1BS arm. The translocation breakpoints between 1BS and alien chromatin fell in three categories: (i) at or near to the centromere, (ii) intercalary between markers UL-Thin5 and Xgwm1130 and (iii) towards the telomere between Xgwm0911 and Xbarc194. Labelled genomic Th. intermedium DNA hybridised to the rye 1RS chromatin under high stringency conditions, indicating the presence of shared tandem repeats among the cereals. The novel small alien fragments may explain the difficulty in developing well-adapted lines carrying Wsm1 despite improved tolerance to the virus. The results will facilitate directed chromosome engineering producing agronomically desirable WSMV-resistant germplasm. PMID:27245423

  15. Analysis of the distribution and structure of integrated Banana streak virus DNA in a range of Musa cultivars.

    Science.gov (United States)

    Geering, A D; Olszewski, N E; Dahal, G; Thomas, J E; Lockhart, B E

    2001-07-01

    Summary Banana streak virus strain OL (BSV-OL) commonly infects new Musa hybrids, and this infection is thought to arise de novo from integrated virus sequences present in the nuclear genome of the plant. Integrated DNA (Musa6+8 sequence) containing the whole genome of the virus has previously been cloned from cv. Obino l'Ewai (Musa AAB group), a parent of many of the hybrids. Using a Southern blot hybridization assay, we have examined the distribution and structure of integrated BSV-OL sequences in a range of Musa cultivars. For cv. Obino l'Ewai, almost every restriction fragment hybridizing to BSV-OL was predicted from the Musa6+8 sequence, suggesting that this is the predominant type of BSV-OL integrant in the genome. Furthermore, since only two junction fragments of Musa/BSV sequence were detected, and the Musa6+8 sequence is believed to be integrated as multiple copies in a tandem array, then the internal Musa spacer sequences must be highly conserved. Similarly sized restriction fragments were detected in four BB group cultivars, but not in six AA or AAA group cultivars, suggesting that the BSV-OL sequences are linked to the B-genome of Musa. We also provide evidence that cv. Williams (Musa AAA group) contains a distinct badnavirus integrant that is closely related to the 'dead' virus integrant previously characterized from Calcutta 4 (Musa acuminata ssp. burmannicoides). Our results suggest that the virus integrant from cv. Williams is linked to the A-genome, and the complexity of the hybridization patterns suggest multiple sites of integration and/or variation in sequence and structure of the integrants. PMID:20573008

  16. Range Resolution of a Streak Tube Imaging Lidar System%条纹管成像激光雷达距离分辨率

    Institute of Scientific and Technical Information of China (English)

    赵文; 韩绍坤

    2013-01-01

    通过参数估计方法对条纹管成像激光雷达的距离分辨率进行了研究,利用数理统计理论分析了距离分辨率的Cramer-Rao下限(CRLB,fCRLB).研究了条纹管激光雷达回波信号统计模型,推导出了条纹管成像激光雷达距离分辨率的fCRLB计算公式,分析了fCRLB随距离间隔的变化关系,利用fCRLB对条纹管激光雷达的距离分辨率的影响因素进行了研究.结果表明,距离分辨率的(f)CRLB随着目标距离间隔的增加而减小,提高回波信号的信噪比和条纹管的扫描速度都可以减小距离间隔估计方差的(f)CRLB,从而提高成像系统距离分辨率;针对特定的条纹管扫描速度,存在最佳激光脉冲发射宽度,使得系统距离分辨率达到最高.%The range resolution of a streak tube imaging lidar (STIL) system is researched based on the parameter estimation theory.According to the theory of mathematics statistics,the Cramer-Rao low bound (CRLB) of range resolution estimate variance is analyzed.Streak tube lidar pulse model is researched,and the formulas of CRLB are given.The influences of range resolution of the STIL system are analyzed.The results show that higher signal-tonoise ratio values and faster streak tube sweep rate are both helpful in range separation estimation efforts.In addition,there is an optimal pulse-width that produces an optimal range resolution for a particular streak tube sweep rate.

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

    Science.gov (United States)

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

    2015-03-01

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

  18. Endophytic Association of Trichoderma asperellum within Theobroma cacao Suppresses Vascular Streak Dieback Incidence and Promotes Side Graft Growth

    Science.gov (United States)

    Nasaruddin, Nasaruddin; Hendarto, Hendarto; Hakkar, Andi Akbar; Agriansyah, Nursalim

    2016-01-01

    Trichoderma species are able to persist on living sapwood and leaves of cacao (Theobroma cacao) in an endophytic relationship. In this research, we evaluated the ability of Trichodema asperellum introduced at the incision site in the bark for side grafting with the concentration of 4 g/10 mL, 4 g/100 mL, and 4 g/1,000 mL (suspended in water) in suppressing vascular streak dieback (VSD) incidence and promoting growth of side grafts in the field. The incidence of VSD in two local clones of cacao, MCC1 and M04, without application of T. asperellum was 71.2% and 70.1% at 21 wk after grafting, respectively. However, when the two clones were treated with a concentration of 4 g/10 mL T. asperellum, the incidence was 20.6% and 21.7%, respectively, compared to 29.1% and 20.9% at 4 g/100 mL and 18.2% and 15.6% at 4 g/1,000 mL. By comparing to the control, the treatment with the same concentrations of T. asperellum listed above, the total number of stomata in MCC1 decreased by 41.9%, 30.2%, and 14.0% and in M04 by 30.5%, 21.9%, and -2.5% (exception), respectively. Otherwise, the total area of stomata opening increased by 91.4%, 99.7%, and 28.6% in MCC1 and by 203.8%, 253.5%, and 35.9% in M04, respectively. Furthermore, the number of buds and branches treated with a mixture concentration on the the two clones increased by 90.7% and 21.7%, respectively. These data showed that the application of T. asperellum to cacao scions while grafting can decrease VSD incidence in side grafts and increase growth of grafts in addition to decreasing total number of stomata, increasing total area of opened stomata, and increasing number of buds and branches. PMID:27790069

  19. Neutron streak camera

    Science.gov (United States)

    Wang, Ching L.

    1983-09-13

    Apparatus for improved sensitivity and time resolution of a neutron measurement. The detector is provided with an electrode assembly having a neutron sensitive cathode which emits relatively low energy secondary electrons. The neutron sensitive cathode has a large surface area which provides increased sensitivity by intercepting a greater number of neutrons. The cathode is also curved to compensate for differences in transit time of the neutrons emanating from the point source. The slower speeds of the secondary electrons emitted from a certain portion of the cathode are matched to the transit times of the neutrons impinging thereupon.

  20. Molecular Characterization of Segments S7 to S10 of a Southern Rice Black-streaked Dwarf Virus Isolate from Maize in Northern China

    Institute of Scientific and Technical Information of China (English)

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

    2011-01-01

    Southern rice black-streaked dwarf virus(SRBSDV)is a novel Fijivirus prevalent in rice in southern and central China, and northern Vietnam. Its genome has 10 segments of double-stranded RNA named S1 to S10according to their size. An isolate of SRBSDV, JNi4, was obtained from naturally infected maize plants from Ji'ning, Shandong province, in the 2008 maize season. Segments S7 to S10 of JNi4 share nucleotide identities of 72.6%-73.1%, 72.3%-73%, 73.9%-74.5% and 77.3%-79%, respectively, with corresponding segments of Rice black-streaked dwarf virus isolates, and identities of 99.7%, 99. 1%-99.7%, 98.9%-99.5%, and 98.6%-99.2% with those of SRBSDV isolates HN and GD. JNi4 forms a separate branch with GD and HN in the phylogenetic trees constructed with genomic sequences of S7 to S10. These results confirm the proposed taxonomic status of SRBSDV as a distinct species of the genus Fijivirus and indicate that JNi4 is an isolate of SRBSDV. Shandong is so far the northernmost region where SRBSDV is found in China.

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

    Science.gov (United States)

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

    2011-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Feng Sun

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

  3. Potential applications of a dual-sweep streak camera system for characterizing particle and photon beams of VUV, XUV, and x-ray FELS

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A. [Argonne National Lab., IL (United States)

    1995-12-31

    The success of time-resolved imaging techniques in the Characterization of particle beams and photon beams of the recent generation of L-band linac-driven or storage ring FELs in the infrared, visible, and ultraviolet wavelength regions can be extended to the VUV, XUV, and x-ray FELs. Tests and initial data have been obtained with the Hamamatsu C5680 dual-sweep streak camera system which includes a demountable photocathode (thin Au) assembly and a flange that allows windowless operation with the transport vacuum system. This system can be employed at wavelengths shorter than 100 nm and down to 1 {Angstrom}. First tests on such a system at 248-nm wavelengths have been performed oil the Argonne Wakefield Accelerator (AWA) drive laser source. A quartz window was used at the tube entrance aperture. A preliminary test using a Be window mounted on a different front flange of the streak tube to look at an x-ray bremsstrahlung source at the AWA was limited by photon statistics. This system`s limiting resolution of {sigma}{approximately}1.1 ps observed at 248 nm would increase with higher incoming photon energies to the photocathode. This effect is related to the fundamental spread in energies of the photoelectrons released from the photocathodes. Possible uses of the synchrotron radiation sources at the Advanced Photon Source and emerging short wavelength FELs to test the system will be presented.

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

    Science.gov (United States)

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

  5. Two virus-encoded RNA silencing suppressors, P14 of Beet necrotic yellow vein virus and S6 of Rice black streak dwarf virus

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lingdi; WANG Zhaohui; WANG Xianbing; LI Dawei; HAN Chenggui; ZHAI Yafeng; YU Jialin

    2005-01-01

    Functional analysis for gene silencing suppressor of P14 gene of Beet necrotic yellow vein virus and S6 gene of Rice black streak dwarf virus was carried out by agro- infiltration with recombinant vectors of Potato virus X. The phenotype observation of green fluorescent protein (GFP) expression and Northern blot showed that the gene silencing of gfp transgenic Nicotiana benthamiana induced by homologous sequence was strongly suppressed by the immixture infiltration of either the P14 or the S6. In the suppressed plants, the gfp mRNA accumulation was higher than that in the non-suppressed controls and the symptoms caused by PVX infection became more severe, especially the gfp DNA methylation of plant genome was significantly inhabited when co-infiltrated with RBSDV S6 gene. These results suggested that these two virus genes were potentially to encode for proteins as RNA silencing suppressors.

  6. 香蕉条斑病毒LAMP快速检测方法的建立%Development of a LAMP method for rapid detection of Banana streak virus

    Institute of Scientific and Technical Information of China (English)

    彭军; 郭立佳; 王国芬; 杨腊英; 汪军; 黄俊生

    2012-01-01

    环介导等温扩增(loop-mediated isothermal amplification/LAMP)是一种特异、灵敏、快速的新型基因检测技术.本研究以香蕉条斑病毒(Banana streak virus,BSV)ORF3保守区域为基础针对6个特定区域设计并筛选了4条LAMP扩增引物,通过对LAMP反应中MgSO4、dNTPs、Betaine等主要试剂浓度进行优化,建立了香蕉BSV的LAMP检测方法,63℃反应90 min后通过在反应产物中添加SYBR Green Ⅰ染料后颜色的变化,肉眼即可判断检测结果.LAMP具有极高的检测特异性和灵敏性,其检测下限约为3.2 ng·μL-1,是PCR检测灵敏度的25倍,能快速、准确地对疑似样品进行检测,本研究对华南地区部分疑似样品的检测结果显示LAMP阳性检出率比PCR检出率高.本文建立的BSV LAMP检测方法是对BSV检测方法的拓展和延伸,为香蕉病毒的快速检测提供技术保障.%Loop-mediated isothermal amplification (LAMP) is a highly sensitive and specific nucleic acid amplification method that can synthesize rapidly large amounts of DNA under isothermal conditions. The LAMP is successfully used to detect plant viruses and other pathogens. Banana streak virus (BSV) is a badna- virus that causes a viral leaf streak disease of banana and plantain (Musa spp. ). Combined the sequences of ORF3 published in GenBank with specific sequence isolated from South China, two pairs of primers (B3/F3, BIP/FIP) were designed targeting the conserved region of BSV ORF3. A rapid detection of BSV was established by a loop-mediated isothermal amplification assay (LAMP) through optimizing the LAMP primers and reaction conditions such as Betaine concentration and MgSO4. BSV-LAMP reaction was carried out at 63℃ for 90 min, the amplified products were colored with SYBR Green I after completion of the reaction, so that the amplification could be detected with naked eyes. The limit of LAMP detection of BSV-infected banana geno- mic DNA was about 3.2 ng · μL-1, which was 25 times more

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

    Science.gov (United States)

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

    2011-02-01

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

  8. Detection and assignment of proteins encoded by rice black streaked dwarf fijivirus S7, S8, S9 and S10.

    Science.gov (United States)

    Isogai, M; Uyeda, I; Lee, B C

    1998-06-01

    The proteins encoded by rice black streaked dwarf fijivirus (RBSDV) genomic segments 7-10 (S7-S10) were characterized. Open reading frames (ORFs) from these segments were expressed as fusion proteins in Escherichia coli. Antibodies raised against the expressed products were used as probes to determine whether the viral ORFs encode structural proteins. In Western blots, antibodies to the expressed S8 and S10 products reacted with a core capsid (65 kDa) and a major outer capsid (56 kDa) protein, respectively, while none of the antibodies to S7 and S9 products reacted with structural proteins. Antisera to RBSDV S7 ORF1 and S9 ORF1 each detected a single protein of the predicted size in total protein extracts from infected rice plants and viruliferous Laodelphax striatellus. Immunoelectron microscopy revealed that antibodies to RBSDV S7 ORF1 and RBSDV S9 ORF1 reacted with tubular structures and viroplasm, respectively, in sections of both infected maize plants and viruliferous L. striatellus. Antisera to ORF2 of S7 and S9 failed to detect any proteins in the infected tissue using either Western blotting or immuno-electron microscopic techniques.

  9. Screening anti-southern rice black-streaked dwarf virus drugs based on S7-1 gene expression in rice suspension cells.

    Science.gov (United States)

    Yu, Dandan; Wang, Zhenchao; Liu, Jing; Lv, Mingming; Liu, Jiaju; Li, Xiangyang; Chen, Zhuo; Jin, Linghong; Hu, Deyu; Yang, Song; Song, Baoan

    2013-08-28

    Southern rice black-streaked dwarf virus (SRBSDV) is a rice pathogen that had an outbreak in southern China in 2010 and caused significant crop losses. Therefore, screening for effective antiviral drugs against SRBSDV is very important. This study used rice suspension cells infected with SRBSDV by polyethylene glycol-mediated uptake for screening antiviral drugs. SRBSDV P7-1, which is coded by the S7-1 gene, has an intrinsic ability to self-interact to form tubules that play an important role in viral infection. Therefore, relative expression level of the SRBSDV S7-1 gene in infected rice suspension cells was assayed by real-time quantitative polymerase chain reaction to evaluate the antiviral activities of various drugs. Dufulin displayed the highest inhibitory activity against SRBSDV S7-1 expression. In addition, changes in peroxidase (POD), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) activities were determined in inoculated and noninoculated cells. The results showed that both POD and PPO activities increased upon dufulin treatment. Furthermore, the validity of this approach was confirmed in an in vivo experiment in which dufulin was found to effectively inhibit SRBSDV.

  10. Identification and profiling of conserved and novel microRNAs in Laodelphax striatellus in response to rice black-streaked dwarf virus (RBSDV infection

    Directory of Open Access Journals (Sweden)

    Jun-Min Li

    2015-03-01

    Full Text Available MicroRNAs (miRNAs are small non-coding endogenous RNA molecules that play important roles in various biological processes. This study examined microRNA profiles of Laodelphax striatellus using the small RNA libraries derived from virus free (VF and rice black-streaked dwarf virus (RBSDV infected (RB insects. A total of 59 mature miRNAs (46 miRNA families were identified as conserved insect miRNAs in both VF and RB libraries. Among these conserved miRNAs, 24 were derived from the two arms of 12 miRNA precursors. Nine conserved L. striatellus miRNAs were up-regulated and 12 were down-regulated in response to RBSDV infection. In addition, a total of 20 potential novel miRNA candidates were predicted in the VF and RB libraries. The miRNA transcriptome profiles and the identification of L. striatellus miRNAs differentially expressed in response to RBSDV infection will contribute to future studies to elucidate the complex miRNA-mediated regulatory network activated by pathogen challenge in insect vectors.

  11. A numerical algorithm to evaluate the transient response for a synchronous scanning streak camera using a time-domain Baum-Liu-Tesche equation

    Science.gov (United States)

    Pei, Chengquan; Tian, Jinshou; Wu, Shengli; He, Jiai; Liu, Zhen

    2016-10-01

    The transient response is of great influence on the electromagnetic compatibility of synchronous scanning streak cameras (SSSCs). In this paper we propose a numerical method to evaluate the transient response of the scanning deflection plate (SDP). First, we created a simplified circuit model for the SDP used in an SSSC, and then derived the Baum-Liu-Tesche (BLT) equation in the frequency domain. From the frequency-domain BLT equation, its transient counterpart was derived. These parameters, together with the transient-BLT equation, were used to compute the transient load voltage and load current, and then a novel numerical method to fulfill the continuity equation was used. Several numerical simulations were conducted to verify this proposed method. The computed results were then compared with transient responses obtained by a frequency-domain/fast Fourier transform (FFT) method, and the accordance was excellent for highly conducting cables. The benefit of deriving the BLT equation in the time domain is that it may be used with slight modifications to calculate the transient response and the error can be controlled by a computer program. The result showed that the transient voltage was up to 1000 V and the transient current was approximately 10 A, so some protective measures should be taken to improve the electromagnetic compatibility.

  12. Cryoseism Vibrational Movement and Sorting of Detritus of Mars' Regolith Bedforms (E.G., ~ Streaks, Gullies): a New, Dry, Midsummer Antarctic Analogue Mechanism

    Science.gov (United States)

    Ford, A. B.

    2015-12-01

    "SNAP!, CRACK!, POP!" The sounds reverberated across newly shaded permafrost of unusual talus aprons (Ford & Andersen, 1967; J. Geol., 75, 722-732) of interior Antarctica (lats. >84°S; Thiel, Pensacola mtns.), coming from ice cracking under tensile failure (cryoseisms). Apron regoliths show conspicuously reversed downslope particle-size sorting and downslope-oriented lineations (debris-cleared tracts; stone stripes) formed by vibrational movement of detritus by midsummer, diurnal cracking of ice. Moving laterally by vibrations away from cracks, with downslope component by gravity, finer detritus becomes concentrated downslope from coarser debris of initial cliff fall — winnowed, as if on a gigantic vibrating shaking table. Slopes outside shade zones remain free of cracking. Diurnal midday shading of solar-warmed, debris-mantled permafrost- and glacier-surface ice at low ambient midsummer temperatures produces high strain-loading rates that exceed tensile toughness of inhomogeneous, polycrystalline ice containing zones of older but sealed cracks. This dry, mechanical, cryoseism mechanism is here proposed also for now waterless Mars and other icy Solar System bodies. Regolith features of Mars' cryosphere may appear different from anrarctic analogues owing to likely operation over tens if not hundreds of millions of years longer than on Earth. The strain distributions in tensile failure of ice better explain a common spacing uniformity of many martian linear features than others' proposed origins, and for some "active" streaks and gully channels, TARS, RSL and dune-slipface channels, as well as for dune orthogonality, diurnal moonquakes and asteroid-regolith detrital sorting (e.g., "rubble-pile" 25143-Itokawa). Because periodic shade from topography (canyons, craters, etc.) is needed, the mechanism is not expected on flattish terrains where more normal annual cooling rates produce the common polygonal tensile fracturing of ice

  13. Research of Distance Mathematical Modeling for Streak Tube Imaging Lidar%条纹管成像激光雷达距离模型的研究

    Institute of Scientific and Technical Information of China (English)

    马晨宁; 韩绍坤; 赵文; 王平

    2012-01-01

    The distance mathematical modeling is the foundation of streak tube imaging lidar (STIL) system. Based on the STIL imaging principle and the experimental observation, the relation of target relative distance to the CCD image distance was theoretically analyzed. The analyzed result shows that the nonlinear relative deviation between target distance and image distance is very small. That means the target distance and CCD image distance present an approximately linear relationship, so the distance mathematical modeling could be processed linearly. A hardware platform was built and two crucial parameters of scanning velocity and position of static reference line were ascertained by measurement. Based on the above, the distance model for STIL system was built and its validity has been verified.%在基于对STIL系统成像原理分析的基础上,对实际目标的相对距离与CCD目标像距离之间的关系进行了理论研究,得出了两者近线性的关系,并依据此线性关系构建出了距离计算模型,搭建了实验平台,对模型中所需的2个重要参数静态基准线的位置和扫描速度分别进行了测定,验证了距离模型可以采用近似线性处理的正确性,基于此实验数据重新修正了距离模型.

  14. Planetary-scale hydraulic jumps and transonic jet-streaks in the MACDA reanalysis of the Martian atmosphere: a comparison with Earth's lower mesosphere

    Science.gov (United States)

    Dowling, Timothy E.; Bradley, Mary Elizabeth; Lewis, Stephen R.; Read, Peter L.

    2016-10-01

    We have analyzed the Mars MACDA V1.0 global reanalysis on potential-temperature surfaces, θ, over the range θ = 400 to 900 K (~30 to ~60 km). The strongest seasonal wind, the northern-winter polar jet, exhibits two intriguing features: i) transonic jet streaks and ii) the juxtaposition of regions of shooting and tranquil flow, in the sense of Froude-number hydraulics, which suggests a planetary-scale hydraulic jump. Mesoscale bores have been studied on Mars, but to our knowledge the above two features have not been reported elsewhere. To characterize the basic state, we examine scatter plots of Ertel potential vorticity, Q, versus Bernoulli streamfunction, B, and fit the linear model Q/Q0 = 1 - μ0 (B-B0). In autumn, winter and spring, the nondimensionalized correlation parameter, μ'0 = (NH)2 μ0, in mid-latitudes is positive and nearly constant in time. Its value is close to unity at the bottom of the study region and gradually decreases with increasing θ (increasing altitude). In northern summer it swings negative. These attributes match Earth's lower mesosphere (θ = 2000 to 3000 K; ~48 to ~62 km). In southern summer, Ls ~ 270○, a hypsometric flaring of the θ layers, which is not seen in northern summer, is associated with the previously reported reduction of Q to approximately zero across the entire southern hemisphere and northern tropics. Between each winter polar jet and pole, especially in the north, there is a large spread of Q over a small domain of B, which is unlike Earth and may be related to the aforementioned hydraulic jump. We are currently examining 3D Lagrangian fluid trajectories to better characterize the rotating hydraulics of the system as a function of season.

  15. The Effect of EDTA and Garlic Extract Combination on Plasma Lipids, Lipoporteins, and Fatty Streaks in Cholesterol Fed Male Rabbit Aorta

    Directory of Open Access Journals (Sweden)

    M R Sharifi

    2004-12-01

    Full Text Available Background: Garlic extract is used in treatment of hypercholesterolemia, although its efficacy isn’t exactly clear. There is a little information about mechanism of garlic effect on plasma lipids. By intervention of garlic in atherogenesis process it has been shown that it has a protective effect against cardiovascular disease. On the other hand, it has been shown that EDTA (Ethylene Diamin Tetra Acetic Acid improves blood flow and decreases the vascular atherosclerotic symptoms. Methods: The objective of this study was to evaluate the effect of EDTA and garlic extract with together on plasma concentration of cholesterol, Triglyceride, LDL, and HDL, and formation of fatty streaks through the phenomena called “chelation therapy” in male Rabbit aorta. 32 male Rabbits were used and divided to 4 groups as group 1: cholesterol – rich diet (CRD + EDTA + Garlic Extract (GE, group 2: CRD + EDTA, Group 3: CRD + GE, Group 4: CRD (control group. The animals were under food and drug diet for 5 weeks. Blood samples of Rabbits were taken before and after the test and then plasma cholesterol, triglyceride, LDL and HDL were measured. Finally, abdominal aorta was studied and pathologically evaluated. Results: The experiments showed the significant decrease of mean cholesterol in case groups and mean triglyceride in the groups which have received EDTA + GE and EDTA. Our results showed that mean LDL and LDL/HDL Ratio in case groups have been decreased in comparison to control group. In addition, there was a significant increase in mean HDL in the group which has received EDTA + GE. Conclusion: In this study it was shown that the using of fresh garlic and EDTA with together has a reductive effect on cholesterol, Triglyceride, and LDL concentration and also has an increasing effect on HDL concentration. But it seems that concomitant using of these tow substances with together strengthen the effect of each one, and it produces a great reduction of the blood

  16. Heritable, de novo resistance to leaf rust and other novel traits in selfed descendants of wheat responding to inoculation with wheat streak mosaic virus.

    Science.gov (United States)

    Seifers, Dallas L; Haber, Steve; Martin, Terry J; McCallum, Brent D

    2014-01-01

    Stable resistance to infection with Wheat streak mosaic virus (WSMV) can be evolved de novo in selfing bread wheat lines subjected to cycles of WSMV inoculation and selection of best-performing plants or tillers. To learn whether this phenomenon might be applied to evolve resistance de novo to pathogens unrelated to WSMV, we examined the responses to leaf rust of succeeding generations of the rust- and WSMV-susceptible cultivar 'Lakin' following WSMV inoculation and derived rust-resistant sublines. After three cycles of the iterative protocol five plants, in contrast to all others, expressed resistance to leaf and stripe rust. A subset of descendant sublines of one of these, 'R1', heritably and uniformly expressed the new trait of resistance to leaf rust. Such sublines, into which no genes from a known source of resistance had been introgressed, conferred resistance to progeny of crosses with susceptible parents. The F1 populations produced from crosses between, respectively, susceptible and resistant 'Lakin' sublines 4-3-3 and 4-12-3 were not all uniform in their response to seedling inoculation with race TDBG. In seedling tests against TDBG and MKPS races the F2s from F1 populations that were uniformly resistant had 3∶1 ratios of resistant to susceptible individuals but the F2s from susceptible F1 progenitors were uniformly susceptible. True-breeding lines derived from resistant individuals in F2 populations were resistant to natural stripe and leaf rust inoculum in the field, while the 'Lakin' progenitor was susceptible. The next generation of six of the 'Lakin'-derived lines exhibited moderate to strong de novo resistance to stem rust races TPMK, QFCS and RKQQ in seedling tests while the 'Lakin' progenitor was susceptible. These apparently epigenetic effects in response to virus infection may help researchers fashion a new tool that expands the range of genetic resources already available in adapted germplasm.

  17. Heritable, de novo resistance to leaf rust and other novel traits in selfed descendants of wheat responding to inoculation with wheat streak mosaic virus.

    Directory of Open Access Journals (Sweden)

    Dallas L Seifers

    Full Text Available Stable resistance to infection with Wheat streak mosaic virus (WSMV can be evolved de novo in selfing bread wheat lines subjected to cycles of WSMV inoculation and selection of best-performing plants or tillers. To learn whether this phenomenon might be applied to evolve resistance de novo to pathogens unrelated to WSMV, we examined the responses to leaf rust of succeeding generations of the rust- and WSMV-susceptible cultivar 'Lakin' following WSMV inoculation and derived rust-resistant sublines. After three cycles of the iterative protocol five plants, in contrast to all others, expressed resistance to leaf and stripe rust. A subset of descendant sublines of one of these, 'R1', heritably and uniformly expressed the new trait of resistance to leaf rust. Such sublines, into which no genes from a known source of resistance had been introgressed, conferred resistance to progeny of crosses with susceptible parents. The F1 populations produced from crosses between, respectively, susceptible and resistant 'Lakin' sublines 4-3-3 and 4-12-3 were not all uniform in their response to seedling inoculation with race TDBG. In seedling tests against TDBG and MKPS races the F2s from F1 populations that were uniformly resistant had 3∶1 ratios of resistant to susceptible individuals but the F2s from susceptible F1 progenitors were uniformly susceptible. True-breeding lines derived from resistant individuals in F2 populations were resistant to natural stripe and leaf rust inoculum in the field, while the 'Lakin' progenitor was susceptible. The next generation of six of the 'Lakin'-derived lines exhibited moderate to strong de novo resistance to stem rust races TPMK, QFCS and RKQQ in seedling tests while the 'Lakin' progenitor was susceptible. These apparently epigenetic effects in response to virus infection may help researchers fashion a new tool that expands the range of genetic resources already available in adapted germplasm.

  18. Optimization of diagnostic RT-PCR protocols and sampling procedures for the reliable and cost-effective detection of Cassava brown streak virus.

    Science.gov (United States)

    Abarshi, M M; Mohammed, I U; Wasswa, P; Hillocks, R J; Holt, J; Legg, J P; Seal, S E; Maruthi, M N

    2010-02-01

    Sampling procedures and diagnostic protocols were optimized for accurate diagnosis of Cassava brown streak virus (CBSV) (genus Ipomovirus, family Potyviridae). A cetyl trimethyl ammonium bromide (CTAB) method was optimized for sample preparation from infected cassava plants and compared with the RNeasy plant mini kit (Qiagen) for sensitivity, reproducibility and costs. CBSV was detectable readily in total RNAs extracted using either method. The major difference between the two methods was in the cost of consumables, with the CTAB 10x cheaper (0.53 pounds sterling=US$0.80 per sample) than the RNeasy method (5.91 pounds sterling=US$8.86 per sample). A two-step RT-PCR (1.34 pounds sterling=US$2.01 per sample), although less sensitive, was at least 3-times cheaper than a one-step RT-PCR (4.48 pounds sterling=US$6.72). The two RT-PCR tests revealed consistently the presence of CBSV both in symptomatic and asymptomatic leaves and indicated that asymptomatic leaves can be used reliably for virus diagnosis. Depending on the accuracy required, sampling 100-400 plants per field is an appropriate recommendation for CBSD diagnosis, giving a 99.9% probability of detecting a disease incidence of 6.7-1.7%, respectively. CBSV was detected at 10(-4)-fold dilutions in composite sampling, indicating that the most efficient way to index many samples for CBSV will be to screen pooled samples. The diagnostic protocols described below are reliable and the most cost-effective methods available currently for detecting CBSV.

  19. 云南水稻上检测到南方水稻黑条矮缩病毒%Detection of Southern rice black streaked dwarf virus (SRBSDV) in rice in Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    丁铭; 尹跃艳; 方琦; 韦加贵; 顾中量; 李红祥; 卢训; 赵健; 张仲凯

    2011-01-01

    Rice samples showing symptoms similar to the disease caused by Southern rice black streaked dwarf virus (SRBSDV, Genus Fijivirus, Family Reoviridae) collected from three municipalities of southern Yunnan were detected by electron microscopy and RT-PCR. Electron microscopy observation of crude infected leaf extracts after negative staining revealed spherical particles of 70 -75 nm, and about 411 bp fragment of RT-PCR shared 97.6% -100% nucleotide identities with reported capsid protein gene of SRBSDV isolates. The phylogenetic tree based on the partial capsid protein gene sequences indicated that the virus causing rice dwarf in Yunnan should be identified as SRBSDV.%南方水稻黑条矮缩病(Southern rice black streaked dwarf disease)是我国南方稻区一种新的水稻病毒病害.自2001年在广东省阳西县首次发现以来,该病危害范围逐年扩大,2009年我国湖南、江西、广东、广西、海南、浙江、福建、湖北和安徽9个水稻主产省(区)及越南北部19个省发病面积约33.33万hm2,基本绝收面积0.67万hm2[1,2],对水稻生产威胁巨大.

  20. 上槽缓冲容量不足导致双向电泳纵向拖尾原因初探%Insufficient buffer capacity in up chamber leads to vertical streaking of two-dimensional electrophoresis

    Institute of Scientific and Technical Information of China (English)

    金科华

    2011-01-01

    Objective To study the effect of buffer capacity in up chamber on vertical streaking (VSTK) of two-dimensional electrophoresis. Methods The same buffer volume was kept in up chamber, VSTK was compared by running two SDS gels or single one in 1×Laemmli buffer (buffer), or two ones in 1. 5× , 2× and 3× buffer in up chamber respectively. Results VSTK appeared severely when two gels were run in 1× buffer, while disappeared when one did When two gels were run in 1. 5 × buffer, VSTK only existed in the region of high molecular weight, and protein spots in the region of medium and low molecular weight were round without streaking. When two gels were run in 2× buffer, compared with 1. 5× buffer, the VSTK in the region of high molecular weight was further improved, and the round protein spots in the region of medium and low molecular weight increased. VSTK disappeared completely when two gels were run in 3× buffer. Conclusion Insufficient buffer capacity in up chamber may lead to vertical streaking.%目的 探讨上槽缓冲容量对双向电泳纵向拖尾的影响.方法 保持上槽缓冲液体积不变,分别采用1×buffer电泳2块或1块SDS胶,或1.5×、2×、3×buffer电泳2块胶,比较纵向拖尾情况.结果 1×buffer电泳2块胶,整块胶出现严重纵向拖尾,电泳1块胶时无纵向拖尾.1.5×buffer电泳2块胶,纵向拖尾只存在于高分子量区,中低分子量区蛋白点呈圆形,无拖尾.2×buffer电泳2块胶,高分子量区纵向拖尾较1.5×buffer进一步减少,中低分子量区圆形蛋白点增多.3×buffer电泳2块胶时,纵向拖尾完全消除.结论 上槽缓冲液缓冲容量不足导致双向电泳纵向拖尾.

  1. 玉米粗缩病抗性遗传研究%Genetic analysis of resistance to Rice black-streaked dwarf virus in maize

    Institute of Scientific and Technical Information of China (English)

    邸垫平; 易晓云; 苗洪芹; 路银贵; 田兰芝

    2012-01-01

    本文选用3个抗病自交系(齐319、X178、沈137)和3个感病自交系(掖107、掖478、沈5003)按照NCⅡ交配设计配制9套杂交组合研究了玉米抗粗缩病遗传规律.2009-2010年在曲阳、保定采用田间自然发病方法鉴定亲本、F1、F2群体的玉米粗缩病抗性,并采用灰飞虱人工接种方法鉴定亲本材料的抗病性.运用QGA station软件的加性-显性-上位性(ADAA)遗传模型进行数据分析,结果表明,显性效应和加性效应是控制玉米粗缩病抗性的主要遗传组分,分别占表型变异的44.8%和13.1%,杂合显性效应表现负向杂种优势,抗病育种可加以利用.加性×加性上位性效应在玉米自交系和杂交组合抗粗缩病遗传中普遍存在,但因材料不同而表现负向或正向效应.玉米粗缩病抗性易受环境影响,显性与环境互作效应方差占表型方差的比率为39.8%,达到极显著水平.因此,培育抗粗缩病玉米品种应依据基因型选配适当的亲本材料,抗病品种宜进行多年多点鉴定筛选.%Maize rough dwarf disease caused by Rice black-streaked dwarf virus(RBSDV) leads to serious economic losses of corn in China. It is an efficient and economical measure to use resistant varieties to control the disease. An experiment was carried out to elucidate the heredity in maize resistance to RBSDV with 9 sets of hybrids crossing between 3 resistant (Qi319, XI78, Shenl37) and 3 susceptible (YelO7, Ye478, Shen5003) lines according to NCII design. The resistance of parents as well as their hybrids F, and F2 populations were identified by natural transmission of planthopper (Laodelphax striatellus) in fields of Quyang and Baoding from 2009 to 2010 and the parents were also evaluated with artificial inoculation. The disease indexes were analyzed with software QGA station based on additive dominance and additive x additive (ADAA) genetic model. The results showed that the dominant and additive effects were the main

  2. Application Analysis of Short-range Ocean Surface Monitoring for Streak Tube Imaging Lidar%条纹管激光成像雷达在近程海面监测应用分析

    Institute of Scientific and Technical Information of China (English)

    盛元平; 孙剑峰; 徐大伟

    2012-01-01

    近程海面监测通常要在低照度条件下,获得高清晰、高分辨目标图像,以提高监测效能。与传统被动红外成像监测相比,激光成像雷达是一种主动成像技术,能获取目标强度像和距离像(统称为四维像),具有较高的目标探测与目标识别概率。分析了美国条纹管激光成像雷达的发展现状及具有的技术优势,阐述了条纹管激光成像雷达采用的闪光式体制、一次成像、高速获取目标数据的原理。指出条纹管激光成像雷达既适用于近程海面监测,也可与现有监测手段,如被动红外、微波雷达等复合使用,提高监测效率。%In order to enhance the efficiency of imaging monitoring, the short-range ocean surface monitoring usually obtains the high-definition and high-resolution images under the low illuminance. Compared with the tradi- tional infrared imaging monitoring, lidar is an active imaging technology, which can obtain the intensity and range image (4D image), so it has the high detection and recognition probability. The development status and technology advantage of U.S. streak tube imaging lidar (STIL) are analyzed. The principles of the flash type system, one-time imaging and high-speed data acquisition are discussed. The streak tube imaging lidar can be used in the short-range ocean monitoring, and can also be combined with other sensor, such as passive infrared and microwave radar to improve the monitor efficiency.

