WorldWideScience

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

    OpenAIRE

    Iusimí Guillén Brizuela; Aimé Broche Hernández; Mayra Rodríguez Casales

    2011-01-01

    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 a...

  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. Choroidal neovascularization after blunt ocular trauma in angioid streaks

    Directory of Open Access Journals (Sweden)

    Kubota M

    2013-07-01

    Full Text Available Masaomi Kubota, Takaaki Hayashi, Kota Arai, Hiroshi TsuneokaDepartment of Ophthalmology, The Jikei University School of Medicine, Tokyo, JapanBackground: Patients with angioid streaks are prone to develop a subretinal hemorrhage after ocular injury, due to fragility of Bruch's membrane.Objective: The purpose of this study was to report a patient with angioid streaks in whom subfoveal choroidal neovascularization (CNV developed after blunt ocular trauma.Case report: A 60-year-old man was accidentally struck in the left eye with a crowbar handle while engaged in the demolition of wooden building materials in May 2011 and was initially evaluated at our hospital. Corrected visual acuity was 0.3 in the right and 1.2 in the left eye, and relative afferent pupillary defect was negative. Funduscopy revealed choroidal atrophy around the optic papillae and angioid streaks radiating from around the optic discs in both eyes. In the right eye, there was macular atrophy. In the left eye, there was a subretinal hemorrhage around the macular region. Fluorescein angiography of the left eye showed a blockage due to subretinal hemorrhage and increasing hyperfluorescent spots superior to the fovea, suggestive of extrafoveal CNV. Spectral-domain optical coherence tomography showed macular thinning in the right eye and no obvious abnormalities near the subfoveal region in the left eye. Two months later, the patient noticed decreased visual acuity in the left eye and was reevaluated. Visual acuity had decreased to 0.7, and well-defined CNV, one disc diameter in size, was presenting slightly superior to the macula, including the subfoveal region. Two weeks later, anti-vascular endothelial growth factor (anti-VEGF antibody (bevacizumab was injected intravitreally; the CNV then regressed, and visual acuity improved to 1.2.Conclusion: Marked improvement in visual acuity with early treatment has not been reported in angioid streaks with subfoveal CNV after ocular injury

  6. 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.

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

    OpenAIRE

    Lee, Ji Woong; Shin, Jae Pil; Kim, Si Yeol

    2011-01-01

    A 56-year-old Korean woman presented with decreased visual acuity of the right eye. She had a history of two photodynamic therapy treatments for choroidal neovascularization (CNV) due to angioid streaks in her left eye with central scarring and low visual acuity. She was diagnosed with subfoveal CNV due to angioid streaks in her right eye and treated with six intravitreal bevacizumab (1.25 mg / 0.05 mL) injections over one year. Best corrected visual acuity improved from 20 / 125 at baseline ...

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

    OpenAIRE

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

    2013-01-01

    The aim of this study is to report clinical course of choroidal neovascularization secondary to angioid streaks (AS) in two patients who underwent intravitreal bevacizumab therapy. Fundus examination, fluorescein angiography (FA) and optical coherence tomography (OCT) revealed the diagnosis of subfoveal classic choroidal neovascularization (CNV) in the right eye in patient 1 and in the left eye in patient 2. After three consecutive bevacizumab injections, visual acuity improved from 20/40 to ...

  9. Long-term follow-up of choroidal neovascularization secondary to angioid streaks: case series and literature review

    Directory of Open Access Journals (Sweden)

    Al-Rashaed S

    2012-07-01

    Full Text Available Saba Al-Rashaed, J Fernando ArevaloKing Khaled Eye Specialist Hospital, Riyadh, Saudi ArabiaBackground: The purpose of this paper is to report the clinical course of choroidal neovascularization (CNV secondary to angioid streaks and the outcomes in response to different treatment modalities.Methods: This was a case series of two consecutive patients (four eyes with CNV secondary to angioid streaks. Visual acuity, ophthalmological examination, color photographs, fluorescein angiography, and optical coherence tomography were used to assess the outcomes of treatment.Results: Two eyes were treated with photodynamic therapy for subfoveal choroidal neovascular membrane, one eye underwent thermal laser photocoagulation for extrafoveal CNV followed by intravitreal bevacizumab for subfoveal CNV, and one eye underwent intravitreal bevacizumab for subfoveal CNV. The follow-up period was 4–6 years. The final visual acuities of all eyes were 20/300 or worse with large submacular fibrosis.Conclusion: CNV secondary to angioid streaks in these two patients had a poor prognosis despite undergoing different types of treatment. Poor outcome was likely related to frequent recurrence and newly developed CNV, which remained a clinical concern in these cases.Keywords: choroidal neovascular membrane, angioid streaks, intravitreal bevacizumab, photodynamic therapy

  10. Progressive symmetric vertical macular wide angioid streak-like lacquer crack

    Directory of Open Access Journals (Sweden)

    Mansour AM

    2016-04-01

    Full Text Available Ahmad M Mansour1,2 1Department of Ophthalmology, American University of Beirut, 2Department of Ophthalmology, Rafic Hariri University Hospital, Beirut, Lebanon Purpose: We report an unusual case of bilateral vertical lacquer crack with no history of ocular trauma and with progressive marked enlargement and consequent visual loss. Methods: Three-year follow-up was completed using best-corrected visual acuity, serial fundus photographs, intravenous fluorescein angiography, and optical coherence tomography. Results: We report the occurrence of lacquer crack in a 43-year-old woman with no history of trauma except for laser in situ keratomileusis surgery for mild myopia (as reported by the patient in the past 5 years and habitual ocular rubbing. Lacquer crack started in the right eye and became evident 1 year later in the left eye. Serial photography after repeated intravitreal injections of ranibizumab for subfoveal choroidal new vessel showed the lacquer crack widened gradually in both eyes. Axial length measurement revealed the presence of high myopia. Best-corrected visual acuity dropped to 20/200 bilaterally. Conclusion: We hypothesize that a thin Bruch's membrane in high myopia is prone for small rupture initially either spontaneously or following laser in situ keratomileusis and subsequent widening of the rupture by oculopression and intravitreal injections from rise in intraocular pressure. Keywords: angioid streak, Bruch's membrane rupture, choroidal rupture, choroidal neovascularization, high myopia, lacquer crack, LASIK

  11. 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

  12. 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

  13. 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...

  14. Progressive symmetric vertical macular wide angioid streak-like lacquer crack

    Science.gov (United States)

    Mansour, Ahmad M

    2016-01-01

    Purpose We report an unusual case of bilateral vertical lacquer crack with no history of ocular trauma and with progressive marked enlargement and consequent visual loss. Methods Three-year follow-up was completed using best-corrected visual acuity, serial fundus photographs, intravenous fluorescein angiography, and optical coherence tomography. Results We report the occurrence of lacquer crack in a 43-year-old woman with no history of trauma except for laser in situ keratomileusis surgery for mild myopia (as reported by the patient) in the past 5 years and habitual ocular rubbing. Lacquer crack started in the right eye and became evident 1 year later in the left eye. Serial photography after repeated intravitreal injections of ranibizumab for subfoveal choroidal new vessel showed the lacquer crack widened gradually in both eyes. Axial length measurement revealed the presence of high myopia. Best-corrected visual acuity dropped to 20/200 bilaterally. Conclusion We hypothesize that a thin Bruch’s membrane in high myopia is prone for small rupture initially either spontaneously or following laser in situ keratomileusis and subsequent widening of the rupture by oculopression and intravitreal injections from rise in intraocular pressure. PMID:27186081

  15. Triton's streaks as windblown dust

    Science.gov (United States)

    Sagan, Carl; Chyba, Christopher

    1990-01-01

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

  16. Streak camera time calibration procedures

    Science.gov (United States)

    Long, J.; Jackson, I.

    1978-01-01

    Time calibration procedures for streak cameras utilizing a modulated laser beam are described. The time calibration determines a writing rate accuracy of 0.15% with a rotating mirror camera and 0.3% with an image converter camera.

  17. 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

  18. Probing scattering phase shifts by attosecond streaking

    OpenAIRE

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

    2011-01-01

    Attosecond streaking is one of the most fundamental processes in attosecond science allowing for a mapping of temporal (i.e. phase) information on the energy domain. We show that on the single-particle level attosecond streaking time shifts contain spectral phase information associated with the Eisenbud-Wigner-Smith (EWS) time delay, provided the influence of the streaking infrared field is properly accounted for. While the streaking phase shifts for short-ranged potentials agree with the ass...