  3. Ultra-high speed laser shadow streak photography for flyer plates driven by magnetic fields%磁驱动飞片的超高速激光阴影扫描摄影技术

    Institute of Scientific and Technical Information of China (English)

    汪伟; 王桂吉; 罗振雄; 莫建军; 尚长水

    2012-01-01

    According to the physical process of flyer plates driven by magnetic fields, an ultra-high speed photographic system including an ultra-high speed rotating mirror streak camera, a micrographic lens suitable for the optical system of the camera and a continuous laser source was developed. An e-lectric-optic switch in series was used to avoid the repetitious exposure on imaging plate of the camera, by which the intense light produced in the course of collision was bated and ID clear-cut streak images of flyer plates driven by an electric gun were obtained firstly at home. Experimental results show that Lyl2 flyer plates with the size of 8 mm×6 mm×0. 7/0. 9 mm can be accelerated in 9-14 km/s within 1. 8 μs when the charge voltages of flyer plate reach in 60-64 kV. The results demonstrate that the charged voltages and the thicknesses of flyer plates have great effect on the movement velocities of the flyer plates. The present work will be helpful for researching flyer velocity and can provide important data for the development of electric guns.%针对磁驱动飞片的物理过程,设计了显微装置和激光阴影照明装置.结合超高速转镜式扫描相机,利用串联式光电开关避免相机像面重复曝光,有效地解决了飞片被碰撞过程中严重影响测试结果的自发强光现象,获得了磁驱动加载下飞片运动过程清晰的一维扫描试验图像.图像分析数据表明,在充电电压为60~64 kV时,可将尺寸为8 mm×6 mm×0.7/0.9 mm的Lyl2铝飞片发射至9~14 km/s的超高速度,且飞片运动速度与充电电压和飞片厚度有关.该项工作为磁驱动飞片运动过程的研究提供了一种重要的测试手段,其测试方法也适用于其它产生强烈杂光的高速碰撞的测试研究.

  4. Rice black-streaked dwarf virus P6 self-interacts to form punctate, viroplasm-like structures in the cytoplasm and recruits viroplasm-associated protein P9-1

    Directory of Open Access Journals (Sweden)

    Yu Jialin

    2011-01-01

    Full Text Available Abstract Background Rice black-streaked dwarf virus (RBSDV, a member of the genus Fijivirus within the family Reoviridae, can infect several graminaceous plant species including rice, maize and wheat, and is transmitted by planthoppers. Although several RBSDV proteins have been studied in detail, functions of the nonstructural protein P6 are still largely unknown. Results In the current study, we employed yeast two-hybrid assays, bimolecular fluorescence complementation and subcellular localization experiments to show that P6 can self-interact to form punctate, cytoplasmic viroplasm-like structures (VLS when expressed alone in plant cells. The region from residues 395 to 659 is necessary for P6 self-interaction, whereas two polypeptides (residues 580-620 and 615-655 are involved in the subcellular localization of P6. Furthermore, P6 strongly interacts with the viroplasm-associated protein P9-1 and recruits P9-1 to localize in VLS. The P6 395-659 region is also important for the P6-P9-1 interaction, and deleting any region of P9-1 abolishes this heterologous interaction. Conclusions RBSDV P6 protein has an intrinsic ability to self-interact and forms VLS without other RBSDV proteins or RNAs. P6 recruits P9-1 to VLS by direct protein-protein interaction. This is the first report on the functionality of RBSDV P6 protein. P6 may be involved in the process of viroplasm nucleation and virus morphogenesis.

  5. A three-nucleotide mutation altering the Maize streak virus Rep pRBR-interaction motif reduces symptom severity in maize and partially reverts at high frequency without restoring pRBR-Rep binding.

    Science.gov (United States)

    Shepherd, Dionne N; Martin, Darren P; McGivern, David R; Boulton, Margaret I; Thomson, Jennifer A; Rybicki, Edward P

    2005-03-01

    Geminivirus infectivity is thought to depend on interactions between the virus replication-associated proteins Rep or RepA and host retinoblastoma-related proteins (pRBR), which control cell-cycle progression. It was determined that the substitution of two amino acids in the Maize streak virus (MSV) RepA pRBR-interaction motif (LLCNE to LLCLK) abolished detectable RepA-pRBR interaction in yeast without abolishing infectivity in maize. Although the mutant virus was infectious in maize, it induced less severe symptoms than the wild-type virus. Sequence analysis of progeny viral DNA isolated from infected maize enabled detection of a high-frequency single-nucleotide reversion of C(601)A in the 3 nt mutated sequence of the Rep gene. Although it did not restore RepA-pRBR interaction in yeast, sequence-specific PCR showed that, in five out of eight plants, the C(601)A reversion appeared by day 10 post-inoculation. In all plants, the C(601)A revertant eventually completely replaced the original mutant population, indicating a high selection pressure for the single-nucleotide reversion. Apart from potentially revealing an alternative or possibly additional function for the stretch of DNA that encodes the apparently non-essential pRBR-interaction motif of MSV Rep, the consistent emergence and eventual dominance of the C(601)A revertant population might provide a useful tool for investigating aspects of MSV biology, such as replication, mutation and evolution rates, and complex population phenomena, such as competition between quasispecies and population turnover. PMID:15722543

  6. Productivity and biochemical properties of green tea in response to full-length and functional fragments of HpaGXooc, a harpin protein from the bacterial rice leaf streak pathogen Xanthomonas oryzae pv. oryzicola

    Indian Academy of Sciences (India)

    Xiaojing Wu; Tingquan Wu; Juying Long; Qian Yin; Yong Zhang; Lei Chen; Ruoxue Liu; Tongchun Gao; Hansong Dong

    2007-09-01

    Harpin proteins from plant pathogenic bacteria can stimulate hypersensitive cell death (HCD), drought tolerance, defence responses against pathogens and insects in plants, as well as enhance plant growth. Recently, we identified nine functional fragments of HpaGXooc, a harpin protein from Xanthomonas oryzae pv. oryzicola, the pathogen that causes bacterial leaf streak in rice. Fragments HpaG1–94, HpaG10–42, and HpaG62–138, which contain the HpaGXooc regions of the amino acid sequence as indicated by the number spans, exceed the parent protein in promoting growth, pathogen defence and HCD in plants. Here we report improved productivity and biochemical properties of green tea (Camellia sinensis) in response to the fragments tested in comparison with HpaGXooc and an inactive protein control. Field tests suggested that the four proteins markedly increased the growth and yield of green tea, and increased the leaf content of tea catechols, a group of compounds that have relevance in the prevention and treatment of human diseases. In particular, HpaG1–94 was more active than HpaGXooc in expediting the growth of juvenile buds and leaves used as green tea material and increased the catechol content of processed teas. When tea shrubs were treated with HpaHXooc and HpaG1–94 compared with a control, green tea yields were over 55% and 39% greater, and leaf catechols were increased by more than 64% and 72%, respectively. The expression of three homologues of the expansin genes, which regulate plant cell growth, and the CsCHS gene encoding a tea chalcone synthase, which critically regulates the biosynthesis of catechols, were induced in germinal leaves of tea plants following treatment with HpaG1–94 or HpaGXooc. Higher levels of gene expression were induced by the application of HpaG1–94 than HpaGXooc. Our results suggest that the harpin protein, especially the functional fragment HpaG1–94, can be used to effectively increase the yield and improve the biochemical

  7. Retinoscopia com luz em faixa em cães fácicos, afácicos e pseudofácicos Streak retinoscopy in phakic, aphakic, and pseudophakic dogs

    Directory of Open Access Journals (Sweden)

    L.A.L. Mobricci

    2009-02-01

    Full Text Available Avaliou-se o erro refracional em 40 cães submetidos ou não à facectomia por facoemulsificação, por meio de retinoscopia com luz em faixa. Distribuídos em quatro grupos de 10 animais cada, foram designados por cães fácicos, cães afácicos (CA, cães pseudofácicos com implante de duas lentes intra-oculares em piggyback (PP e cães pseudofácicos com implante de uma lente intra-ocular veterinária de 41D (PL. As avaliações foram realizadas por ceratometria, ecobiometria ultra-sônica e retinoscopia. A média da curvatura corneana foi de 40,46±2,44D. O poder dióptrico obtido por retinoscopia foi de 18,50D no grupo CA, 5,25D no grupo PP e 2,00D no grupo PL. A retinoscopia com luz em faixa constituiu um método eficaz para avaliar a refração ocular em cães, mas foi dificultada quando da presença de opacidade de meios oculares. Todos os animais apresentaram-se hipermétropes, em diferentes graus; o astigmatismo ceratométrico cirurgicamente induzido foi discreto.The refraction error in dogs submitted or not to phakectmy, by phakoemulsification by streak retinoscopy was evaluated. Forty dogs were distributed in four groups of 10 animals each, and were designated by phakic, aphakic (AD, pseudo-phakic with two piggyback intraocular lenses (PD, and pseudo-phakic with one intraocular 41D veterinary lens implant (LD. The evaluation was performed by keratometry, ultrasonic echobiometry, and retinoscopy. The mean corneal curvature was 40.46±2.44D. The dioptric power obtained by retinoscopy was 18.50D in AD group, 5.25D in PD group, and 2.00D in LD group. The retinoscopy was an efficient method to evaluate ocular refraction in dogs, but was more complex in ocular opacity presence. All animals presented different levels of hypermetropy, and the surgically induced astigmatism was discrete.

  8. HEAVY ION FUSION SCIENCE VIRTUAL NATIONAL LABORATORY 2nd QUARTER 2010 MILESTONE REPORT. Develop the theory connecting pyrometer and streak camera spectrometer data to the material properties of beam heated targets and compare to the data

    International Nuclear Information System (INIS)

    This milestone has been accomplished. We have extended the theory that connects pyrometer and streak spectrometer data to material temperature on several fronts and have compared theory to NDCX-I experiments. For the case of NDCX-I, the data suggests that as the metallic foils are heated they break into droplets (cf. HIFS VNL Milestone Report FY 2009 Q4). Evaporation of the metallic surface will occur, but optical emission should be directly observable from the solid or liquid surface of the foil or from droplets. However, the emissivity of hot material may be changed from the cold material and interference effects will alter the spectrum emitted from small droplets. These effects have been incorporated into a theory of emission from droplets. We have measured emission using streaked spectrometry and together with theory of emission from heated droplets have inferred the temperature of a gold foil heated by the NDCX-I experiment. The intensity measured by the spectrometer is proportional to the emissivity times the blackbody intensity at the temperature of the foil or droplets. Traditionally, a functional form for the emissivity as a function of wavelength (such as a quadratic) is assumed and the three unknown emissivity parameters (for the case of a quadratic) and the temperature are obtained by minimizing the deviations from the fit. In the case of the NDCX-I experiment, two minima were obtained: at 7200 K and 2400 K. The best fit was at 7200 K. However, when the actual measured emissivity of gold was used and when the theoretical corrections for droplet interference effects were made for emission from droplets having radii in the range 0.2 to 2.0 microns, the corrected emissivity was consistent with the 2400 K value, whereas the fit emissivity at 7200 K shows no similarity to the corrected emissivity curves. Further, an estimate of the temperature obtained from beam heating is consistent with the lower value. This exercise proved to be a warning to be skeptical

  9. The Key Techniques for Comprehensive Control on Southern Rice Black-streaked Dwarf Virus%南方水稻黑条矮缩病综合防控关键技术研究

    Institute of Scientific and Technical Information of China (English)

    钟玲; 段德康; 蔡德珍; 赖昌秀; 张国光; 刘方义; 杨迎青; 兰波; 李湘民

    2014-01-01

    为探明南方水稻黑条矮缩病的综合防控关键技术,从品种抗性筛选和药剂防治方法两方面开展了研究。于2011年在全省4个县对54个中、晚稻品种进行了田间抗性鉴定,结果表明:水稻品种之间的抗性有较大的差异,平均病丛率在0.5%以下的有岳优9113等7个品种,为相对抗(耐)病品种;平均病丛率在0.51%~2.99%的有金优77等42个品种;平均病丛率在3.0%以上的有金佳丝苗等5个品种,为相对感病品种。2012年在全省3个县开展了不同药剂及不同使用方法的田间药效试验,结果表明:南方水稻黑条矮缩病防治的有效方法是使用25%吡蚜酮可湿性粉剂药剂拌种(20 g/kg种子)、移栽前2 d和移栽后15 d各使用25%吡蚜酮喷雾1次(每667 m220 g);不采用药剂拌种或者低剂量拌种(25%吡蚜酮10 g/kg种子)的防效均显著地低于该药剂20 g/kg种子剂量拌种的防效;2%宁南霉素水剂单独使用时对南方水稻黑条矮缩病的防效较差,且与25%吡蚜酮混合使用后,并没有显著性地提高防效。%To define the key techniques for comprehensive control on southern rice black -streaked dwarf vi-rus (SRBSDV),the resistance screening of different varieties to SRBSDV was studied .Firstly,the field resistanceidentification of 54 middle-and late rice varieties was carried out in 4 counties in 2011.The result revealed that the resistance of rice cultivars differed greatly .The average diseased bundle rates of 7 cultivars were lower than 0.5%and they were comparatively resistant or tolerant cultivars .The average diseased bundle rates of 5 cultivars were higher than 3.0%and they belonged to susceptible cultivars .In 2012,the field control effects of different pesticides and different application methods were tested in 3 counties .The results showed the effective control method of SRBSDV was a complex one ,including seed soaking with 20 g

  10. Tracking the source regions of Southern rice black-streaked dwarf virus (SRBSDV)occurred in Wuyi county, Zhejiang province, China in 2009, transmitted by Sogatella furcifera(Horváth)(Homoptera: Delphacidae)%浙江武义2009年南方水稻黑条矮缩病的毒源地分析

    Institute of Scientific and Technical Information of China (English)

    赵悦; 吴璀献; 朱旭东; 蒋学辉; 张孝羲; 翟保平

    2011-01-01

    2009年,浙江省境内首次出现南方水稻黑条矮缩病毒(Southern rice black-streaked dwarf virus,SRBSDV),且仅武义县有发病现象.因为该病毒病是一种虫媒病毒,且白背飞虱Sogatella furcifera(Horváth)是主要传毒介体,所以本文通过白背飞虱灯下诱虫情况调查、迁飞轨迹模拟、天气学背景分析以及毒源地分析,阐释了2009年浙江省武义县发现的南方水稻黑条矮缩病的供毒源地分布情况,以及白背飞虱携毒的传递路径,并讨论了轨迹模拟中各生物学参数的设定方法,从而为剖析该病毒的宏观流行规律奠定科学基础.结果显示:(1)通过对白背飞虱迁入武义的主要虫源地与经鉴定的南方水稻黑条矮缩病发病区域的叠加分析,明确了浙江武义的可能毒源地分布于两广、闽南、赣南四省区境内;(2)西南低空急流及偏南气流是白背飞虱将我国南方的病毒远距离传送到武义县境内的动力源;(3)白背飞虱随下沉气流和降雨在武义境内的集中降落是南方水稻黑条矮缩病在当地暴发的触发条件.%In 2009, Southern rice black-streaked dwarf virus (SRBSDV) appeared first time in Zhejiang province, while only in Wuyi county morbidity phenomenon occurred. Since this virus is a kind of arbovirus, and the white-backed planthopper, Sogatella fwrcifera (Horvdth) (WBPH), is its main transmitted vector, we used light trap catch data, migration trajectory simulation, synoptic meteorological background and virus infection to study the pathways of WBPH in Wuyi, Zhejiang, 2009. In this way, the possible source regions of SRBSDV transmitted by its vector WBPH were analyzed, and the biological parameters for trajectory analysis were determined based on the numerical simulation. This research aims to establish scientific basis for the macro-epidemic researching of SRBSDV. The results illustrated that:(1) through the overlapping analysis of the virus incidence area and the

  11. 水稻南方黑条矮缩病毒湖南鼎城株系S10片段的基因组序列分析%Sequence Analysis of Genome Segment S10 of Hunan Dingcheng Isolate of Southern Rice Black-Streaked Dwarf Virus

    Institute of Scientific and Technical Information of China (English)

    崔亚; 朱俊子; 周倩; 蒋坚; 高必达

    2012-01-01

    运用RT-PCR技术克隆了水稻南方黑条矮缩病毒(southern rice black-streaked dwarf virus,SRBSDV)湖南鼎城株系的基因组S10片段(SRBSDV-HuNDC S10),并对其全序列进行了测定和生物信息学分析.结果显示,SRBSDV-HuNDC S10片段全长为1 797 bp (登录号:JQ337964),含有1个ORF,编码557个氨基酸残基的衣壳蛋白,推测分子量约62.6 kD,推测等电点为7.62,与已报道的广东、海南和云南分离物病毒的S10作比较,它们的核苷酸相似性分别为99.7%、99.0%和98.4%,氨基酸相似性分别为100.0%、99.5%和99.3%.对SRBSDV-HuNDC S10及部分Fijiviruses病毒对应片段在5' URT与3' URT存在的保守序列和互补序列进行了归纳,对其ORF编码的氨基酸序列进行了motif查找,得到该属(Fijiviruses)氨基酸序列的10个保守区段.此外,进行了糖基化位点、磷酸化位点及B细胞抗原表位预测,发现了3个可能的N端豆蔻酰基化位点,可能与病毒的侵染机制有关.%The full-length cDNA of the genome segment S10 of Dingcheng isolate of Southern Rice Black-Streaked Dwarf Virus was cloned and the complete nucleotide sequence was determined, as well as its bioinformatics analysis. Results show that the S10 is 1 797 bp (JQ337964), has an open reading frame (ORF), encodes a capsid protein containing 557 amino acid residues. Its molecular weight is about 62.6 kD and its isoelectric point is 7.62. Compared with other known viruses such as Guangdong isolates, Hainan isolates and Yunnan isolates, the nucleotide identities of S10 segment are 99.7%, 99.0% and 98.4%, respectively, and their amino acid identities are 100.0%, 99.5% and 99.3% respectively. Conservative sequence and complementary sequence in the 5' URT and 3' URT of SRBSDV-HuNDC S10 and corresponding segments of the Fijiviruses viruses were analyzed, and 10 conservative segment of Fijiviruses viruses were founded by searching the motif of amino acid sequence encoded by ORF. Moreover, the glycosylation sites

  12. 水稻南方黑条矮缩病毒湖南鼎城株系S10片段的基因组序列分析%Sequence Analysis of Genome Segment S10 of Hunan Dingcheng Isolate of Southern Rice Black-Streaked Dwarf Virus

    Institute of Scientific and Technical Information of China (English)

    崔亚; 朱俊子; 周倩; 蒋坚; 高必达

    2012-01-01

    The full-length cDNA of the genome segment S10 of Dingcheng isolate of Southern Rice Black-Streaked Dwarf Virus was cloned and the complete nucleotide sequence was determined,as well as its bioinformatics analysis.Results show that the S10 is 1 797 bp(JQ337964),has an open reading frame(ORF),encodes a capsid protein containing 557 amino acid residues.Its molecular weight is about 62.6 kD and its isoelectric point is 7.62.Compared with other known viruses such as Guangdong isolates,Hainan isolates and Yunnan isolates,the nucleotide identities of S10 segment are 99.7%,99.0% and 98.4%,respectively,and their amino acid identities are 100.0%,99.5% and 99.3% respectively.Conservative sequence and complementary sequence in the 5' URT and 3' URT of SRBSDV-HuNDC S10 and corresponding segments of the Fijiviruses viruses were analyzed,and 10 conservative segment of Fijiviruses viruses were founded by searching the motif of amino acid sequence encoded by ORF.Moreover,the glycosylation sites,phosphorylation sites and B cell epitope were predicted.Three possible N-myristoylation sites were found,which may be involved in virus infection.%运用RT-PCR技术克隆了水稻南方黑条矮缩病毒(southern rice black-streaked dwarf virus,SRBSDV)湖南鼎城株系的基因组S10片段(SRBSDV-HuNDCS10),并对其全序列进行了测定和生物信息学分析。结果显示,SRBSDV-HuNDC S10片段全长为1797bp(登录号:JQ337964),含有1个ORF,编码557个氨基酸残基的衣壳蛋白,推测分子量约62.6kD,推测等电点为7.62,与已报道的广东、海南和云南分离物病毒的S10作比较,它们的核苷酸相似性分别为99.7%、99.0%和98.4%,氨基酸相似性分别为100.0%、99.5%和99.3%。对SRBSDV-HuNDCS10及部分Fijiviruses病毒对应片段在5'URT与3'URT存在的保守序列和互补序列进行了归纳,对其ORF编码的氨基酸序列进行了motif查找,得到该属(Fijiviruses)氨基酸序列的10个保守区段。此

  13. Spectral response calibration of Au and Csl transmission photocathodes of X-ray streak camera in a 60-5500 eV photon energy region%软X射线条纹相机透射式Au与CsI阴极谱响应灵敏度标定

    Institute of Scientific and Technical Information of China (English)

    曾鹏; 袁铮; 邓博; 袁永腾; 李志超; 刘慎业; 赵屹东; 洪才浩; 郑雷; 崔明启

    2012-01-01

    本文利用北京同步辐射光源(BSRF),提出了对条纹相机Au和Csl透射阴极谱响应灵敏度进行绝对标定的方案,给出了在60—5500 eV能区的绝对谱响应灵敏度,标定不确定度好于10%.同时,基于Henke等人的计算模型,给出了透射阴极的相对谱响应灵敏度,并且进行了CH支撑衬底X射线透过率的修正.结果表明标定值与理论值符合较好.%A method is described of measuring absolute spectral response for Au and CsI transmission photocathodes in soft X-ray streak camera,which is of great importance for the inertial confinement fusion(ICF) diagnostics.Transmission photocathode is conventionally employed as photo-to-electron conversion accessories.To derive quantity information of X-ray spectra,the absolute response of photocathode must be calibrated in a range of interest.Here Au and CsI transmission photocathodes with slits are calibrated respectively on Beijing Synchrotron Radiation Facility(BSRF),in a photon energy range of 60 eV—5500 eV.This method has an uncertainty less than 10%and good feasibility.Calibration results are in good agreement with the calculation results obtained from the Henke’s photon emission model,with CH substrate effect revised.

  14. Metal artifact reduction method using metal streaks image subtraction

    Energy Technology Data Exchange (ETDEWEB)

    Pua, Rizza D.; Cho, Seung Ryong [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-04-15

    Many studies have been dedicated for metal artifact reduction (MAR); however, the methods are successful to varying degrees depending on situations. Sinogram in-painting, filtering, iterative method are some of the major categories of MAR. Each has its own merits and weaknesses. A combination of these methods or hybrid methods have also been developed to make use of the different benefits of two techniques and minimize the unfavorable results. Our method focuses on the in-paitning approach and a hybrid MAR described by Xia et al. Although in-painting scheme is an effective technique in reducing the primary metal artifacts, a major drawback is the reintroduction of new artifacts that can be caused by an inaccurate interpolation process. Furthermore, combining the segmented metal image to the corrected nonmetal image in the final step of a conventional inpainting approach causes an issue of incorrect metal pixel values. Our proposed method begins with a sinogram in-painting approach and ends with an image-based metal artifact reduction scheme. This work provides a simple, yet effective solution for reducing metal artifacts and acquiring the original metal pixel information. The proposed method demonstrated its effectiveness in a simulation setting. The proposed method showed image quality that is comparable to the standard MAR; however, quantitatively more accurate than the standard MAR.

  15. High-Speed Observer: Automated Streak Detection in SSME Plumes

    Science.gov (United States)

    Rieckoff, T. J.; Covan, M.; OFarrell, J. M.

    2001-01-01

    A high frame rate digital video camera installed on test stands at Stennis Space Center has been used to capture images of Space Shuttle main engine plumes during test. These plume images are processed in real time to detect and differentiate anomalous plume events occurring during a time interval on the order of 5 msec. Such speed yields near instantaneous availability of information concerning the state of the hardware. This information can be monitored by the test conductor or by other computer systems, such as the integrated health monitoring system processors, for possible test shutdown before occurrence of a catastrophic engine failure.

  16. Illusory Streaks from Corners and Their Perceptual Integration

    OpenAIRE

    Roncato, Sergio; Guidi, Stefano; Parlangeli, Oronzo; Battaglini, Luca

    2016-01-01

    Perceptual grouping appears both as organized forms of real figural units and as illusory or “phantom” figures. The phenomenon is visible in the Hermann grid and in configurations which generate color spreading, e.g., “neon effects.” These configurations, generally regular repetitive patterns, appear to be crossed by illusory bands filled with a brighter shade or a colored tinge connecting the various loci of illusory effects. In this work, we explore a particular new illusion showing a group...

  17. Pseudoxantoma elasticum, as a repetitive upper gastrointestinal hemorrhage cause in a pregnant woman

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Pseudoxantoma elasticum is a rare, hereditary,multisystemic disease affecting the skin, eye, and cardiovascular system. A twenty-eight-year-old female has presented to emergency unit with the complaint of gastrointestinal hemorrhage. This patient, who had been monitored in the gastroenterology clinic more than 10 times in the past 8 years, noted a repetitive hemorrhage during her previous pregnancy in her history. The examination of the patient revealed the following signs and symptoms: atrophy in the epithelium of the retina pigment; typical angioid streaks and peau d'orange finding in the fundus; thinning of the retinal nerve fiber in OCT (optic coherence tomography);bilateral and reticular papillary lesions with yellowish-color in the neck region (plucked chicken appearance);presence of bleeding foci in fundus; and nephrocalcinosis in kidneys. In light of these symptoms, the patient was diagnosed with pseudoxantoma elasticum. Skin biopsy confirmed the pseudoxantoma elasticum diagnose. PXE is an uncommon, hereditary disease. Early diagnosis of pseudoxantoma elasticum cases, is important for minimalizing systemic complications and informing the other family members through genetic counseling.

  18. An update on the ocular phenotype in patients with pseudoxanthoma elasticum

    Directory of Open Access Journals (Sweden)

    Martin eGliem

    2013-04-01

    Full Text Available Pseudoxanthoma elasticum (PXE is an inherited multi-system disorder characterized by ectopic mineralization and fragmentation of elastic fibres in the skin, the elastic laminae of blood vessels and Bruch membrane in the eye. Biallelic mutations in the ABC transporter gene ABCC6 on chromosome 16 are responsible for the disease.The pathophysiology is incompletely understood. However, there is consent that a metabolic alteration leads to dysfunction in extracellular calcium homeostasis and subsequent calcification of connective tissues rich in elastic fibres. This review summarizes and aims at explaining the variety of phenotypic ocular findings in patients with PXE. Specialised imaging techniques including white light fundus photography, blue light autofluorescence, near-infrared confocal reflectance imaging, high resolution optical coherence tomography, fluorescein and indocyanin green angiography have revealed characteristic lesions at the ocular fundus of PXE patients. These include the classic signs of angioid streaks, peau d’orange, comet lesions and choroidal neovascularisations (CNV, but also the more recently recognised features such as chorioretinal atrophy, subretinal fluid independent from CNV, pattern dystrophy-like changes, debris accumulation under the retinal pigment epithelium, and a decreased fluorescence on late phase indocyanine green angiography.

  19. Interaction between four rice proteins and P7-2, an unstructural viral protein encoded by Rice black streaked dwarf virus S7%四种水稻蛋白与水稻黑条矮缩病毒编码非结构蛋白 P7-2的互作分析

    Institute of Scientific and Technical Information of China (English)

    张上林; 孙丽英; 陈剑平

    2013-01-01

    Rice black streaked dwarf virus (RBSDV), a member of the genus Fijivirus, infects maize and rice plants and causes significant yield losses in Asia .RBSDV has a genome of 10 dsRNAs and encodes 12 proteins.Six of these proteins (P1, P2, P3, P4, P8 and P10) are structural components of the viral particle .There are six non-structural proteins, P5, P6, P7-1, P7-2, P9-1, and P9-2.Among those non-structural proteins, P5, P6 and P9-1 have been shown to involve in viroplasm formation and P 7-1 has been identified to form the cytoplasmic tubular-like structures that serve as a conduit for virion movement between cells .The function of P7-2 and P9-2 is still unknow . In this study , we utilized protein Pull-Down assay and liquid chromatography-tandem mass spectrometry ( LC-MS/MS) techniques to identify the proteins from rice ( Oryza sativa) that interact with P7-2.Four proteins were found to bind P7-2 by Pull-Down assay.Two of them are transcription-associated proteins, one is an aminotransferase and the other one is a putative chaperonin 60 beta precursor .Using real-time quantitative PCR , the transcript expression lev-els of transcription-associated protein and putative chaperonin 60 beta precursor were up-regulated by RBSDV infec-tion.In contrast , the transcript expression of aminotransferase protein was suppressed by RBSDV infection .%水稻黑条矮缩病毒( RBSDV)是斐济病毒属的成员之一,可侵染玉米和水稻等作物,给亚洲地区的田间生产带来严重的损失。 RBSDV有10条双链RNA(double strand RNA, dsRNA)基因组,编码12个蛋白。其中6个蛋白是病毒粒子的结构成分(P1,P2,P3,P4,P8,P10),6个非结构蛋白分别为P5,P6,P7-1,P7-2,P9-1, P9-2。在非结构蛋白中,P5,P6和P9-1已被证实参与形成毒质结构,P7-1被认为可在细胞质中形成类似管状的结构作为病毒胞间扩散的通道,P7-2和P9-2的功能目前尚不明确。

  20. Construction and Self-activated Detection of the Baits of HC-Pro,P3N-PIPO,CP and VPg from Sugarcane streak mosaic virus for Yeast Two Hybrid System%甘蔗条纹花叶病毒 HC-Pro、P3N-PIPO、CP 和 VPg基因酵母双杂交诱饵表达载体的构建及自激活检测

    Institute of Scientific and Technical Information of China (English)

    翟玉山; 彭磊; 杨永庆; 邓宇晴; 程光远; 郑艳茹; 徐景升

    2016-01-01

    为探索甘蔗条纹花叶病毒与甘蔗的互作机制,利用酵母双杂交技术筛选与 SCSMV 互作的甘蔗因子基因,利用 PCR 技术克隆了 SCSMV 的 HC-Pro、P3N-PIPO、CP 和 VPg 的编码区,构建到酵母双杂交诱饵载体 pGBKT7上,获得了 pGBKT7-HC-Pro、pGBKT7-P3N-PIPO、pGBKT7-CP 和 pGBKT7-VPg 4个诱饵载体。结果显示,将重组质粒转化酵母 Y2HGold 酵母菌株后,酵母菌株在 SD/-Trp 平板上生长良好,表明重组诱饵质粒表达产物对酵母细胞无毒性;在SD/-Trp/X-α-gal 平板上长出白色菌落未变蓝,在 SD/-Leu、SD/-Trp/-Ade、SD/-Trp/-His 和 SD/-Trp/X-α-gal/AbA 平板上不能生长,表明重组诱饵质粒表达产物对 MEL1、ADE2、HIS3和 AUR1-C 报告基因无自激活作用。构建的诱饵表达载体可以作为诱饵用于文库筛选,为探索 SCSMV 侵染机制和发病机理奠定了基础。%Sugarcane streak mosaic virus (SCSMV) is one of the main pathogens causing mosaic syndrome on sugarcane.Yeast two hybrid system (Y2HS) is the main technique to investigate the mechanism between pathogen with host plant.In order to elucidate the interaction between the SCSMV and sugarcane by Y2HS,the coding se-quences of HC-Pro,P3N-PIPO,CP and VPg from SCSMV were cloned into the pGBKT7,respectively,to generate 4 bait vectors,pGBKT7-HC-Pro,pGBKT7-P3N-PIPO,pGBKT7-CP and pGBKT7-VPg.Then the 4 bait vectors were transformed into the yeast strain Y2HGold,respectively.All the Y2HGold strains containing the bait vectors grew well on the SD/-Trp media as the control.It suggested that the proteins encoded by the baits were not toxic to yeast. All these 4 transformed yeast strains developed white but not blue plaques on the SD/-Trp/X-α-gal media.And they could not survive on the SD/-Leu,SD/-Trp/-Ade,SD/-Trp/-His or SD/-Trp/X-α-gal/AbA media,which indicating the bait proteins could not activate the report genes

  1. Efeitos do Banana streak virus no desenvolvimento de cultivares de bananeira Effects of banana streak virus on the development of banana cultivars

    Directory of Open Access Journals (Sweden)

    Daniela Garcia Silveira

    2007-06-01

    Full Text Available Este trabalho avaliou, em condições de casa de vegetação, os efeitos da infecção pelo BSV no crescimento de cinco cultivares de bananeira. Mudas micropropagadas das cultivares SH 3640, FHIA 18, Caipira, Thap Maeo e Pioneira foram inoculadas com BSV pela cochonilha Planacoccus citri Risso. Como controles utilizaram-se mudas não inoculadas e inoculadas com cochonilhas não virulíferas. Avaliou-se a altura das plantas, o diâmetro do pseudocaule, o número de folhas, a área foliar e as massas da matéria seca da parte aérea e da raiz. Os primeiros sintomas do BSV foram detectados 15 dias após a inoculação em todas as plantas inoculadas com o vírus. Houve diferenças estatísticas significativas nas variáveis analisadas, concluindo-se que o vírus afetou o desenvolvimento das plantas de todas as cultivares avaliadas.On this study, the BSV effects on five banana cultivars were evaluated under greenhouse conditions. Micropropagated plants of cultivars SH 3640, FHIA 18, Caipira, Thap Maeo and Pioneira were inoculated with BSV using mealybug Planacoccus citri Risso as a vector. Controls plants were inoculated with non-viruliferous mealybugs or not inoculated. Plant height, pseudostem diameter, number of leaves, foliar area and root and shoot dry mass were evaluated. Disease symptoms were first visible 15 days after plant inoculation with virus. Statistical differences were detected for the host growth variables evaluated. It was concluded that BSV affected significantly the growth of all studied cultivars.

  2. Genetic insights into Graminella nigrifrons competence for Maize fine streak virus infection and transmission

    Science.gov (United States)

    Insects are critical for the spread of most plant virus diseases, with >75% of plant viruses depending on an insects for transmission to new, uninfected hosts. However, little is known about the molecular and cellular factors in the insect that are important for virus transmission. The black-faced l...

  3. X-ray imaging of JET. A design study for a streak camera application

    International Nuclear Information System (INIS)

    A single dimensional imaging system is proposed which will image a strip of the JET plasma up to 320 times per shot with a time resolution of better than 50 μs using the bremsstrahlung X-rays. The images are obtained by means of a pinhole camera followed by an X-ray image intensifier system the output of which is in turn digitised by a photodiode array. The information is stored digitally in a fast memory and is immediately available for display or analysis. (author)

  4. Focus-independent particle size measurement from streak images: a comparison of multivariate methods.

    Science.gov (United States)

    Tazik, Shawna K; Pearl, Megan R; Rekully, Cameron M; Viole, Nicholas S; DeJong, Stephanie A; Shaw, Timothy J; Richardson, Tammi L; Myrick, Michael L

    2015-03-01

    Our laboratories have recently developed a flow-through imaging photometer to characterize and classify fluorescent particles between 3 and 47 μm in size. The wide aperture of the objective lens (0.7 NA) required for measuring spectral fluorescence of single particles restricts the depth of field, such that a large sample volume results in many particles that are out of focus. Here, we describe numerical methods for determining the size of these objects, regardless of their distance from the focal plane, using image processing and multivariate calibration. An intensity profile is extracted from the images and is used as the input for a variety of calibration methods, including partial least squares, neural networks, and support vector machines. The capabilities of these methods are examined to establish the best method for particle sizing that is independent of focus. We found that support vector machines provided the best results, with size estimation error of ±3.1 μm. PMID:25599099

  5. Willapa NWR: Initial Survey Instructions for Streaked Horned Lark Monitoring - Habitat Quality

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The endemic subspecies of the Pacific coastal form of horned lark is found only in western Oregon and Washington. As its population and distribution has decreased...

  6. Monitoring Western Snowy Plover and Streaked Horned Lark Populations [Leadbetter Point]: Willapa Bay National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This project was funded through the Region 1 Inventory and Monitoring Initiative RFP in 2011. The objectives of this project are to conduct Western Snowy Plover...

  7. Hausdorff Distance evaluation of orthodontic accessories' streaking artifacts in 3D model superimposition

    Directory of Open Access Journals (Sweden)

    José Rino Neto

    2012-10-01

    Full Text Available The aim of this study was to determine whether image artifacts caused by orthodontic metal accessories interfere with the accuracy of 3D CBCT model superimposition. A human dry skull was subjected three times to a CBCT scan: at first without orthodontic brackets (T1, then with stainless steel brackets bonded without (T2 and with orthodontic arch wires (T3 inserted into the brackets' slots. The registration of image surfaces and the superimposition of 3D models were performed. Within-subject surface distances between T1-T2, T1-T3 and T2-T3 were computed and calculated for comparison among the three data sets. The minimum and maximum Hausdorff Distance units (HDu computed between the corresponding data points of the T1 and T2 CBCT 3D surface images were 0.000000 and 0.049280 HDu, respectively, and the mean distance was 0.002497 HDu. The minimum and maximum Hausdorff Distances between T1 and T3 were 0.000000 and 0.047440 HDu, respectively, with a mean distance of 0.002585 HDu. In the comparison between T2 and T3, the minimum, maximum and mean Hausdorff Distances were 0.000000, 0.025616 and 0.000347 HDu, respectively. In the current study, the image artifacts caused by metal orthodontic accessories did not compromise the accuracy of the 3D model superimposition. Color-coded maps of overlaid structures complemented the computed Hausdorff Distances and demonstrated a precise fusion between the data sets.

  8. Not all streaks are the same: Individual differences in risk preferences during runs of gains and losses

    Directory of Open Access Journals (Sweden)

    Christopher T. Ball

    2012-07-01

    Full Text Available Runs of gains and losses are particularly salient to decision makers because of their perceived departure from randomness, as well as their immediate impact on the financial status of the decision makers. Past research has focused on decision making biases that relate to faulty conceptions of chance and luck, such as the gambler's fallacy and the hot hand effect. Participants in the current study bet on the outcomes of a long sequence of simulated coin tosses. Risk preferences were found to change as a function of run valence (i.e., losses vs. gains, run length, and financial status. Individuals were found to differ in the effect of all of these factors, in their responses to runs of gains and losses in sequential risky choice.

  9. β-Catenin Regulates Primitive Streak Induction through Collaborative Interactions with SMAD2/SMAD3 and OCT4

    DEFF Research Database (Denmark)

    Funa, Nina Sofi Ayumi; Schachter, Karen; Lerdrup, Mads;

    2015-01-01

    demonstrate a broader role for b-catenin in PS formation by analyzing its genome-wide binding in a human embryonic stem cell model of PS induction. b-catenin occupies regulatory regions in numerous PS and neural crest genes, and direct interactions between b-catenin and the Nodal effectors SMAD2/SMAD3...... specification. This study provides mechanistic insight into how Wnt signaling controls early cell lineage decisions....

  10. The Use of Fungal Endophytes Against Vascular Streak Dieback (VSD) Oncobasidium theobromae on Seedling of Cocoa Plant

    OpenAIRE

    Nur, Amin; Muslim, Salam; Asman; Ryan,, Tony; Danial, Rahim

    2014-01-01

    Fungal endophytes are Fungus that live within plant tissues without causing symptoms of disease. A host plant and fungal endophytes living on it have a mutulistic relathionship. The host provides substrate and space for the endophytes to grow while the fungal endophytes promote plant growth and protect the plant hosts from pests and diseases. The research aimed to investigate of fungal endopohytes e.g Aspergillus sp, Beauveria sp, Culvularia sp, and Trichoderma sp isolated from healthy branch...

  11. A streak camera based fiber optic pulsed polarimetry technique for magnetic sensing to sub-mm resolution

    Science.gov (United States)

    Smith, R. J.; Weber, T. E.

    2016-11-01

    The technique of fiber optic pulsed polarimetry, which provides a distributed (local) measurement of the magnetic field along an optical fiber, has been improved to the point where, for the first time, photocathode based optical detection of backscatter is possible with sub-mm spatial resolutions. This has been realized through the writing of an array of deterministic fiber Bragg gratings along the fiber, a so-called backscatter-tailored optical fiber, producing a 34 000-fold increase in backscatter levels over Rayleigh. With such high backscatter levels, high repetition rate lasers are now sufficiently bright to allow near continuous field sensing in both space and time with field resolutions as low as 0.005 T and as high as 170 T over a ˜mm interval given available fiber materials.

  12. ‘My independent streak may get in the way’: how older adults respond to falls prevention education in hospital

    Science.gov (United States)

    Hill, Anne-Marie; Francis-Coad, Jacqueline; Haines, Terry P; Waldron, Nicholas; Etherton-Beer, Christopher; Flicker, Leon; Ingram, Katharine; McPhail, Steven M

    2016-01-01

    Objectives The aim of the study was to determine how providing individualised falls prevention education facilitated behaviour change from the perspective of older hospital patients on rehabilitation wards and what barriers they identified to engaging in preventive strategies. Design A prospective qualitative survey. Methods Older patients (n=757) who were eligible (mini-mental state examination score>23/30) received falls prevention education while admitted to eight rehabilitation hospital wards in Western Australia. Subsequently, 610 participants were surveyed using a semistructured questionnaire to gain their response to the in-hospital education and their identified barriers to engaging in falls prevention strategies. Deductive content analysis was used to map responses against conceptual frameworks of health behaviour change and risk taking. Results Participants who responded (n=473) stated that the education raised their awareness, knowledge and confidence to actively engage in falls prevention strategies, such as asking for assistance prior to mobilising. Participants’ thoughts and feelings about their recovery were the main barriers they identified to engaging in safe strategies, including feeling overconfident or desiring to be independent and thinking that staff would be delayed in providing assistance. The most common task identified as potentially leading to risk-taking behaviour was needing to use the toilet. Conclusions Individualised education assists older hospital rehabilitation patients with good levels of cognition to engage in suitable falls prevention strategies while on the ward. Staff should engage with patients to understand their perceptions about their recovery and support patients to take an active role in planning their rehabilitation. PMID:27466244

  13. Influences of a-tocopherol on cholesterol metabolism and fatty streak development in apolipoprotein E-deficient mice fed an atherogenic diet

    Directory of Open Access Journals (Sweden)

    Peluzio M.C.G.

    2001-01-01

    Full Text Available Although the role of oxidized lipoproteins is well known in atherogenesis, the role of vitamin E supplementation is still controversial. There is also little information about cholesterol metabolism (hepatic concentration and fecal excretion in the new models of atherosclerosis. In the present study, we evaluated the effect of moderate vitamin E supplementation on cholesterol metabolism and atherogenesis in apolipoprotein E (apo E-deficient mice. Apo E-deficient mice were fed an atherogenic diet containing 40 or 400 mg/kg of alpha-tocopherol acetate for 6 weeks. Total cholesterol in serum and liver and 3-OH-alpha-sterols in feces, and fecal excretion of bile acids were determined and histological analyses of aortic lesion were performed. A vitamin E-rich diet did not affect body weight, food intake or serum cholesterol. Serum and hepatic concentrations of cholesterol as well as sterol concentration in feces were similar in both groups. However, when compared to controls, the alpha-tocopherol-treated mice showed a reduction of about 60% in the atherosclerotic lesions when both the sum of lesion areas and the average of the largest lesion area were considered. These results demonstrate that supplementation of moderate doses of alpha-tocopherol was able to slow atherogenesis in apo E-deficient mice and to reduce atherogenic lipoproteins without modifying the hepatic pool or fecal excretion of cholesterol and bile acids.

  14. Cooperative Recovery Initiative 2016: Increasing Populations of Western Snowy Plovers and Streaked Horned Larks at Willapa National Wildlife Refuge and Adjacent Coastal Beaches

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Project goals include measurable improvement in the number of breeding pairs of snowy plovers at Leadbetter Point and enhance their reproductive success to achieve...

  15. Study of pomegranate (Punica granatum L. peel extract containing anthocyanins on fatty streak formation in the renal arteries in hypercholesterolemic rabbits

    Directory of Open Access Journals (Sweden)

    Fatemeh Sharifiyan

    2016-01-01

    Conclusion: The results of this study indicate that consumption of pomegranate peel extract containing anthocyanins (polyphenol content 1 g/kg diet despite of a significant increase in serum antioxidant capacity cannot protect the kidneys from hypercholesterolemia-induced damages during the treatment period.

  16. Positive selection and intragenic recombination contribute to high allelic diversity in effector genes of Mycosphaerella fijiensis, causal agent of the black leaf streak disease of banana

    NARCIS (Netherlands)

    Stergiopoulos, I.; Cordovez da Cunha, V.; Okmen, B.; Beenen, H.G.; Kema, G.H.J.; Wit, de P.J.G.M.

    2014-01-01

    Previously, we have determined the nonhost-mediated recognition of the MfAvr4 and MfEcp2 effector proteins from the banana pathogen Mycosphaerella fijiensis in tomato, by the cognate Cf-4 and Cf-Ecp2 resistance proteins, respectively. These two resistance proteins could thus mediate resistance again

  17. Study of pomegranate (Punica granatum L.) peel extract containing anthocyanins on fatty streak formation in the renal arteries in hypercholesterolemic rabbits

    OpenAIRE

    Fatemeh Sharifiyan; Ahmad Movahedian-Attar; Nafiseh Nili; Sedigheh Asgary

    2016-01-01

    Background: The influence of the supplementation of pomegranate peel extract containing anthocyanins on atherosclerotic plaque formation induced by hypercholesterolemia was investigated in renal arteries in rabbits. Materials and Methods: After the determination of polyphenol and anthocyanin′s content of P. granatum peel hydroalcoholic extract, 30 male rabbits were randomly divided into three groups. They were fed basic diet, hypercholesterolemic diet and hypercholesterolemic diet along w...

  18. The Effect of EDTA and Garlic Extract Combination on Plasma Lipids, Lipoporteins, and Fatty Streaks in Cholesterol Fed Male Rabbit Aorta

    OpenAIRE

    Sharifi, M. R.; S Javdan; M FESHARAKI

    2004-01-01

    Background: Garlic extract is used in treatment of hypercholesterolemia, although its efficacy isn’t exactly clear. There is a little information about mechanism of garlic effect on plasma lipids. By intervention of garlic in atherogenesis process it has been shown that it has a protective effect against cardiovascular disease. On the other hand, it has been shown that EDTA (Ethylene Diamin Tetra Acetic Acid) improves blood flow and decreases the vascular atherosclerotic symptoms. Methods: Th...

  19. THE STUDY OF STORM RAINFALL CAUSED BY INTERACTION BETWEEN THE NON-ZONAL HIGH LEVEL JET STREAK AND TYPHOON IN THE DISTANCE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, statistics were analyzed concerning correlation between the storm rainfall far from typhoon and non-zonal upper-level jet stream. The results show that the jet stream at 200 hPa is constantly SW (90.2 %) during the period in which storm rainfall occurs. Rainfall area lies in the right rear regions of the jet axes. While the storm intensifies, the jet tends to be stronger and turn non-zonal. With the MM4 model, numerical simulation and diagnosis were carried out for Typhoon No.9711 (Winnie) on August 19 to 20, 1997. The distant storm rainfall is tightly correlative to the jet and low-level typhoon trough. The divergence field of jet is related to the v component. The upper level can cause the allobaric wind convergence at low level. This is the result of the form of low-level typhoon trough and the strength of the storm. By scale analysis, it is found that there is a branch of middle scale transverse inverse circulation in the right entrance regions behind the jet below the 300-hPa level, which is very important to the maintenance and strengthening of storm rainfall. This branch of inverse circulation is relative to the reinforcement of jet's non-zonal characteristics. From the field of mesoscale divergence field and non-zonal wind field, we know that the stronger symmetry caused by transverse circulation in the two sides of the jet, rainfall's feedback and reinforcement of jet's non-zonal characteristics had lead to positive feedback mechanism that was favorable of storm rainfall's strengthening.

  20. Toward the positional cloning of qBlsr5a, a QTL underlying resistance to bacterial leaf streak, using overlapping sub-CSSLs in rice.

    Directory of Open Access Journals (Sweden)

    Xiaofang Xie

    Full Text Available Bacterial leaf steak (BLS is one of the most destructive diseases in rice. Studies have shown that BLS resistance in rice is quantitatively inherited, controlled by multiple quantitative trait loci (QTLs. A QTL with relatively large effect, qBlsr5a, was previously mapped in a region of ∼ 380 kb on chromosome 5. To fine map qBlsr5a further, a set of overlapping sub-chromosome segment substitution lines (sub-CSSLs were developed from a large secondary F2 population (containing more than 7000 plants, in which only the chromosomal region harboring qBlsr5a was segregated. By genotyping the sub-CSSLs with molecular markers covering the target region and phenotyping the sub-CSSLs with artificial inoculation, qBlsr5a was delimited to a 30.0-kb interval, in which only three genes were predicted. qRT-PCR analysis indicated that the three putative genes did not show significant response to the infection of BLS pathogen in both resistant and susceptible parental lines. However, two nucleotide substitutions were found in the coding sequence of gene LOC_Os05g01710, which encodes the gamma chain of transcription initiation factor IIA (TFIIAγ. The nucleotide substitutions resulted in a change of the 39th amino acid from valine (in the susceptible parent to glutamic acid (in the resistant parent. Interestingly, the resistant parent allele of LOC_Os05g01710 is identical to xa5, a major gene resistant to bacterial leaf blight (another bacterial disease of rice. These results suggest that LOC_Os05g01710 is very possibly the candidate gene of qBlsr5a.

  1. DETECTABLE NEUTRON YIELD THRESHOLD OF NEUTRON STREAK IMAGE TUBE%中子扫描变象管的最小可探测脉冲中子产额

    Institute of Scientific and Technical Information of China (English)

    廖华; 张焕文; 杨勤劳; 董改云

    2000-01-01

    本文从噪音理论出发导出了中子扫描变象管的探测方程 ,从而求得了中子扫描变象管可探测的最小脉冲中子产额,而且讨论了记录系统灵敏度对探测阈的影响.中子扫描变象管的静态实验证实了聚乙烯加碘化铯组合中子阴极的可行性和理论分析的正确性.

  2. [Age-related Macular Degeneration in the Japanese].

    Science.gov (United States)

    Yoshimura, Nagahisa

    2016-03-01

    agreement. We also found more cases of PCV among the Japanese than among the French. II. PCV. About 50% of exudative AMD cases in the Japanese population are PCV. Because of its peculiar angiographic findings, PCV has long been considered to be a distinct clinical entity different from the usual exudative AMD. Also, there have been serious discussions on the nature of PCV. In our analyses, about 20% of PCV cases show rather large lesion sizes that exceed the vascular arcade. Scar formation in the macula and compromised vision are frequent findings in such cases. The occurrence of PCV in the inferior staphyloma or in angioid streaks shows heterogeneity in PCV. These findings suggest that PCV may be a finding on indocyanine green angiography rather than a distinct clinical entity. Spectral domain OCT examination shows that the branching vascular network of PCV is located between the retinal pigment epithelium and Bruch's membrane. In cases with retinal pigment epithelial detachment, CNV from the branching vascular network was found to extend along the roof of the detached retinal pigment epithelium. Such findings show that the branching vascular network of PCV is type 1 CNV. Complement factor H (CFH) and age-related maculopathy 2 (ARMS2)/High temperature requirement 1 (HTRA1) located on chromosome 10 (10q26) are well-established disease susceptible genes of AMD. In the Japanese, the prevalence of CFH Y402H gene polymorphism is low and ARMS2/HITRA1 plays a more important role in the development of AMD. In ARMS2 A69S polymorphism, a large deletion/insertion (443de1/54ins) that is reported in Caucasians was also found in Japanese. Thus, the genetic background of Caucasian and Japanese AMD is quite similar, as is also the case with exudative AMD and PCV. Our findings show that PCV is not a distinct clinical entity but is a subtype of exudative AMD. III. Exudative AMD with choroidal vascular hyperpermeability. Choroidal vascular hyperpermeability observed in central serous

  3. Dicty_cDB: Contig-U11858-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available nzymatic polyprotein; Includes: RecNam... 45 0.007 AF214005_1( AF214005 |pid:none) Banana streak virus polyp...Pol polyprotein; AltName: Full=Pr125P... 42 0.061 AY750155_3( AY750155 |pid:none) Banana...234_3( AJ002234 |pid:none) Banana streak OL virus coding regi... 40 0.23 DQ451009...40 0.23 DQ859899_3( DQ859899 |pid:none) Banana streak virus isolate TRY, c... 40 ...7 chromo... 38 0.88 AY493509_3( AY493509 |pid:none) Banana streak GF virus, compl

  4. 水稻黑条矮缩病毒江苏玉米分离物全基因组序列及进化分析%Phylogenetic analysis of whole genome of Rice black-streaked dwarf virus isolated from Zea mays in Jiangsu province, China

    Institute of Scientific and Technical Information of China (English)

    王增辉; 王德亚; 王国鲁; 侯艳敏; 赵凯茜; 于成明; 张振甲; 师科荣; 李向东

    2016-01-01

    The whole genome of RBSDV was cloned by RT-PCR from maize in Jiangsu province of China,and designated RBSDV-JS.Size of genome segments and characteristic of ORFs encoded by RBSDV-JS are largely the same as previously reported RBSDV isolates.Nucleotide sequence alignment and phylogenetic trees showed that reassortment among RBSDV isolates occurs frequently.It is also suggested that RBSDV-JS isolate has high-est sequence identity with RBSDV-HuB isolated from Hubei province and RBSDV-HeB isolated from Hebei province,and has the lowest similarity with RBSDV-AH-MX8 isolated from Anhui province.Furthermore,RNA recombination played different roles during the evolution of various segments of RBSDV.No RNA recombination was detected in S1,S2 and S4,whereas S3,S5,S6,S8 and S10 showed low-frequency of RNA recombination.For S7 and S9,RNA recombination was frequently detected,especially the S7 segment with a striking high frequency of RNA recombination.%利用RT-PCR从江苏玉米上克隆水稻黑条矮缩病毒(RBSDV)的全基因组,其基因组10个片段核苷酸数目和蛋白编码情况与已报道的RBSDV分离物基本一致.基因组的序列一致性分析和系统进化树表明,RBSDV基因组片段间存在频繁的RNA重排现象;江苏玉米分离物(JS)与湖北玉米分离物(HuB)和河北小麦分离物(HeB)的整体亲缘关系较近,而与安徽分离物(AH-MX8)的整体亲缘关系最远.综合本研究及前人对S8和S10的研究,RBSDV基因组不同片段的进化中RNA重组的作用不同:S1、S2和S4中没有RNA重组;S3、S5、S6、S8和S10中存在低频率重组;S7和S9存在较高频率重组,其中S7的高频率重组尤为显著.

  5. 通过构建单染色体片段代换系验证水稻细菌性条斑病抗性QTL qBlsr3d%Verification of QTL qBlsr3d Conferring Resistance to Bacterial Leaf Streak in Rice by Constructing SSSL

    Institute of Scientific and Technical Information of China (English)

    曹金良; 陈志伟; 林德塨; 吴为人; 谢小芳

    2014-01-01

    单染色体片段代换系是QTL精细定位的理想材料。水稻对细菌性条斑病的抗性属于典型的数量抗性。本研究以课题组构建的携有多个细条病抗性QTL (qBlsr3d, qBlsr5a和qBlsr5b)的近等基因系H359R为供体亲本,以感病品种H359为受体亲本,通过杂交,多次回交和自交,并结合分子标记辅助选择,成功构建了仅携有QTL qBlsr3d的单染色体片段代换系,命名为H359-BLSR3D。进一步通过分子标记定位分析表明:渗入区段位于第3号染色体分子标记3DSSR3和3DSSR12之间,物理距离约为1250 kb。田间接种鉴定表明:H359-BLSR3D与感病亲本H359间的细条病抗性差异显著,结果证明了抗性QTL qBlsr3d的真实存在。H359-BLSR3D将为QTL qBlsr3d的精细定位和最终克隆奠定基础。%Chromosome segment substitution line (CSSL) is an ideal material for fine mapping of QTL. Bacterial leaf steak (BLS) resistance in rice is quantitatively inherited. In the present study, using near-isogenic lines H359R with multi-resistant QTLs (qBlsr3d, qBlsr5a, qBlsr5b) as the donor parent (constructed by our group previous) and H359 as the recurrent parent, by cross, back-cross, self-cross and marker-based selection, single segment substitution line (SSSL) with qBlsr3d was developed. Further mapping showed that:the target fragment is located within a 1 250 kb region between markers 3DSSR3 and 3DSSR12 on chromosome 3. Inoculation experiment showed that the resistrance was statistically significant between H359-BLSR3D and H359, the result testify that QTL qBlsr3d is truly exsit. H359-BLSR3D would provide the basis for QTL qBlsr3d fine mapping and its final cloning.

  6. Ardea purpurea madagascariensis, nov. subsp. from Madagascar

    NARCIS (Netherlands)

    Oort, van E.D.

    1910-01-01

    The purple heron of Madagascar is a much darker bird than Ardea purpurea L. of Europe and Africa. The fore part of the throat and the neck are streaked with black like in this species, but the black streaks are broader and more numerous. The black lines, running down each side of the neck are much b

  7. SECRET OF A BALL LIGHTNING

    Directory of Open Access Journals (Sweden)

    E.V. Savich

    2013-04-01

    Full Text Available A ball lightning is a natural phenomenon that occurs at a streak lightning stroke with its action by thermal and magnetic energy releasing around the streak lightning channel and transforming, in the end, the surrounding air into a steam cloud that transits into ferroelectric state under the magnetic field action.

  8. Unified Approach to Real Numbers in Various Mathematical Settings

    OpenAIRE

    Lešnik, Davorin

    2014-01-01

    We provide a setting-independent definition of reals by introducing the notion of a streak. We show that various standard constructions of reals satisfy our definition. We study the structure of reals by noting that its pieces correspond to reflections on the category of streaks.

  9. EVEN-SKIPPED HOMEOBOX 1 controls human ES cell differentiation by directly repressing GOOSECOID expression

    DEFF Research Database (Denmark)

    Kalisz, Mark; Winzi, Maria Karin; Bisgaard, Hanne Cathrine;

    2012-01-01

    TGFß signaling patterns the primitive streak, yet little is known about transcriptional effectors that mediate the cell fate choices during streak-like development in mammalian embryos and in embryonic stem (ES) cells. Here we demonstrate that cross-antagonistic actions of EVEN-SKIPPED HOMEOBOX 1...

  10. Nonlinear Transient Growth and Boundary Layer Transition

    Science.gov (United States)

    Paredes, Pedro; Choudhari, Meelan M.; Li, Fei

    2016-01-01

    Parabolized stability equations (PSE) are used in a variational approach to study the optimal, non-modal disturbance growth in a Mach 3 at plate boundary layer and a Mach 6 circular cone boundary layer. As noted in previous works, the optimal initial disturbances correspond to steady counter-rotating streamwise vortices, which subsequently lead to the formation of streamwise-elongated structures, i.e., streaks, via a lift-up effect. The nonlinear evolution of the linearly optimal stationary perturbations is computed using the nonlinear plane-marching PSE for stationary perturbations. A fully implicit marching technique is used to facilitate the computation of nonlinear streaks with large amplitudes. To assess the effect of the finite-amplitude streaks on transition, the linear form of plane- marching PSE is used to investigate the instability of the boundary layer flow modified by spanwise periodic streaks. The onset of bypass transition is estimated by using an N- factor criterion based on the amplification of the streak instabilities. Results show that, for both flow configurations of interest, streaks of sufficiently large amplitude can lead to significantly earlier onset of transition than that in an unperturbed boundary layer without any streaks.

  11. Structure of turbulent wedges created by isolated surface roughness

    Science.gov (United States)

    Kuester, Matthew S.; White, Edward B.

    2016-04-01

    Isolated surface roughness in a laminar boundary layer can create a wedge of turbulence that spreads laterally into the surrounding laminar flow. Some recent studies have identified high- and low-speed streaks along the exterior of turbulent wedges. In this experiment, developing turbulent wedges are measured to observe the creation of these streaks. Naphthalene shear stress surface visualization and hotwire measurements are utilized to investigate the details of turbulent wedges created by cylinders in a laminar flat-plate boundary layer. Both the surface visualization and the hotwire measurements show high- and low-speed streaks in the wake of the cylinder that devolve into a turbulent wedge. The turbulent wedge spreading is associated with the emergence of these high- and low-speed streaks along the outside of the wedge. As the wedge evolves in the streamwise direction, these streaks persist inside of the core of the wedge, while new, lower amplitude streaks form along the outside of the wedge. Adding asymmetry to the cylinder moved the virtual origin closer to the roughness and increased the vortex shedding frequency, while adding small-scale roughness features did not strongly affect turbulent wedge development. Intermittency calculations additionally show the origin of the turbulent core inside of the wedge. The structure and spacing of the high-speed streaks along the extremities of the turbulent wedge give insight into the spreading angle of the turbulent wedge.

  12. Transition Delay in Hypersonic Boundary Layers via Optimal Perturbations

    Science.gov (United States)

    Paredes, Pedro; Choudhari, Meelan M.; Li, Fei

    2016-01-01

    The effect of nonlinear optimal streaks on disturbance growth in a Mach 6 axisymmetric flow over a 7deg half-angle cone is investigated in an e ort to expand the range of available techniques for transition control. Plane-marching parabolized stability equations are used to characterize the boundary layer instability in the presence of azimuthally periodic streaks. The streaks are observed to stabilize nominally planar Mack mode instabilities, although oblique Mack mode disturbances are destabilized. Experimentally measured transition onset in the absence of any streaks correlates with an amplification factor of N = 6 for the planar Mack modes. For high enough streak amplitudes, the transition threshold of N = 6 is not reached by the Mack mode instabilities within the length of the cone, but subharmonic first mode instabilities, which are destabilized by the presence of the streaks, reach N = 6 near the end of the cone. These results suggest a passive flow control strategy of using micro vortex generators to induce streaks that would delay transition in hypersonic boundary layers.

  13. Correction of absorption-edge artifacts in polychromatic X-ray tomography in a scanning electron microscope for 3D microelectronics

    International Nuclear Information System (INIS)

    X-ray tomography is widely used in materials science. However, X-ray scanners are often based on polychromatic radiation that creates artifacts such as dark streaks. We show this artifact is not always due to beam hardening. It may appear when scanning samples with high-Z elements inside a low-Z matrix because of the high-Z element absorption edge: X-rays whose energy is above this edge are strongly absorbed, violating the exponential decay assumption for reconstruction algorithms and generating dark streaks. A method is proposed to limit the absorption edge effect and is applied on a microelectronic case to suppress dark streaks between interconnections

  14. Correction of absorption-edge artifacts in polychromatic X-ray tomography in a scanning electron microscope for 3D microelectronics

    Energy Technology Data Exchange (ETDEWEB)

    Laloum, D., E-mail: david.laloum@cea.fr [Université Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles (France); Printemps, T.; Bleuet, P. [Université Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Lorut, F. [STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles (France)

    2015-01-15

    X-ray tomography is widely used in materials science. However, X-ray scanners are often based on polychromatic radiation that creates artifacts such as dark streaks. We show this artifact is not always due to beam hardening. It may appear when scanning samples with high-Z elements inside a low-Z matrix because of the high-Z element absorption edge: X-rays whose energy is above this edge are strongly absorbed, violating the exponential decay assumption for reconstruction algorithms and generating dark streaks. A method is proposed to limit the absorption edge effect and is applied on a microelectronic case to suppress dark streaks between interconnections.

  15. Correction of absorption-edge artifacts in polychromatic X-ray tomography in a scanning electron microscope for 3D microelectronics

    Science.gov (United States)

    Laloum, D.; Printemps, T.; Lorut, F.; Bleuet, P.

    2015-01-01

    X-ray tomography is widely used in materials science. However, X-ray scanners are often based on polychromatic radiation that creates artifacts such as dark streaks. We show this artifact is not always due to beam hardening. It may appear when scanning samples with high-Z elements inside a low-Z matrix because of the high-Z element absorption edge: X-rays whose energy is above this edge are strongly absorbed, violating the exponential decay assumption for reconstruction algorithms and generating dark streaks. A method is proposed to limit the absorption edge effect and is applied on a microelectronic case to suppress dark streaks between interconnections.

  16. Polarization Effects in Attosecond Photoelectron Spectroscopy

    DEFF Research Database (Denmark)

    Baggesen, Jan Conrad; Madsen, Lars Bojer

    2010-01-01

    following the field instead. We show that polarization effects may lead to an apparent temporal shift that needs to be properly accounted for in the analysis. The effect may be isolated and studied by angle-resolved photoelectron spectroscopy from oriented polar molecules. We also show that polarization......We study the influence of polarization effects in streaking by combined atto- and femtosecond pulses. The polarization-induced terms alter the streaking spectrum. The conventional streaking spectrum, which maps to the vector potential of the femtosecond pulse, is modified by a contribution...

  17. Nuclear test experimental science

    Energy Technology Data Exchange (ETDEWEB)

    Struble, G.L.; Middleton, C.; Bucciarelli, G.; Carter, J.; Cherniak, J.; Donohue, M.L.; Kirvel, R.D.; MacGregor, P.; Reid, S. (eds.)

    1989-01-01

    This report discusses research being conducted at Lawrence Livermore Laboratory under the following topics: prompt diagnostics; experimental modeling, design, and analysis; detector development; streak-camera data systems; weapons supporting research.

  18. Experimental characterisation of a novel viscoelastic rectifier design

    DEFF Research Database (Denmark)

    Jensen, Kristian Ejlebjærg; Okkels, Fridolin; Szabo, Peter;

    2012-01-01

    A planar microfluidic system with contractions and obstacles is characterized in terms of anisotropic flow resistance due to viscoelastic effects. The working mechanism is illustrated using streak photography, while the diodicity performance is quantified by pressure drop measurements. The point ...

  19. The genomes of Mycosphaerella graminicola and M. fijiensis

    NARCIS (Netherlands)

    Goodwin, S.B.; Kema, G.H.J.

    2014-01-01

    Mycosphaerella graminicola (synonym: Zymoseptoria tritici) and Mycosphaerella fijiensis in the Ascomycetes order Capnodiales are economically important pathogens causing Septoria tritici blotch of wheat and black Sigatoka or leaf streak of banana, respectively. Both diseases occur wherever their res

  20. MEASURING GENETIC STABILITY IN BACTERIA OF POTENTIAL USE IN GENETIC ENGINEERING

    Science.gov (United States)

    Four commonly used conjugation techniques, colony cross streak (CCS), broth mating (BM), combined spread plate (CSP), and membrane filtration (MF), were compared with each other regarding reliability, sensitivity, and complexity in evaluating the transfer of conjugative plasmids....

  1. Automated Cosmetic Improvement of Mosaics from the Lunar Orbiter Atlas

    Science.gov (United States)

    Byrne, C. J.

    2002-03-01

    Lunar Orbiter images are improved by a program that mimimizes the bright lines between framelets and streaking, sometimes called the "venetian blind" effect. The program runs automatically on a PC using Windows.

  2. FCH_Eremophila_alpestris_strigata_2013

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify (in general) the areas where critical habitat for the Streaked Horned Lark (Eremophila alpestris strigata) occur. Maps published in the Federal...

  3. How to Avoid Headlight Glare

    Science.gov (United States)

    ... All Glass Clear and Clean Streaks, smudges, and road grime on your windows catch and refract light. This includes the inside of your windshield. Chemicals from the plastic in your car’s interior slowly build up on ...

  4. 49 CFR 213.337 - Defective rails.

    Science.gov (United States)

    2010-10-01

    ... through it. A crack or rust streak may show under the head close to the web or pieces may be split off the... weld means a field or plant weld containing any discontinuities or pockets, exceeding 5 percent of...

  5. 49 CFR 213.113 - Defective rails.

    Science.gov (United States)

    2010-10-01

    ... head, and extending into or through it. A crack or rust streak may show under the head close to the web... reported as separate defects. (14) Defective weld means a field or plant weld containing...

  6. Nuclear test experimental science

    International Nuclear Information System (INIS)

    This report discusses research being conducted at Lawrence Livermore Laboratory under the following topics: prompt diagnostics; experimental modeling, design, and analysis; detector development; streak-camera data systems; weapons supporting research

  7. High resolution time- and 2-dimensional space-resolved x-ray imaging of plasmas at NOVA

    International Nuclear Information System (INIS)

    A streaked multiple pinhole camera technique, first used by P. Choi et al. to record time- and 2-D space-resolved soft X-ray images of plasma pinches, has been implemented on laser plasmas at NOVA. The instrument is particularly useful for time-resolved imaging of small sources ( 2.5 key imaging, complementing the existing 1--3 key streaked X-ray microscope capabilities at NOVA

  8. Influence of cyclic temperature transients on the creep behaviour of heat exchanger tubes

    Energy Technology Data Exchange (ETDEWEB)

    Zottmaier, R.; Over, H.H.; Schubert, F.; Nickel, H.