  19. Bilamellar type streak tube design

    International Nuclear Information System (INIS)

    In ICF experiments, high dynamic range, high temporal and spatial resolution X-ray streak camera is a necessary diagnosis tool. To meet this requirement, a streak tube which uses bilamellar electrode lens and quadrupolar lens to focus electrons has been designed. This tube uses different ways to focus electrons in temporal axis and spatial axis. In temporal axis, it uses two effectively. The spatial resolution of this tube reaches 40 lp/mm even at the edge of photocathode, the temporal resolution is about 10 ps and the effective length of photocathode is 20 mm. Using different focusing ways in temporal and spatial directions, the tube will not focus electrons to a small spot, compared with conventional rotary and symmetric tubes, and thus its space charge effect is much weaker, and dynamic range is much larger. (authors)

  20. Wind vs. Dust Devil Streaks

    Science.gov (United States)

    2004-01-01

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

  1. Numerical simulation of attosecond nanoplasmonic streaking

    Energy Technology Data Exchange (ETDEWEB)

    Skopalova, E; Lei, D Y; Witting, T; Arrell, C; Frank, F; Sonnefraud, Y; Maier, S A; Tisch, J W G; Marangos, J P, E-mail: e.skopalova07@imperial.ac.uk [Blackett Laboratory, Department of Physics, Imperial College London, London SW7 2AZ (United Kingdom)

    2011-08-15

    The characterization of the temporal profile of plasmonic fields is important both from the fundamental point of view and for potential applications in ultrafast nanoplasmonics. It has been proposed by Stockman et al (2007 Nat. Photonics 1 539) that the plasmonic electric field can be directly measured by the attosecond streaking technique; however, streaking from nanoplasmonic fields differs from streaking in the gas phase because of the field localization on the nanoscale. To understand streaking in this new regime, we have performed numerical simulations of attosecond streaking from fields localized in nanoantennas. In this paper, we present simulated streaked spectra for realistic experimental conditions and discuss the plasmonic field reconstruction from these spectra. We show that under certain circumstances when spatial averaging is included, a robust electric field reconstruction is possible.

  2. Nonlinear streak computation using boundary region equations

    International Nuclear Information System (INIS)

    The boundary region equations (BREs) are applied for the simulation of the nonlinear evolution of a spanwise periodic array of streaks in a flat plate boundary layer. The well-known BRE formulation is obtained from the complete Navier–Stokes equations in the high Reynolds number limit, and provides the correct asymptotic description of three-dimensional boundary layer streaks. In this paper, a fast and robust streamwise marching scheme is introduced to perform their numerical integration. Typical streak computations present in the literature correspond to linear streaks or to small-amplitude nonlinear streaks computed using direct numerical simulation (DNS) or the nonlinear parabolized stability equations (PSEs). We use the BREs to numerically compute high-amplitude streaks, a method which requires much lower computational effort than DNS and does not have the consistency and convergence problems of the PSE. It is found that the flow configuration changes substantially as the amplitude of the streaks grows and the nonlinear effects come into play. The transversal motion (in the wall normal-streamwise plane) becomes more important and strongly distorts the streamwise velocity profiles, which end up being quite different from those of the linear case. We analyze in detail the resulting flow patterns for the nonlinearly saturated streaks and compare them with available experimental results. (paper)

  3. Earth and planetary aeolian streaks: A review

    Science.gov (United States)

    Cohen-Zada, Aviv Lee; Blumberg, Dan Gabriel; Maman, Shimrit

    2016-03-01

    Wind streaks are abundant aeolian features that have been observed on planetary surfaces by remote sensing means. They have been widely studied, particularly on Mars and Venus and to a much lesser extent on Earth. In imagery, these streaks appear as elongated features that are easily distinguishable from their surroundings. Geomorphologically, these streaks have, thus far, been interpreted as the presence or absence of small loose particles on the surface, deposited or eroded, respectively, by wind. However, the use of different (optical and radar) remote-sensing tools to study wind streaks has led to uncertain interpretations of these features and has hindered their geomorphological definition. Since wind streaks indicate the prevailing wind direction at the time of their formation, they may be used to map near-surface winds and to estimate atmospheric circulation patterns. The aim of this article is to review the main studies focusing on wind streaks and to present the most up-to-date knowledge on this topic. Moreover, a new perspective for wind streak research is suggested: As 'wind streak' is a collective term for a variety of aeolian features that when viewed from above appear as distinctive albedo surface patterns, we suggest that the term should not be used to refer to a geomorphological feature. Since the definition of wind streaks is constrained to remote sensing rather than to geomorphology and is affected by the inherent biases of remote sensing methods, we suggest that 'wind streaks' should be used as a collective term for aeolian surfaces that are discernable from above as bright and dark patterns due to alterations in the characteristics of the surface or to the presence of bedforms. To better understand the mechanisms, time-frames, climate compatibility of wind streaks and the influences of remote sensing on their appearance, we have compiled a new database containing more than 2,900 Earth wind streaks. A comprehensive study of these Earth wind

  4. Probing scattering phase shifts by attosecond streaking

    International Nuclear Information System (INIS)

    Attosecond streaking is one of the most fundamental processes in attosecond science allowing for a mapping of temporal (i.e. phase) information on the energy domain. We show that on the single-particle level attosecond streaking time shifts contain spectral phase information associated with the Eisenbud-Wigner-Smith (EWS) time delay, provided the infuence of the streaking infrared feld is properly accounted for. While the streaking phase shifts for short-ranged potentials agree with the associated EWS delays, Coulomb potentials require special care. We show that the interaction between the outgoing electron and the combined Coulomb and IR laser felds lead to a streaking phase shift that can be described classically.

  5. Probing scattering phase shifts by attosecond streaking

    CERN Document Server

    Pazourek, Renate; Doblhoff-Dier, Katharina; Feist, Johannes; Lemell, Christoph; Tökési, Karoly; Burgdörfer, Joachim

    2011-01-01

    Attosecond streaking is one of the most fundamental processes in attosecond science allowing for a mapping of temporal (i.e. phase) information on the energy domain. We show that on the single-particle level attosecond streaking time shifts contain spectral phase information associated with the Eisenbud-Wigner-Smith (EWS) time delay, provided the influence of the streaking infrared field is properly accounted for. While the streaking phase shifts for short-ranged potentials agree with the associated EWS delays, Coulomb potentials require special care. We show that the interaction between the outgoing electron and the combined Coulomb and IR laser fields lead to a streaking phase shift that can be described classically.

  6. Atomic and molecular phases through attosecond streaking

    DEFF Research Database (Denmark)

    Baggesen, Jan Conrad; Madsen, Lars Bojer

    2011-01-01

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

  7. 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}_...

  8. Compact Optical Technique for Streak Camera Calibration

    International Nuclear Information System (INIS)

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

  9. Performance comparison of streak camera recording systems

    International Nuclear Information System (INIS)

    Streak camera based diagnostics are vital to the inertial confinement fusion program at Sandia National Laboratories. Performance characteristics of various readout systems coupled to an EGG-AVO streak camera were analyzed and compared to scaling estimates. The purpose of the work was to determine the limits of the streak camera performance and the optimal fielding conditions for the Amador Valley Operations (AVO) streak camera systems. The authors measured streak camera limitations in spatial resolution and sensitivity. Streak camera limits on spatial resolution are greater than 18 lp/mm at 4% contrast. However, it will be difficult to make use of any resolution greater than this because of high spatial frequency variation in the photocathode sensitivity. They have measured a signal to noise of 3,000 with 0.3 mW/cm2 of 830 nm light at a 10 ns/mm sweep speed. They have compared lens coupling systems with and without micro-channel plate intensifiers and systems using film or charge coupled device (CCD) readout. There were no conditions where film was found to be an improvement over the CCD readout. Systems utilizing a CCD readout without an intensifier have comparable resolution, for these source sizes and at a nominal cost in signal to noise of 3, over those with an intensifier. Estimates of the signal-to-noise for different light coupling methods show how performance can be improved

  10. Compact Optical Technique for Streak Camera Calibration

    International Nuclear Information System (INIS)

    The National Ignition Facility (NIF) is under construction at the Lawrence Livermore National Laboratory (LLNL) for the U.S. Department of Energy Stockpile Stewardship Program. Optical streak cameras are an integral part of the experimental diagnostics instrumentation. To accurately reduce data from the streak cameras a temporal calibration is required. This article describes a technique for generating trains of precisely timed short-duration optical pulses1 (optical comb generators) that are suitable for temporal calibrations. These optical comb generators (Figure 1) are used with the LLNL optical streak cameras. They are small, portable light sources that produce a series of temporally short, uniformly spaced, optical pulses. Comb generators have been produced with 0.1, 0.5, 1, 3, 6, and 10-GHz pulse trains of 780-nm wavelength light with individual pulse durations of ∼25-ps FWHM. Signal output is via a fiber-optic connector. Signal is transported from comb generator to streak camera through multi-mode, graded-index optical fibers. At the NIF, ultra-fast streak-cameras are used by the Laser Fusion Program experimentalists to record fast transient optical signals. Their temporal resolution is unmatched by any other transient recorder. Their ability to spatially discriminate an image along the input slit allows them to function as a one-dimensional image recorder, time-resolved spectrometer, or multichannel transient recorder. Depending on the choice of photocathode, they can be made sensitive to photon energies from 1.1 eV to 30 keV and beyond. Comb generators perform two important functions for LLNL streak-camera users. First, comb generators are used as a precision time-mark generator for calibrating streak camera sweep rates. Accuracy is achieved by averaging many streak camera images of comb generator signals. Time-base calibrations with portable comb generators are easily done in both the calibration laboratory and in situ. Second, comb signals are applied

  11. 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 %.

  12. Probing scattering phase shifts by attosecond streaking

    International Nuclear Information System (INIS)

    Complete text of publication follows. The emerging field of attoscience enables the investigation of electron dynamics as well as timing information of photoionization processes. Attosecond streaking has developed into a powerful tool to achieve temporal resolution on the sub-100 attosecond time scale. It is based on a pump-probe setting with an extreme ultraviolet (XUV) pulse of a few hundred attoseconds duration serving as pump and a phase-controlled few-cycle infrared (IR) pulse as probe. Temporal information about the photoionization process can thus be mapped onto the energy axis in analogy to conventional streaking. We studied attosecond streaking of the release time of electrons in atomic photoemission by solving the time-dependent Schroedinger equation (TDSE) for effective one-electron systems. We presented calculations also employing a restricted ionization model (RIM) in the TDSE. We verified that the trajectory effects on the time shift resulting from the interaction between the outgoing electron and the combined Coulomb and IR laser fields can be described classically. We have shown that Eisenbud-Wigner-Smith (EWS) time shifts (or energy variation of the scattering phase) for short-ranged potentials become accessible by attosecond streaking provided both initial-state dependent entrance channel and final-state exit channel distortions are properly accounted for. For Coulomb potentials the coupling between the IR streaking field and the Coulomb field which depends on the final energy of the free electron dominates the extracted streaking time shift but can be accounted for classically. In addition we have identified considerable state dependent time shifts for easily polarizable initial states which are of quantum mechanical origin. Accounting for polarization of the initial state, the remaining difference of time delays between ionization from states with different angular momentum can be related to the EWS delay of the centrifugal potential

  13. 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.

  14. 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.

  15. 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...

  16. Hitting Is Contagious in Baseball: Evidence from Long Hitting Streaks

    OpenAIRE

    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 streaks of length games, including a total observations were compiled. Treatment and control sample groups ( ) were constructed from core lineups of players on the streaking batter’s team. The percentile method bootstrap was used to calcu...

  17. Streak camera system for prompt display of laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Baumgart, J.S.; Justice, R.; Bender, S.

    1989-01-01

    The streak camera is a useful tool for doing imaging experiments. Its high bandwidth and large information carrying capacity provide great flexibility in data recording. This paper describes a streak system used to make two-dimensional measurements on a pulsed laser system. The streak system measures beam position, full width, relative intensity, and shape on multiple pulses in a single sweep. These measurements are analyzed in real time and displayed for user feedback. 18 figs.

  18. Laser interferometry: streaked shadowgraphy and Schlieren imaging

    International Nuclear Information System (INIS)

    Optical diagnostics are extensively used to probe plasmas because they do not perturb the measured medium. Among them, the measurements of the refractive index and its variations give direct access to the electronic density, its gradients and the hydrodynamics of the plasma. Schlieren and shadowgraphy show qualitatively the density gradients and can even give quantitative information if certain conditions are fulfulled, in particular symmetry. Laser interferometry gives a very precise density measurement in a cylindrical plasma. Time resolution is achieved either using ultra-short laser pulses or using a streak camera. The authors illustrate such methods, describing some optical diagnostics of a laser produced plasma. (Auth.)

  19. Compact optical technique for streak camera calibration

    International Nuclear Information System (INIS)

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

  20. 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.

  1. Streaked, x-ray-transmission-grating spectrometer

    International Nuclear Information System (INIS)

    A free standing x-ray transmission grating has been coupled with a soft x-ray streak camera to produce a time resolved x-ray spectrometer. The instrument has a temporal resolution of approx. 20 psec, is capable of covering a broad spectral range, 2 to 120 A, has high sensitivity, and is simple to use requiring no complex alignment procedure. In recent laser fusion experiments the spectrometer successfully recorded time resolved spectra over the range 10 to 120 A with a spectral resolving power, lambda/Δlambda of 4 to 50, limited primarily by source size and collimation effects

  2. 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...

  3. Note: X-ray streak camera sweep speed calibration

    International Nuclear Information System (INIS)

    X-ray streak cameras are extensively used to study transient x-ray processes in experiments carried out on various laser facilities at the Research Center of Laser Fusion. Precise calibration and clear description of the sweep speed of the x-ray streak camera are vital for obtaining precise temporal information to understand the fast physics phenomena. An x-ray streak camera named wide-slit x-ray streak camera has been calibrated using a small-scale laser facility with pulse duration of 8 ps. Sweep speeds on most part of the output screen (charge coupled device) are obtained. These calibration results can be used to correct the nonlinearity of sweep speed in measurement of temporal processes.

  4. 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

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

    Science.gov (United States)

    Gorgisyan, I; Ischebeck, R; Prat, E; Reiche, S; Rivkin, L; Juranić, P

    2016-05-01

    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. PMID:27140142

  6. 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.

  7. Study of Geometric Parameters of Slope Streaks on Mars.

    Science.gov (United States)

    Brusnikin, Eugene; Kreslavsky, Mikhail; Karachevtseva, Irina; Zubarev, Anatoliy; Patratiy, Vyacheslav

    2015-04-01

    Slope streaks are a unique active phenomenon observed in low-latitude dusty regions on Mars. They are dark markings formed by an unknown type of run-away downslope propagation of surface disturbance. There are two kinds of hypotheses of their formation mechanism: "dry", involving granular follow, in particular, dust avalanche, and "wet", involving liquid flow, in particular, percolation of concentrated brines in shallow subsurface (1). Study of geometric characteristics of the slope streaks, especially their slopes, is a way to decipher their origin. We are carrying out an extensive set of measurements of geometric parameters of the slope streaks. We use stereo pairs of images obtained by High Resolution Imaging Science Experiment (HiRISE) onboard MRO orbital mission to Mars. These stereo pairs potentially allow geometric measurements (both horizontal and vertical) with accuracy on an order of a meter. Unfortunately, the digital terrain model is currently released for only one stereo pair in the regions of slope streak occurrence, and we have to work with raw, unprocessed stereo pairs. We perform direct photogrammetric measurements using PHOTOMOD software complex (http://www.racurs.ru/). We use our custom software to import "raw" HiRISE imgas (EDRs) and supplementary geometric information from SPICE into PHOTOMOD (2). We select tens to a hundred meters long segments in the beginning and the end of selected streaks and register length, azimuth, and slope of each segment. We also search for anomalously gentle parts of streaks. We analyze the obtained results by means of ESRI ArcGIS software. Our survey is in progress. So far we registered over a hundred of streaks. We found that the extent of the streaks varies from several meters to hundreds of meters. The streaks are formed in locales with a slope from 17 to 37 degrees. The lower boundary indicates that the streaks can propagate on slopes that are significantly gentler than the static angle of repose. Distal

  8. Streak detection and analysis pipeline for optical images

    Science.gov (United States)

    Virtanen, J.; Granvik, M.; Torppa, J.; Muinonen, K.; Poikonen, J.; Lehti, J.; Säntti, T.; Komulainen, T.; Flohrer, T.

    2014-07-01

    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. We focus on the low signal-to-noise (SNR) detection of objects with high angular velocities, resulting in long and faint object trails, or streaks, in the optical images. The currently available, mature image processing algorithms for detection and astrometric reduction of optical data cover objects that cross the sensor field-of-view comparably slowly, and, particularly for satellites, within a rather narrow, predefined range of angular velocities. By applying specific tracking techniques, the objects appear point-like or as short trails in the exposures. However, the general survey scenario is always a 'track-before-detect' problem, resulting in streaks of arbitrary lengths. Although some considerations for low-SNR processing of streak-like features are available in the current image processing and computer vision literature, algorithms are not readily available yet. In the ESA-funded StreakDet (Streak detection and astrometric reduction) project, we develop and evaluate an automated processing pipeline applicable to single images (as compared to consecutive frames of the same field) obtained with any observing scenario, including space-based surveys and both low- and high-altitude populations. The algorithmic

  9. 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.

  10. 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.