    1986-10-01

    Due to thermal fluxes hot streaks exist in the coolant media of heat exchanger components. They cause alternating cyclically secondary stresses in the component walls which superpose on the primary stresses due to internal pressure or bending. Experimentally it was shown that hot streaks at high temperatures influence the creep behaviour very strongly. Dependent on the ratio of primary and secondary stresses the creep rate of the components is higher than the creep behaviour at the highest cycle temperature under primary stresses only.

  9. High speed photography, videography, and photonics V; Proceedings of the Meeting, San Diego, CA, Aug. 17-19, 1987

    Science.gov (United States)

    Johnson, Howard C. (Editor)

    1988-01-01

    Recent advances in high-speed optical and electrooptic devices are discussed in reviews and reports. Topics examined include data quantification and related technologies, high-speed photographic applications and instruments, flash and cine radiography, and novel ultrafast methods. Also considered are optical streak technology, high-speed videographic and photographic equipment, and X-ray streak cameras. Extensive diagrams, drawings, graphs, sample images, and tables of numerical data are provided.

  10. Photophysics and photochemistry of horseradish peroxidase A2 upon ultraviolet illumination

    DEFF Research Database (Denmark)

    Petersen, Maria Teresa Neves; Petersen, Steffen B.; Klitgaard, Søren;

    2007-01-01

    residues and of the heme group leads to changes indicative of heme leaving the molecule and/or that photo-induced chemical changes occur in the heme moiety. Our studies bring new insight into light induced reactions in proteins. We show how streak camera technology can be of outstanding value to follow...... such ultra-fast processes and how streak camera data can be correlated with protein structural changes. Udgivelsesdato: MAR 15...

  11. The multifocal electroretinogram (mfERG) in the pig

    DEFF Research Database (Denmark)

    Voss Kyhn, Maria; Kiilgaard, Jens Folke; Lopez, Ana Garcia;

    2007-01-01

    To establish a method allowing multifocal electroretinography (mfERG) recording with simultaneous fundus monitoring on anaesthetized pigs. In addition we characterize the peaks of the porcine mfERG trace, and compare the visual streak area with the optic nerve head, a known non-response area....... Finally we illustrate the feasibility of the method by performing mfERG after an induced laser burn in the visual streak....

  12. Dynamics of laser-guided alternating current high voltage discharges

    Science.gov (United States)

    Daigle, J.-F.; Théberge, F.; Lassonde, P.; Kieffer, J.-C.; Fujii, T.; Fortin, J.; Châteauneuf, M.; Dubois, J.

    2013-10-01

    The dynamics of laser-guided alternating current high voltage discharges are characterized using a streak camera. Laser filaments were used to trigger and guide the discharges produced by a commercial Tesla coil. The streaking images revealed that the dynamics of the guided alternating current high voltage corona are different from that of a direct current source. The measured effective corona velocity and the absence of leader streamers confirmed that it evolves in a pure leader regime.

  13. Application of Arnoldi method to boundary layer instability

    Science.gov (United States)

    Zhang, Yong-Ming; Luo, Ji-Sheng

    2015-12-01

    The Arnoldi method is applied to boundary layer instability, and a finite difference method is employed to avoid the limit of the finite element method. This modus operandi is verified by three comparison cases, i.e., comparison with linear stability theory (LST) for two-dimensional (2D) disturbance on one-dimensional (1D) basic flow, comparison with LST for three-dimensional (3D) disturbance on 1D basic flow, and comparison with Floquet theory for 3D disturbance on 2D basic flow. Then it is applied to secondary instability analysis on the streaky boundary layer under spanwise-localized free-stream turbulence (FST). Three unstable modes are found, i.e., an inner mode at a high-speed center streak, a sinuous type outer mode at a low-speed center streak, and a sinuous type outer mode at low-speed side streaks. All these modes are much more unstable than Tollmien-Schlichting (TS) waves, implying the dominant contribution of secondary instability in bypass transition. The modes at strong center streak are more unstable than those at weak side streaks, so the center streak is ‘dangerous’ in secondary instability. Project supported by the National Natural Science Foundation of China (Grant Nos. 11202147, 11332007, 11172203, and 91216111) and the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120032120007).

  14. A phase space approach for detection and removal of rain in video

    Science.gov (United States)

    Santhaseelan, Varun; Asari, Vijayan K.

    2012-01-01

    Nowadays, the widespread use of computer vision algorithms in surveillance systems and autonomous robots has increased the demand for video enhancement algorithms. In this paper, we propose an algorithm based on phase congruency features to detect and remove rain and thus improve the quality of video. We make use of the following characteristics of rain streaks in video in order to detect them: (1) rain streaks do not occlude the scene at all instances, (2) all the rain streaks in a frame are oriented in a single direction, and (3) presence of rain streak at a particular pixel causes a positive change in intensity. Combining all these properties we are able to detect rain streaks in a particular frame using phase congruency features. The pixels in a frame which are identified as rain streaks are then replaced using the pixel information of its spatial and temporal neighbors which are not affected by rain. When this method is used in conjunction with phase correlation, we are able to remove rain of medium density from videos even when complex camera movement is involved.

  15. A numerical study on the evolution and structure of a stress-driven free-surface turbulent shear flow

    Science.gov (United States)

    Tsai, Wu-Ting; Chen, Shi-Ming; Moeng, Chin-Hoh

    2005-12-01

    Turbulent shear flow beneath a flat free surface driven by a surface stress is simulated numerically to gain a better understanding of the hydrodynamic processes governing the scalar transfer across the air-water interface. The simulation is posed to mimic the subsequent development of a wind-driven shear layer as in a previous experiment except that the initiation of the surface waves is inhibited, thus focusing on the boundary effect of the stress-imposed surface on the underlying turbulent flow and vice versa. Despite the idealizations inherent in conducting the simulation, the computed flow exhibits the major surface features, qualitatively similar to those that appear in the laboratory and field experiments. Two distinct surface signatures, namely elongated high-speed streaks and localized low-speed spots, are observed in the simulated flow. Including temperature as a passive tracer and describing an upward heat flux at the surface, we obtain high-speed streaks that are colder and low-speed spots that are warmer than the surrounding regions. The high-speed streaks, arranged with somewhat equal cross-spacing of centimetres scale, are formed by an array of streamwise jets within the viscous sublayer immediately next to the surface. Beneath the streaks, counter-rotating streamwise vortex pairs are observed among other prevailing elongated vortices. However, they are significantly shorter in length and more irregular than their corresponding high-speed streaks at the surface. Accompanying the more organized high-speed streaks, localized regions of low streamwise velocity emerge randomly on the surface. These low-speed spots are attributed to strong upwelling flows which disrupt the viscous sublayer and also bring up the submerged fluids of low streamwise velocity. The occasional interruptions of the streamwise high-speed jets by the upwelling flows account for bifurcation or dislocation of the surface streaks. Statistics of the turbulence are presented and their

  16. Stability Analysis of Roughness Array Wake in a High-Speed Boundary Layer

    Science.gov (United States)

    Choudhari, Meelan; Li, Fei; Edwards, Jack

    2009-01-01

    Computations are performed to examine the effects of both an isolated and spanwise periodic array of trip elements on a high-speed laminar boundary layer, so as to identify the potential physical mechanisms underlying an earlier transition to turbulence as a result of the trip(s). In the context of a 0.333 scale model of the Hyper-X forebody configuration, the time accurate solution for an array of ramp shaped trips asymptotes to a stationary field at large times, indicating the likely absence of a strong absolute instability in the mildly separated flow due to the trips. A prominent feature of the wake flow behind the trip array corresponds to streamwise streaks that are further amplified in passing through the compression corner. Stability analysis of the streaks using a spatial, 2D eigenvalue approach reveals the potential for a strong convective instability that might explain the earlier onset of turbulence within the array wake. The dominant modes of streak instability are primarily sustained by the spanwise gradients associated with the streaks and lead to integrated logarithmic amplification factors (N factors) approaching 7 over the first ramp of the scaled Hyper-X forebody, and substantially higher over the second ramp. Additional computations are presented to shed further light on the effects of both trip geometry and the presence of a compression corner on the evolution of the streaks.

  17. Statistical analysis of turbulent super-streamwise vortices based on observations of streaky structures near the free surface in the smooth open channel flow

    Science.gov (United States)

    Zhong, Qiang; Chen, Qigang; Wang, Hao; Li, Danxun; Wang, Xingkui

    2016-05-01

    Long streamwise-elongated high- and low-speed streaks are repeatedly observed near the free surface in open channel flows in natural rivers and lab experiments. Super-streamwise vortex model has been proposed to explain this widespread phenomenon for quite some time. However, statistical evidence of the existence of the super-streamwise vortices as one type of coherent structures is still insufficient. Correlation and proper orthogonal decomposition (POD) analysis based on PIV experimental data in the streamwise-spanwise plane near the free surface in a smooth open channel flow are employed to investigate this topic. Correlation analysis revealed that the streaky structures appear frequently near the free surface and their occurrence probability at any spanwise position is equal. The spanwise velocity fluctuation usually flows from low-speed streaks toward high-speed streaks. The average spanwise width and spacing between neighboring low (or high) speed streaks are approximately h and 2h respectively. POD analysis reveals that there are streaks with different spanwise width in the instantaneous flow fields. Typical streamwise rotational movement can be sketched out directly based on the results from statistical analyses. Point-by-point analysis indicates that this pattern is consistent everywhere in the measurement window and is without any inhomogeneity in the spanwise direction, which reveals the essential difference between coherent structures and secondary flow cells. The pattern found by statistical analysis is consistent with the notion that the super-streamwise vortices exist universally as one type of coherent structure in open channel flows.

  18. High speed photography, videography, and photonics III; Proceedings of the Meeting, San Diego, CA, August 22, 23, 1985

    Science.gov (United States)

    Ponseggi, B. G. (Editor); Johnson, H. C. (Editor)

    1985-01-01

    Papers are presented on the picosecond electronic framing camera, photogrammetric techniques using high-speed cineradiography, picosecond semiconductor lasers for characterizing high-speed image shutters, the measurement of dynamic strain by high-speed moire photography, the fast framing camera with independent frame adjustments, design considerations for a data recording system, and nanosecond optical shutters. Consideration is given to boundary-layer transition detectors, holographic imaging, laser holographic interferometry in wind tunnels, heterodyne holographic interferometry, a multispectral video imaging and analysis system, a gated intensified camera, a charge-injection-device profile camera, a gated silicon-intensified-target streak tube and nanosecond-gated photoemissive shutter tubes. Topics discussed include high time-space resolved photography of lasers, time-resolved X-ray spectrographic instrumentation for laser studies, a time-resolving X-ray spectrometer, a femtosecond streak camera, streak tubes and cameras, and a short pulse X-ray diagnostic development facility.

  19. Virtual Simulations as Preparation for Lab Exercises: Assessing Learning of Key Laboratory Skills in Microbiology and Improvement of Essential Non-Cognitive Skills

    DEFF Research Database (Denmark)

    Makransky, Guido; Warming Thisgaard, Malene; Gadegaard, Helen

    2016-01-01

    bacteria on agar plates. All students were blindly assessed on their ability to perform the streaking technique in the physical lab, and were administered a pre and post-test to determine their knowledge of microbiology, intrinsic motivation to study microbiology, and self-efficacy in the field......Objective To investigate if a virtual laboratory simulation (vLAB) could be used to replace a face to face tutorial (demonstration) to prepare students for a laboratory exercise in microbiology. Methods A total of 189 students who were participating in an undergraduate biology course were randomly...... selected into a vLAB or demonstration condition. In the vLAB condition students could use a vLAB at home to 'practice' streaking out bacteria on agar plates in a virtual environment. In the demonstration condition students were given a live demonstration from a lab tutor showing them how to streak out...

  20. Formation of spanwise vorticity in oblique turbulent bands of transitional plane Couette flow, part 2: modelling and stability analysis

    CERN Document Server

    Rolland, Joran

    2016-01-01

    This article presents a modelling of the formation of spanwise vorticity in the turbulent streaks of the oblique bands and spots of transitional plane Couette flow. A functional model is designed to mimic the coherent flow in the streaks. The control parameters of the model are extracted from Direct Numerical Simulations (DNS) statistical data. A Reynolds stress is proposed to study the effect on the instability of this additional force maintaining the baseflow. Local (quasi-parallel) temporal stability analysis is performed on that model to investigate the linear development of the spanwise vorticity. Results show that average profiles, even if they have an inflection, are stable: the shear layers inside the velocity streaks are responsible for the vorticity formation. Emphasis is put on the convective or absolute nature of the instability, depending on the location in the band. This shows that a transition from a convective to an absolute instability occurs in the zone in between fully turbulent and laminar...

  1. The investigation of coherent structures in the wall region of a supersonic turbulent boundary layer based on DNS database

    Institute of Scientific and Technical Information of China (English)

    HUANG ZhangFeng; ZHOU Heng; LUO JiSheng

    2007-01-01

    Through temporal mode direct numerical simulation, flow field database of a fully developed turbulent boundary layer on a flat plate with Mach number 4.5 and Reynolds number Reθ=1094 has been obtained. Commonly used detection methods in experiments are applied to detecting coherent structures in the flow field,and it is found that coherent structures do exist in the wall region of a supersonic turbulent boundary layer. The detected results show that a low-speed streak is detected by using the Mu-level method, the rising parts of this streak are detected by using the second quadrant method, and the crossing regions from a low-speed streak to the high-speed one are detected by using the VITA method respectively.Notwithstanding that different regions are detected by different methods, they are all accompanied by quasi-stream-wise vortex structures.

  2. The investigation of coherent structures in the wall region of a supersonic turbulent boundary layer based on DNS database

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Through temporal mode direct numerical simulation, flow field database of a fully developed turbulent boundary layer on a flat plate with Mach number 4.5 and Reynolds number Reθ =1094 has been obtained. Commonly used detection meth- ods in experiments are applied to detecting coherent structures in the flow field, and it is found that coherent structures do exist in the wall region of a supersonic turbulent boundary layer. The detected results show that a low-speed streak is de- tected by using the Mu-level method, the rising parts of this streak are detected by using the second quadrant method, and the crossing regions from a low-speed streak to the high-speed one are detected by using the VITA method respectively. Notwithstanding that different regions are detected by different methods, they are all accompanied by quasi-stream-wise vortex structures.

  3. Aspergillus triggers phenazine production in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jensen, Britt Guillaume; Jelsbak, Lars; Søndergaard, Ib;

    Objectives: Pseudomonas aeruginosa is an opportunistic human pathogen, commonly infecting cystic fibrosis (CF) patients. Aspergilli, especially Aspergillus fumigatus, are also frequently isolated from CF patients. Our aim was to examine the possible interaction between P. aeruginosa and different...... Aspergillus species. Methods: A suspension of fungal spores was streaked onto WATM agar plates. After 24 hours incubation at 37 °C, a P. aeruginosa overnight culture was streaked out perpendicular to the fungal streak. The plates were incubated at 37 °C for five days, examined and plugs were extracted...... in the contact area of A. niger, A. flavus, A. oryzae, but not A. fumigatus. In addition, other metabolites with UV chromophores similar to the phenazines were only found in the contact zone between Aspergillus and Pseudomonas. No change in secondary metabolite profiles were seen for the Aspergilli, when...

  4. Nitrile versus Latex for Glove Juice Sampling.

    Directory of Open Access Journals (Sweden)

    Timothy F Landers

    Full Text Available The objective of this study was to explore the utility of nitrile gloves as a replacement for latex surgical gloves in recovering bacteria from the hands. Two types of nitrile gloves were compared to latex gloves using the parallel streak method. Streaks of Klebsiella pneumoniae and Staphylococcus aureus were made on tryptic soy agar plates, and the zones of inhibition were measured around pieces of glove material placed on the plates. Latex gloves produced a mean zone of inhibition of 0.28 mm, compared to 0.002 mm for nitrile gloves (p<.001. While the parallel streak method is not intended as a quantitative estimate of antimicrobial properties, these results suggest that nitrile may be a viable alternative to latex in glove juice sampling methods, since nitrile avoids the risk of latex exposure.

  5. Chirped Auger electron emission due to field-assisted post-collision interaction

    Directory of Open Access Journals (Sweden)

    Bonitz M.

    2013-03-01

    Full Text Available We have investigated the Auger decay in the temporal domain by applying a terahertz streaking light field. Xenon and krypton atoms were studied by implementing the free-electron laser in Hamburg (FLASH as well as a source of high-order harmonic radiation combined with terahertz pulses from an optical rectification source. The observed linewidth asymmetries in the streaked spectra suggest a chirped Auger electron emission which is understood in terms of field-assisted post-collision interaction. The experimentally obtained results agree well with model calculations.

  6. Time-domain diagnostics in the picosecond regime

    International Nuclear Information System (INIS)

    The measurement of bunch length and longitudinal profile for microbunches of electrons and positrons in the ps and sub-ps regime will be a critical part of validating performance of proposed facilities. Data will be presented showing single-sweep streak camera results at σres ∼ 68 fs and projected synchroscan sweep resolution at σ ∼ 600 fs. Additionally, an rf cavity operating in a transverse magnetic mode has recently been shown to produce σres ∼ 280 fs when used with a low-emittance beam. The potential for dual-sweep streak work with σres < 1 ps on the fast axis is also described

  7. Nitrile versus Latex for Glove Juice Sampling.

    Science.gov (United States)

    Landers, Timothy F; Dent, Anthony

    2014-01-01

    The objective of this study was to explore the utility of nitrile gloves as a replacement for latex surgical gloves in recovering bacteria from the hands. Two types of nitrile gloves were compared to latex gloves using the parallel streak method. Streaks of Klebsiella pneumoniae and Staphylococcus aureus were made on tryptic soy agar plates, and the zones of inhibition were measured around pieces of glove material placed on the plates. Latex gloves produced a mean zone of inhibition of 0.28 mm, compared to 0.002 mm for nitrile gloves (pglove juice sampling methods, since nitrile avoids the risk of latex exposure. PMID:25333880

  8. Analysis of shock wave propagation from explosives using computational simulations and artificial schlieren imaging

    Science.gov (United States)

    Armstrong, Christopher; Hargather, Michael

    2014-11-01

    Computational simulations of explosions are performed using the hydrocode CTH and analyzed using artificial schlieren imaging. The simulations include one and three-dimensional free-air blasts and a confined geometry. Artificial schlieren images are produced from the density fields calculated via the simulations. The artificial schlieren images are used to simulate traditional and focusing schlieren images of explosions. The artificial schlieren images are compared to actual high-speed schlieren images of similar explosions. Computational streak images are produced to identify time-dependent features in the blast field. The streak images are used to study the interaction between secondary shock waves and the explosive product gas contact surface.

  9. [Artefacts in the CT scan caused by surgical clips and central venous catheters and the use of new materials].

    Science.gov (United States)

    Schadel, A; Böttcher, H D; Haverkamp, U; Wagner, W; Schmilowski, G M

    1984-03-01

    When metal clips and venous catheters have been used the computerized tomography shows artifacts, which make it computerized tomography shows artifacts, which make it difficult to have a reliable and accurate diagnosis, because the X- raying of the metal clips and the venous catheter gives radiating lines, so called streaking. We have tested new materials for the metal clips and a new polymer to replace the substance of the venous catheter with the intention that the materials should have the same density as the normal tissues. With a new metal for the clips and a new polymer for the venous catheters, mixed with metal ions, the computerized tomography does not show streaking.

  10. Shape Measurement of a Sewer Pipe Using a Mobile Robot with Computer Vision

    Directory of Open Access Journals (Sweden)

    Kikuhito Kawasue

    2013-01-01

    Full Text Available A mobile robot equipped with two lasers and a CCD camera for pipe inspection is proposed. Circular laser streaks that appeared on the inner surface of the pipe reveal the shape of the pipe. The 3D shape of a sewer pipe can be reconstructed considering the movement of the mobile robot along the pipe. Since the tilt of the mobile robot with respect to the axis of the pipe appears as the deformation between two circular streaks, the shape of a sewer pipe can be measured accurately, regardless of the tilt of the robot.

  11. AcEST: BP916028 [AcEST

    Lifescience Database Archive (English)

    Full Text Available tr|Q5EP42|Q5EP42_9VIRU ORF III polyprotein OS=Banana streak Mys ... 33 9.3 tr|Q4Y0X3|Q4Y0X3_PLACH Putative ... ORF III polyprotein OS=Banana streak Mys virus PE=4 SV=1 Length = 1869 Score = 32.7 bits (73), Expect = 9.3...GHFA EC Sbjct: 772 HASHARIEKRKHLIRNKKCKCYLCGDEGHFAREC 805 >tr|Q5EP42|Q5EP42_9VIRU

  12. The effect of perceived streakiness on the shot-taking behaviour of basketball players.

    Science.gov (United States)

    Csapo, Peter; Avugos, Simcha; Raab, Markus; Bar-Eli, Michael

    2015-01-01

    We examine behavioural changes of basketball players arising from the hot-hand belief and use data of 1216 National Basketball Association games to measure the effect of cold and hot streaks on three proxies of shot difficulty. We find that the more consecutive shots players make (miss), the more difficult (easier) shots become along the three dimensions. Furthermore, most players' performance seems to improve during hot streaks because they attempt more difficult shots while no significant decrease in shooting accuracy takes place. This might explain why most previous studies could not find empirical evidence for the hot-hand belief in basketball when considering in-game field goal shooting.

  13. First measurements of electron-beam transit times and micropulse elongation in a photoelectric injector at the High-Brightness Accelerator FEL (HIBAF)

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H.; Carlsten, B.E.; Feldman, R.B.

    1990-01-01

    Key aspects of the dynamics of a photoelectric injector (PEI) on the Los Alamos High-Brightness Accelerator FEL (HIBAF) facility have been investigated using a synchroscan streak camera. By phase-locking the streak camera sweep to the reference 108.3 MHz rf signal, the variations of micropulse temporal elongations (30 to 80% over the drive-laser pulse length) and of transit times (25 ps for a 16{degree}-phase change) were observed for the first time. These results were in good agreement with PARMELA simulations. 2 refs., 8 figs.

  14. Attosecond nanoscale near-field sampling

    CERN Document Server

    Förg, Benjamin; Suessmann, Frederik; Foerster, Michael; Krueger, Michael; Ahn, Byung-Nam; Wintersperger, Karen; Zherebtsov, Sergey; Guggenmos, Alexander; Pervak, Vladimir; Kessel, Alexander; Trushin, Sergei; Azzeer, Abdallah; Stockman, Mark; Kim, Dong-Eon; Krausz, Ferenc; Hommelhoff, Peter; Kling, Matthias

    2015-01-01

    The promise of ultrafast light field driven electronic nanocircuits has stimulated the development of the new research field of attosecond nanophysics. An essential prerequisite for advancing this new area is the ability to characterize optical nearfields from light interaction with nanostructures with sub cycle resolution. Here, we experimentally demonstrate attosecond nearfield retrieval with a gold nanotip using streaking spectroscopy. By comparison of the results from gold nanotips to those obtained for a noble gas, the spectral response of the nanotip near field arising from laser excitation can be extracted. Monte Carlo MC trajectory simulations in near fields obtained with the macroscopic Maxwells equations elucidate the streaking mechanism on the nanoscale.

  15. Five new species of the genus Helota from Sikkim and Darjeeling

    NARCIS (Netherlands)

    Ritsema Cz., C.

    1893-01-01

    This handsome species is closely allied to Helota curvipes Oberth. ¹) from the Himalaya, but at once distinguished by its more robust shape, by the coppery colour of the upper surface, by the broad fulvous streaks on the sides of the pronotum, and by the broadly subtruncate apices of the elytra in t

  16. New species of Pachyteria, a genus of Longicorn Coleoptera

    NARCIS (Netherlands)

    Ritsema Cz., C.

    1881-01-01

    Length of the male 28 mm., of the female 32 mm.; breadth at the shoulders in the male 8,5 mm., in the female 10 mm. The head (labrum and mandibles excepted), the prothorax and a streak on the apical half of the elytra along the suture metallic green, the remaining portion of the apical half of the e

  17. Fluorescence Relaxation Kinetics from Rhodopsin and Isorhodopsin

    OpenAIRE

    Doukas, A G; Lu, P. Y.; Alfano, R. R.

    1981-01-01

    The fluorescence kinetics of bovine rhodopsin and isorhodopsin excited with a single picosecond laser pulse have been measured with a streak camera. The rise and the decay time of the intrinsic fluorescence emission from rhodopsin and isorhodopsin are found to be

  18. High speed photography, videography, and photonics IV; Proceedings of the Meeting, San Diego, CA, Aug. 19, 20, 1986

    Science.gov (United States)

    Ponseggi, B. G. (Editor)

    1986-01-01

    Various papers on high-speed photography, videography, and photonics are presented. The general topics addressed include: photooptical and video instrumentation, streak camera data acquisition systems, photooptical instrumentation in wind tunnels, applications of holography and interferometry in wind tunnel research programs, and data analysis for photooptical and video instrumentation.

  19. Quantitative Comparison of Commercial and Non-Commercial Metal Artifact Reduction Techniques in Computed Tomography

    NARCIS (Netherlands)

    Wagenaar, Dirk; van der Graaf, Emiel R.; van der Schaaf, Arjen; Greuter, Marcel J. W.

    2015-01-01

    Objectives Typical streak artifacts known as metal artifacts occur in the presence of strongly attenuating materials in computed tomography (CT). Recently, vendors have started offering metal artifact reduction (MAR) techniques. In addition, a MAR technique called the metal deletion technique (MDT)

  20. A Simple Way to Estimate the Soft X-ray Class of Far-Side Solar Flares Observed with STEREO/EUVI

    CERN Document Server

    Chertok, I M; Grechnev, V V

    2015-01-01

    Around the peaks of substantial flares, bright artifact nearly horizontal saturation streaks (B-streaks) corresponding to the brightest parts of the flare sources appear in the STEREO/EUVI 195 \\AA\\ images. We show that the length of such B-streaks can be used for the solution of an actual problem of evaluating the soft X-ray flux and class of far-side flares registered with double STEREO spacecraft but invisible from Earth. For this purpose from data on about 350 flares observed from January 2007 to July 2014 (mainly exceeding the GOES M1.0 level) both with GOES and STEREO, an empirical relation is established correlating the GOES 1-8 \\AA\\ peak flux and the B-streak length. This allowed us for the same years to estimate the soft X-ray classes for approximately 65 strong far-side flares observed by STEREO. The results of this simple and prompt method are consistent with the estimations of Nitta et al. (Solar Phys., 288, 241, 2013) based on the calculations of the EUVI full-disk digital number output. In additi...

  1. Foliar Diseases of Apiaceae Crops in Coastal California

    Science.gov (United States)

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

  2. Combating a Global Threat to a Clonal Crop: Banana Black Sigatoka Pathogen Pseudocercospora fijiensis (Synonym Mycosphaerella fijiensis) Genomes Reveal Clues for Disease Control

    NARCIS (Netherlands)

    Arango Isaza, Rafael E.; Diaz-Trujillo, Caucasella; Dhillon, Braham; Aerts, Andrea; Carlier, Jean; Crane, Charles F.; V. de Jong, Tristan; de Vries, Ineke; Dietrich, Robert; Farmer, Andrew D.; Fortes Fereira, Claudia; Garcia, Suzana; Guzman, Mauricio; Hamelin, Richard C.; Lindquist, Erika A.; Mehrabi, Rahim; Quiros, Olman; Schmutz, Jeremy; Shapiro, Harris; Reynolds, Elizabeth; Scalliet, Gabriel; Souza Manoel, Jr.; Stergiopoulos, Ioannis; Van der Lee, Theo A. J.; De Wit, Pierre J. G. M.; Zapater, Marie-Françoise; Zwiers, Lute-Harm; Grigoriev, Igor V.; Goodwin, Stephen B.; Kema, Gert H. J.

    2016-01-01

    Black Sigatoka or black leaf streak disease, caused by the ascomycete fungus Pseudocercospora fijiensis, inflicts huge costs on banana producers, due to crop losses and expenses for disease control. The global banana export trade relies on Cavendish clones that are highly susceptible to P. fijiensis

  3. Simulation of attosecond-resolved imaging of the plasmon electric field in metallic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Prell, James S.; Borja, Lauren J. [Department of Chemistry, University of California, Berkeley, CA, 94720-1460 (United States); Neumark, Daniel M. [Department of Chemistry, University of California, Berkeley, CA, 94720-1460 (United States); Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720 (United States); Leone, Stephen R. [Department of Chemistry, University of California, Berkeley, CA, 94720-1460 (United States); Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720 (United States); Department of Physics, University of California, Berkeley, CA, 94720-1460 (United States)

    2013-02-15

    Sub-cycle photoelectron streaking from silver plasmonic nanospheres is simulated using few-cycle laser pulses tuned both on and off the plasmon resonance (376 nm vs 800 nm, respectively) to initiate the plasmon. Phase-locked, isolated attosecond XUV pulses induce photoemission from the nanospheres, and two different types of streaking of the photoelectrons occur simultaneously due to the laser and plasmon electric fields. Streaking is simulated over a wide range of excitation pulse intensities, and final velocity distributions for the photoelectrons emitted at different times are calculated. The resulting velocity distributions exhibit several characteristics attributable to the plasmon electric field. The dipole moment amplitude can be reconstructed using velocity map imaging or time-of-flight photoelectron velocity measurements without separate measurement of the laser electric field or deconvolution using an assumed streaking trace shape. These results indicate that photoelectron experiments in table-top set-ups can provide unprecedented spatio-temporal information about sub-cycle plasmon dynamics in metallic nanostructures. (copyright 2012 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. 78 FR 61451 - Endangered and Threatened Wildlife and Plants; Determination of Endangered Status for the Taylor...

    Science.gov (United States)

    2013-10-03

    ... adult nymphalid butterflies (butterflies in the family Nymphalidae) (Murphy et al. 2004, p. 22; Page et... Threatened Wildlife and Plants; Determination of Endangered Status for the Taylor's Checkerspot Butterfly and... Endangered Status for the Taylor's Checkerspot Butterfly and Threatened Status for the Streaked Horned...

  5. Denoising and artefact reduction in dynamic flat detector CT perfusion imaging using high speed acquisition: first experimental and clinical results.

    Science.gov (United States)

    Manhart, Michael T; Aichert, André; Struffert, Tobias; Deuerling-Zheng, Yu; Kowarschik, Markus; Maier, Andreas K; Hornegger, Joachim; Doerfler, Arnd

    2014-08-21

    Flat detector CT perfusion (FD-CTP) is a novel technique using C-arm angiography systems for interventional dynamic tissue perfusion measurement with high potential benefits for catheter-guided treatment of stroke. However, FD-CTP is challenging since C-arms rotate slower than conventional CT systems. Furthermore, noise and artefacts affect the measurement of contrast agent flow in tissue. Recent robotic C-arms are able to use high speed protocols (HSP), which allow sampling of the contrast agent flow with improved temporal resolution. However, low angular sampling of projection images leads to streak artefacts, which are translated to the perfusion maps. We recently introduced the FDK-JBF denoising technique based on Feldkamp (FDK) reconstruction followed by joint bilateral filtering (JBF). As this edge-preserving noise reduction preserves streak artefacts, an empirical streak reduction (SR) technique is presented in this work. The SR method exploits spatial and temporal information in the form of total variation and time-curve analysis to detect and remove streaks. The novel approach is evaluated in a numerical brain phantom and a patient study. An improved noise and artefact reduction compared to existing post-processing methods and faster computation speed compared to an algebraic reconstruction method are achieved.

  6. Reduction of artefacts caused by hip implants in CT-based attenuation-corrected PET images using 2-D interpolation of a virtual sinogram on an irregular grid

    NARCIS (Netherlands)

    Abdoli, Mehrsima; de Jong, Johan R.; Pruim, Jan; Dierckx, Rudi A. J. O.; Zaidi, Habib

    2011-01-01

    Purpose Metallic prosthetic replacements, such as hip or knee implants, are known to cause strong streaking artefacts in CT images. These artefacts likely induce over-or underestimation of the activity concentration near the metallic implants when applying CT-based attenuation correction of positron

  7. Design and commissioning of a new beam port for visible light diagnostics at the ANKA storage ring

    Energy Technology Data Exchange (ETDEWEB)

    Hiller, Nicole; Hofmann, Andre; Huttel, Erhard; Kehrer, Benjamin; Klein, Marit; Judin, Vitali; Marsching, Sebastian; Mueller, Anke-Susanne; Plech, Anton; Smale, Nigel [Karlsruhe Institute of Technology, Karlsruhe (Germany)

    2011-07-01

    In 2010 a new beam port, dedicated to streak camera measurements using visible light, was put in operation at the ANKA storage ring in Karlsruhe. This talk gives an overview over the design considerations and present simulations of the optical components of the port. In addition, results of beam studies based on this system are shown.

  8. Measurements of bunch length and shape at the ANKA storage ring

    Energy Technology Data Exchange (ETDEWEB)

    Hiller, Nicole; Fitterer, Miriam; Hillenbrand, Steffen; Huttel, Erhard; Hofmann, Andre; Judin, Vitali; Klein, Marit; Marsching, Sebastian; Mueller, Anke-Susanne; Plech, Anton; Smale, Nigel; Sonnad, Kiran [Karlsruhe Institute of Technology, Karlsruhe (Germany); Bruendermann, Erik; Krueger, Matthias [Physikalische Chemie II, Ruhr University, Bochum (Germany); Tavares Fernandes, Pedro [Karlsruhe Institute of Technology, Karlsruhe (Germany); Brazilian Synchrotron Light Laboratory (LNLS) (Brazil)

    2010-07-01

    Various methods are in use at the ANKA storage ring to determine the length and, if possible, the shape of the electron bunches. This presentation gives an overview of the different methods and studies performed. Emphasis will be put on streak camera measurements and the technique of intensity autocorrelation with semi-conductor detectors.

  9. The Draft Genome Sequence of Mycosphaerella fijiensis, the Black Sigatoka Pathogen of Banana

    Science.gov (United States)

    Mycosphaerella fijiensis is a fungal pathogen of banana and the causal agent of the devastating Black Sigatoka or black leaf streak disease. Its control requires weekly fungicide applications when bananas are grown under disease-conducive conditions, which mostly represent precarious tropical enviro...

  10. Ultrafast polarized fluorescence measurements on monomeric and self-associated melittin

    NARCIS (Netherlands)

    Pandit, A.; Larsen, O.F.A.; Stokkum, van I.H.M.; Grondelle, van R.; Kraayenhof, R.; Amerongen, van H.

    2003-01-01

    The anisotropic and magic-angle fluorescence decay of the single tryptophan (Trp) residue of melittin, a bee venom peptide, was investigated by time-resolved fluorescence anisotropy using a streak camera setup. The peptide was dissolved either in distilled water or in Hepes/NaOH buffer containing lo

  11. Region-specific regulation of posterior axial elongation during vertebrate embryogenesis

    NARCIS (Netherlands)

    Neijts, Roel; Simmini, Salvatore; Giuliani, Fabrizio; van Rooijen, Carina; Deschamps, Jacqueline

    2014-01-01

    BACKGROUND: The vertebrate body axis extends sequentially from the posterior tip of the embryo, fueled by the gastrulation process at the primitive streak and its continuation within the tailbud. Anterior structures are generated early, and subsequent nascent tissues emerge from the posterior growth

  12. High voltage short plus generation based on avalanche circuit

    International Nuclear Information System (INIS)

    Simulate the avalanche circuit in series with PSPICE module, design the high voltage short plus generation circuit by avalanche transistor in series for the sweep deflection circuit of streak camera. The output voltage ranges 1.2 KV into 50 ohm load. The rise time of the circuit is less than 3 ns. (authors)

  13. Validity of spherical quantitative refractometry: application to laser-produced plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Benattar, R.; Popovics, C.