  11. Streak Camera Performance with Large-Format CCD Readout

    International Nuclear Information System (INIS)

    The ICF program at Livermore has a large inventory of optical streak cameras that were built in the 1970s and 1980s. The cameras include micro-channel plate image-intensifier tubes (IIT) that provide signal amplification and early lens-coupled CCD readouts. Today, these cameras are still very functional, but some replacement parts such as the original streak tube, CCD, and IIT are scarce and obsolete. This article describes recent efforts to improve the performance of these cameras using today's advanced CCD readout technologies. Very sensitive, large-format CCD arrays with efficient fiber-optic input faceplates are now available for direct coupling with the streak tube. Measurements of camera performance characteristics including linearity, spatial and temporal resolution, line-spread function, contrast transfer ratio (CTR), and dynamic range have been made for several different camera configurations: CCD coupled directly to the streak tube, CCD directly coupled to the IIT, and the original configuration with a smaller CCD lens coupled to the IIT output. Spatial resolution (limiting visual) with and without the IIT is 8 and 20 lp/mm, respectively, for photocathode current density up to 25% of the Child-Langmuir (C-L) space-charge limit. Temporal resolution (fwhm) deteriorates by about 20% when the cathode current density reaches 10% of the C-L space charge limit. Streak tube operation with large average tube current was observed by illuminating the entire slit region through a Ronchi ruling and measuring the CTR. Sensitivity (CCD electrons per streak tube photoelectron) for the various configurations ranged from 7.5 to 2,700 with read noise of 7.5 to 10.5 electrons. Optimum spatial resolution is achieved when the IIT is removed. Maximum dynamic range requires a configuration where a single photoelectron from the photocathode produces a signal that is 3 to 5 times the read noise

  12. Readout and processing devices for picosecond streak cameras

    International Nuclear Information System (INIS)

    The use of streak cameras in laboratories working on Laser Fusion is still too often limited by the long procedure required for film processing before delivering an useful diagnostic. Here we present different ways (vacuum low level TV tube, linear solid state array of photodiodes) developed in our laboratory to readout the images of streak cameras. They provide time resolution in the 10 ps range, with one to 32 spatial channels and may be interfaced with the computer data acquisition system now used in Limeil

  13. Soft x-ray streak camera for laser fusion applications

    International Nuclear Information System (INIS)

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

  14. Reliable and Repeatable Characterization of Optical Streak Cameras

    International Nuclear Information System (INIS)

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

  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. Temporal characteristics calibration for an X-ray streak camera

    International Nuclear Information System (INIS)

    X-ray streak cameras are very important in inertial confinement fusion experiments. The characterization of the cameras should be carried out to ensure the reliability and accuracy of the experimental data. The temporal characteristics of the X-ray streak camera, such as sweep speed and temporal resolution, were calibrated for the first time on the 20 TW laser facility at High Power Laser and Physics Joint Laboratory of Shanghai. Results of the calibration experiments show that some of the specifications of the X-ray camera have changed compared with their nominal values. With these calibration data, the processing and the analysis of the ICF experimental results are turned out to be more creditable. (authors)

  18. 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.

  19. 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.

  20. 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

  1. Energy sharing in the two-electron attosecond streak camera

    International Nuclear Information System (INIS)

    Using the recently developed concept of the two-electron streak camera (see Emmanouilidou et al 2010 New J. Phys. 12 103024), we studied the energy sharing between the two ionizing electrons in single-photon double ionization of He(1s2s). We found 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 two-electron streak camera resolves the time delays between the emission of the two electrons for different energy sharings.

  2. Energy sharing in the two-electron attosecond streak camera

    Energy Technology Data Exchange (ETDEWEB)

    Price, H; Emmanouilidou, A [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Staudte, A, E-mail: a.emmanouilidou@ucl.ac.uk [Joint Laboratory for Attosecond Science, University of Ottawa and National Research Council, 100 Sussex Drive, Ottawa, ON K1A 0R6 (Canada)

    2011-09-15

    Using the recently developed concept of the two-electron streak camera (see Emmanouilidou et al 2010 New J. Phys. 12 103024), we studied the energy sharing between the two ionizing electrons in single-photon double ionization of He(1s2s). We found 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 two-electron streak camera resolves the time delays between the emission of the two electrons for different energy sharings.

  3. Design of microcontroller based system for automation of streak camera

    International Nuclear Information System (INIS)

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

  4. 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)

  5. Design of microcontroller based system for automation of streak camera

    Science.gov (United States)

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

    2010-08-01

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

  6. Streaking at high energies with electrons and positrons

    International Nuclear Information System (INIS)

    State-of-the-art attosecond metrology deals with the detection and characterization of photon pulses with typical energies up to the hundreds of eV and time resolution of several tens of attoseconds. Such short pulses are used for example to control the motion of electrons on the atomic scale or to measure inner-shell atomic dynamics. The next challenge of time-resolving the inner-nuclear dynamics, transient meson states and resonances requires photon pulses below attosecond duration and with energies exceeding the MeV scale. Here we discuss a detection scheme for time-resolving high-energy gamma ray pulses down to the zeptosecond timescale. The scheme is based on the concept of attosecond streak imaging, but instead of conversion of photons into electrons in a nonlinear medium, the high-energy process of electron-positron pair creation is utilized. These pairs are produced in vacuum through the collision of a test pulse to be characterized with an intense laser pulse, and they acquire additional energy and momentum depending on their phase in the streaking pulse at the moment of production. A coincidence measurement of the electron and positron momenta after the interaction provides information on the pair production phase within the streaking pulse. We examine the limitations imposed by quantum radiation reaction in multiphoton Compton scattering on this detection scheme, and discuss other necessary conditions to render the scheme feasible in the upcoming Extreme Light Infrastructure (ELI) laser facility.

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

    OpenAIRE

    Nagele, S; Pazourek, R; Feist, J.; Doblhoff-Dier, K; Lemell, C.; Tőkési, K; Burgdörfer, J.

    2011-01-01

    Attosecond streaking of atomic photoemission holds the promise to provide unprecedented information on the release time of the photoelectron. We show that attosecond streaking phase shifts indeed contain timing (or spectral phase) information associated with the Eisenbud-Wigner-Smith time delay matrix of quantum scattering. However, this is only accessible if the influence of the streaking infrared (IR) field on the emission process is properly accounted for. The IR probe field can strongly m...

  8. 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.

  9. 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

  10. Mechanism for propagation of the step leader of streak lightning

    International Nuclear Information System (INIS)

    A hypothetical scheme for the development of the step leader of streak lightning is discussed. The mathematical problem of modeling the propagation of the leader in this scheme is stated. The main parameters of the leader are estimated: the length and propagation velocity of the step, the average propagation velocity, etc. This is compared with data from observations in nature. The propagation of the leader is simulated numerically. Results of the calculation are presented for two 'flashes' of the step leader. 25 refs., 6 figs

  11. 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...

  12. 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

  13. Microprocessor-controlled, wide-range streak camera

    Energy Technology Data Exchange (ETDEWEB)

    Amy E. Lewis, Craig Hollabaugh

    2006-09-01

    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.

  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. Calibration and correction of sweep rate nonlinearity of the streak camera

    International Nuclear Information System (INIS)

    A method for etalon design is reported, which is used for the calibration for sweep nonlinearity of streak camera and the test of its dynamic range with appropriate etalon, and the method of intensity correction dot by dot, the sweep nonlinearity of C1587 streak camera has been calibrated and automatically corrected by computer

  16. Absolute calibration of the soft X-ray streak camera static characteristic

    International Nuclear Information System (INIS)

    The soft X-ray streak camera is very important detection tool for studying soft X-ray time characteristics. We have calibrated its absolute energy response in terms of X rays provided by synchrotron Radiation Source on the BSRF. The combined uncertainty of quantum efficiency of the streak camera in 100-1000 eV photon energy region is 23%

  17. 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.

  18. 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.

  19. Numerical simulation of streak ICT electron optics focusing characteristics

    International Nuclear Information System (INIS)

    The image converter tube is a core component in the streak cameras. Its operation was introduced and the model for its internal electronic optical system was built. Numerical simulations were done by ANSYS based on the finite element method, in which the functional is solved by Hamilton principle. The distribution of the electrostatic field was calculated in an operation voltage and the tracks of electrons were calculated in different operation voltages. The results agree well with that of the symmetric electrostatic field theoretical analysis. They also indicate that the size and shape of electrode has a slight influence on imaging, and the proper voltages(containing accelerating, focusing and anode voltages) has more. (authors)

  20. Interference effects in angular streaking with a rotating terahertz field

    Science.gov (United States)

    Kazansky, A. K.; Bozhevolnov, A. V.; Sazhina, I. P.; Kabachnik, N. M.

    2016-01-01

    A method of angular streaking with a rotating terahertz electric field for photoelectrons produced by femtosecond extreme ultraviolet pulses is suggested and theoretically analyzed. The method can be used for free electron laser (FEL) pulse characterization on a shot-to-shot basis. It is shown that in related measurements an interesting phenomenon appears: formation of very bright and sharp features in the angular resolved electron spectra measured in the plane perpendicular to the collinear beam direction. These features are similar to the conventional caustics in the wave propagation. The caustics are accompanied by a well-developed interference structure. The intensity distribution along the caustic is determined by the envelope of the FEL pulse.

  1. Experimental calibration of sweep speed for optic streak camera

    International Nuclear Information System (INIS)

    In order to accurately measure the velocity of shock waves, an optic streak camera was calibrated. In the different period of time, the sweep speed of the camera was measured at different sweep grade and different position. Results of the calibration experiments obviously show that the initial sweep speed was slower than the terminal sweep speed at 10 ns/15mm and 5ns/15mm grade, but the terminal sweep speed was slower at 2ns/15mm grade. The sweep speed of the camera was unequal in the different period of time. It indicated that analyzing data by average sweep speed and sweep nonlinearity was inapplicable because of the camera's aging. (authors)

  2. Attosecond Streaking in the Low-Energy Region

    International Nuclear Information System (INIS)

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

  3. 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.

  4. Flat-field response and geometric distortion measurements of optical streak cameras

    International Nuclear Information System (INIS)

    To accurately measure pulse amplitude, shape, and relative time histories of optical signals with an optical streak camera, it is necessary to correct each recorded image for spatially-dependent gain nonuniformity and geometric distortion. Gain nonuniformities arise from sensitivity variations in the streak-tube photocathode, phosphor screen, image-intensifier tube, and image recording system. These nonuniformities may be severe, and have been observed to be on the order of 100% for some LLNL optical streak cameras. Geometric distortion due to optical couplings, electron-optics, and sweep nonlinearity not only affects pulse position and timing measurements, but affects pulse amplitude and shape measurements as well. By using a 1.053-μm, long-pulse, high-power laser to generate a spatially and temporally uniform source as input to the streak camera, the combined effects of flat-field response and geometric distortion can be measured under the normal dynamic operation of cameras with S-1 photocathodes. Additionally, by using the same laser system to generate a train of short pulses that can be spatially modulated at the input of the streak camera, we can effectively create a two-dimensional grid of equally-spaced pulses. This allows a dynamic measurement of the geometric distortion of the streak camera. We will discuss the techniques involved in performing these calibrations, will present some of the measured results for LLNL optical streak cameras, and will discuss software methods to correct for these effects. 6 refs., 6 figs

  5. 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.

  6. 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.

  7. Stabilization of the hypersonic boundary layer by finite-amplitude streaks

    Science.gov (United States)

    Ren, Jie; Fu, Song; Hanifi, Ardeshir

    2016-02-01

    Stabilization of two-dimensional disturbances in hypersonic boundary layer flows by finite-amplitude streaks is investigated using nonlinear parabolized stability equations. The boundary-layer flows at Mach numbers 4.5 and 6.0 are studied in which both first and second modes are supported. The streaks considered here are driven either by the so-called optimal perturbations (Klebanoff-type) or the centrifugal instability (Görtler-type). When the streak amplitude is in an appropriate range, i.e., large enough to modulate the laminar boundary layer but low enough to not trigger secondary instability, both first and second modes can effectively be suppressed.

  8. 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.

  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.

    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

  10. 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....

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

    International Nuclear Information System (INIS)

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

  12. Effect of Process Variables on the Formation of Streak Defects on Anodized Aluminum Extrusions: An Overview

    Science.gov (United States)

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

    2012-04-01

    Streak defects are often present on anodized extrusions of 6xxx series aluminum alloys, increasing the fabrication cost of these products. Moreover, streaking often only becomes visible after etching and anodizing treatments, rather than in the as-extruded condition, making it difficult to identify the original causes and influencing factors of these defects. In this paper, various process variables that influence the formation of streak defects on anodized aluminium extrusions are reviewed on the basis of a literature review, industrial practice and experimental results. The influencing factors involved in various processing steps such as billet quality, extrusion process, die design and etching process are considered. Effective measures for preventing the formation of streak defects in industrial extrusion products are discussed.

  13. 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...

  14. 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.)

  15. 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

  16. 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.)

  17. 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

  18. Effects of streaking laser intensity on the characterization of isolated attosecond pulses

    Science.gov (United States)

    Wang, He; Khan, Sabih; Chini, Michael; Chen, Shouyuan; Chang, Zenghu

    2009-05-01

    Single isolated attosecond extreme ultraviolet (XUV) pulses can be characterized by streaking photoelectrons using a near infrared (NIR) laser field. Classically, the streaking resolution is determined by the Rayleigh criterion, which requires the minimum NIR intensity of 5.5x10^13 W/cm^2 to resolve 90 as XUV pulses. Under such high NIR intensity, the electrons generated from multi-photon processes overlap with the streaked electrons in the spectrogram, which unavoidably introduces errors in the final XUV reconstruction. When the FROG-CRAB (Frequency-Resolved Optical Gating for Complete Reconstruction of Attosecond Bursts) technique is used to reconstruct the XUV pulses from the spectrogram, it was found that the minimum streaking intensity needed to resolve single attosecond pulses is dependent on the maximum count of the spectrogram. With a peak count of 100 in the spectrogram, chirped attosecond pulses with spectral bandwidth supporting 90-as transform limited pulse durations can be retrieved from the spectrogram with streaking intensity two orders of magnitude smaller than that derived from the Rayleigh criterion. Such low streaking field intensity is desirable to suppress the ATI background, which is important for the characterization of even shorter XUV attosecond pulses because it significantly reduces the intensity constraints on the experiments.

  19. The resistance of cocoa hybrids to vascular-streak dieback

    Directory of Open Access Journals (Sweden)

    Agung Wahyu Soesilo

    2011-08-01

    Full Text Available Breeding for VSD resistance on cocoa was carried out by inter-crossing the selected clones of TSH 858, KW 162, KW 163, KW 165, KEE 2, ICS 13 and NIC 7 which were selected based on the criteria of VSD resistance, productivity and cross-compatibility. This research has objective to evaluate hybrids of the crossess for VSD resistance, inheritance of the resistance and selecting the most valuable parental-clones for further crossess. Fourteen hybrids and one control were tested 14 in the randomized-completely block design with 4 blocks where in each plot 16 trees planted at Kaliwining Experimental Station in Jember. The resistance was evaluated in the field by scoring the symptoms in the range of 0—6 at 7 year after planting. The scores were varied significantly among the hybrids in the range of 2.19—4.53. Hybrids which were generated from the crosses of resistant clones performed lower number of the score than the hybrids generated from crosses between two susceptible clones (TSH 858 x NIC 7 which performed highest score. The hybrids classified as resistant were TSH 858 x KW 162 (F1 and reciprocal, KW 162 x KEE 2 (F1 and reciprocal, KW 162 x ICS 13, KW 165 x KEE 2. Of the parental clones, KW 162 is the most promising parent as lower score obtained when used it as male or female compared to KEE 2 which performed quite similar of the score with TSH 858 as susceptible parent. Therefore, it could be supposed that KW 162 has better combining ability than KEE 2 where these resistant-clones showed different segregation of their resistance. The resistance was segregated by KW 162 in term of ratio 15 resistant : 1 susceptible while KEE 2 the ratio 1 resistant: 1 susceptible.Key words: Theobroma cocoa L., hybrid, resistance, vascular-streak dieback.

  20. 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

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

    CERN Document Server

    Nagele, Stefan; Feist, Johannes; Doblhoff-Dier, Katharina; Lemell, Christoph; T\\Hokési, Karoly; Burgdörfer, Joachim

    2011-01-01

    Attosecond streaking of atomic photoemission holds the promise to provide unprecedented information on the release time of the photoelectron. We show that attosecond streaking phase shifts indeed contain timing (or spectral phase) information associated with the Eisenbud-Wigner-Smith time delay matrix of quantum scattering. However, this is only accessible if the influence of the streaking infrared (IR) field on the emission process is properly accounted for. The IR probe field can strongly modify the observed streaking phase shift. We show that the part of the phase shift ("time shift") due to the interaction between the outgoing electron and the combined Coulomb and IR laser fields can be described classically. By contrast, the strong initial-state dependence of the streaking phase shift is only revealed through the solution of the time-dependent Schr\\"odinger equation in its full dimensionality. We find a time delay between the hydrogenic 2s and 2p initial states in He+ exceeding 20as for a wide range of I...