    1983-02-01

    We report an experimental laser technique of quantitative Schlieren imaging of spherical plasmas combined with streak camera recording. We show that quantitative refractometry applies for small values of refraction angles, i.e., when the law giving the refraction angle versus the impact parameter of rays passing through the plasma is a linearly decreasing function.

  14. STS-83 Onboard Photo: Comet Hale-Bopp

    Science.gov (United States)

    1997-01-01

    This is a Microgravity Science Laboratory-1 (MLS-1) onboard STS-83 photo of the most recent comet to date, Hale-Bopp, which passed by Earth during the spring and summer of 1997. In this view, the comet is visible during sunset. The streaks and distorted lights seen in the bottom of the photo are city lights and petroleum fires.

  15. Pigmentary mosaicism following the lines of Blaschko in a girl with a double aneuploidy mosaicism : (47,XX,+7/45,X)

    NARCIS (Netherlands)

    Niessen, RC; Jonkman, MF; Muis, N; Hordijk, R; van Essen, AJ

    2005-01-01

    We report on a 6-year-old girl with linear streaks of apparent hypopigmentation and hyperpigmentation following the Blaschko lines, growth retardation, bupthalmos of the left eye, and mild mental retardation. She had a 45,X karyotype in lymphocytes. In cultured fibroblasts a double aneuploidy mosaic

  16. The Hot Hand Exists in Volleyball and Is Used for Allocation Decisions

    Science.gov (United States)

    Raab, Markus; Gula, Bartosz; Gigerenzer, Gerd

    2012-01-01

    The "hot hand" belief in sports refers to the conviction that a player has a higher chance of making a shot after two or three successful shots than after two or three misses (resulting in "streaks"). This belief is usually considered a cognitive fallacy, although it has been conjectured that in basketball the defense will attack a"hot" player and…

  17. Acute lymphangitis in a preschool child: A case report

    Directory of Open Access Journals (Sweden)

    Loh Huai Seng

    2012-12-01

    Full Text Available A 3-year old preschool boy presented with apruritic red streak at the dorsum of his right foot travelingupward from the affected site which was red and swollen.Insect sting was the more likely trigger which had causedthe cellulitis and subsequently the acute lymphangitis.

  18. On the purification and preliminary crystallographic analysis of isoquinoline 1-oxidoreductase from Brevundimonas diminuta 7

    OpenAIRE

    Boer, D. Roeland; Müller, Axel; Fetzner, Susanne; Lowe, David J.; Romão, Maria João

    2004-01-01

    Crystallization of isoquinoline 1-oxidoreductase from B. diminuta was achieved using two different crystallization buffers. Streak-seeding and cross-linking were essential to obtain well diffracting crystals. Suitable cryo-conditions were found and a structure solution was obtained by molecular replacement.

  19. Primary Angiosarcoma of the Womb: A Case Report

    Institute of Scientific and Technical Information of China (English)

    Jinliang Ping; Jishun Dong; Jianzhong Mao; Ping Lu; Hua Zhao

    2006-01-01

    @@ Case Report A 35-year-old patient was admitted to the hospital on March 27th,2005 because of profuse leukorrhea for 3 months and progressive abdominal pain for half a month. The leukorrhea, which started for no apparert reason, contained streaks of blood and had an odor.

  20. Reduction of dental filling metallic artifacts in CT-based attenuation correction of PET data using weighted virtual sinograms optimized by a genetic algorithm

    NARCIS (Netherlands)

    Abdoli, Mehrsima; Ay, Mohammad Reza; Ahmadian, Alireza; Dierckx, Rudi A. J. O.; Zaidi, Habib

    2010-01-01

    Purpose: The presence of metallic dental fillings is prevalent in head and neck PET/CT imaging and generates bright and dark streaking artifacts in reconstructed CT images. The resulting artifacts would propagate to the corresponding PET images following CT-based attenuation correction (CTAC). This

  1. Clough-Tocher interpolation of virtual sinogram in a Delaunay triangulated grid for metal artifact reduction of PET/CT images

    NARCIS (Netherlands)

    Abdoli, M.; de Long, J. R.; Pruim, J.; Dierckx, R. A. J. O.; Zaidi, H.

    2011-01-01

    Metallic implants, such as hip implants, are known to induce streaking artifacts in CT images which can cause over/underestimation of the activity uptake in CT-based attenuation corrected PET images. Hence, metal artifact reduction (MAR) of CT images is essential in order to obtain accurate quantifi

  2. DNA phylogeny, morphology and pathogenicity of Botryosphaeria species on grapevines

    NARCIS (Netherlands)

    Niekerk, van J.M.; Crous, P.W.; Groenewald, J.Z.; Fourie, P.H.; Halleen, F.

    2004-01-01

    Several species of Botr yosphaeria are known to occur on grapevines, causing a wide range of disorders including bud mortality, dieback, brown wood streaking and bunch rot. In this study the 11 Botryosphaeria spp. associated with grapevines growing in various parts of the world, but primarily in Sou

  3. Diabetic Ulcer (Neurogenic Ulcer)

    Science.gov (United States)

    ... commonly occur on the pressure points of the foot: the ball, heel, and side of the foot if a person's shoes are too tight. However, ... streaking up the leg, drainage of the area, pain, foul odor, rising blood glucose, ... of the top of the foot. Your doctor may have you wear a special ...

  4. Study of short-wavelength turbulence in dense plasmas. Annual progress report, September 8, 1981-August 7, 1982

    International Nuclear Information System (INIS)

    A solid-target facility and a Thomson scattering apparatus for the study of laser-induced turbulence has been constructed and tested. Initial problems with prelase have been overcome. In an ongoing experiment on the saturation of SBS, considerable progress has been made in the form of streaked Thomson scattering data on the space and time behavior of the ion wave

  5. How-to-Do-It. Isolation of Pure Cultures from Mixed Cultures: A Modern Approach.

    Science.gov (United States)

    Benathen, Isaiah A.

    1990-01-01

    Described is an alternative method of culture isolation that uses streaking on specialized media. An activity in which different media are tested for selectivity is presented including a list of materials and procedures. A chart of colony morphology is given. (CW)

  6. Metal artifact reduction strategies for improved attenuation correction in hybrid PET/CT imaging

    NARCIS (Netherlands)

    Abdoli, Mehrsima; Dierckx, Rudi A. J. O.; Zaidi, Habib

    2012-01-01

    Metallic implants are known to generate bright and dark streaking artifacts in x-ray computed tomography (CT) images, which in turn propagate to corresponding functional positron emission tomography (PET) images during the CT-based attenuation correction procedure commonly used on hybrid clinical PE

  7. Gentamycin inhibits the growth of Malassezia pachydermatis in culture

    NARCIS (Netherlands)

    Aspiroz, C.; Gilaberte, Y.; Rezusta, A.; Boekhout, T.; Rubio, M.C.

    2010-01-01

    Background: Malassezia pachydermatis is a yeast of importance in both veterinary and human medicine. Aims: To know if M. pachydermatis grow on micological media with high concentrations of gentamycin. Methods: Twenty M. pachydermatis strains were streaked on Sabouraud Dextrose Agar plates with diffe

  8. 77 FR 61937 - Endangered and Threatened Wildlife and Plants; Listing Taylor's Checkerspot Butterfly and...

    Science.gov (United States)

    2012-10-11

    ... Segments under the Endangered Species Act (61 FR 4722, February 7, 1996). (14) Whether we could improve or... high magnitude and reassigned it an LPN of 3 (69 FR 24876; May 4, 2004). In 2006, the streaked horned... training activities (71 FR 53755; September 12, 2006) were imminent threats to the subspecies....

  9. Registration of OK05312, a high-yielding hard winter wheat donor of Cmc4 for wheat curl mite resistance

    Science.gov (United States)

    Wheat streak mosaic (WSM) is a devastating disease in the High Plains region that is advancing eastward toward lower elevations. Its control is best achieved by combining known disease resistance genes with resistance to the insect vector. A hard red winter (HRW) wheat (Triticum aestivum L.) germpla...

  10. Cdx2 is essential for embryonic axial growth and identity of the adult intestinal stem cells

    NARCIS (Netherlands)

    Simmini, Salvatore

    2015-01-01

    During mouse development, progenitor cells, allocated along the primitive streak and in the tailbud, lay down descendants that contribute to the generation of all primordia of the trunk and tail tissues of the embryo. Evidence suggested that a pool of these progenitor cells, with stem cell-like pote

  11. Denoising and artefact reduction in dynamic flat detector CT perfusion imaging using high speed acquisition: first experimental and clinical results

    Science.gov (United States)

    Manhart, Michael T.; Aichert, André; Struffert, Tobias; Deuerling-Zheng, Yu; Kowarschik, Markus; Maier, Andreas K.; Hornegger, Joachim; Doerfler, Arnd

    2014-08-01

    Flat detector CT perfusion (FD-CTP) is a novel technique using C-arm angiography systems for interventional dynamic tissue perfusion measurement with high potential benefits for catheter-guided treatment of stroke. However, FD-CTP is challenging since C-arms rotate slower than conventional CT systems. Furthermore, noise and artefacts affect the measurement of contrast agent flow in tissue. Recent robotic C-arms are able to use high speed protocols (HSP), which allow sampling of the contrast agent flow with improved temporal resolution. However, low angular sampling of projection images leads to streak artefacts, which are translated to the perfusion maps. We recently introduced the FDK-JBF denoising technique based on Feldkamp (FDK) reconstruction followed by joint bilateral filtering (JBF). As this edge-preserving noise reduction preserves streak artefacts, an empirical streak reduction (SR) technique is presented in this work. The SR method exploits spatial and temporal information in the form of total variation and time-curve analysis to detect and remove streaks. The novel approach is evaluated in a numerical brain phantom and a patient study. An improved noise and artefact reduction compared to existing post-processing methods and faster computation speed compared to an algebraic reconstruction method are achieved.

  12. Leonardsenite, MgAlF5(H2O)(2), a new mineral species from Eldfell Volcano, Heimaey Island, Iceland

    DEFF Research Database (Denmark)

    Mitolo, Donatella; Garavelli, Anna; Zunic, Tonci Balic;

    2013-01-01

    Leonardsenite (IMA2011-059), with ideal formula MgAlF5(H2O)(2), is a new fumarole mineral from Eldfell volcano, Iceland. It has also been found in volcanic encrustations from the Hekla crater, Iceland. The mineral forms a soft and friable mass of white crystals up to 20 mu m in length. The streak...

  13. The Nucleotide Sequence of Blackberry chlorotic ringspot and Strawberry necrotic shock viruses

    Science.gov (United States)

    Small fruit crops were thought to be infected with distinct stains of Tobacco streak virus (TSV) for more than 50 years. Two novel ilarviruses, Blackberry chlorotic ringspot virus (BCRV) and Strawberry necrotic shock virus (SNSV) were found to infect small fruit crops. Using TSV specific molecular ...

  14. 时文选读

    Institute of Scientific and Technical Information of China (English)

    李国营

    2002-01-01

    The huge, heavy spaceship that was born in the Cold War but outlived the century of Communism had died in a magnificent streak(线条) of fire across the South Pacific. After 15 years, 86, 320 orbits and 2.1 billion miles, Mir has completed its successful mission,

  15. Edge states for the turbulence transition in the asymptotic suction boundary layer

    CERN Document Server

    Kreilos, Tobias; Schneider, Tobias M; Eckhardt, Bruno

    2013-01-01

    We demonstrate the existence of an exact invariant solution to the Navier-Stokes equations for the asymptotic suction boundary layer. The identified periodic orbit with a very long period of several thousand advective time units is found as a local dynamical attractor embedded in the stability boundary between laminar and turbulent dynamics. Its dynamics captures both the interplay of downstream oriented vortex pairs and streaks observed in numerous shear flows as well as the energetic bursting that is characteristic for boundary layers. By embedding the flow into a family of flows that interpolates between plane Couette flow and the boundary layer we demonstrate that the periodic orbit emerges in a saddle-node infinite-period (SNIPER) bifurcation of two symmetry-related travelling wave solutions of plane Couette flow. Physically, the long period is due to a slow streak instability which leads to a violent breakup of a streak associated with the bursting and the reformation of the streak at a different spanwi...

  16. Direct Numerical Simulation Sediment Transport in Horizontal Channel

    Energy Technology Data Exchange (ETDEWEB)

    Uhlmann, M.

    2006-07-01

    We numerically simulate turbulent flow in a horizontal plane channel over a bed of mobile particles. All scales of fluid motion are resolved without modeling and the phase interface is accurately represented. Our results indicate a possible scenario for the onset of erosion through collective motion induced by buffer-layer streaks. (Author) 27 refs.

  17. 78 FR 61505 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Taylor's...

    Science.gov (United States)

    2013-10-03

    ... subject to the combined threats of plane strikes and constant management to minimize bird populations... in the Federal Register (77 FR 61937) a proposed rule to list the Taylor's checkerspot butterfly and... definition of critical habitat for the Taylor's checkerspot butterfly and streaked horned lark. We...

  18. Identification of an emergent bacterial blight of garlic in Brazil

    Science.gov (United States)

    Outbreaks of a bacterial blight disease occurred on garlic (Allium sativum) cultivars Roxo Caxiense, Quiteria and Cacador in Southern Brazil, and threatened the main production regions of Rio Grande do Sul State. Symptoms were characterized by watersoaked reddish streaks along the leaf midrib, follo...

  19. The role of detrital anhydrite in diagenesis of aeolian sandstones (Upper Rotliegend, The Netherlands): Implications for reservoir-quality prediction

    NARCIS (Netherlands)

    Henares, S.; Bloemsma, M.R.; Donselaar, M.E.; Mijnlieff, H.F.; Redjosentono, A.E.; Veldkamp, H.G.; Weltje, G.J.

    2014-01-01

    The Rotliegend (Upper Permian) reservoir interval in the Southern Permian Basin (SPB) contains low-permeability streaks corresponding to anhydrite-cemented intervals. An integrated study was conducted using core, cuttings, thin sections and well-log data from a gas exploration well and two geotherma

  20. Moving metal artifact reduction in cone-beam CT scans with implanted cylindrical gold markers

    Energy Technology Data Exchange (ETDEWEB)

    Toftegaard, Jakob, E-mail: jaktofte@rm.dk; Fledelius, Walther; Worm, Esben S.; Poulsen, Per R. [Department of Oncology, Aarhus University Hospital, Aarhus 8000 (Denmark); Seghers, Dieter; Huber, Michael; Brehm, Marcus [Varian Medical Systems, Imaging Laboratory GmbH, Baden-Daettwil 5405 (Switzerland); Elstrøm, Ulrik V. [Department of Medical Physics, Aarhus University Hospital, Aarhus 8000 (Denmark)

    2014-12-15

    Purpose: Implanted gold markers for image-guided radiotherapy lead to streaking artifacts in cone-beam CT (CBCT) scans. Several methods for metal artifact reduction (MAR) have been published, but they all fail in scans with large motion. Here the authors propose and investigate a method for automatic moving metal artifact reduction (MMAR) in CBCT scans with cylindrical gold markers. Methods: The MMAR CBCT reconstruction method has six steps. (1) Automatic segmentation of the cylindrical markers in the CBCT projections. (2) Removal of each marker in the projections by replacing the pixels within a masked area with interpolated values. (3) Reconstruction of a marker-free CBCT volume from the manipulated CBCT projections. (4) Reconstruction of a standard CBCT volume with metal artifacts from the original CBCT projections. (5) Estimation of the three-dimensional (3D) trajectory during CBCT acquisition for each marker based on the segmentation in Step 1, and identification of the smallest ellipsoidal volume that encompasses 95% of the visited 3D positions. (6) Generation of the final MMAR CBCT reconstruction from the marker-free CBCT volume of Step 3 by replacing the voxels in the 95% ellipsoid with the corresponding voxels of the standard CBCT volume of Step 4. The MMAR reconstruction was performed retrospectively using a half-fan CBCT scan for 29 consecutive stereotactic body radiation therapy patients with 2–3 gold markers implanted in the liver. The metal artifacts of the MMAR reconstructions were scored and compared with a standard MAR reconstruction by counting the streaks and by calculating the standard deviation of the Hounsfield units in a region around each marker. Results: The markers were found with the same autosegmentation settings in 27 CBCT scans, while two scans needed slightly changed settings to find all markers automatically in Step 1 of the MMAR method. MMAR resulted in 15 scans with no streaking artifacts, 11 scans with 1–4 streaks, and 3 scans

  1. Moving metal artifact reduction in cone-beam CT scans with implanted cylindrical gold markers

    International Nuclear Information System (INIS)

    Purpose: Implanted gold markers for image-guided radiotherapy lead to streaking artifacts in cone-beam CT (CBCT) scans. Several methods for metal artifact reduction (MAR) have been published, but they all fail in scans with large motion. Here the authors propose and investigate a method for automatic moving metal artifact reduction (MMAR) in CBCT scans with cylindrical gold markers. Methods: The MMAR CBCT reconstruction method has six steps. (1) Automatic segmentation of the cylindrical markers in the CBCT projections. (2) Removal of each marker in the projections by replacing the pixels within a masked area with interpolated values. (3) Reconstruction of a marker-free CBCT volume from the manipulated CBCT projections. (4) Reconstruction of a standard CBCT volume with metal artifacts from the original CBCT projections. (5) Estimation of the three-dimensional (3D) trajectory during CBCT acquisition for each marker based on the segmentation in Step 1, and identification of the smallest ellipsoidal volume that encompasses 95% of the visited 3D positions. (6) Generation of the final MMAR CBCT reconstruction from the marker-free CBCT volume of Step 3 by replacing the voxels in the 95% ellipsoid with the corresponding voxels of the standard CBCT volume of Step 4. The MMAR reconstruction was performed retrospectively using a half-fan CBCT scan for 29 consecutive stereotactic body radiation therapy patients with 2–3 gold markers implanted in the liver. The metal artifacts of the MMAR reconstructions were scored and compared with a standard MAR reconstruction by counting the streaks and by calculating the standard deviation of the Hounsfield units in a region around each marker. Results: The markers were found with the same autosegmentation settings in 27 CBCT scans, while two scans needed slightly changed settings to find all markers automatically in Step 1 of the MMAR method. MMAR resulted in 15 scans with no streaking artifacts, 11 scans with 1–4 streaks, and 3 scans

  2. Seepage phenomena on Mars at subzero temperature

    Science.gov (United States)

    Kereszturi, Akos; Möhlmann, Diedrich; Berczi, Szaniszlo; Ganti, Tibor; Horvath, Andras; Kuti, Adrienn; Pocs, Tamas; Sik, Andras; Szathmary, Eors

    At the southern hemisphere of Mars seasonal slope structures emanating from Dark Dune Spots are visible on MGS MOC, and MRO HiRISE images. Based on their analysis two groups of streaks could be identified: diffuse and fan shaped ones forming in an earlier phase of local spring, probably by CO2 gas jets, and confined streaks forming only on steep slopes during a later seasonal phase. The dark color of the streaks may arise from the dark color of the dune grains where surface frost disappeared above them, or caused by the phase change of the water ice to liquid-like water, or even it may be influenced by the solutes of salts in the undercooled interfacial water The second group's morphology (meandering style, ponds at their end), morphometry, and related theoretical modelling suggest they may form by undercooled water that remains in liquid phase in a thin layer around solid grains. We analyzed sequence of images, temperature and topographic data of Russel (54S 12E), Richardson (72S 180E) and an unnamed crater (68S 2E) during southern spring. The dark streaks here show slow motion, with an average speed of meter/day, when the maximal daytime temperature is between 190 and 220 K. Based on thermophysical considerations a thin layer of interfacial water is inevitable on mineral surfaces under the present conditions of Mars. With 10 precipitable micrometer of atmospheric water vapor, liquid phase can be present down about 190 K. Under such conditions dark streaks may form by the movement of grains lubricatred by interfacial water. This possibility have various consequences on chemical, mechanical or even possible astrobiological processes on Mars. Acknowledgment: This work was supported by the ESA ECS-project No. 98004 and the Pro Renovanda Cultura Hungariae Foundation.

  3. Three-dimensional instability analysis of boundary layers perturbed by streamwise vortices

    Science.gov (United States)

    Martín, Juan A.; Paredes, Pedro

    2016-08-01

    A parametric study is presented for the incompressible, zero-pressure-gradient flat-plate boundary layer perturbed by streamwise vortices. The vortices are placed near the leading edge and model the vortices induced by miniature vortex generators (MVGs), which consist in a spanwise-periodic array of small winglet pairs. The introduction of MVGs has been experimentally proved to be a successful passive flow control strategy for delaying laminar-turbulent transition caused by Tollmien-Schlichting (TS) waves. The counter-rotating vortex pairs induce non-modal, transient growth that leads to a streaky boundary layer flow. The initial intensity of the vortices and their wall-normal distances to the plate wall are varied with the aim of finding the most effective location for streak generation and the effect on the instability characteristics of the perturbed flow. The study includes the solution of the three-dimensional, stationary, streaky boundary layer flows by using the boundary region equations, and the three-dimensional instability analysis of the resulting basic flows by using the plane-marching parabolized stability equations. Depending on the initial circulation and positioning of the vortices, planar TS waves are stabilized by the presence of the streaks, resulting in a reduction in the region of instability and shrink of the neutral stability curve. For a fixed maximum streak amplitude below the threshold for secondary instability (SI), the most effective wall-normal distance for the formation of the streaks is found to also offer the most stabilization of TS waves. By setting a maximum streak amplitude above the threshold for SI, sinuous shear layer modes become unstable, as well as another instability mode that is amplified in a narrow region near the vortex inlet position.

  4. Simultaneous Spectral Temporal Adaptive Raman Spectrometer - SSTARS

    Science.gov (United States)

    Blacksberg, Jordana

    2010-01-01

    Raman spectroscopy is a prime candidate for the next generation of planetary instruments, as it addresses the primary goal of mineralogical analysis, which is structure and composition. However, large fluorescence return from many mineral samples under visible light excitation can render Raman spectra unattainable. Using the described approach, Raman and fluorescence, which occur on different time scales, can be simultaneously obtained from mineral samples using a compact instrument in a planetary environment. This new approach is taken based on the use of time-resolved spectroscopy for removing the fluorescence background from Raman spectra in the laboratory. In the SSTARS instrument, a visible excitation source (a green, pulsed laser) is used to generate Raman and fluorescence signals in a mineral sample. A spectral notch filter eliminates the directly reflected beam. A grating then disperses the signal spectrally, and a streak camera provides temporal resolution. The output of the streak camera is imaged on the CCD (charge-coupled device), and the data are read out electronically. By adjusting the sweep speed of the streak camera, anywhere from picoseconds to milliseconds, it is possible to resolve Raman spectra from numerous fluorescence spectra in the same sample. The key features of SSTARS include a compact streak tube capable of picosecond time resolution for collection of simultaneous spectral and temporal information, adaptive streak tube electronics that can rapidly change from one sweep rate to another over ranges of picoseconds to milliseconds, enabling collection of both Raman and fluorescence signatures versus time and wavelength, and Synchroscan integration that allows for a compact, low-power laser without compromising ultimate sensitivity.

  5. Ultra-fast diagnosis technique based on image super-resolution%变像管扫描相机超分辨诊断技术研究

    Institute of Scientific and Technical Information of China (English)

    牛丽红; 苏秉华; 安玉磊

    2011-01-01

    时间分辨力是变像管扫描相机的重要技术参数,提出了将超分辨率图像复原理论应用于超快诊断研究,首先阐述了图像超分辨率复原在超快诊断中应用的可能性,给出了变像管扫描相机图像点扩散函数的分析和计算方法.最后,基于Poisson-MMAP (MPMAP)超分辨力复原算法,获得了Au阴极X射线变像管扫描相机的图像复原结果,实验结果证明了方法的有效性,为变像管扫描相机时间分辨力的提高提供了一种新的途径.%Super-resolution restoration is employed with image converted tube streak camera to improve time resolution of camera. The feasibility of the image of streak camera being processed by super-resolution restoring is presented. The point spread function of streak image is described and formulated. The image restoration results of X-ray streak camera of Au photo-cathode are obtained with Poisson-MMAP ( MPMAP) algorithm. The experimental results show that the super-resolution image restoration on ultra-fast diagnosis can be used for improving time resolution of image converted tube streak camera.

  6. A high spatio-temporal resolution optical pyrometer at the ORION laser facility

    Science.gov (United States)

    Floyd, Emma; Gumbrell, Edward T.; Fyrth, Jim; Luis, James D.; Skidmore, Jonathan W.; Patankar, Siddharth; Giltrap, Samuel; Smith, Roland

    2016-11-01

    A streaked pyrometer has been designed to measure the temperature of ≈100 μm diameter heated targets in the warm dense matter region. The diagnostic has picosecond time resolution. Spatial resolution is limited by the streak camera to 4 μm in one dimension; the imaging system has superior resolution of 1 μm. High light collection efficiency means that the diagnostic can transmit a measurable quantity of thermal emission at temperatures as low as 1 eV to the detector. This is achieved through the use of an f/1.4 objective, and a minimum number of reflecting and refracting surfaces to relay the image over 8 m with no vignetting over a 0.4 mm field of view with 12.5× magnification. All the system optics are highly corrected, to allow imaging with minimal aberrations over a broad spectral range. The detector is a highly sensitive Axis Photonique streak camera with a P820PSU streak tube. For the first time, two of these cameras have been absolutely calibrated at 1 ns and 2 ns sweep speeds under full operational conditions and over 8 spectral bands between 425 nm and 650 nm using a high-stability picosecond white light source. Over this range the cameras had a response which varied between 47 ± 8 and 14 ± 4 photons/count. The calibration of the optical imaging system makes absolute temperature measurements possible. Color temperature measurements are also possible due to the wide spectral range over which the system is calibrated; two different spectral bands can be imaged onto different parts of the photocathode of the same streak camera.

  7. Experimental Study of Turbulent Boundary Layers on Groove/Smooth Flat Surfaces

    Institute of Scientific and Technical Information of China (English)

    Hongwei MA; Qiao TIAN; Hui WU

    2005-01-01

    This paper presents an experimental investigation of the turbulent boundary layers on both groove and smooth flat surfaces. The flow structures were shown in a water tunnel using the hydrogen-bubble flow visualization technique. The measurement results indicate that: (1) the grooves can effectively reduce accumulation of low-speed fluids, decrease the number of the low-speed streaks and depress oscillation of the streaks in the sublayer; (2) the grooves can restrain forming of the horseshoe vortices in the buffer region; (3) the grooves bate oscillation and kinking of the quasi-streamwise vortices and restrain production of the hairpin vortices and the ring vortices, reducing both frequency and intensity of the turbulence bursting; (4) the grooves directly affect the flow structures in the sublayer of the boundary layer and then modulate the flow field up to the buffer region and the logarithmic region by restraining development and interaction of the vortices.

  8. Determination of the longitudinal phase space distribution produced with the TTF photo injector

    International Nuclear Information System (INIS)

    The longitudinal phase space distribution of the beam produced with the rf photo injector of the TESLA Test Facility at DESY is mainly determined by the longitudinal laser pulse shape and the compression due to the rf acceleration field in the rf gun. The longitudinal electron distribution is measured with a high resolution streak camera using synchrotron radiation at the spectrometer dipole (E - 200 MeV). The same streak camera is used to measure the UV laser pulse shape. The longitudinal distribution of the laser and the electron beam can alternatively be determined by Fourier transform spectroscopy. The energy spread of the beam is determined by measuring the beam profile in the dispersive section using optical transition radiation. Dephasing of the superconducting accelerating cavities and variation of bunch compression parameters allow further measurements of the longitudinal phase space distribution. (authors)

  9. Development behavior of liquid plasma produced by YAG laser

    CERN Document Server

    Yamada, J; Yamada, Jun; Tsuda, Norio

    2004-01-01

    The laser induced plasma in liquid hasn't been studied enough. In liquid, the laser induced plasma may be able to resolve the hazardous material called the environment material. Then, the plasma produced in liquid by the laser light is studied and the plasma development is observed by a streak camera. The ultra pure water or the ultra pure water with a melted NaCl is used as a test liquid. The liquid plasma is produced by the fundamental wave of YAG laser. When NaCl concentration is varied, the plasma development behavior is obserbed by streak camera. The liquid plasma develops backward. The plasma is produced from many seeds and It consists of a group of plasmas. However, the liquid plasma produced by second harmonic wave of YAG laser develops as a single plasma. The development mechanism is investigated from the growth rate of backward plasma. The backward plasma develops by breakdown wave and radiation supported shock wave.

  10. Formation of spanwise vorticy in oblique turbulent bands of transitional plane Couette flow, part 1: Numerical experiments

    CERN Document Server

    Rolland, Joran

    2014-01-01

    This article investigates the formation of spanwise vorticity in the velocity streaks of the oblique laminar- turbulent bands of plane Couette flow (PCF) by mean of Direct Numerical Simulations (DNS). The spanwise vorticity is created by a roll-up type development of the streamwise-wall normal shear layer of the velocity streaks. It is advected by the large scale flow along the bands. We propose a criterion on spanwise vorticity which detects these events in order to perform systematic measurements. Beside of the streamwise and spanwise correlation lengths of the rolls, their advection velocity is measured and shown to match the large scale flow along the band near the turbulent region. Eventually, we discuss the possible relation between ejection of vorticity away from the bands near the laminar region and the size of said laminar region.

  11. A second pass correction method for calcification artifacts in digital breast tomosynthesis

    Science.gov (United States)

    Erhard, Klaus; Grass, Michael; Nielsen, Tim

    2011-03-01

    Digital breast tomosynthesis (DBT) allows a quasi-3D reconstruction of the breast with high in-plane and poor depth resolution by the principles of limited angle tomography. The limited angular range and the coarse angular sampling result in prominent streak artifacts arising from high-contrast structures such as calcifications. These artifacts do not only degrade the image quality but also hold the risk of overlaying suspicious tissue structure in neighbouring slices, which might therefore be overlooked. This work presents a second pass method for correcting these kinds of high-contrast streak artifacts. In a first pass reconstruction the candidate highcontrast calcifications are segmented and subtracted from the original projection data to generate a subsequent artifact-free second pass reconstruction. The method is demonstrated in a simulation study using software breast phantoms, which have been derived from segmented MRI data.

  12. The effect of unsteadiness on the time-mean thermal loads in a turbine stage

    Science.gov (United States)

    Kirtley, K. R.; Celestina, M. L.; Adamczyk, J. J.

    1993-01-01

    Two steady numerical analysis methods and one unsteady method are used to study the viscous three-dimensional flow in the middle stage of the Pratt & Whitney alternate design Space Shuttle Main Engine fuel turbine. The principal characteristic of this flow is that the secondary flows generated in the rotor blade reconfigure a radial inlet total temperature distortion into one with a pitchwise exit hot streak distortion. Secondary flows in the following vane redistribute the radial variation while unsteadiness causes a segregation of hot and cold flow from the hot streak within the vane. Such redistribution and segregation can lead to unexpected thermal loads and reduced durability. The physical phenomena and the ability of a steady analysis to capture them are investigated by performing a numerical experiment whereby the results of the two steady analysis methods are compared to the time-mean of the unsteady simulation. The flow physics related to the segregation and mixing of total temperature are discussed.

  13. The retrospective gambler's fallacy

    Directory of Open Access Journals (Sweden)

    Daniel M. Oppenheimer

    2009-08-01

    Full Text Available The gambler's fallacy (Tune, 1964 refers to the belief that a streak is more likely to end than chance would dictate. In three studies, participants exhibited a extit{retrospective gambler's fallacy} (RGF in which an event that seems rare appears to come from a longer sequence than an event that seems more common. Study 1 demonstrates this bias for streaks, while Study 2 does so with single rare events and shows that the appearance of rarity is more important than actual rarity. Study 3 extends these findings from abstract gambling domains into real world domains to demonstrate the generalizability of the effects. The RGF follows from the law of small numbers (Tversky and Kahneman, 1971 and has many applications, from perceptions of the social world to philosophical debates about the existence of multiple universes.

  14. Characterization of induced nanoplasmonic fields in time-resolved photoemission from gold nanospheres: a classical trajectory approach

    Science.gov (United States)

    Saydanzad, Erfan; Thumm, Uwe

    2016-05-01

    Attosecond time-resolved (XUV-pump, IR-probe) spectroscopy has been shown to be a powerful method for investigating the electron dynamics in atoms, and this technique is now being transferred to the investigation of electronic excitations, electron propagation, and collective electronic (plasmonic) effects in solids. Based on classical trajectory calculations, we simulated (i) the final photoelectron velocity distribution in order to provide observable velocity-map images for gold nanospheres of 10 and 100 nm diameter and (ii) streaked photoemission spectra. By analyzing our numerical results, we illustrate how spatio-temporal information about the sub-IR-cycle plasmonic and electronic dynamics is encoded in velocity-map images and streaked photoelectron spectra. Supported by the NE/KS NSF-EPSCOR program.

  15. Transition and self-sustained turbulence in dilute suspensions of finite-size particles

    CERN Document Server

    Lashgari, Iman; Brandt, Luca

    2015-01-01

    We study the transition to turbulence of channel flow of finite-size particle suspensions at low volume fraction, i.e. $\\Phi \\approx 0.001$. The critical Reynolds number above which turbulence is sustained reduces to $Re \\approx 1675$, in the presence of few particles, independently of the initial condition, a value lower than that of the corresponding single-phase flow, i.e. $Re\\approx1775$. In the dilute suspension, the initial arrangement of the particles is important to trigger the transition at a fixed Reynolds number and particle volume fraction. As in single phase flows, streamwise elongated disturbances are initially induced in the flow. If particles can induce oblique disturbances with high enough energy within a certain time, the streaks breakdown, flow experiences the transition to turbulence and the particle trajectories become chaotic. Otherwise, the streaks decay in time and the particles immigrate towards the channel core in a laminar flow.

  16. A semi-classical approach for solving the time-dependent Schrödinger equation in inhomogeneous electromagnetic fields

    Science.gov (United States)

    Li, Jianxiong; Thumm, Uwe

    2016-05-01

    During the IR-streaked XUV photoemission from nanoparticles, the net IR electric field varies over the spatial extension of the target, an effect that for metallic particles is further enhanced by strong induced plasmonic polarization. This spatial dependence prevents the convenient use of ``Volkov states'' [solutions of the time-dependent Schrödinger equation for a free electron in a spatially homogeneous (cw) electromagnetic field] as approximate final states in quantum-mechanical photoemission calculations. To obtain the wave function of a free electron in a spatially inhomogeneous electromagnetic field, we propose a semi-classical approach based on time-dependent WKB theory. Generalizing ordinary Volkov states, this method provides a simple expression for modeling the final photoelectron state. We employ such generalized Volkov states to calculate the streaked photoelectron spectra from gold nanospheres and assess their accurary. Supported by the NSD-EPSCoR program, NSF, and the USDoE.