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

    International Nuclear Information System (INIS)

    Attosecond streaking of atomic photoemission holds the promise to provide unprecedented information on the release time of the photoelectron. We show that attosecond streaking phase shifts indeed contain timing (or spectral phase) information associated with the Eisenbud-Wigner-Smith time delay matrix of quantum scattering. However, this is only accessible if the influence of the streaking infrared (IR) field on the emission process is properly accounted for. The IR probe field can strongly modify the observed streaking phase shift. We show that the part of the phase shift ('time shift') due to the interaction between the outgoing electron and the combined Coulomb and IR laser fields can be described classically. By contrast, the strong initial-state dependence of the streaking phase shift is only revealed through the solution of the time-dependent Schroedinger equation in its full dimensionality. We find a time delay between the hydrogenic 2s and 2p initial states in He+ exceeding 20 as for a wide range of IR intensities and XUV energies. (fast track communication)

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

    Energy Technology Data Exchange (ETDEWEB)

    Nagele, S; Pazourek, R; Doblhoff-Dier, K; Lemell, C; Burgdoerfer, J [Institute for Theoretical Physics, Vienna University of Technology, 1040 Vienna (Austria); Feist, J [ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Tokesi, K, E-mail: stefan.nagele@tuwien.ac.at, E-mail: renate.pazourek@tuwien.ac.at [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), 4001 Debrecen (Hungary)

    2011-04-28

    Attosecond streaking of atomic photoemission holds the promise to provide unprecedented information on the release time of the photoelectron. We show that attosecond streaking phase shifts indeed contain timing (or spectral phase) information associated with the Eisenbud-Wigner-Smith time delay matrix of quantum scattering. However, this is only accessible if the influence of the streaking infrared (IR) field on the emission process is properly accounted for. The IR probe field can strongly modify the observed streaking phase shift. We show that the part of the phase shift ('time shift') due to the interaction between the outgoing electron and the combined Coulomb and IR laser fields can be described classically. By contrast, the strong initial-state dependence of the streaking phase shift is only revealed through the solution of the time-dependent Schroedinger equation in its full dimensionality. We find a time delay between the hydrogenic 2s and 2p initial states in He{sup +} exceeding 20 as for a wide range of IR intensities and XUV energies. (fast track communication)

  4. Ets2-dependent trophoblast signalling is required for gastrulation progression after primitive streak initiation.

    Science.gov (United States)

    Polydorou, Christiana; Georgiades, Pantelis

    2013-01-01

    Although extraembryonic ectoderm trophoblast signals the embryo for primitive streak initiation, a prerequisite for gastrulation, it is unknown whether it also signals for the progression of gastrulation after primitive streak initiation. Here, using Ets2-/- mice, we show that trophoblast signalling is also required in vivo for primitive streak elongation, completion of intraembryonic mesoderm epithelial-mesenchymal transition and the development of anterior primitive streak derivatives such as the node. We show that Ets2-dependent trophoblast signalling is required for the maintenance of high levels of Nodal and Wnt3 expression in the epiblast and for the induction of Snail expression in the primitive streak, between embryonic day 6.3 and 6.7. Within extraembryonic ectoderm trophoblast, Ets2 maintains the expression of the transcription factors Elf5, Cdx2 and Eomes, and that of the signalling molecule Bmp4. We propose a model that provides a genetic explanation as to how Ets2 in trophoblast mediates the progression of gastrulation within the epiblast. PMID:23552073

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

    International Nuclear Information System (INIS)

    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:Al2O3 solid state laser oscillator and also a fiber oscillator

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

    International Nuclear Information System (INIS)

    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.

  7. 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.

  8. 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.

  9. Observation of hard X-ray pulses with a highly sensitive streak camera

    CERN Document Server

    Hara, T; Kitamura, H; Ishikawa, T

    2001-01-01

    We have developed a highly sensitive X-ray streak camera system, which synchronously operates with the RF signal of the SPring-8 storage ring. The streak camera was installed at an undulator beamline of SPring-8, and the beam loading effect for various electron bunch structures (filling pattern) has been observed. The camera has also been operated as a timing monitor for a synchronization system of synchrotron radiation and a Ti:sapphire laser. The highly sensitive X-ray streak camera system can be used not only as an accelerator diagnosis, but also as a fast temporal detector for beamline applications, such as the observation of fast temporal transitions of diffraction images and relaxation process.

  10. Time-resolved photoemission by attosecond streaking. Extraction of time information

    International Nuclear Information System (INIS)

    Complete text of publication follows. Attosecond streaking is one of the most spectacular applications within the emerging field of attoscience. Streaking is based on a variant of a pump-probe setting with an extreme ultraviolet (XUV) pulse of a few hundred attoseconds serving as a pump and a phase controlled few-cycle infrared (IR) pulse as a probe. Electrons emitted in the presence of an IR field are accelerated to different final momenta and energies depending on the value of the vector potential at the release time. Thus, time information is mapped onto the energy axis in analogy to conventional streaking. Attosecond streaking of atomic photoemission holds the promise to provide unprecedented information on the release time of the photoelectron. We have shown that attosecond streaking phase shifts indeed contain timing (or spectral phase) information associated with the Eisenbud - Wigner - Smith (EWS) time delay matrix of quantum scattering. We have identified on the one-electron (or independent particle) level considerable state dependent time shifts that can be observed in attosecond streaking and which are of quantum mechanical origin. We found a time delay between the hydrogenic 2s and 2p initial states in He+ exceeding 20 as for a wide range of IR intensities and XUV energies (see Fig. 1). In addition, we have identified large time shifts which result from the coupling between the IR streaking field and the Coulomb field which depend on the final energy of the free electron and can be accounted for classically. The EWS time shift (or energy variation of the scattering phase) is found to be accessible by streaking only if both initial-state-dependent entrance channel and final-state exit channel distortions are properly accounted for. For such a scenario we have shown that time delays on the single-digit attosecond scale due to short-ranged potentials are in reach. Acknowledgements This work was supported by the FWF-Austria, grant nos SFB016 and P21141-N16

  11. The two-electron attosecond streak camera for time-resolving intra-atomic collisions

    Energy Technology Data Exchange (ETDEWEB)

    Emmanouilidou, A [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Staudte, A; Corkum, P B, E-mail: a.emmanouilidou@ucl.ac.u [Joint Laboratory for Attosecond Science, University of Ottawa and National Research Council, 100 Sussex Drive, Ottawa, ON, K1A 0R6 (Canada)

    2010-10-15

    We generalize the one-electron attosecond streak camera to time-resolve the correlated two-electron escape dynamics during a collision process involving a deep core electron. The collision process is triggered by an extreme ultraviolet (XUV) attosecond pulse (single-photon absorption) and probed by a weak infrared field. The principle of our two-electron streak camera is that by placing the maximum of the vector potential of the probing field at the time of collision, we get the maximum splitting of the inter-electronic angle of escape. We thereby determine the time of collision.

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, C.-H.; Thumm, U. [Department of Physics, Kansas State University, Manhattan, Kansas 66506 (United States)

    2011-12-15

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

  13. 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.

  14. 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

  15. Attosecond streaking of shake-up and Auger electrons in xenon

    Directory of Open Access Journals (Sweden)

    Drescher M.

    2013-03-01

    Full Text Available We present first results of simultaneous attosecond streaking measurements of shake-up electrons and Auger electrons emitted from xenon. We extract relative photo-emission delays for electrons emitted from the 4d, 5s and 5p subshell, as well as for the 5p−25d correlation satellite (shake-up electrons.

  16. Attosecond streaking of shake-up and Auger electrons in xenon

    Science.gov (United States)

    Verhoef, A. J.; Mitrofanov, A.; Krikunova, M.; Kabachnik, N. M.; Drescher, M.; Baltuska, A.

    2013-03-01

    We present first results of simultaneous attosecond streaking measurements of shake-up electrons and Auger electrons emitted from xenon. We extract relative photo-emission delays for electrons emitted from the 4d, 5s and 5p subshell, as well as for the 5p-25d correlation satellite (shake-up electrons).

  17. 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.

  18. 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

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

    Science.gov (United States)

    Aggarwal, Aditya; Singh, Hardeep; Mahendru, Sanjay; Brajesh, Vimalendu; Singh, Sukhdeep; Khare, Ashish; Kothari, Umang; Khazanchi, Rakesh Kumar

    2015-01-01

    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. PMID:26933280

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

    International Nuclear Information System (INIS)

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

  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. Streaking artifact reduction for quantitative susceptibility mapping of sources with large dynamic range.

    Science.gov (United States)

    Wei, Hongjiang; Dibb, Russell; Zhou, Yan; Sun, Yawen; Xu, Jianrong; Wang, Nian; Liu, Chunlei

    2015-10-01

    Quantitative susceptibility mapping (QSM) is a novel MRI technique for the measurement of tissue magnetic susceptibility in three dimensions. Although numerous algorithms have been developed to solve this ill-posed inverse problem, the estimation of susceptibility maps with a wide range of values is still problematic. In cases such as large veins, contrast agent uptake and intracranial hemorrhages, extreme susceptibility values in focal areas cause severe streaking artifacts. To enable the reduction of these artifacts, whilst preserving subtle susceptibility contrast, a two-level QSM reconstruction algorithm (streaking artifact reduction for QSM, STAR-QSM) was developed in this study by tuning a regularization parameter to automatically reconstruct both large and small susceptibility values. Compared with current state-of-the-art QSM methods, such as the improved sparse linear equation and least-squares (iLSQR) algorithm, STAR-QSM significantly reduced the streaking artifacts, whilst preserving the sharp boundaries for blood vessels of mouse brains in vivo and fine anatomical details of high-resolution mouse brains ex vivo. Brain image data from patients with cerebral hematoma and multiple sclerosis further illustrated the superiority of this method in reducing streaking artifacts caused by large susceptibility sources, whilst maintaining sharp anatomical details. STAR-QSM is implemented in STI Suite, a comprehensive shareware for susceptibility imaging and quantification. PMID:26313885

  3. 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 LC many of the...

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

    Science.gov (United States)

    Quevedo, H. J.; McCormick, M.; Wisher, M.; Bengtson, Roger D.; Ditmire, T.

    2016-01-01

    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.

  5. Large dynamic range femtosecond soft X-ray streak image tube

    International Nuclear Information System (INIS)

    The research of inertial confinement fusion demands a streak image tube with femtosecond temporal resolution and large dynamic range. In order to obtain a setup in the practical application, a novel soft X-ray streak image tube was proposed and designed. A planar symmetric electrostatic cylindrical lens with five electrodes was introduced into the image tube model, which has a strong ability to focus the electron beam, and has no cross-over effects as in the axial-symmetrical system. The cylindrical lens can shorten the length of image tube, reduce the transit time dispersion, and restrain space charge effects, thus enlarging the dynamic range and improving the temporal resolution. The simulation results show that if the photoelectron's initial energy spread is 1.6 eV, and the slit area is 10 mm × 20 μm, the useful dynamic range of 100 is obtained with 500 fs temporal resolution. (authors)

  6. 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

  7. 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

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

    International Nuclear Information System (INIS)

    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

  9. 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.

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

    International Nuclear Information System (INIS)

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

  11. 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.

  12. P 600/650 X-ray streak camera with optimized spatio-temporal resolution

    International Nuclear Information System (INIS)

    This paper presents the latest performances of the P 600 X-ray streak camera designed for laser fusion experiments. It reaches very high performances in the 1.5 to 10 keV range: 16 to 20 pl.mm-1 for the maximum sweep speed which corresponds to a 2 ps theoretical time resolution. We discuss its adaptation to the soft X-ray spectral range down to 100 eV

  13. 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...

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

    OpenAIRE

    Lee, Siwon; Kim, Jin-Ho; Choi, Ji-Young; Jang, Won-Cheoul

    2015-01-01

    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 scre...

  15. 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...

  16. 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...

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

    Science.gov (United States)

    Pei, Chengquan; Wu, Shengli; Tian, Jinshou; Liu, Zhen; Fang, Yuman; Gao, Guilong; Liang, Lingliang; Wen, Wenlong

    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.

  19. 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.

    2016-01-01

    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 21 nt 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

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

    Science.gov (United States)

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

    2014-06-24

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

  1. Precise measurement of a subpicosecond electron single bunch by the femtosecond streak camera

    International Nuclear Information System (INIS)

    Precise measurement of a subpicosecond electron single bunch by the femtosecond streak camera is presented. The subpicosecond electron single bunch of energy 35 MeV was generated by the achromatic magnetic pulse compressor at the S-band linear accelerator of nuclear engineering research laboratory (NERL), University of Tokyo. The electric charge per bunch and beam size are 0.5 nC and the horizontal and vertical beam sizes are 3.3 and 5.5 mm (full width at half maximum; FWHM), respectively. Pulse shape of the electron single bunch is measured via Cherenkov radiation emitted in air by the femtosecond streak camera. Optical parameters of the optical measurement system were optimized based on much experiment and numerical analysis in order to achieve a subpicosecond time resolution. By using the optimized optical measurement system, the subpicosecond pulse shape, its variation for the differents rf phases in the accelerating tube, the jitter of the total system and the correlation between measured streak images and calculated longitudinal phase space distributions were precisely evaluated. This measurement system is going to be utilized in several subpicosecond analyses for radiation physics and chemistry. (orig.)

  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. 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

  4. Attosecond streaking of molecules in the low-energy region studied by a wavefunction splitting scheme

    International Nuclear Information System (INIS)

    We present a theoretical study of the low-energy photoelectron spectra of hydrogen molecular ion generated by a single attosecond pulse in the presence of an infrared (IR) laser field. In order to investigate this type of attosecond streaking of molecules, we developed a very efficient grid-based numerical method to solve the two-centre time-dependent Schrödinger equation (TDSE) in the prolate spheroidal coordinates. Specifically, the radial coordinate is discretized with the finite-element discrete variable representation (FE-DVR) for easy parallel computation and the angular coordinate with the usual DVR. A wavefunction splitting scheme is utilized to reduce the demanding requirement of the computational resource to solve the corresponding TDSE when an IR field is present. After verification of the accuracy and efficiency of our method, we then apply it to investigate the attosecond streaking spectra of H+2 in the low-energy region. In contrast to the usual attosecond streaking in the high-energy region, part of the low-energy electrons may be driven back to rescatter with the residual two-centre core. Very interesting interference structures are present in the low-energy region. When the internuclear distance is small, they are very similar to what we have recently observed in the atomic case. (paper)

  5. 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

  6. 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.

  7. 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...

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. A sampling ultra-high-speed streak camera based on the use of a unique photomultiplier

    International Nuclear Information System (INIS)

    An apparatus reproducing the ''streak'' mode of a high-speed camera is proposed for the case of a slit AB whose variations in luminosity are repetitive. A photomultiplier, analysing the object AB point by point, and a still camera, photographing a slit fixed on the oscilloscope screen parallel to the sweep direction are placed on a mobile platform P. The movement of P assures a time-resolved analysis of AB. The resolution is of the order of 2.10-9 s, and can be improved

  13. Calibration data processing of streak camera with nonlinear-least-squares method

    International Nuclear Information System (INIS)

    The result of full-screen sweeping rates of streak camera(SC) is obtained using a nonlinear-least-squares method. The uncertainty of this method is about 0.04%, far below SC's systematic uncertainty. Full-screen result eliminates nonlinearity and space-distortion of sweeping rates, minimizes the error of SC's measurement to about 1.5%.The robustness and time-efficiency of this method make full-screen calibration of time-domain and space-domain feasible. (authors)

  14. 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.

  15. 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 ...

  16. 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...

  17. 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.

  18. Fiber scintillator/streak camera detector for burn history measurement in inertial confinement fusion experiment

    International Nuclear Information System (INIS)

    To measure the burn history in an inertial confinement fusion experiment, we have developed a new neutron detector based on plastic scintillation fibers. Twenty-five fiber scintillators were arranged in a geometry compensation configuration by which the time-of-flight difference of the neutrons is compensated by the transit time difference of light passing through the fibers. Each fiber scintillator is spliced individually to an ultraviolet optical fiber that is coupled to a streak camera. We have demonstrated a significant improvement of sensitivity compared with the usual bulk scintillator coupled to a bundle of the same ultraviolet fibers. copyright 1997 American Institute of Physics

  19. Multislit streak camera investigation of plasma focus in the steady-state rundown phase

    International Nuclear Information System (INIS)

    The technique of multislit streak photography was applied to investigate the plasma focus in the steady-state run-down phase. This enabled the axial and radial positions, and the rundown velocity of the current-carrying plasma sheath to be measured simultaneously. From these measurements, the radial profile of the plasma sheath in the plasma focus tube could be reconstructed and the plasma current was calculated. These calculated currents represented about 70% of the total circuit current flowing out of the capacitor bank, and these agreed with earlier results which were obtained via computer simulations of the measured voltage and current waveforms

  20. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Shiraga, H.; Miyanaga, N.; Heya, M.; Nakasuji, M.; Aoki, Y.; Azechi, H.; Yamanaka, T.; Mima, K. [Institute of Laser Engineering, Osaka University, 2-6 Yamada-Oka, Suita, Osaka 565 (Japan)

    1997-01-01

    Ultrafast two-dimensional x-ray imaging is required for diagnosing laser-driven inertial confinement fusion plasmas. Image sampling technique with x-ray streak cameras can meet this requirement. Multi-imaging x-ray streak camera method (MIXS) with temporal and spatial resolutions of 10 ps and 15 {mu}m, respectively, has been developed and successfully utilized for diagnosing the uniformity and heating process of the imploded core plasmas. The two-dimensional sampling-image x-ray streak camera method is also presented. Two types of spectroscopic applications of the MIXS have been developed recently. One is multichannel MIXS, which has three MIXS channels with various spectral responses for time-resolved two-dimensional temperature measurement of the plasmas. Another is monochromatic MIXS for temperature, density, and mixing measurement, in which monochromatic images with Bragg crystals are coupled to MIXS. {copyright} {ital 1997 American Institute of Physics.}

  2. Picosecond-resolved X-ray absorption spectroscopy at low signal contrast using a hard X-ray streak camera

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Bernhard W.; Rose-Petruck, Christoph; Jiao, Yishuo

    2015-06-24

    A picosecond-resolving hard-X-ray streak camera has been in operation for several years at Sector 7 of the Advanced Photon Source (APS). Several upgrades have been implemented over the past few years to optimize integration into the beamline, reduce the timing jitter, and improve the signal-to-noise ratio. These include the development of X-ray optics for focusing the X-rays into the sample and the entrance slit of the streak camera, and measures to minimize the amount of laser light needed to generate the deflection-voltage ramp. For the latter, the photoconductive switch generating the deflection ramp was replaced with microwave power electronics. With these, the streak camera operates routinely at 88 MHz repetition rate, thus making it compatible with all of the APS fill patterns including use of all the X-rays in the 324-bunch mode. Sample data are shown to demonstrate the performance.