  17. Partial removal of correlated noise in thermal imagery

    International Nuclear Information System (INIS)

    Correlated noise occurs in many imaging systems such as scanners and push-broom imagers. The sources of correlated noise can be from the detectors, pre-amplifiers and sampling circuits. Correlated noise appears as streaking along the scan direction of a scanner or in the along track direction of a push-broom imager. We have developed algorithms to simulate correlated noise and pre-filter to reduce the amount of streaking while not destroying the scene content. The pre- filter in the Fourier domain consists of the product of two filters. One filter models the correlated noise spectrum, the other is a windowing function e.g. Gaussian or Hanning window with variable width to block high frequency noise away from the origin of the Fourier Transform of the image data. We have optimized the filter parameters for various scenes and find improvements of the RMS error of the original minus the pre-filtered noisy image

  18. Slow Magneto-acoustic Waves Observed above Quiet-Sun Region in a Dark Cavity

    CERN Document Server

    Liu, Jiajia; Wang, Yuming; Liu, Rui; Wang, Bin; Liao, Chijian; Shen, Chenglong; Zheng, Huinan; Miao, Bin; Su, Zhenpeng; Wang, S

    2012-01-01

    Waves play a crucial role in diagnosing the plasma properties of various structures in the solar corona and coronal heating. Slow magneto-acoustic (MA) waves are one of the important magnetohydrodynamic waves. In past decades, numerous slow MA waves were detected above the active regions and coronal holes, but rarely found elsewhere. Here, we investigate a `tornado'-like structure consisting of quasi-periodic streaks within a dark cavity at about 40--110 Mm above the quiet-Sun region on 2011 September 25. Our analysis reveals that these streaks are actually slow MA wave trains. The properties of these wave trains, including the phase speed, compression ratio, kinetic energy density, etc., are similar to those of the reported slow MA waves, except that the period of these waves is about 50 s, much shorter than the typical reported values (3--5 minutes).

  19. Ionization in Orthogonal Two-Color Laser Fields - Origin and Phase Dependence of Trajectory-Resolved Coulomb Effects

    CERN Document Server

    Richter, Martin; Schöffler, Markus; Jahnke, Till; Schmidt, Lothar Ph H; Dörner, Reinhard

    2016-01-01

    We report on electron momentum distributions from single ionization of Ar in strong orthogonally polarized two-color (OTC) laser fields measured with the COLTRIMS technique. We study the effect of Coulomb focusing whose signature is a cusp like feature in the center of the electron momentum spectrum. While the direct electrons show the expected strong dependence on the phase between the two colors, surprisingly the Coulomb focused structure is almost not influenced by the weak second harmonic streaking field. This effect is explained by the use of a CTMC simulation which describes the tunneled electron wave packet in terms of classical trajectories under the influence of the combined Coulomb- and OTC laser field. We find a subtle interplay between the initial momentum of the electron upon tunneling, the ionization phase and the action of the Coulomb field that makes the Coulomb focused part of the momentum spectrum apparently insensitive to the weaker streaking field.

  20. Towards a theory of attosecond transient recorder

    CERN Document Server

    Krasovskii, E E

    2009-01-01

    Laser assisted photoemission by a chirped subfemtosecond extreme ultraviolet (XUV) pulse is considered within an exactly solvable quantum-mechanical model. Special emphasis is given to the energy dependence of photoexcitation cross-section. The streaked spectra are analyzed within the classical picture of initial time-momentum distribution r_ini(p,t) of photoelectrons mapped to the final energy scale. The actual time-momentum distribution in the absence of the probe laser field is shown to be a poor choice for r_ini, and a more adequate ansatz is suggested. The semiclassical theory offers a simple practically useful approximation for streaked spectra. Its limitations for sufficiently long chirped XUV pulses are established.

  1. In-situ Structural Studies during PBO Fiber Spinning by Synchrotron WAXD/SAXS

    Science.gov (United States)

    Ran, Shaofeng; Burger, Christian; Fang, Dufei; Zong, Xinhua; Cruz, Sharon; Hsiao, Benjamin; Chu, Benjamin; Bubeck, Robert; Yabuki, Kazuyuki; Teramoto, Yoshihiko; Martin, David; Johnson, Michael; Cunniff, Philip

    2001-03-01

    A spinning unit was adapted to the Advanced Polymers Beamline at X27C of the National Synchrotron Light Source (NSLS), Brookhaven National Lab (BNL) to perform in-situ fiber spinning studies. WAXD patterns indicated that the structure before coagulation had a lyotropic liquid-crystalline order that cannot be simply nematic. After the fiber had passed through the coagulation water bath, ranging from 25-60 C, a significant ordering had taken place. The meridian peaks showed streaks. Two models, a Pi-interacting sanidic lyotropic solution and a crystal with translational disorder, could be used to explain the structures before and after coagulation. SAXS patterns of the PBO fiber after coagulation showed equatorial streaks.

  2. Attosecond experiments on plasmonic nanostructures principles and experiments

    CERN Document Server

    Schötz, Johannes

    2016-01-01

    Johannes Schötz presents the first measurements of optical electro-magnetic near-fields around nanostructures with subcycle-resolution. The ability to measure and understand light-matter interactions on the nanoscale is an important component for the development of light-wave-electronics, the control and steering of electron dynamics with the frequency of light, which promises a speed-up by several orders of magnitude compared to conventional electronics. The experiments presented here on metallic nanotips, widely used in experiments and applications, do not only demonstrate the feasibility of attosecond streaking as a unique tool for fundamental studies of ultrafast nanophotonics but also represent a first important step towards this goal. Contents Electron Scattering in Solids Attosecond Streaking from Metal Nanotips Target Groups Lecturers and students of physics, especially in the area of nanophotonics and attosecond physics About the Author Johannes Schötz received his Master's degree in physics and cu...

  3. Regularized Iterative Weighted Filtered Back-Projection for Few-View Data Photoacoustic Imaging

    Science.gov (United States)

    Peng, Dong

    2016-01-01

    Photoacoustic imaging is an emerging noninvasive imaging technique with great potential for a wide range of biomedical imaging applications. However, with few-view data the filtered back-projection method will create streak artifacts. In this study, the regularized iterative weighted filtered back-projection method was applied to our photoacoustic imaging of the optical absorption in phantom from few-view data. This method is based on iterative application of a nonexact 2DFBP. By adding a regularization operation in the iterative loop, the streak artifacts have been reduced to a great extent and the convergence properties of the iterative scheme have been improved. Results of numerical simulations demonstrated that the proposed method was superior to the iterative FBP method in terms of both accuracy and robustness to noise. The quantitative image evaluation studies have shown that the proposed method outperforms conventional iterative methods. PMID:27594896

  4. Femtosecond Pulse Propagation in a Highly Nonlinear Photonic Crystal Fiber

    Directory of Open Access Journals (Sweden)

    J. F. Gabayno

    2004-12-01

    Full Text Available Femtosecond pulses are launched into a highly nonlinear photonic crystal fiber (PCF. The input and output spectra were measured using a monochromator and streak camera. The spectrum of the output from a 50 cm PCF pumped at 794 nm for different pump powers features asymmetric side lobes due to intrapulse Raman scattering. Similar measurements on a 100 cm PCF pumped at 795 nm highlight the appearance of blueshifted peaks as a result of energy transfer of solitons to dispersive waves. Broadening in the spectrum is observed and attributed to Raman-scattering-induced soliton self-frequency shift. Spectrograms of both input and output pulses into a 50 cm PCF are captured using a streak camera. The spectrum reveals that individual modes observed on the spectrogram are actually a decomposition of the input pulse.

  5. A high-resolving-power x-ray spectrometer for the OMEGA EP Laser (invited)

    Science.gov (United States)

    Nilson, P. M.; Ehrne, F.; Mileham, C.; Mastrosimone, D.; Jungquist, R. K.; Taylor, C.; Stillman, C. R.; Ivancic, S. T.; Boni, R.; Hassett, J.; Lonobile, D. J.; Kidder, R. W.; Shoup, M. J.; Solodov, A. A.; Stoeckl, C.; Theobald, W.; Froula, D. H.; Hill, K. W.; Gao, L.; Bitter, M.; Efthimion, P.; Meyerhofer, D. D.

    2016-11-01

    A high-resolving-power x-ray spectrometer has been developed for the OMEGA EP Laser System based on a spherically bent Si [220] crystal with a radius of curvature of 330 mm and a Spectral Instruments (SI) 800 Series charge-coupled device. The instrument measures time-integrated x-ray emission spectra in the 7.97- to 8.11-keV range, centered on the Cu Kα1 line. To demonstrate the performance of the spectrometer under high-power conditions, Kα1,2 emission spectra were measured from Cu foils irradiated by the OMEGA EP laser with 100-J, 1-ps pulses at focused intensities above 1018 W/cm2. The ultimate goal is to couple the spectrometer to a picosecond x-ray streak camera and measure temperature-equilibration dynamics inside rapidly heated materials. The plan for these ultrafast streaked x-ray spectroscopy studies is discussed.

  6. Time delays in correlated photoemission processes

    Science.gov (United States)

    Pazourek, R.; Nagele, S.; Burgdörfer, J.

    2015-09-01

    We theoretically study time-resolved two-photon double ionization (TPDI) of helium as probed by attosecond streaking. We review recent advances in the understanding of the photoelectric effect in the time domain and discuss the differences between one- and two-photon ionization, as well as one- and two-electron emission. We perform exact ab-initio simulations for attosecond streaking experiments in the sequential TPDI regime and compare the results to the two-electron Eisenbud-Wigner-Smith delay for the process. Our calculations directly show that the timing of the emission process sensitively depends on the energy sharing between the two outgoing electrons. In particular, we identify Fano-like interferences in the relative time delay of the two emitted electrons when the sequential ionization channel occurs via intermediate excited ionic (shake-up) states. Furthermore, we find that the photoemission time delays are only weakly dependent on the relative emission angle of the ejected electrons.

  7. Slit-Drum Camera For Projectile Studies

    Science.gov (United States)

    Liangyi, Chen; Shaoxiang, Zhou; Guanhua, Cha; Yuxi, Hu

    1983-03-01

    The' model XF-70 slit-drum camera has been developed to record projectile in flight for observation and acquisition. It has two operation modes: (1) synchro-ballistic photography, (2) streak record. The film is located on the inner surface of rotating drum to make it travel. The folding mirror is arranged to reflect light beam 90 degree on to film. The assembly of folding mirror and slit aperture can be together rotated about the optical axis of objective so that the camera makes a feature of recording projectile having any launching angle either in synchro-ballistic photography or in streak record through prerotating the folding mirror assembly by an appropriate angle. The mechanical-electric shutter preventing film from reexposing is close to the slit aperture. The loading mechanism is designed for use in daylight. LED fiducial mark and timing mark are printed at the edges of the frame for accurate measurements.

  8. Streaky signal in seismic normal mode band observed at Syowa Station, Antarctica

    OpenAIRE

    早河, 秀章; 澁谷, 和雄; 土井, 浩一郎; 青山, 雄一; 金尾, 政紀; 池田, 博

    2010-01-01

    Background free oscillations are known as continuous and global signals on noise level in seismic normal mode band. These were found from record of superconducting gravimeter (SG) at Syowa Station, Antarctica in 1998 [Nawa et al. 1998], and then were confirmed at various sites. Other unknown slightly broad spectrum peaks were also found as streak on spectrogram in seismic normal mode band of Syowa SG data. But these signals ware not found in gravimeter and seismometer records from any other s...

  9. Comparison of pure and hybrid iterative reconstruction techniques with conventional filtered back projection: Image quality assessment in the cervicothoracic region

    Energy Technology Data Exchange (ETDEWEB)

    Katsura, Masaki, E-mail: mkatsura-tky@umin.ac.jp [Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Sato, Jiro; Akahane, Masaaki; Matsuda, Izuru; Ishida, Masanori; Yasaka, Koichiro; Kunimatsu, Akira; Ohtomo, Kuni [Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan)

    2013-02-15

    Objectives: To evaluate the impact on image quality of three different image reconstruction techniques in the cervicothoracic region: model-based iterative reconstruction (MBIR), adaptive statistical iterative reconstruction (ASIR), and filtered back projection (FBP). Methods: Forty-four patients underwent unenhanced standard-of-care clinical computed tomography (CT) examinations which included the cervicothoracic region with a 64-row multidetector CT scanner. Images were reconstructed with FBP, 50% ASIR-FBP blending (ASIR50), and MBIR. Two radiologists assessed the cervicothoracic region in a blinded manner for streak artifacts, pixilated blotchy appearances, critical reproduction of visually sharp anatomical structures (thyroid gland, common carotid artery, and esophagus), and overall diagnostic acceptability. Objective image noise was measured in the internal jugular vein. Data were analyzed using the sign test and pair-wise Student's t-test. Results: MBIR images had significant lower quantitative image noise (8.88 ± 1.32) compared to ASIR images (18.63 ± 4.19, P < 0.01) and FBP images (26.52 ± 5.8, P < 0.01). Significant improvements in streak artifacts of the cervicothoracic region were observed with the use of MBIR (P < 0.001 each for MBIR vs. the other two image data sets for both readers), while no significant difference was observed between ASIR and FBP (P > 0.9 for ASIR vs. FBP for both readers). MBIR images were all diagnostically acceptable. Unique features of MBIR images included pixilated blotchy appearances, which did not adversely affect diagnostic acceptability. Conclusions: MBIR significantly improves image noise and streak artifacts of the cervicothoracic region over ASIR and FBP. MBIR is expected to enhance the value of CT examinations for areas where image noise and streak artifacts are problematic.

  10. Evaluation of CT to cerebral tissue degeneration and atrophy of 23 Wilson disease patients%CT对23例Wilson患者脑组织变性及脑萎缩的评估价值

    Institute of Scientific and Technical Information of China (English)

    刘剑立; 张纯利; 韩立亭; 关长群

    2002-01-01

    Objective To explore image manifestation of Wilson disease. Method To analyze brain and liver CT image manifestation of 23 Wilson disease patients. Result Brain CT image of all patients showed multiple site point or streak, low- density soft lesions accompanied by distension of cerebral ventricle, sulus deepen. Liver CT image of 4 patients showed liver sclerosis characters with irregular shape and rough and uneven in surface. Conclusion Brain CT has important reference value to diagnosis and evaluation of Wilson disease. ``

  11. Nematode resistance in bananas : screening results on some new Mycosphaerella resistant banana hybrids

    OpenAIRE

    Quénéhervé, Patrick; Salmon, F.; Topart, Patrick; Horry, J. P.

    2009-01-01

    Banana hybrids with resistance to Yellow Sigatoka and Black Leaf Streak disease were evaluated for resistance to the burrowing nematode Radopholus similis and to the lesion nematode Pratylenchus coVeae in a growth chamber at 24-28. Plants produced by tissue culture were acclimatised for 6 weeks prior to inoculation. Forty-five days after inoculation with nematodes, the root systems were processed and nematode numbers assessed. Two cultivars of Grande Naine (Musa AAA, Cavendish subgroup, ITC12...

  12. Antibiogram of bacterial species isolated from canine pyometra

    OpenAIRE

    Madhu Swamy; Varun Bassessar; Yamini Verma

    2013-01-01

    Aim: The aim of the present work was to ascertain the bacterial flora causing pyometra in female dogs and their antibiotic sensitivity. Materials and Methods: A study was conducted to determine the antibiogram of bacterial species isolated from 20 female dogs diagnosed with pyometra. The vaginal discharge was collected by sterile swab and streaked smoothly over Mueller Hinton medium and sensitivity towards antibiotics was determined by measuring the zone of inhibition using a Hi-media scale. ...

  13. Nanolesions induced by heavy ions in human tissues: Experimental and theoretical studies

    OpenAIRE

    Marcus Bleicher; Lucas Burigo; Marco Durante; Maren Herrlitz; Michael Krämer; Igor Mishustin; Iris Müller; Francesco Natale; Igor Pshenichnov; Stefan Schramm; Gisela Taucher-Scholz; Cathrin Wälzlein

    2012-01-01

    The biological effects of energetic heavy ions are attracting increasing interest for their applications in cancer therapy and protection against space radiation. The cascade of events leading to cell death or late effects starts from stochastic energy deposition on the nanometer scale and the corresponding lesions in biological molecules, primarily DNA. We have developed experimental techniques to visualize DNA nanolesions induced by heavy ions. Nanolesions appear in cells as “streaks&...

  14. Development and Application of Single-Ended Picosecond Laser Diagnostics

    OpenAIRE

    Kaldvee, Billy

    2012-01-01

    Light detection and ranging (lidar), a method for nonintrusive, single-ended, and range resolved measurements, has been developed and applied for combustion related diagnostics. Employing picosecond laser pulse durations and detectors providing temporal resolution on the order of picoseconds, lidar has been applied successfully for both quantitative temperature- and species concentration measurements, obtaining an ultimate range resolution of 0.46 cm. The use of a streak camera as detector...

  15. A novel iterative reconstruction algorithm allows reduced dose multidetector-row CT imaging of mechanical prosthetic heart valves

    OpenAIRE

    Habets, Jesse; Symersky, Petr; de Mol, Bas A. J. M.; Willem P Th M Mali; Leiner, Tim; Budde, Ricardo P.J.

    2011-01-01

    Multidetector-row CT is promising for prosthetic heart valve (PHV) assessment but retrospectively ECG-gated scanning has a considerable radiation dose. Recently introduced iterative reconstruction (IR) algorithms may enable radiation dose reduction with retained image quality. Furthermore, PHV image quality on the CT scan mainly depends on extent of PHV artifacts. IR may decrease streak artifacts. We compared image noise and artifact volumes in scans of mechanical PHVs reconstructed with conv...

  16. Reduction of artefacts caused by hip implants in CT-based attenuation-corrected PET images using 2-D interpolation of a virtual sinogram on an irregular grid

    Energy Technology Data Exchange (ETDEWEB)

    Abdoli, Mehrsima; Jong, Johan R. de; Pruim, Jan; Dierckx, Rudi A.J.O. [University of Groningen, Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen (Netherlands); Zaidi, Habib [University of Groningen, Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen (Netherlands); Geneva University Hospital, Division of Nuclear Medicine and Molecular Imaging, Geneva (Switzerland); Geneva University, Geneva Neuroscience Center, Geneva (Switzerland)

    2011-12-15

    Metallic prosthetic replacements, such as hip or knee implants, are known to cause strong streaking artefacts in CT images. These artefacts likely induce over- or underestimation of the activity concentration near the metallic implants when applying CT-based attenuation correction of positron emission tomography (PET) images. Since this degrades the diagnostic quality of the images, metal artefact reduction (MAR) prior to attenuation correction is required. The proposed MAR method, referred to as virtual sinogram-based technique, replaces the projection bins of the sinogram that are influenced by metallic implants by a 2-D Clough-Tocher cubic interpolation scheme performed in an irregular grid, called Delaunay triangulated grid. To assess the performance of the proposed method, a physical phantom and 30 clinical PET/CT studies including hip prostheses were used. The results were compared to the method implemented on the Siemens Biograph mCT PET/CT scanner. Both phantom and clinical studies revealed that the proposed method performs equally well as the Siemens MAR method in the regions corresponding to bright streaking artefacts and the artefact-free regions. However, in regions corresponding to dark streaking artefacts, the Siemens method does not seem to appropriately correct the tracer uptake while the proposed method consistently increased the uptake in the underestimated regions, thus bringing it to the expected level. This observation is corroborated by the experimental phantom study which demonstrates that the proposed method approaches the true activity concentration more closely. The proposed MAR method allows more accurate CT-based attenuation correction of PET images and prevents misinterpretation of tracer uptake, which might be biased owing to the propagation of bright and dark streaking artefacts from CT images to the PET data following the attenuation correction procedure. (orig.)

  17. Reducing the effects of metal artefact using high keV monoenergetic reconstruction of dual energy CT (DECT) in hip replacements

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Mark [Norfolk and Norwich University Hospital, Norwich (United Kingdom); Norwich Radiology Academy, Norwich (United Kingdom); Reid, Karen [Norfolk and Norwich University Hospital, Norwich (United Kingdom); Toms, Andoni P. [Norfolk and Norwich University Hospital and University of East Anglia, Norwich (United Kingdom)

    2013-02-15

    The aim of this study was to determine whether high keV monoenergetic reconstruction of dual energy computed tomography (DECT) could be used to overcome the effects of beam hardening artefact that arise from preferential deflection of low energy photons. Two phantoms were used: a Charnley total hip replacement set in gelatine and a Catphan 500. DECT datasets were acquired at 100, 200 and 400 mA (Siemens Definition Flash, 100 and 140 kVp) and reconstructed using a standard combined algorithm (1:1) and then as monoenergetic reconstructions at 10 keV intervals from 40 to 190 keV. Semi-automated segmentation with threshold inpainting was used to obtain the attenuation values and standard deviation (SD) of the streak artefact. High contrast line pair resolution and background noise were assessed using the Catphan 500. Streak artefact is progressively reduced with increasing keV monoenergetic reconstructions. Reconstruction of a 400 mA acquisition at 150 keV results in reduction in the volume of streak artefact from 65 cm{sup 3} to 17 cm{sup 3} (74 %). There was a decrease in the contrast to noise ratio (CNR) at higher tube voltages, with the peak CNR seen at 70-80 keV. High contrast spatial resolution was maintained at high keV values. Monoenergetic reconstruction of dual energy CT at increasing theoretical kilovoltages reduces the streak artefact produced by beam hardening from orthopaedic prostheses, accompanied by a modest increase in heterogeneity of background image attenuation, and decrease in contrast to noise ratio, but no deterioration in high contrast line pair resolution. (orig.)

  18. α-Tris(2,4-pentanedionato-κ2O,O’)-chromium(III) at 290 and 110 K: a new δ phase at 110 K

    OpenAIRE

    von Chrzanowski, L.S.; Lutz, M; Spek, A.L.

    2007-01-01

    The crystal structure of the title compound, [Cr(C5H7O2)3], has been determined at 290 and 110 K to provide information on thermal vibrations and disorder. The polymorph at room temperature has been reported [Morosin (1965). Acta Cryst. 19, 131-137]. The reinvestigation of this structure, presented here, indicates the presence of weak uninterpretable supercell reflections together with disorder streaks. The discussed structure can thus be considered as an average structure. After cooling to 1...

  19. Early-time measurements of laser-plasma conditions in OMEGA-upgrade ICF targets. Final report, April 1, 1998--January 31, 1999

    Energy Technology Data Exchange (ETDEWEB)

    Griem, H.R.; Elton, R.C.

    1998-02-08

    All of the experimental results from OMEGA shots described here are from CY-1998 experiments under an (extended) FY-98 grant. This research involves fielding at LLE their two flat-field euv spectrographs in the 30--250 {angstrom} range, mainly utilizing on one o them a gated stripline microchannel plate as a time-resolved detector, with photographic recording. The experimental layout for the 1998 experiments is shown. During the week beginning May 3, 1998, the authors obtained 24 data shots over 4 days, and fielded both the time-gated extreme ultraviolet (euv) spectrograph mounted external to the target chamber, as well as their newly-constructed TIM-mounted euv spectrograph mounted closer to the target with time-integrated photographic recording on a trial basis. They also had available the LLE/LLNL streak x-ray spectrograph and x-ray imaging cameras. In this series, the first two shots appeared from the x-ray streak spectra to be normal in the sense that the spectral line emissions from the two coatings sequenced beginning with magnesium followed by aluminum as the coatings were vaporized. Unfortunately, on the following shots in this campaign it became increasingly apparent that conditions had changed radically, and later analyses showed that x-ray spectra lines from the deep aluminum undercoating appeared initially along with weak magnesium lines, indicating a premature vaporization of the magnesium heavier top layer. The second campaign in 1998 occurred during the week beginning October 18, 1998 and consisted of 21 data shots over two extended (12-hour) days following setup. For this series the authors again used their externally-mounted euv spectrography with time resolution and the x-ray streak spectrograph and imaging cameras. Much to their relief, it was immediately evident from the x-ray streak spectra obtained that significant ablation of the magnesium coatings by a (presumed) prepulse was not present, as it had been in the May campaign.

  20. Status of longitudinal bunch diagnostics at the ANKA storage ring

    Energy Technology Data Exchange (ETDEWEB)

    Hiller, Nicole; Huttel, Erhard; Judin, Vitali; Kehrer, Benjamin; Klein, Marit; Marsching, Sebastian; Meuter, Christina; Mueller, Anke-Susanne; Nakneimueang, Somprasong; Nasse, Michael J.; Schuh, Marcel; Schwarz, Markus; Smale, Nigel [Karlsruher Institut fuer Technologie (Germany)

    2012-07-01

    ANKA, the synchrotron radiation facility at the Karlsruhe Institute of Technology, is operated in a special low-alpha-mode on a regular basis. With the recent installation of a visible light diagnostics beamline further studies of bunch lengthening and deformation could be performed with our streak camera for different machine settings within the low-alpha operation (different bunch currents, energies, alphas, RF voltages). This presentation gives an overview of the various studies.

  1. Types of Maize Virus Diseases and Progress in Virus Identification Techniques in China

    Institute of Scientific and Technical Information of China (English)

    Cui Yu; Zhang Ai-hong; Ren Ai-jun; Miao Hong-qin

    2014-01-01

    There are a total of more than 40 reported maize viral diseases worldwide. Five of them have reportedly occurred in China. They are maize rough dwarf disease, maize dwarf mosaic disease, maize streak dwarf disease, maize crimson leaf disease, maize wallaby ear disease and corn lethal necrosis disease. This paper reviewed their occurrence and distribution as well as virus identification techniques in order to provide a basis for virus identification and diagnosis in corn production.

  2. Bacterial cell culture

    OpenAIRE

    sprotocols

    2014-01-01

    ### Materials 1. Glass culture tubes with metal caps and labels - Growth medium, from media room or customized - Glass pipette tubes - Parafilm ### Equipment 1. Vortexer - Fireboy or Bunsen burner - Motorized pipette - Micropipettes and sterile tips ### Procedure For a typical liquid culture, use 5 ml of appropriate medium. The amount in each tube does not have to be exact if you are just trying to culture cells for their precious DNA. 1. Streak an a...

  3. Improved total variation minimization method for few-view computed tomography image reconstruction

    OpenAIRE

    Hu, Zhanli; Zheng, Hairong

    2014-01-01

    Background Due to the harmful radiation dose effects for patients, minimizing the x-ray exposure risk has been an area of active research in medical computed tomography (CT) imaging. In CT, reducing the number of projection views is an effective means for reducing dose. The use of fewer projection views can also lead to a reduced imaging time and minimizing potential motion artifacts. However, conventional CT image reconstruction methods will appears prominent streak artifacts for few-view da...

  4. Estimation de vitesse par analyse d'images acquises en filé : Application à la caractérisation de la distribution centrifuge de granules d'engrais.

    OpenAIRE

    Villette, Sylvain

    2006-01-01

    This dissertation demonstrates that motion blurred images acquired in the vicinity of the spinning disc of a fertiliser centrifugal spreader can be used to estimate the outlet velocity components of the granules. First, a recursive linear filter is applied to the image to detect the streak axes corresponding to the granule trajectories. This filter was specifically developed for our research by means of the Canny method and an edge model based on an experimental approach. Secondly, the trajec...

  5. 励起された平面衝突噴流の伝熱機構

    OpenAIRE

    三好, 啓史; 金子, 順一; 榊原 潤

    2001-01-01

    Wall temperature and velocity of a stagnation region of a plane impinging jet were measured by using thermochromic liquid crystal (TLC) and PIV. The plane jet was excited in time and space by adding suction / blowing type disturbances produced by servomotor-driven injectors. Surface temperature distribution showed unsteady streaks in parallel to a wall jet direction. The lowest spatial-averaged-wall temperature and vorticity intensity on the wall could be realized when the phase angle of the ...

  6. Dermoscopic Features of Pigmented Bowen's Disease in a Japanese Female Mimicking Malignant Melanoma

    OpenAIRE

    Takayuki Inoue; Ken Kobayashi; Mizuki Sawada; Sumiko Ishizaki; Haruo Ito; Mariko Fujibayashi; Masaru Tanaka

    2010-01-01

    Various structures have been reported for dermoscopic features of pigmented Bowen's disease (BD), which could be a mimic of various pigmented skin lesions. A 79-year-old Japanese woman presented with a 3-year history of brown-black macule on her right upper arm without symptom. Dermoscopic examination demonstrated irregular flossy streaks, irregular brown dots/globules, blue-whitish regression structures, and overlaying whitish scaly areas. We suspected pigmented skin lesions including seborr...

  7. Picosecond fluorescence of cryptomonad biliproteins. Effects of excitation intensity and the fluorescence decay times of phycocyanin 612, phycocyanin 645, and phycoerythrin 545.

    OpenAIRE

    Guard-Friar, D; MacColl, R; Berns, D S; Wittmershaus, B; Knox, R S

    1985-01-01

    The fluorescence of purified biliproteins (phycocyanin 645, phycocyanin 612, and phycoerythrin 545) from three cryptomonads, Chroomonas species, Hemiselmis virescens, and Rhodomonas lens, and C-phycocyanin from Anacystis nidulans has been time resolved in the picosecond region with a streak camera system having less than or equal to 2-ps jitter. The fluorescence lifetimes of phycocyanins from Chroomonas species and Hemiselmis virescens are 1.5 +/- 0.2 ns and 2.3 +/- 0.2 ns, respectively, rega...

  8. Angular anisotropy of time delay in XUV/IR photoionization of H$_2^+$

    CERN Document Server

    Serov, Vladislav V

    2016-01-01

    We develop a novel technique for modeling of atomic and molecular ionization in superposition of XUV and IR fields with characteristics typical for attosecond streaking and RABBITT experiments. The method is based on solving the time-dependent Schr\\"odinger equation in the coordinate frame expanding along with the photoelectron wave packet. The efficiency of the method is demonstrated by calculating angular anisotropy of photoemission time delay of the H$_2^+$ ion in a field configuration of recent RABBITT experiments.

  9. 光电成像与器件

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    TN143 2001053448中子扫描变象管的最小可探测脉冲中子产额=Detectable neutron yield threshold of neutron streak image tubes[刊,中]/廖华,张焕文,杨勤劳,董改云(中科院西安光机所.陕西,西安(710068))//光子学报.—2000,29(11).—1024-1027

  10. Measurement of RT amplitudes and wavelengths of laser driven plates

    Energy Technology Data Exchange (ETDEWEB)

    Frank, A.M.; Gillespie, C.H.

    1997-10-16

    A laser drive plate, that is a dense solid plate drive by a laser heated, lower density plasma, is inherently Raleigh-Taylor (R-T) unstable, We have previously indicated that observed surface perturbation on the plate are probably R-T instabilities, initiated by the mode structure of the driving laser beam. Using a semi- transparent impact target viewed with a polarized Epi-Illuminated Confocal Streak Microscope, has allowed us to measure the amplitude and growth of the instability.

  11. Picosecond x-ray measurements from 100 eV to 30 keV

    International Nuclear Information System (INIS)

    Picosecond x-ray measurements relevant to the Livermore Laser Fusion Program are reviewed. Resolved to 15 picoseconds, streak camera detection capabilities extend from 100 eV to higher than 30 keV, with synchronous capabilities in the visible, near infrared, and ultraviolet. Capabilities include automated data retrieval using charge coupled devices (CCD's), absolute x-ray intensity levels, novel cathodes, x-ray mirror/reflector combinations, and a variety of x-ray imaging devices

  12. Severe aortic regurgitation and partial anomalous pulmonary venous connection in a Turner syndrome patient.

    Science.gov (United States)

    Yin, Kanhua; Li, Jun; Zhu, Kai; Wang, Yulin; Lai, Hao; Wang, Chunsheng

    2015-11-01

    Turner syndrome (TS) is one of the most common sex chromosome diseases. Short stature (if untreated) and ovarian dysgenesis (streak ovary) are two typical clinical manifestations of these patients. A variety of cardiovascular abnormalities has been found associated with TS. We report a 29-year-old TS patient with severe aortic regurgitation, bicuspid aortic valve (BAV) and partial anomalous pulmonary venous connection (PAPVC). We discuss the diagnostic and surgical management of cardiovascular complications in TS patients. PMID:26716053

  13. Skylab-barium alpha and beta L = 6 field-line tracing experiments

    International Nuclear Information System (INIS)

    Events SKYLAB-BARIUM ALPHA (27 November 1973) and BETA (4 December 1973) were shaped-charge barium field-line tracing experiments near L approximately equal to 6, conducted jointly by the Los Alamos Scientific Laboratory and the University of Alaska Geophysical Institute. Image-orthicon and pulsed intensified auroral cameras provided data for triangulating the fast ion streaks. Using the POGO 10-68, epoch 1965.0, field-line model with Mead-Fairfield corrections for the outer field, the triangulated positions of the fast ion streak were projected down to the 100 km altitude northern conjugate surface. The projected positions moved toward magnetic east with a velocity of 725 m/sec for both SKYLAB-BARIUM ALPHA and BETA. Assuming only an E x B/B2 force, this drift velocity is consistent with an electric field toward magnetic south of 39 mV/m. Radiometric analysis of the filtered, intensified auroral camera records gave observed peak radiance values of about 2 x 10-11 watts/cm2-Sr in the 455.4 nm line of Ba+. The barium in the portion of the ion streak for which radiometric data were obtained had initial injection velocities of 9.5 to 13.5 km/sec in both events. This portion of the ion streak for both SKYLAB-BARIUM ALPHA and BETA contained approximately 4 x 1023 ions compared to the 6.4 x 1024 atoms contained in the barium liner. Ion inventory estimates are based on a solution of the statistical equilibrium equations. Corrections have been made in the ion inventory calculations for Doppler shifts of the solar spectrum as received in the rest frame of the high-velocity barium ions

  14. Heat wave brings an unprecedented red tide to San Francisco Bay

    Science.gov (United States)

    Cloern, James E.; Schraga, Tara S.; Lopez, Cary B.

    2005-01-01

    An exceptional red tide in San Francisco Bay was observed on 8 September 2004. The red tide had chlorophyll concentrations approaching 200 mg/m3 (Figure 1) in red/purple surface streaks containing high abundances of the dinoflagellate Akashiwo sanguinea. Red tides and harmful algal blooms (HABs) are common features of coastal ecosystems, and their growing frequency is a suspected outcome of coastal eutrophication.

  15. Development of Methods for Scatter Artifact Correction in Industrial X-ray Cone-beam Computed Tomography

    OpenAIRE

    Schörner, Karsten

    2012-01-01

    Scattered radiation presents a major cause of image degradation for industrial X-ray cone-beam CT scanners. It introduces several kinds of artifacts in reconstructed CT volumes, such as streaks, a general loss of contrast, and inhomogeneities known as cupping artifact. In this work, we study different scattering sources which contribute to the total detected signal and we develop methods for the correction of these secondary contributions. A novel method, based on the temporal modulation of t...

  16. Medical image of the week: pneumomediastinum

    OpenAIRE

    Baalachandran R; Mahmoud N; Meinke L

    2014-01-01

    A 38-year-old gentleman was flown to the emergency room after being involved in a motor vehicle accident. In the field, he had a Glasgow Coma Scale of about 7 and cricothyrotomy was performed to establish an airway. He sustained severe head and chest injuries, with extensive subcutaneous emphysema. Chest X-ray (Figure 1) and CT scan (Figure 2) revealed pneumomediastinum with classical “continuous diaphragm sign” (red arrows), lucent streaks outlining the ascending aorta (blue arrows) and ext...

  17. LIVA : a data reduction program for line-imaging ORVIS measurements.

    Energy Technology Data Exchange (ETDEWEB)

    Ao, Tommy

    2009-06-01

    LIVA (Line-Imaging Velocimetry Analysis) is a program for reducing data of a line-imaging optically recording velocity interferometer system (ORVIS) diagnostic. LIVA uses the Fourier transform method to extract phase information from recorded streak camera images. The extracted phase shift is used to infer target velocity as a function of space and time. The program can be run in any current version of MATLAB (2008a or later) or as a Windows XP executable.

  18. Picosecond x-ray measurements from 100 eV to 30 keV

    Energy Technology Data Exchange (ETDEWEB)

    Attwood, D.T.; Kauffman, R.L.; Stradling, G.L.

    1980-10-15

    Picosecond x-ray measurements relevant to the Livermore Laser Fusion Program are reviewed. Resolved to 15 picoseconds, streak camera detection capabilities extend from 100 eV to higher than 30 keV, with synchronous capabilities in the visible, near infrared, and ultraviolet. Capabilities include automated data retrieval using charge coupled devices (CCD's), absolute x-ray intensity levels, novel cathodes, x-ray mirror/reflector combinations, and a variety of x-ray imaging devices.

  19. Comparison of methods by TLC and HPTLC for determination of aflatoxin M1 in milk and B1 in eggs Comparação de metodologia para análise de aflatoxina M1 em leite e aflatoxina B1 em ovos por CCD e CCDAE

    OpenAIRE

    Scussel, V. M.

    2003-01-01

    Milk and egg matrixes were assayed for aflatoxin M1 (AFM1) and B1 (AFB1) respectively, by AOAC official and modified methods with detection and quantification by thin layer chromatography (TLC) and high performance thin layer chromatography (HPTLC). The modified methods: Blanc followed by Romer, showed to be most appropriate for AFM1 analysis in milk. Both methods reduced emulsion formation, produced cleaner extracts, no streaking spots, precision and accuracy improved, especially when quanti...

  20. A novel method for measuring energy loss in electron rings

    OpenAIRE

    Byrd, John M.; De Santis, Stefano

    2001-01-01

    We present a novel method for measuring the energy loss per turn in an electron storage ring. The method involves the accurate measurement of the change in the rotation period of an uncaptured electron bunch using a dual-sweep streak camera. In our opinion, this method is more direct and accurate than other techniques. We present examples of measurements performed at the Advanced Light Source.

  1. Realtime Surface Shear Stress Control with MEMS Sensors/Actuators in Turbulent Boundary Layers

    Science.gov (United States)

    Huang, Adam; Lew, James; Ho, Chih-Ming; Xu, Yong; Tai, Yu-Chong

    2003-11-01

    High-speed surface streaks in turbulent boundary layers have been attributed to approximately 40friction drag. A real-time control system for reducing surface shear stress has being developed. The system consists of two linear arrays of MEMS surface shear stress imagers for providing control and feedback measurements and a recently developed, micro-machined flap-type actuator for interaction with the streak structures. Driven by a constant temperature anemometry circuit with an overheat ratio of 12sensitivity of 100 mV/Pa and frequency response of 20 kHz. The micro-machined bubble-flap actuator is essentially a thin silicon cantilever beam which hangs/sits on top of a silicone diaphragm molded into a bulk etched silicon cavity. The flap shape used is a 3mm long (streamwise) by 1mm wide rectangular beam, with a thickness of 40 um. Actuation is achieved by pneumatically inflating the silicone diaphragm, which then pushes up the silicon beam. The current flap can achieve off-plane deflections of over 130 um at frequencies up to 150 Hz, with a rise time of 2ms and a fall time of 4ms. Experiments are carried out with the system installed onto the wall of a 2-D turbulent wind tunnel. At Re 10k, corresponding to flow velocity of 10 m/s, time-averaged reduction of 4achieved continuous actuation at 130 um and 150 Hz. Furthermore, in offline data processing, it has been found that the actuator interacting with the streak structures has reduce the peak shear stress of a streak by an additional 0.2 Pa, or about 50

  2. A distinct tospovirus causing necrotic straek on alstroemeria sp. in Colombia

    OpenAIRE

    Mehraban, A.; Botermans, M.; Verhoeven, J.Th.J.; Meekes, E.; Saaijer, J.; Peters, D.; Goldbach, R.W.; Kormelink, R.J.M.

    2010-01-01

    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. Identification and characterization of potyviruses of Alstroemeria spp

    OpenAIRE

    Bouwen, L.; Vlugt, van der, R.A.A.

    1996-01-01

    Several viruses have been reported to infect Alstroemeria. The two most important ones are considered to be Alstroemeria mosaic (AIMV) and Alstroemeria streak virus (AISV). Both AIMV and AISV react in ELISA with a commonly used antiserum to AIMV. There are indications that potyviruses other than AIMV and AISV also occur in Alstroemeria. The present study was initiated to identify and characterise these potyviruses. A strategy was developed that is aimed at separation of these viruses and thei...

  4. Flowfield Analysis of Savonius-type Wind Turbine blade

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Tae Hyun; Chang, Se Myong [Kunsan National Univ., Kunsan (Korea, Republic of); Seo, Hyun Soo [Korea Institute of Energy Research, Daejeon (Korea, Republic of)

    2007-07-01

    In this paper, we researched flow of 8000 {approx} 24000 Reynolds number around a blade model of Savonius-type wind turbine with experimental and numerical method. For the blade shape of arc, we analyzed flowfield with streak-image flow visualization, measured wake, computed drag coefficients, and compared them for given angle of attacks. The result of research can be used to design aerodynamic performance of Savonius-type turbine rotor directly.

  5. Børn, fedt og hjerte-kar-sygdomme

    DEFF Research Database (Denmark)

    Michaelsen, Kim F.; Dyerberg, Jørn; Falk, Erling;

    2002-01-01

    Children do not normally develop atherosclerosis. However, the do develop fatty streaks in the aorta. These are reversible. During the first years of life dietary fat has an influence on blood lipids, and other traditional risk factors influence vascular function, but the consequences are unknown...... that a teaspoon of fat is added to each serving of home made mashed food or porridge to prevent the diet from being so hypocaloric that it has a negative effect on growth....

  6. Viscous liquid flow on Martian dune slopes

    OpenAIRE

    Dobrovolskis, Anthony R.

    2014-01-01

    The observed temporary dark streaks on some dune slopes on Mars may be due to thin sheets of water (or some other liquid) trickling downhill. This note corrects conceptual errors in a previous paper (M\\"{o}hlmann and Kereszturi 2010, Icarus 207, 654-658) which affect the velocity profile of such flows, and produce over-estimates of their depths and mass fluxes by factors of almost two.

  7. Macrophage Myeloperoxidase Regulation by Granulocyte Macrophage Colony-Stimulating Factor in Human Atherosclerosis and Implications in Acute Coronary Syndromes

    OpenAIRE

    Sugiyama, Seigo; Okada, Yoshikatsu; Sukhova, Galina K.; Virmani, Renu; Heinecke, Jay W.; Libby, Peter

    2001-01-01

    Inflammation and oxidative stress contribute to the pathogenesis of many human diseases including atherosclerosis. Advanced human atheroma contains high levels of the enzyme myeloperoxidase that produces the pro-oxidant species, hypochlorous acid (HOCl). This study documents increased numbers of myeloperoxidase-expressing macrophages in eroded or ruptured plaques causing acute coronary syndromes. In contrast, macrophages in human fatty streaks contain little or no myeloperoxidase. Granulocyte...

  8. SELECTINS IN CORONARY ATHEROSCLEROTIC DISEASE:A REVIEW

    Institute of Scientific and Technical Information of China (English)

    李远方; 胡健

    2001-01-01

    The development of atherosclerotic lesions appears to be inflammatory in nature. It involves the recruitment of blood monocytes to the vascular endothelium, followed by intimal infiltration. Monocytes differentiate to macrophages, then internalize lipids to form foam cells, thus develop fatty streak lesion. A wide range of adhesion molecules governs these interactions between cells, among these molecules are selectins. Selectins mediate the first step in leukocyte adhesion at sites of inflammation or injury, characterized by rolling and tethering

  9. High pressure Hugoniot of sapphire

    Energy Technology Data Exchange (ETDEWEB)

    Erskine, D.

    1993-07-01

    The Hugoniot of sapphire was measured from 80 GPa to 340 GPa in shock-wave experiments using projectiles accelerated by a two stage gas gun. Transit times of the shock waves were measured either optically with a streak camera or through electrical pin contacts. The Hugoniot in this pressure range fits U{sub s}=8.74+0.96 U{sub p}in km/s.

  10. Refractive error among urban preschool children in Xuzhou, China

    OpenAIRE

    Wang, XiaoJuan; Liu, Dan; Feng, Ruifang; Zhao, Huashuo; Wang, Qinmei

    2014-01-01

    The prevalence of refractive errors in urban preschool children in Xuzhou, China remains unknown. Children attending twelve randomly selected kindergartens participated in this study. Visual acuity, ocular alignment, cover-uncover test, cycloplegic refraction, slit-lamp and funduscopy were performed under a standardized testing environment. Cycloplegic streak retinoscopy was performed for all subjects. The mean spherical equivalent (SE) refractive error was the main outcome measure. Emmetropi...

  11. Studies on the antibacterial activity potential of commonly used food preservatives

    OpenAIRE

    Anoop Kumar Shee; R.Balaji Raja; Deepika Sethi; Anushree Kunhambu,; Arunachalam, Kantha D

    2010-01-01

    The efficacy of those food preservatives in terms of antibacterial activity potential has not been dealt with in an elaborate manner. This study focuses on the quantitative antibacterial activity potential analysis of 2 food preservatives namely salt and sugar on bacterial strains. The MH agar medium Petri plates were streaked withmutton broth alone as the control and mutton broth with added food preservatives salt and sugar in separate concentrations as test. The growth pattern on the agar m...

  12. A POD-based analysis of turbulence in the reduced nonlinear dynamics system

    Science.gov (United States)

    Nikolaidis, M.-A.; Farrell, B. F.; Ioannou, P. J.; Gayme, D. F.; Lozano-Durán, A.; Jiménez, J.

    2016-04-01

    The structure of turbulence in a reduced model of turbulence (RNL) is analyzed by means of a Proper Orthogonal Decomposition (POD modes). POD analysis was carried out on two different components of the flow, the roll/streak and the perturbation structure. The POD structure in both RNL and direct numerical simulations (DNS) is similar and this correspondence suggests that the dynamics retained in RNL are the essential dynamical ingredients underlying the self-sustaining mechanism of the turbulent state.

  13. Analysis of photoluminescence decay kinetics of aluminum phthalocyanine nanoparticles interacting with immune cells

    OpenAIRE

    F. G. Bystrov; V. I. Makarov; POMINOVA D.V.; A. V. Ryabova; V. B. Loschenov

    2016-01-01

    This work is dedicated to the study of the photoluminescence kinetics of aluminum phthalocyanine nanoparticles in colloidal solutions at different pH and in the interaction with immune cells (macrophages). For measurements we used a registration system based on Hamamatsu streak camera (C10627-13 Hamamatsu Photonics) with picosecond temporal resolution (15 ps), conjugated with the fiberoptic spectrometer and picosecond laser pumping. The changes in fluorescence decay kinetics as additional lif...

  14. Modeling for driving systems of four-high rolling mill

    Institute of Scientific and Technical Information of China (English)

    贺建军; 喻寿益; 钟掘

    2002-01-01

    A modeling method for driving systems of four-high rolling mill was put forward in order to analyze the origin of rolling mill's chatter that brings about light and shade streaks on the surface of steel strip from aspect of electromechanical coupling. The process and steps of modeling method was introduced by means of an example. The correctness of the model and the feasibility of the modeling method were verified in simulation experiment.

  15. Experimental Investigation of Two-Dimensional Shock Initiation Process of Cast Composition B

    Institute of Scientific and Technical Information of China (English)

    黄风雷; 胡湘渝

    2004-01-01

    A two-streak high-speed photography measuring system is designed, which can successfully record the reactive shock front and the reaction profile within the run distance of shock initiation under two-dimensional shock initiation. The strong reaction delay time and the shape of reaction shock front are determined in the cast composition B (RDX/TNT/60/40). A low level reaction zone has been found and analyzed.

  16. How we managed a difficult to ventilate patient

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Garg

    2015-01-01

    Full Text Available A 40-year-old female presented with respiratory difficulty, cough and sputum with blood streaking. Her right lung was destroyed, and trachea was shifted to the same side. On mechanical ventilation, she developed hypoxia and rise in blood pressure. Ventilator was not delivering set tidal volume. After looking into the cause, it was decided to reintubate the patient with new endotracheal tube after cutting bevel. Thereafter, there was successful ventilation.

  17. SHAPES - Spatial, High-Accuracy, Position-Encoding Sensor for multi-point, 3-D position measurement of large flexible structures

    Science.gov (United States)

    Nerheim, N. M

    1987-01-01

    An electro-optical position sensor for precise simultaneous measurement of the 3-D positions of multiple points on large space structures is described. The sensor data rate is sufficient for most control purposes. Range is determined by time-of-flight correlation of short laser pulses returned from retroreflector targets using a streak tube/CCD detector. Angular position is determined from target image locations on a second CCD. Experimental verification of dynamic ranging to multiple targets is discussed.

  18. Standardization of Operator-Dependent Variables Affecting Precision and Accuracy of the Disk Diffusion Method for Antibiotic Susceptibility Testing.

    Science.gov (United States)

    Hombach, Michael; Maurer, Florian P; Pfiffner, Tamara; Böttger, Erik C; Furrer, Reinhard

    2015-12-01

    Parameters like zone reading, inoculum density, and plate streaking influence the precision and accuracy of disk diffusion antibiotic susceptibility testing (AST). While improved reading precision has been demonstrated using automated imaging systems, standardization of the inoculum and of plate streaking have not been systematically investigated yet. This study analyzed whether photometrically controlled inoculum preparation and/or automated inoculation could further improve the standardization of disk diffusion. Suspensions of Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 29213 of 0.5 McFarland standard were prepared by 10 operators using both visual comparison to turbidity standards and a Densichek photometer (bioMérieux), and the resulting CFU counts were determined. Furthermore, eight experienced operators each inoculated 10 Mueller-Hinton agar plates using a single 0.5 McFarland standard bacterial suspension of E. coli ATCC 25922 using regular cotton swabs, dry flocked swabs (Copan, Brescia, Italy), or an automated streaking device (BD-Kiestra, Drachten, Netherlands). The mean CFU counts obtained from 0.5 McFarland standard E. coli ATCC 25922 suspensions were significantly different for suspensions prepared by eye and by Densichek (P counts that were closer to the CLSI/EUCAST target of 10(8) CFU/ml than those resulting from Densichek preparation. No significant differences in the standard deviations of the CFU counts were observed. The interoperator differences in standard deviations when dry flocked swabs were used decreased significantly compared to the differences when regular cotton swabs were used, whereas the mean of the standard deviations of all operators together was not significantly altered. In contrast, automated streaking significantly reduced both interoperator differences, i.e., the individual standard deviations, compared to the standard deviations for the manual method, and the mean of the standard deviations of all operators

  19. Characterization of phytopathogenic fungi, bacteria, nematodes and viruses in four commercial varieties of heliconia (heliconia sp.) / caracterización de hongos, bacterias, nemátodos y virus fitopatógenos en cuatro variedades comerciales de heliconia

    OpenAIRE

    López Cardona, Nathali; Castaño Zapata, Jairo

    2012-01-01

    Analysis of 914 samples of roots, rhizomes, pseudostems, inflorescences and leaves of four commercial varieties of heliconia, cultivated at the municipality of Chinchiná– Caldas (Colombia), allowed to identify five genera of plant pathogenic fungi (Rhizoctonia, Fusarium, Colletotrichum, Helminthosporium and Curvularia), three genera of plant pathogenic bacteria (Ralstonia, Pseudomonas and Erwinia), two species of viruses (Banana streak virus (BSV, Badnavirus,) and Cucumber mosaic virus ...

  20. CHARACTERIZATION OF PHYTOPATHOGENIC FUNGI, BACTERIA, NEMATODES AND VIRUSES IN FOUR COMMERCIAL VARIETIES OF HELICONIA (Heliconia sp.) CARACTERIZACIÓN DE HONGOS, BACTERIAS, NEMÁTODOS Y VIRUS FITOPATÓGENOS EN CUATRO VARIEDADES COMERCIALES DE HELICONIA (Heliconia sp. )

    OpenAIRE

    Nathali López Cardona; Jairo Castaño Zapata

    2012-01-01

    Abstract. Analysis of 914 samples of roots, rhizomes, pseudostems, inflorescences and leaves of four commercial varieties of heliconia, cultivated at the municipality of Chinchiná-Caldas (Colombia), allowed to identify five genera of plant pathogenic fungi (Rhizoctonia, Fusarium, Colletotrichum, Helminthosporium and Curvularia), three genera of plant pathogenic bacteria (Ralstonia, Pseudomonas and Erwinia), two species of viruses (Banana streak virus (BSV, Badnavirus,) and Cucumber mosaic vir...

  1. Impedance Analysis of Longitudinal Bunch Shape Measurements at PLS

    CERN Document Server

    Hwang, Ilmoon; Kim Eun San; Yoon, Moohyun

    2005-01-01

    We measured the longitudinal bunch shape by streak camera at 2.5 GeV Pohang Light Source. The impedances estimated by a series R+L model indicate a resistance R= 960 ohm, an inductance L= 80 nH and a longitudinal impedance Z/n= 0.53 ohm. The scaling law for the bunch lengthenig is expressed as I0

  2. Chirp of monolithic colliding pulse mode-locked diode lasers

    DEFF Research Database (Denmark)

    Hofmann, M.; Bischoff, S.; Franck, Thorkild;

    1997-01-01

    Spectrally resolved streak camera measurements of picosecond pulses emitted by hybridly colliding pulse mode-locked (CPM) laser diodes are presented in this letter. Depending on the modulation frequency both blue-chirped (upchirped) and red-chirped (downchirped) pulses can be observed. The two...... different regimes and the transition between them are characterized experimentally and the behavior is explained on the basis of our model for the CPM laser dynamics. (C) 1997 American Institute of Physics....

  3. Development of expressed sequence tag and expressed sequence tag–simple sequence repeat marker resources for Musa acuminata

    OpenAIRE

    Passos, Marco A. N.; de Oliveira Cruz, Viviane; Emediato, Flavia L; de Camargo Teixeira, Cristiane; Souza, Manoel T; Matsumoto, Takashi; Rennó Azevedo, Vânia C.; Ferreira, Claudia F; Amorim, Edson P; de Alencar Figueiredo, Lucio Flavio; Martins, Natalia F; de Jesus Barbosa Cavalcante, Maria; Baurens, Franc-Christophe; da Silva, Orzenil Bonfim; Pappas, Georgios J

    2012-01-01

    Background and aims Banana (Musa acuminata) is a crop contributing to global food security. Many varieties lack resistance to biotic stresses, due to sterility and narrow genetic background. The objective of this study was to develop an expressed sequence tag (EST) database of transcripts expressed during compatible and incompatible banana–Mycosphaerella fijiensis (Mf) interactions. Black leaf streak disease (BLSD), caused by Mf, is a destructive disease of banana. Microsatellite markers were...

  4. On a long neglected player: The religious dimension in poverty alleviation. The example of the so-called ‘Prosperity Gospel’ in Africa

    OpenAIRE

    Schliesser, Christine

    2014-01-01

    Much of poverty alleviation theory and practice fails to sufficiently consider the following crucial factor: the religious dimension. This paper elaborates this thesis by focusing on the African context and the valuable resources African religious communities and movements can provide in the struggle against poverty. One particularly influential streak of present-time African religiousness serves as a case study: the so-called ‘Prosperity Gospel’ as part of Pentecostal Christianity. The autho...

  5. FOREX-A Fiber Optics Diagnostic System For Study Of Materials At High Temperatures And Pressures

    Science.gov (United States)

    Smith, D. E.; Roeske, F.

    1983-03-01

    We have successfully fielded a Fiber Optics Radiation EXperiment system (FOREX) designed for measuring material properties at high temperatures and pressures on an underground nuclear test. The system collects light from radiating materials and transmits it through several hundred meters of optical fibers to a recording station consisting of a streak camera with film readout. The use of fiber optics provides a faster time response than can presently be obtained with equalized coaxial cables over comparable distances. Fibers also have significant cost and physical size advantages over coax cables. The streak camera achieves a much higher information density than an equivalent oscilloscope system, and it also serves as the light detector. The result is a wide bandwidth high capacity system that can be fielded at a relatively low cost in manpower, space, and materials. For this experiment, the streak camera had a 120 ns time window with a 1.2 ns time resolution. Dynamic range for the system was about 1000. Beam current statistical limitations were approximately 8% for a 0.3 ns wide data point at one decade above the threshold recording intensity.

  6. Optical Spectroscopy of a Mega-Ampere Dense Plasma Focus

    Science.gov (United States)

    Dutra, Eric; Bennett, Nichelle; Hagen, Edward; Hunt, Eugene; Hsu, Scott; Koch, Jeffrey; Ross, Patrick; Waltman, Thomas

    2015-11-01

    An optical streaked spectroscopy system was developed to evaluate the spectral emission of the run-down, run-in and pinch phase on the Gemini Dense Plasma Focus (DPF). Time-resolved emission spectra were captured for hydrogen, deuterium, argon, and krypton gas from these phases. The emission was focused onto a fiber, and fed to a spectrometer that was coupled to a streak camera. Spectra of hydrogen, deuterium, argon, and krypton gas were modeled using Spec3D. Plasma parameters including electron density and temperature, from LSP simulations of the DPF discharge, were loaded into the Spec3D simulation to evaluate the emission spectra. Spectra collected from DPF on the streaked spectrometer system were then compared to the Spec3D simulations, and used to verify known optical emission lines for the various gases and to identify possible contaminants. This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946, and by Los Alamos National Laboratory, under Contract no. DE-AC52-06NA25396 with the U.S. Department of Energy. DOE/NV/25946-2519.

  7. Male-male pheromone signalling in a lekking Drosophila.

    Science.gov (United States)

    Widemo, Fredrik; Johansson, Björn G

    2006-03-22

    Interest in sex pheromones has mainly been focused on mate finding, while relatively little attention has been given to the role of sex pheromones in mate choice and almost none to competition over mates. Here, we study male response to male pheromones in the lekking Drosophila grimshawi, where males deposit long-lasting pheromone streaks that attract males and females to the leks and influence mate assessment. We used two stocks of flies and both stocks adjusted their pheromone depositing behaviour in response to experimental manipulation, strongly indicating male ability to distinguish between competitors from qualitative differences in pheromone streaks alone. This is the first example of an insect distinguishing between individual odour signatures. Pheromone signalling influenced competition over mates, as males adjusted their investment in pheromone deposition in response to foreign pheromone streaks. Both sexes adapt their behaviour according to information from olfactory cues in D. grimshawi, but the relative benefits from male-female, as compared to male-male signalling, remain unknown. It seems likely that the pheromone signalling system originally evolved for attracting females to leks. The transition to a signalling system for conveying information about individuals may well, however, at least in part have been driven by benefits from male-male signalling.

  8. Monte Carlo dose calculation in dental amalgam phantom.

    Science.gov (United States)

    Aziz, Mohd Zahri Abdul; Yusoff, A L; Osman, N D; Abdullah, R; Rabaie, N A; Salikin, M S

    2015-01-01

    It has become a great challenge in the modern radiation treatment to ensure the accuracy of treatment delivery in electron beam therapy. Tissue inhomogeneity has become one of the factors for accurate dose calculation, and this requires complex algorithm calculation like Monte Carlo (MC). On the other hand, computed tomography (CT) images used in treatment planning system need to be trustful as they are the input in radiotherapy treatment. However, with the presence of metal amalgam in treatment volume, the CT images input showed prominent streak artefact, thus, contributed sources of error. Hence, metal amalgam phantom often creates streak artifacts, which cause an error in the dose calculation. Thus, a streak artifact reduction technique was applied to correct the images, and as a result, better images were observed in terms of structure delineation and density assigning. Furthermore, the amalgam density data were corrected to provide amalgam voxel with accurate density value. As for the errors of dose uncertainties due to metal amalgam, they were reduced from 46% to as low as 2% at d80 (depth of the 80% dose beyond Zmax) using the presented strategies. Considering the number of vital and radiosensitive organs in the head and the neck regions, this correction strategy is suggested in reducing calculation uncertainties through MC calculation. PMID:26500401

  9. M-band flat-response design of X-ray transmission photocathode%透射式X射线光阴极的M带平响应设计

    Institute of Scientific and Technical Information of China (English)

    高扬; 曹柱荣; 李晋; 杨志文; 陈韬; 黎宇坤; 刘慎业

    2013-01-01

    The diagnosis of X-ray flux with high temporal and spatial resolutions is important in the researches of hohlraum physics, and spectral response coupling and design of spectrum rebuilding unit are key issues in the design of flat-response streak camera. Based on the study of the spectral response characteristics of streak camera and X-ray transmission photocathode, compound filter is adopted to realize the M-band band-pass flat-response of streak camera. The calculation shows that the flatness of spectral response is better than 2.7% with an acceptable band pass effect.%获取高时空分辨的M带X射线辐射能流信息是黑腔物理研究的重要内容之一,条纹相机平响应存在谱响应耦合、谱改造元件结构设计等问题.通过对条纹相机和透射式X射线光阴极谱响应特性的研究,提出组合滤片调制法以实现条纹相机M带带通平响应.计算表明,在M带能区内谱灵敏度不平整度仅为2.7%,带通效果良好.

  10. PTK7 marks the first human developmental EMT in vitro.

    Directory of Open Access Journals (Sweden)

    David N Chan

    Full Text Available Epithelial to mesenchymal transitions (EMTs are thought to be essential to generate diversity of tissues during early fetal development, but these events are essentially impossible to study at the molecular level in vivo in humans. The first EMT event that has been described morphologically in human development occurs just prior to generation of the primitive streak. Because human embryonic stem cells (hESCs and induced pluripotent stem cells (hiPSCs are thought to most closely resemble cells found in epiblast-stage embryos prior to formation of the primitive streak, we sought to determine whether this first human EMT could be modeled in vitro with pluripotent stem cells. The data presented here suggest that generating embryoid bodies from hESCs or hiPSCs drives a procession of EMT events that can be observed within 24-48 hours after EB generation. These structures possess the typical hallmarks of developmental EMTs, and portions also display evidence of primitive streak and mesendoderm. We identify PTK7 as a novel marker of this EMT population, which can also be used to purify these cells for subsequent analyses and identification of novel markers of human development. Gene expression analysis indicated an upregulation of EMT markers and ECM proteins in the PTK7+ population. We also find that cells that undergo this developmental EMT retain developmental plasticity as sorting, dissociation and re-plating reestablishes an epithelial phenotype.

  11. Simulated Photoelectron-Based Imaging of Localized Surface Plasmons with Attosecond Resolution

    Science.gov (United States)

    Prell, James; Borja, Lauren; Gandman, Andrey; Whitmore, Desire; Neumark, Daniel; Leone, Stephen

    2013-03-01

    Simulations of proposed photoelectron streaking experiments in the presence of an oscillating plasmon field are presented. The results indicate that localized surface plasmon dephasing can be imaged with attosecond resolution using electron time-of-flight (TOF) or velocity map imaging (VMI) techniques. In the simulation, localized surface plasmons are excited in metal nanoparticles by a few-cycle infrared or visible laser pulse. Using time-delayed single, isolated attosecond x-ray pulses, electrons are photoemitted from the metallic nanoparticles and streaked by both the plasmon and laser electric fields. The effects of these two fields in the streaking spectra and images can be separated so that the temporal evolution of the plasmon electric field can be directly extracted. The plasmon electric field induces a broadening of the photoelectron speed distribution with an envelope directly proportional to that of the plasmon dipole moment. Plasmon-induced oscillation of the angular distribution in VMI is predicted to report the spatial distribution of the plasmon electric field for nanoparticles with high aspect ratios. The simulations indicate that these techniques can be used to map plasmon dynamics with unprecedented temporal resolution.

  12. SU-E-I-38: Improved Metal Artifact Correction Using Adaptive Dual Energy Calibration

    Energy Technology Data Exchange (ETDEWEB)

    Dong, X; Elder, E; Roper, J; Dhabaan, A [Winship Cancer Institute of Emory University (United States)

    2015-06-15

    Purpose: The empirical dual energy calibration (EDEC) method corrects for beam-hardening artifacts, but shows limited performance on metal artifact correction. In this work, we propose an adaptive dual energy calibration (ADEC) method to correct for metal artifacts. Methods: The empirical dual energy calibration (EDEC) method corrects for beam-hardening artifacts, but shows limited performance on metal artifact correction. In this work, we propose an adaptive dual energy calibration (ADEC) method to correct for metal artifacts. Results: Highly attenuating copper rods cause severe streaking artifacts on standard CT images. EDEC improves the image quality, but cannot eliminate the streaking artifacts. Compared to EDEC, the proposed ADEC method further reduces the streaking resulting from metallic inserts and beam-hardening effects and obtains material decomposition images with significantly improved accuracy. Conclusion: We propose an adaptive dual energy calibration method to correct for metal artifacts. ADEC is evaluated with the Shepp-Logan phantom, and shows superior metal artifact correction performance. In the future, we will further evaluate the performance of the proposed method with phantom and patient data.

  13. Frequency-Domain Tomography for Single-shot, Ultrafast Imaging of Evolving Laser-Plasma Accelerators

    Science.gov (United States)

    Li, Zhengyan; Zgadzaj, Rafal; Wang, Xiaoming; Downer, Michael

    2011-10-01

    Intense laser pulses propagating through plasma create plasma wakefields that often evolve significantly, e.g. by expanding and contracting. However, such dynamics are known in detail only through intensive simulations. Laboratory visualization of evolving plasma wakes in the ``bubble'' regime is important for optimizing and scaling laser-plasma accelerators. Recently snap-shots of quasi-static wakes were recorded using frequency-domain holography (FDH). To visualize the wake's evolution, we have generalized FDH to frequency-domain tomography (FDT), which uses multiple probes propagating at different angles with respect to the pump pulse. Each probe records a phase streak, imprinting a partial record of the evolution of pump-created structures. We then topographically reconstruct the full evolution from all phase streaks. To prove the concept, a prototype experiment visualizing nonlinear index evolution in glass is demonstrated. Four probes propagating at 0, 0.6, 2, 14 degrees to the index ``bubble'' are angularly and temporally multiplexed to a single spectrometer to achieve cost-effective FDT. From these four phase streaks, an FDT algorithm analogous to conventional CT yields a single-shot movie of the pump's self-focusing dynamics.

  14. Low energy x-ray and electron physics and technology for high-temperature plasma diagnostics. Annual scientific report, August 9, 1983-August 8, 1984

    International Nuclear Information System (INIS)

    This contract has concentrated upon completing development of a new spectrographic system and procedures for achieving absolute spectrometry on laser-produced plasma x-ray sources (as are currently needed for the ICF and x-ray laser diagnostic programs). The new system utilizes two spectrographic channels, one time-resolving and the other time-integrating. A specially designed x-ray streak camera has been designed and constructed here this year which has the required 40 mm entrance slit and 10 picosecond time resolution. A photographic, time-integrating camera is applied to the second channel and it allows an absolute calibration of the x-ray streak camera by providing for each spectral line measured the corresponding number of photons emitted per pulse/stearadian from the point source. Analytical x-ray photographic response functions have been developed which permit a simple and accurate conversion (via a microcomputer) of photographic densities to x-ray intensities. Presented in this report are preprints of five works on the development of this new spectrographic system, of the special x-ray streak camera and of the methods for the characterization of photographic films for absolute x-ray spectrometry. Separate abstracts are presented for each

  15. Indentation Size Effects in Single Crystal Copper as Revealed by Synchrotron X-ray Microdiffraction

    Energy Technology Data Exchange (ETDEWEB)

    Feng, G.; Budiman, A. S.; Nix, W. D.; Tamura, N.; Patel, J. R.

    2007-11-19

    The indentation size effect (ISE) has been observed in numerous nanoindentation studies on crystalline materials; it is found that the hardness increases dramatically with decreasing indentation size - a 'smaller is stronger' phenomenon. Some have attributed the ISE to the existence of strain gradients and the geometrically necessary dislocations (GNDs). Since the GND density is directly related to the local lattice curvature, the Scanning X-ray Microdiffraction ({mu}SXRD) technique, which can quantitatively measure relative lattice rotations through the streaking of Laue diffractions, can used to study the strain gradients. The synchrotron {mu}SXRD technique we use - which was developed at the Advanced Light Source (ALS), Berkeley Lab - allows for probing the local plastic behavior of crystals with sub-micrometer resolution. Using this technique, we studied the local plasticity for indentations of different depths in a Cu single crystal. Broadening of Laue diffractions (streaking) was observed, showing local crystal lattice rotation due to the indentation-induced plastic deformation. A quantitative analysis of the streaking allows us to estimate the average GND density in the indentation plastic zones. The size dependence of the hardness, as found by nanoindentation, will be described, and its correlation to the observed lattice rotations will be discussed.

  16. Monte Carlo dose calculation in dental amalgam phantom.

    Science.gov (United States)

    Aziz, Mohd Zahri Abdul; Yusoff, A L; Osman, N D; Abdullah, R; Rabaie, N A; Salikin, M S

    2015-01-01

    It has become a great challenge in the modern radiation treatment to ensure the accuracy of treatment delivery in electron beam therapy. Tissue inhomogeneity has become one of the factors for accurate dose calculation, and this requires complex algorithm calculation like Monte Carlo (MC). On the other hand, computed tomography (CT) images used in treatment planning system need to be trustful as they are the input in radiotherapy treatment. However, with the presence of metal amalgam in treatment volume, the CT images input showed prominent streak artefact, thus, contributed sources of error. Hence, metal amalgam phantom often creates streak artifacts, which cause an error in the dose calculation. Thus, a streak artifact reduction technique was applied to correct the images, and as a result, better images were observed in terms of structure delineation and density assigning. Furthermore, the amalgam density data were corrected to provide amalgam voxel with accurate density value. As for the errors of dose uncertainties due to metal amalgam, they were reduced from 46% to as low as 2% at d80 (depth of the 80% dose beyond Zmax) using the presented strategies. Considering the number of vital and radiosensitive organs in the head and the neck regions, this correction strategy is suggested in reducing calculation uncertainties through MC calculation.

  17. Monte carlo dose calculation in dental amalgam phantom

    Directory of Open Access Journals (Sweden)

    Mohd Zahri Abdul Aziz

    2015-01-01

    Full Text Available It has become a great challenge in the modern radiation treatment to ensure the accuracy of treatment delivery in electron beam therapy. Tissue inhomogeneity has become one of the factors for accurate dose calculation, and this requires complex algorithm calculation like Monte Carlo (MC. On the other hand, computed tomography (CT images used in treatment planning system need to be trustful as they are the input in radiotherapy treatment. However, with the presence of metal amalgam in treatment volume, the CT images input showed prominent streak artefact, thus, contributed sources of error. Hence, metal amalgam phantom often creates streak artifacts, which cause an error in the dose calculation. Thus, a streak artifact reduction technique was applied to correct the images, and as a result, better images were observed in terms of structure delineation and density assigning. Furthermore, the amalgam density data were corrected to provide amalgam voxel with accurate density value. As for the errors of dose uncertainties due to metal amalgam, they were reduced from 46% to as low as 2% at d80 (depth of the 80% dose beyond Zmax using the presented strategies. Considering the number of vital and radiosensitive organs in the head and the neck regions, this correction strategy is suggested in reducing calculation uncertainties through MC calculation.

  18. Astrophotography issue

    Science.gov (United States)

    Fedida, Simon

    2009-10-01

    Regarding David Pye and Ray Crundwell's picture of Sirius (July p21), I think it is possible that the colours shown in the star streak are artefacts of the Bayer pattern on the front of the camera's CCD, particularly if the track is only a few pixels wide. The Bayer pattern is a layer of dye filters coated over the CCD glass in a red-green-blue (RGB) dot pattern. Single CCD cameras use software to synthesize the final colour of a pixel from the relative response of a group of CCD pixels depending on whether each CCD pixel is behind an R, G or B filter. So a point source like a star, finely focused, may not cover enough CCD pixels and their filters to give the correct colour balance. Moving the camera to give a streak just illuminates different groups of pixels, resulting in a varying colour balance. So, how wide (in pixels) is the star streak, and does it cover an adequate number of pixels to give the correct colour balance?

  19. Time-resolved soft-x-ray studies of energy transport in layered and planar laser-driven targets

    International Nuclear Information System (INIS)

    New low-energy x-ray diagnostic techniques are used to explore energy-transport processes in laser heated plasmas. Streak cameras are used to provide 15-psec time-resolution measurements of subkeV x-ray emission. A very thin (50 μg/cm2) carbon substrate provides a low-energy x-ray transparent window to the transmission photocathode of this soft x-ray streak camera. Active differential vacuum pumping of the instrument is required. The use of high-sensitivity, low secondary-electron energy-spread CsI photocathodes in x-ray streak cameras is also described. Significant increases in sensitivity with only a small and intermittant decrease in dynamic range were observed. These coherent, complementary advances in subkeV, time-resolved x-ray diagnostic capability are applied to energy-transport investigations of 1.06-μm laser plasmas. Both solid disk targets of a variety of Z's as well as Be-on-Al layered-disk targets were irradiated with 700-psec laser pulses of selected intensity between 3 x 1014 W/cm2 and 1 x 1015 W/cm2

  20. Hydrodynamics simulations of 2 (omega) laser propagation in underdense gasbag plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Meezan, N B; Divol, L; Marinak, M M; Kerbel, G D; Suter, L J; Stevenson, R M; Slark, G E; Oades, K

    2004-04-05

    Recent 2{omega} laser propagation and stimulated Raman backscatter (SRS) experiments performed on the Helen laser have been analyzed using the radiation-hydrodynamics code hydra. These experiments utilized two diagnostics sensitive to the hydrodynamics of gasbag targets: a fast x-ray framing camera (FXI) and an SRS streak spectrometer. With a newly implemented nonlocal thermal transport model, hydra is able to reproduce many features seen in the FXI images and the SRS streak spectra. Experimental and simulated side-on FXI images suggest that propagation can be explained by classical laser absorption and the resulting hydrodynamics. Synthetic SRS spectra generated from the hydra results reproduce the details of the experimental SRS streak spectra. Most features in the synthetic spectra can be explained solely by axial density and temperature gradients. The total SRS backscatter increases with initial gasbag fill density up to {approx} 0.08 times the critical density, then decreases. Images from a near-backscatter camera (NBI) show that severe beam spray is not responsible for the trend in total backscatter. Filamentation does not appear to be a significant factor in gasbag hydrodynamics. The simulation and analysis techniques established here can be used in upcoming experimental campaigns on the Omega laser facility and the National Ignition Facility.

  1. High Sensitivity Imprint Measurements on Nike Laser

    Science.gov (United States)

    Karasik, Max

    2005-10-01

    Hydrodynamic instability seeded by laser non-uniformity (laser imprint) is an important factor in performance of direct-drive ICF targets. Most of the imprint occurs during the initial low-intensity (``foot'') part of the pulse, necessary to compress the target to achieve high gain. Experiments are carried out on Nike KrF laser with induced spatial incoherence (ISI) smoothing. The amount of imprint is varied by changing the uniformity the foot of the pulse. The resulting Raleigh-Taylor (RT) amplified areal mass non-uniformity is measured by face-on x-ray radiography using Bragg reflection from a curved crystal coupled to an x-ray streak camera. The streak camera was recently retrofitted with a new high sensitivity CCD camera. The sensitivity of the CCD has enabled it to be fiberoptically coupled directly to the streak camera output, without an image intensifier and lens coupling. This gave an increased overall spatial resolution as well as lower noise. Because of the strong short wavelength component of RT amplified imprint, the increased resolution and lower noise resulted in much lower noise floor in the measurement. Experimental results are compared with 2D simulations using FAST hydrocode for a range of foot uniformities and intensities. Work supported by the U. S. DOE/NNSA.

  2. North-south comparison of springtime dark slope structures on Mars, and the possibility of liquid water

    Science.gov (United States)

    Kereszturi, A.; Berczi, Sz.; Horvath, A.; Ganti, T.; Kuti, A.; Pocs, T.; Sik, A.; Szathmary, E.

    2008-09-01

    Introduction Various polar seasonal surface albedo structures were analyzed by several authors in the past [1, 2, 3, 4, 5, 6, 7, 8, 8, 9], partly in connection with the possibility of liquid water. In our previous work [10] we identified two groups of slope streaks emanating form Dark Dune Spots of polar dunes, which grow in size and number during spring with the advancement of the season. The diffuse shaped group appears earlier and formed probably by CO2 geysers [8]. The confine shaped group appears in a later seasonal phase, when the temperature is higher. They are probably connected with exposed water-ice on the surface, and may formed by the seepage of undercooled interfacial water on microscopic scale [11]. Methods For the analysis of northern slope structures we used MGS MOC, MRO HiRISE images, and MRG TES data [12] using the "vanilla" software. Temperature data show annual trend, and were derived for daytime. Note that the surface temperature values have spatial resolution around 3 km, and they can be taken only as a rough approach of the surface temperature of the whole dune complex, and not different parts of it. Discussion The target area of the analysis was (84N 233E) in the northern circumpolar sand sea, with 300-500 m diameter overlapping dunes. We searched for springtime confined and elongated dark slope streaks, similar to those, which we observed at south. Basic similarities between northern and southern structures are: 1. streaks always emanate from Dark Dune Spots in downward direction, 2. streaks are present in local spring, when the temperature is above the CO2 buffered level, suggesting there are parts of the surface without CO2 ice, where possibly H2O ice is exposed (Fig. 1.), 4. the streaks show branching pattern (Fig. 2.). Basic differences between the northern and southern structures: 1. at north there is a dark annulus around the Dark Dune Spots, which is absent at south, 2. there are fewer and fainter diffuse streaks of gas jet activity

  3. 皮秒级时间分辨超快高能脉冲激光光谱%Picosecond time-resolved spectroscopy of ultrafast & high energy pulsed laser

    Institute of Scientific and Technical Information of China (English)

    王小鹏; 薛战理; 曹锋

    2012-01-01

    介绍了一种利用光电摄谱法和条纹管相结合测量ps级时间分辨超快高能脉冲激光光谱的方法.论述了条纹相机工作原理和平面衍射光栅的分光原理,分析指出利用介绍的装置,可以实现波长300 nm~1 600 nm、脉宽>2 ps超快高能脉冲激光的光谱测量.采用1 054 nm超快高能脉冲激光器,实验得到了条纹像,对条纹像进行数据处理后得到测量光谱曲线,通过能量标定后,得到了超快高能脉冲激光器实际光谱曲线,验证了ps级时间分辨超快高能脉冲激光光谱方法.讨论了系统中耦合透镜组对光谱测量和光纤色散角对条纹图像的影响,论述了ps级时间分辨超快高能脉冲激光光谱的作用.随着务纹管制造技术的飞速发展,该方法可用于fs级激光光谱的测量.%The method for measuring the spectrum of ultrafast & high energy pulsed laser in picosecond pulse width was presented with combination of photoelectrical spectrography and streak camera. The operating principle of streak camera and spectrophometric principle of plane diffraction grating were described respectively. Through thorough"analysis, we pointed out that the spectral measurement of ultrafast & high energy pulsed laser with wavelength in 300nm~1600nm and pulse width above 2 ps could be achieved by using our described facility. The streak image was obtained by utilizing ultrafast & high energy pulsed laser in 1054nm wavelength, and the measured spectral curve was derived by processing the data of streak camera, then the actual spectral curve was also given by calibrating the related energy parameters, the method for measuring the spectrum of ultrafast & high energy pulsed laser in picosecond pulse width was proved. The influence of coupling lens on measuring spectrum and grating fiber's dispersion angle on streak image were analyzed finally, furthermore the role of spectrum for ultrafast & high energy pulsed laser with picosecond pulse width was

  4. SU-E-J-58: Dosimetric Verification of Metal Artifact Effects: Comparison of Dose Distributions Affected by Patient Teeth and Implants

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M; Kang, S; Lee, S; Suh, T [Department of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of); Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea (Korea, Republic of); Lee, J [Konkuk University Medical Center, Seoul (Korea, Republic of); Research Institute of Health Science, Korea University, Seoul (Korea, Republic of); Park, J [Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea (Korea, Republic of); Dept. of Pediatrics and Molecular Imaging Program at Stanford, Stanford University, Stanford (United States); Park, H [Department of Radiation Oncology, Ajou University School of Medicine, Suwon (Korea, Republic of); Lee, B [Research Institute of Health Science, Korea University, Seoul (Korea, Republic of); Daejeon Sun Hospital, Daejeon (Korea, Republic of)

    2014-06-01

    Purpose: Implant-supported dentures seem particularly appropriate for the predicament of becoming edentulous and cancer patients are no exceptions. As the number of people having dental implants increased in different ages, critical dosimetric verification of metal artifact effects are required for the more accurate head and neck radiation therapy. The purpose of this study is to verify the theoretical analysis of the metal(streak and dark) artifact, and to evaluate dosimetric effect which cause by dental implants in CT images of patients with the patient teeth and implants inserted humanoid phantom. Methods: The phantom comprises cylinder which is shaped to simulate the anatomical structures of a human head and neck. Through applying various clinical cases, made phantom which is closely allied to human. Developed phantom can verify two classes: (i)closed mouth (ii)opened mouth. RapidArc plans of 4 cases were created in the Eclipse planning system. Total dose of 2000 cGy in 10 fractions is prescribed to the whole planning target volume (PTV) using 6MV photon beams. Acuros XB (AXB) advanced dose calculation algorithm, Analytical Anisotropic Algorithm (AAA) and progressive resolution optimizer were used in dose optimization and calculation. Results: In closed and opened mouth phantom, because dark artifacts formed extensively around the metal implants, dose variation was relatively higher than that of streak artifacts. As the PTV was delineated on the dark regions or large streak artifact regions, maximum 7.8% dose error and average 3.2% difference was observed. The averaged minimum dose to the PTV predicted by AAA was about 5.6% higher and OARs doses are also 5.2% higher compared to AXB. Conclusion: The results of this study showed that AXB dose calculation involving high-density materials is more accurate than AAA calculation, and AXB was superior to AAA in dose predictions beyond dark artifact/air cavity portion when compared against the measurements.

  5. A two-wavelength imaging pyrometer for measuring particle temperature, velocity and size in thermal spray processes

    International Nuclear Information System (INIS)

    An imaging pyrometer has been developed to measure the surface temperature of hot metal objects and to measure particle temperature, velocity and size in thermal spray, spray-fonning and atomization processes. The two-wavelength surface imaging pyrometer provides true temperature measurement with high resolution, even when the surface has emissivity variation caused by roughness or oxidation. The surface imaging pyrometer has been calibrated for use in a material processing lab calibration over the range of 1000 to 3000 deg K, and these results are described. The particle imaging pyrometer has a field of view that spans the entire particle stream in typical thermal spray devices, and provides continuous measurement of the entire particle stream. Particle temperature and velocity are critical parameters for producing high quality spray coatings efficiently and reliably. The software locates the particle streaks in the image, and determines the intensity ratio for each particle streak pair to obtain the temperature. The dimensions of the particle streak image are measured to determine the velocity and size. Because the vision-based sensor samples the entire particle stream in every video frame, the particle temperature, velocity and size data are updated at 30 Hz at all points in the particle stream. Particle measurements in a plasma spray at NIST are described. In this paper, we will describe our experiments with ceramic powders, in which measurements have been made at several positions along the particle stream. The particle data are represented as profiles across the particle stream, histograms of the full particle stream or time histories of the full-stream average. The results are compared and calibrated with other temperature and diagnostic measurement systems. (author)

  6. Virtual Simulations as Preparation for Lab Exercises: Assessing Learning of Key Laboratory Skills in Microbiology and Improvement of Essential Non-Cognitive Skills

    Science.gov (United States)

    Makransky, Guido; Thisgaard, Malene Warming; Gadegaard, Helen

    2016-01-01

    Objective To investigate if a virtual laboratory simulation (vLAB) could be used to replace a face to face tutorial (demonstration) to prepare students for a laboratory exercise in microbiology. Methods A total of 189 students who were participating in an undergraduate biology course were randomly selected into a vLAB or demonstration condition. In the vLAB condition students could use a vLAB at home to ‘practice’ streaking out bacteria on agar plates in a virtual environment. In the demonstration condition students were given a live demonstration from a lab tutor showing them how to streak out bacteria on agar plates. All students were blindly assessed on their ability to perform the streaking technique in the physical lab, and were administered a pre and post-test to determine their knowledge of microbiology, intrinsic motivation to study microbiology, and self-efficacy in the field of microbiology prior to, and after the experiment. Results The results showed that there were no significant differences between the two groups on their lab scores, and both groups had similar increases in knowledge of microbiology, intrinsic motivation to study microbiology, as well as self-efficacy in the field of microbiology. Conclusion Our data show that vLABs function just as well as face to face tutorials in preparing students for a physical lab activity in microbiology. The results imply that vLABs could be used instead of face to face tutorials, and a combination of virtual and physical lab exercises could be the future of science education. PMID:27253395

  7. SU-E-J-58: Dosimetric Verification of Metal Artifact Effects: Comparison of Dose Distributions Affected by Patient Teeth and Implants

    International Nuclear Information System (INIS)

    Purpose: Implant-supported dentures seem particularly appropriate for the predicament of becoming edentulous and cancer patients are no exceptions. As the number of people having dental implants increased in different ages, critical dosimetric verification of metal artifact effects are required for the more accurate head and neck radiation therapy. The purpose of this study is to verify the theoretical analysis of the metal(streak and dark) artifact, and to evaluate dosimetric effect which cause by dental implants in CT images of patients with the patient teeth and implants inserted humanoid phantom. Methods: The phantom comprises cylinder which is shaped to simulate the anatomical structures of a human head and neck. Through applying various clinical cases, made phantom which is closely allied to human. Developed phantom can verify two classes: (i)closed mouth (ii)opened mouth. RapidArc plans of 4 cases were created in the Eclipse planning system. Total dose of 2000 cGy in 10 fractions is prescribed to the whole planning target volume (PTV) using 6MV photon beams. Acuros XB (AXB) advanced dose calculation algorithm, Analytical Anisotropic Algorithm (AAA) and progressive resolution optimizer were used in dose optimization and calculation. Results: In closed and opened mouth phantom, because dark artifacts formed extensively around the metal implants, dose variation was relatively higher than that of streak artifacts. As the PTV was delineated on the dark regions or large streak artifact regions, maximum 7.8% dose error and average 3.2% difference was observed. The averaged minimum dose to the PTV predicted by AAA was about 5.6% higher and OARs doses are also 5.2% higher compared to AXB. Conclusion: The results of this study showed that AXB dose calculation involving high-density materials is more accurate than AAA calculation, and AXB was superior to AAA in dose predictions beyond dark artifact/air cavity portion when compared against the measurements

  8. A Novel Prior- and Motion-Based Compressed Sensing Method for Small-Animal Respiratory Gated CT.

    Directory of Open Access Journals (Sweden)

    Juan F P J Abascal

    Full Text Available Low-dose protocols for respiratory gating in cardiothoracic small-animal imaging lead to streak artifacts in the images reconstructed with a Feldkamp-Davis-Kress (FDK method. We propose a novel prior- and motion-based reconstruction (PRIMOR method, which improves prior-based reconstruction (PBR by adding a penalty function that includes a model of motion. The prior image is generated as the average of all the respiratory gates, reconstructed with FDK. Motion between respiratory gates is estimated using a nonrigid registration method based on hierarchical B-splines. We compare PRIMOR with an equivalent PBR method without motion estimation using as reference the reconstruction of high dose data. From these data acquired with a micro-CT scanner, different scenarios were simulated by changing photon flux and number of projections. Methods were evaluated in terms of contrast-to-noise-ratio (CNR, mean square error (MSE, streak artefact indicator (SAI, solution error norm (SEN, and correction of respiratory motion. Also, to evaluate the effect of each method on lung studies quantification, we have computed the Jaccard similarity index of the mask obtained from segmenting each image as compared to those obtained from the high dose reconstruction. Both iterative methods greatly improved FDK reconstruction in all cases. PBR was prone to streak artifacts and presented blurring effects in bone and lung tissues when using both a low number of projections and low dose. Adopting PBR as a reference, PRIMOR increased CNR up to 33% and decreased MSE, SAI and SEN up to 20%, 4% and 13%, respectively. PRIMOR also presented better compensation for respiratory motion and higher Jaccard similarity index. In conclusion, the new method proposed for low-dose respiratory gating in small-animal scanners shows an improvement in image quality and allows a reduction of dose or a reduction of the number of projections between two and three times with respect to previous PBR

  9. Motion-aware temporal regularization for improved 4D cone-beam computed tomography

    Science.gov (United States)

    Mory, Cyril; Janssens, Guillaume; Rit, Simon

    2016-09-01

    Four-dimensional cone-beam computed tomography (4D-CBCT) of the free-breathing thorax is a valuable tool in image-guided radiation therapy of the thorax and the upper abdomen. It allows the determination of the position of a tumor throughout the breathing cycle, while only its mean position can be extracted from three-dimensional CBCT. The classical approaches are not fully satisfactory: respiration-correlated methods allow one to accurately locate high-contrast structures in any frame, but contain strong streak artifacts unless the acquisition is significantly slowed down. Motion-compensated methods can yield streak-free, but static, reconstructions. This work proposes a 4D-CBCT method that can be seen as a trade-off between respiration-correlated and motion-compensated reconstruction. It builds upon the existing reconstruction using spatial and temporal regularization (ROOSTER) and is called motion-aware ROOSTER (MA-ROOSTER). It performs temporal regularization along curved trajectories, following the motion estimated on a prior 4D CT scan. MA-ROOSTER does not involve motion-compensated forward and back projections: the input motion is used only during temporal regularization. MA-ROOSTER is compared to ROOSTER, motion-compensated Feldkamp–Davis–Kress (MC-FDK), and two respiration-correlated methods, on CBCT acquisitions of one physical phantom and two patients. It yields streak-free reconstructions, visually similar to MC-FDK, and robust information on tumor location throughout the breathing cycle. MA-ROOSTER also allows a variation of the lung tissue density during the breathing cycle, similar to that of planning CT, which is required for quantitative post-processing.

  10. Isolation of Campylobacter from Brazilian broiler flocks using different culturing procedures.

    Science.gov (United States)

    Vaz, C S L; Voss-Rech, D; Pozza, J S; Coldebella, A; Silva, V S

    2014-11-01

    Conventional culturing methods enable the detection of Campylobacter in broiler flocks. However, laboratory culture of Campylobacter is laborious because of its fastidious behavior and the presence of competing nontarget bacteria. This study evaluated different protocols to isolate Campylobacter from broiler litter, feces, and cloacal and drag swabs. Samples taken from commercial Brazilian broiler flocks were directly streaked onto Preston agar (PA), Campy-Line agar (CLA), and modified charcoal cefoperazone deoxycholate agar (mCCDA) and also enriched in blood-free Bolton broth (bfBB) for 24 and 48 h followed by plating onto the different selective media. Higher numbers of Campylobacter-positive cloacal and drag swab samples were observed using either direct plating or enrichment for 24 h before plating onto PA, compared with enrichment for 48 h (P Campylobacter in broiler litter and feces samples. Analysis of directly plated samples revealed that higher Campylobacter levels were detected in feces streaked onto PA (88.8%), cloacal swabs plated onto mCCDA (72.2%), drag swabs streaked onto CLA or mCCDA (69.4%), and litter samples inoculated onto PA (63.8%). Preston agar was the best agar to isolate Campylobacter from directly plated litter samples (P Campylobacter in other samples. The isolated Campylobacter strains were phenotypically identified as Campylobacter jejuni or Campylobacter coli. The predominant contaminant observed in the Campylobacter cultures was Proteus mirabilis, which was resistant to the majority of antimicrobial agents in selective media. Together, these data showed that direct plating onto PA and onto either CLA or mCCDA as the second selective agar enabled the reliable isolation of thermophilic Campylobacter species from broiler samples. Finally, Campylobacter was detected in all broiler flocks sampled.

  11. Hypocholesterolemic effect of physically refined rice bran oil: studies of cholesterol metabolism and early atherosclerosis in hypercholesterolemic hamsters.

    Science.gov (United States)

    Ausman, Lynne M; Rong, Ni; Nicolosi, Robert J

    2005-09-01

    Physically refined rice bran oil containing 2-4% nontriglyceride components as compared to other vegetable oils appears to be associated with lipid lowering and antiinflammatory properties in several rodent, primate and human models. These experiments were designed to investigate possible mechanisms for the hypocholesterolemic effect of the physically refined rice bran oil and to examine its effect on aortic fatty streak formation. In the first experiment, 30 hamsters were fed, for 8 weeks, chow-based diets plus 0.03% added cholesterol and 5% (wt/wt) coconut, canola, or physically refined rice bran oil (COCO, CANOLA or PRBO animal groups, respectively). Both plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were significantly reduced in PRBO but not in CANOLA relative to COCO. PRBO also showed a significant 15-17% reduction in cholesterol absorption and significant 30% increase in neutral sterol (NS) excretion with no effect on bile acid (BA) excretion. Both CANOLA and PRBO showed a significant 300-500% increase in intestinal 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and significant (>25%) decrease in hepatic HMG-CoA reductase activities with respect to COCO. In a second experiment, 36 hamsters were fed chow-based diets with 0.05% added cholesterol, 10% coconut oil and 4% additional COCO, CANOLA or PRBO. Relative to COCO and CANOLA, plasma TC and LDL-C were significantly reduced in PRBO. Early atherosclerosis (fatty streak formation) was significantly reduced (48%) only in PRBO, relative to the other two. These results suggest that the lipid lowering found in PRBO is associated with decreased cholesterol absorption, but not hepatic cholesterol synthesis, and that the decrease in fatty streak formation with this oil may be associated with its nontriglyceride components not present in the other two diets.

  12. Attosecond clocking of scattering dynamics in dielectrics

    Science.gov (United States)

    Kling, Matthias

    2016-05-01

    In the past few years electronic-device scaling has progressed rapidly and miniaturization has reached physical gate lengths below 100 nm, heralding the age of nanoelectronics. Besides the effort in size scaling of integrated circuits, tremendous progress has recently been made in increasing the switching speed where strong-field-based ``dielectric-electronics'' may push it towards the petahertz frontier. In this contest, the investigation of the electronic collisional dynamics occurring in a dielectric material is of primary importance to fully understand the transport properties of such future devices. Here, we demonstrate attosecond chronoscopy of electron collisions in SiO2. In our experiment, a stream of isolated aerodynamically focused SiO2 nanoparticles of 50 nm diameter was delivered into the laser interaction region. Photoemission is initiated by an isolated 250 as pulse at 35 eV and the electron dynamics is traced by attosecond streaking using a delayed few-cycle laser pulse at 700 nm. Electrons were detected by a kilohertz, single-shot velocity-map imaging spectrometer, permitting to separate frames containing nanoparticle signals from frames containing the response of the reference gas only. We find that the nanoparticle photoemission exhibits a positive temporal shift with respect to the reference. In order to understand the physical origin of the shift we performed semi-classical Monte-Carlo trajectory simulations taking into account the near-field distributions in- and outside the nanoparticles as obtained from Mie theory. The simulations indicate a pronounced dependence of the streaking time shift near the highest measured electron energies on the inelastic scattering time, while elastic scattering only shows a small influence on the streaking time shift for typical dielectric materials. We envision our approach to provide direct time-domain access to inelastic scattering for a wide range of dielectrics.

  13. Clinical applications of iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Eberl, S. [Royal Prince Alfred Hospital, Camperdown, NSW (Australia). Department of PET and Nuclear Medicine

    1998-03-01

    Expectation maximisation (EM) reconstruction largely eliminates the hot and cold streaking artifacts characteristic of filtered-back projection (FBP) reconstruction around localised hot areas, such as the bladder. It also substantially reduces the problem of decreased inferior wall counts in MIBI myocardial perfusion studies due to ``streaking`` from high liver uptake. Non-uniform attenuation and scatter correction, resolution recovery, anatomical information, e.g. from MRI or CT tracer kinetic modelling, can all be built into the EM reconstruction imaging model. The properties of ordered subset EM (OSEM) have also been used to correct for known patient motion as part of the reconstruction process. These uses of EM are elaborated more fully in some of the other abstracts of this meeting. Currently we use OSEM routinely for: (i) studies where streaking is a problem, including all MIBI myocardial perfusion studies, to avoid hot liver inferior wall artifact, (ii) all whole body FDG PET, all lung V/Q SPECT (which have a short acquisition time) and all gated {sup 201}TI myocardial perfusion studies due to improved noise characteristics of OSEM in these studies; (iii) studies with measured, non-uniform attenuation correction. With the accelerated OSEM algorithm, iterative reconstruction is practical for routine clinical applications and we have found OSEM to provide clearly superior reconstructions for the areas listed above and are investigating its application to other studies. In clinical use, we have not found OSEM to introduce artifacts which would not also occur with FBP, e.g. uncorrected patient motion will cause artifacts with both OSEM and FBP.

  14. Towards attosecond measurement in molecules and at surfaces

    Science.gov (United States)

    Marangos, Jonathan

    2015-05-01

    1) We will present a number of experimental approaches that are being developed at Imperial College to make attosecond timescale measurements of electronic dynamics in suddenly photoionized molecules and at surfaces. A brief overview will be given of some of the unanswered questions in ultrafast electron and hole dynamics in molecules and solids. These questions include the existence of electronic charge migration in molecules and how this process might couple to nuclear motion even on the few femtosecond timescale. How the timescale of photoemission from a surface may differ from that of an isolated atom, e.g. due to electron transport phenomena associated with the distance from the surface of the emitting atom and the electron dispersion relation, is also an open question. 2) The measurement techniques we are currently developing to answer these questions are HHG spectroscopy, attosecond pump-probe photoelectron/photoion studies, and attosecond pump-probe transient absorption as well as attosecond streaking for measuring surface emission. We will present recent advances in generating two synchronized isolated attosecond pulses at different colours for pump-probe measurements (at 20 eV and 90 eV respectively). Results on generation of isolated attosecond pulses at 300 eV and higher photon energy using a few-cycle 1800 nm OPG source will be presented. The use of these resources for making pump-probe measurements will be discussed. Finally we will present the results of streaking measurement of photoemission wavepackets from two types of surface (WO3 and a evaporated Au film) that show a temporal broadening of ~ 100 as compared to atomic streaks that is consistent with the electron mean free path in these materials. Work supported by ERC and EPSRC.

  15. Virtual Simulations as Preparation for Lab Exercises: Assessing Learning of Key Laboratory Skills in Microbiology and Improvement of Essential Non-Cognitive Skills.

    Directory of Open Access Journals (Sweden)

    Guido Makransky

    Full Text Available To investigate if a virtual laboratory simulation (vLAB could be used to replace a face to face tutorial (demonstration to prepare students for a laboratory exercise in microbiology.A total of 189 students who were participating in an undergraduate biology course were randomly selected into a vLAB or demonstration condition. In the vLAB condition students could use a vLAB at home to 'practice' streaking out bacteria on agar plates in a virtual environment. In the demonstration condition students were given a live demonstration from a lab tutor showing them how to streak out bacteria on agar plates. All students were blindly assessed on their ability to perform the streaking technique in the physical lab, and were administered a pre and post-test to determine their knowledge of microbiology, intrinsic motivation to study microbiology, and self-efficacy in the field of microbiology prior to, and after the experiment.The results showed that there were no significant differences between the two groups on their lab scores, and both groups had similar increases in knowledge of microbiology, intrinsic motivation to study microbiology, as well as self-efficacy in the field of microbiology.Our data show that vLABs function just as well as face to face tutorials in preparing students for a physical lab activity in microbiology. The results imply that vLABs could be used instead of face to face tutorials, and a combination of virtual and physical lab exercises could be the future of science education.

  16. The Investigation of Nail Disorders in Patients with Chronic Renal Failure Undergoing Hemodialysis

    Directory of Open Access Journals (Sweden)

    Perihan Öztürk

    2012-06-01

    Full Text Available Objective: Nail changes are often observed in patients with end-stage renal disease. These changes may occur due to chronic renal failure itself or to the treatment. This study aims to investigate the frequency of nail findings in patients undergoing hemodialysis therapy and to compare with healthy controls. Methods: One hundred and four patients with chronic renal failure treated with hemodialysis, and 104 healthy controls without any dermatological and sistemic diseases, were examined for nail signs. Groups were compared for the incidence of nail findings. Results: 74.4% of hemodialysis patients, and 51.9% of controls had at least one nail finding. The most common signs in hemodialysis patients were (58.7% absence of lunula, (40.5% streaking, (15.7% terry nail and (14.9% half and half nail. In the control group, the most common signs were vertical streaking (36.5%, absence of lunula (8.7% and coilonichi (2.9%. In hemodialysis patients, absence of lunula, beau lines, onycomycosis, terry nail, half and half nail and splinter hemorrhages were found to be significantly higher (p<0.05. Conclusion: The frequency of nail diseases in hemodialysis patients is higher than in the healthy control group. In our study, absence of lunula is the most frequently observed finding in hemodialysis patients. Although the second most common nail change was vertical streaking, it was not different from the control group statistically. We recommend that, when hemodialysis patients are examined, nail examination (as a part of physical examination should be performed. (Turk J Dermatol 2012; 6: 35-8

  17. Single cell lineage analysis of mouse embryonic stem cells at the exit from pluripotency

    Directory of Open Access Journals (Sweden)

    Jamie Trott

    2013-08-01

    Understanding how interactions between extracellular signalling pathways and transcription factor networks influence cellular decision making will be crucial for understanding mammalian embryogenesis and for generating specialised cell types in vitro. To this end, pluripotent mouse Embryonic Stem (mES cells have proven to be a useful model system. However, understanding how transcription factors and signalling pathways affect decisions made by individual cells is confounded by the fact that measurements are generally made on groups of cells, whilst individual mES cells differentiate at different rates and towards different lineages, even in conditions that favour a particular lineage. Here we have used single-cell measurements of transcription factor expression and Wnt/β-catenin signalling activity to investigate their effects on lineage commitment decisions made by individual cells. We find that pluripotent mES cells exhibit differing degrees of heterogeneity in their expression of important regulators from pluripotency, depending on the signalling environment to which they are exposed. As mES cells differentiate, downregulation of Nanog and Oct4 primes cells for neural commitment, whilst loss of Sox2 expression primes cells for primitive streak commitment. Furthermore, we find that Wnt signalling acts through Nanog to direct cells towards a primitive streak fate, but that transcriptionally active β-catenin is associated with both neural and primitive streak commitment. These observations confirm and extend previous suggestions that pluripotency genes influence lineage commitment and demonstrate how their dynamic expression affects the direction of lineage commitment, whilst illustrating two ways in which the Wnt signalling pathway acts on this network during cell fate assignment.

  18. High resolution modeling of the cusp density anomaly

    Science.gov (United States)

    Brinkman, D. G.; Walterscheid, R. L.; Clemmons, J. H.

    2013-12-01

    The Earth's magnetospheric cusp provides direct access of energetic particles to the thermosphere causing an ionization anomaly. The energy from these particles along with Joule heating, and ion drag forcing play a direct role in determining the neutral density structure in the cusp region. Measurements by the CHAMP (390-460 km altitudes) have shown a region of strong enhanced density attributed to upwelling caused by the combination of particle and Joule heating. The Streak mission (325-123 km) observed a relative depletion in density in the cusp which was attributed to soft particle precipitation not being adequate to cause upwelling at the lower altitudes sampled by Streak and relatively harder precipitation in adjacent areas. Recent attempts to model the cusp density anomaly with Global Circulation Models (GCM) have focused on extreme cases with forcing extending over latitudinal cusp widths of 4 degrees or more which are at the extreme upper end of the observations. Even at one degree latitudinal resolution the cusp features are marginally captured. More typical cusps widths of 1-2 degrees in latitude require finer resolution to resolve. We use a high-resolution numerical model of the thermosphere to simulate the atmospheric response to the relevant forcing by realistically specifying the particle heating, Joule heating, and ion drag forcing to examine the dependence of the magnitude of the cusp density anomaly and the corresponding wind structure on the characteristics of the forcing in the cusp. We ran simulations for cusp widths of 4 and 2 degrees latitude using a model resolution of 20 km. We found that reducing the cusp width by half reduced the density response in the cusp by half, but that the wind response was only slightly decreased. We compare the model results to CHAMP and Streak observations and assess the relative contributions of these mechanisms in explaining the distinctive features of the observations. Acknowledgements: This research was

  19. Cavitation on a semicircular leading-edge plate and NACA0015 hydrofoil: Visualization and velocity measurement

    Science.gov (United States)

    Kravtsova, A. Yu.; Markovich, D. M.; Pervunin, K. S.; Timoshevskii, M. V.; Hanjalić, K.

    2014-12-01

    Using high-speed visualization and particle image velocimetry (PIV), cavitating flows near a plane plate with a rounded leading edge and NACA0015 hydrofoil at angles of attack from 0° to 9° are studied. In the experiments, several known types of cavitation, as well as some differences, were detected with variation of the cavitation number. In particular, at small angles of attack (up to 3°), cavitation on the plate appears in the form of a streak array; on the hydrofoil, it appears in the form of individual bubbles. For the NACA0015 hydrofoil, isolated and intermittent streaks are divided and grow in regimes with developed cavitation; then, however, they merge in bubble clouds and form an extremely regular cellular structure. With an increase in the angle of attack to 9°, the structure of the cavitation cavity on the hydrofoil is changed by the streak structure, like in the case with the plate. In this work, it is shown that PIV permits one to measure the velocity in cavitating flows, in particular, within the gas-vapor phase. It was established from the analysis of distributions of the average flow velocity and moments of velocity fluctuations that the cavitation generation is caused by the development of the carrier fluid flow near the leading edge of the hydrofoil. Down the stream, however, the flow structure strongly depends on the cavitation regime, which is seen from the comparison of the distributions with the case of a single-phase flow. The presented measurements qualitatively verify general trends and show some quantitative distinctions for the two considered flowpast bodies.

  20. Visualizing expanding warm dense matter heated by laser-generated ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Woosuk [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-24

    This PowerPoint presentation concluded with the following. We calculated the expected heating per atom and temperatures of various target materials using a Monte Carlo simulation code and SESAME EOS tables. We used aluminum ion beams to heat gold and diamond uniformly and isochorically. A streak camera imaged the expansion of warm dense gold (5.5 eV) and diamond (1.7 eV). GXI-X recorded all 16 x-ray images of the unheated gold bar targets proving that it could image the motion of the gold/diamond interface of the proposed target.