  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. 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.

  5. Remote control of a streak camera for real time bunch size measurement in LEP

    CERN Document Server

    Burns, A J; De Vries, J C

    1995-01-01

    A double sweep streak camera, built by industry according to CERN specifications, has been used for a number of years to provide real time three-dimensional measurements of bunches in LEP, by means of a dedicated synchrotron light source. Originally requiring local manipulation in an underground lab close to the LEP tunnel, the camera can now be fully operated via the control system network. Control functions, such as the adjustment of lens and mirror positions, the selection of camera weep speeds, and the setting of 12 ps resolution trigger timing, are handled by various networked VME systems, as is real time image processing. Bunch dimension averages are transferred every few seconds via the control system to the LEP measurement database, and a dedicated high bandwidth video transmission allows the streak camera images and processed results to be viewed in real time (at 25 Hz) in the LEP control room. Feedback control loops for light intensity, trigger timing and image tracking allow the setup to provide us...

  6. PS-1/S1 picosecond streak camera application for multichannel laser system diagnostics

    International Nuclear Information System (INIS)

    A PS-1/S1 picosecond image-tube streak camera (ITSC) with slit scan (streak camera), developed and manufactured at the General Physics Institute RAS, has been used to measure the spatiotemporal characteristics of ultrashort laser pulses generated by a petawatt-power laser installation 'FEMTO' at the Institute of Laser Physics Research in Sarov. It is found that such a camera is suitable for measuring the spatial and temporal parameters of single laser pulses with an accuracy of about one picosecond. It is shown that the intensity time profile of a train of picosecond pulses may be precisely defined for the pulses separated in time by a few picoseconds. The camera allows the contrast of radiation to be determined with a high (no less than 103) accuracy; spatial distribution of the laser pulses can be measured with an accuracy of tens of microns, and the temporal separation of single laser pulses can be identified with an accuracy of 1 – 1.5 ps. (extreme light fields and their applications)

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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...

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

    Science.gov (United States)

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

  14. 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...

  15. 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

  16. 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-...

  17. Temporal characterization of individual harmonics of an attosecond pulse train by THz streaking

    Science.gov (United States)

    Ardana-Lamas, F.; Erny, C.; Stepanov, A. G.; Gorgisyan, I.; Juranić, P.; Abela, R.; Hauri, C. P.

    2016-04-01

    We report on the temporal pulse characteristics of individual harmonics in an attosecond pulse train by means of photoelectron streaking in a strong low-frequency transient. The scheme allows one to retrieve the pulse durations and first-order chirp of individual harmonics without the need for temporal scanning. The measurements were performed using an intense THz field generated by a tilted phase front technique in LiNbO3. We compared the performance of Xe clusters and atomic He as a detection medium and retrieved the temporal properties for harmonics of order 19, 21, 23, 25, and 27. Our measurements confirm that the individual pulse durations and linear chirp decrease by harmonic order.

  18. Analysis of Unsteady Transonic Flow Fields by Means of the Colour Streak Schlieren Method

    Directory of Open Access Journals (Sweden)

    J. Ulrych

    2004-01-01

    Full Text Available This article deals with a new approach to the investigation of unsteady transonic flow fields around aerodynamic models and in blade cascades using a schlieren method of flow visualisation. The principle and the application of the Colour Streak Schlieren Method (CSSM are defined. The characteristic flow field features were observed and analysed around an oscillating NACA 0012 airfoil under the conditions of transonic free stream Mach number (M∞ = 0.9, initial angle of attack (α = +4 deg, one amplitude of oscillation (Δα=±3 deg, and three frequencies of model oscillation (f = 1, 15, 30 Hz. There is a description of the terminal shock wave hysteresis across the investigated area, which was revealed in particular cases. Application possibilities of CSSM and its further development are discussed.

  19. 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...

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

    Science.gov (United States)

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

    2010-01-01

    The authors describe a method to capture optical data and construct digitized streak images for analysis of high-speed phenomena with unpredictable timing by using a high-speed video camera and software routines. Advances in high-speed video camera technology have led to development of cameras with frame rates (1 x 10(6) frames per second) and spatial resolution (1280 x 800 pixels) suitable to capture fast phenomena, such as detonation in high explosives ( or = 1 s) are maintained in a rolling buffer in volatile memory allowing the entire frame sequence to be recorded pretrigger, thus obviating the need for precisely located diagnostic triggers. The method described was used to capture the progression of luminous reaction during the deflagration-to-detonation transition of the HMX-based (octahydro-1, 3, 5, 7-tetranitro-1, 3, 5, 7-tetrazocine) plastic bonded explosive (PBX) formulation during cookoff. PMID:20113140

  1. Pulsed versus direct current calibration of a proximity focused x-ray streak camera

    International Nuclear Information System (INIS)

    The absolute sensitivity of a proximity focused x-ray streak tube was measured with dc Henke tube x-ray line sources. Calibration covered the photon energy range from 0.930 to 8.05 keV at five points. These data were compared to a model of sensitivity based on photocathode response and matched the model well on a relative scale. A pulsed comparison was performed using a laser-plasma x-ray source. The calculated camera sensitivity was folded with the measured spectrum and compared to measured film exposures. The predicted exposures were 6.5 times less than the measured exposures, verifying concerns that the proximity focused tube response is nonlinear with flux at low, dc flux levels. Results of dc recalibrations that varied flux levels determined the extent of this phenomenon

  2. Absolutely calibrated soft-x-ray streak camera for laser-fusion applications

    International Nuclear Information System (INIS)

    The intensity output of a soft-x-ray streak camera was calibrated (SXRSC) in order to make absolute flux measurements of x rays emitted from laser-produced plasmas. The SXRSC developed at LLNL is used to time-resolve x-ray pulses to better than 20 ps. The SXRSC uses a Au photocathode on a thin carbon substrate which is sensitive to x rays from 100 eV to greater than 10 keV. Calibrations are done in the dynamic mode using a small laser-produced x-ray source. The SXRSC is calibrated by comparing its integrated signal to the output of calibrated x-ray diodes monitoring the source strength. The measured SXRSC response is linear over greater than two orders of magnitude. Using these calibrations, absolute intensities can be measured to an accuracy of +-30%

  3. Streaking Temporal Double-Slit Interference by an Orthogonal Two-Color Laser Field

    Science.gov (United States)

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

    2015-04-01

    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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. GPU-accelerated Faint Streak Detection for Uncued Surveillance of LEO

    Science.gov (United States)

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

    2013-09-01

    By astronomical standards, small objects (GGT), Inc. of Gilroy, CA, in collaboration with the University of New Mexico (UNM), is building two proof-of-concept wide-field imaging systems to test, develop and prove a novel streak detection technique. The imaging systems are built from off-the-shelf optics and detectors resulting in a 350mm aperture and a 6 square degree field of view. For streak detection, field of view is of critical importance because the maximum exposure time on the object is limited by its crossing time. In this way, wider fields of view impact surveys for LEO objects both by increasing the survey volume and increasing sensitivity. Using our newly GPU-accelerated detection scheme, the proof-of-concept systems are expected to be able to detect objects fainter than 12th magnitude moving at 1 degree per second and possibly as faint as 13th magnitude for slower moving objects. Meter-class optical systems using these techniques should be able to detect objects fainter than 14th magnitude, which is roughly equivalent to a golf ball at 1000km altitude. The goal of this work is to demonstrate a scalable system for near real time detection of fast moving objects that can be then handed off to other instruments capable of tracking and characterizing them. The two proof-of-concept systems, separated by ~30km, work together by taking simultaneous images of the same volume to constrain the orbits of detected objects using parallax measurements. These detections will then be followed-up by photometric observations taken at UNM to independently assess the objects and the quality of the derived orbits. We believe this will demonstrate the potential of small telescope arrays for detecting and cataloguing heretofore unknown LEO objects.

  10. Technique for in situ calibration of an x-ray streak camera in the nanosecond regime using a high density Z-pinch

    International Nuclear Information System (INIS)

    A technique for calibrating an x-ray streak camera in situ has been developed. It has been applied to an x-ray streak camera installed on a collapsing gas shell Z-pinch. The calibration was done by simultaneously measuring the emitted x-rays using a pinhole camera, an InP:Fe photoconductive detector, and the streak camera. The spatial dimension of the streak image was calibrated by integrating the film density over time and fitting the resulting data to the corresponding information taken from an x-ray pinhole image. The temporal calibration was obtained by similarly fitting the film density from the x-ray streak image as a function of time integrated over the appropriate part of the spatial dimension with the signal from an InP:Fe photoconductive detector. By using this technique we have found a spatial magnification of the streak camera system consistent with the results derived from the geometrical optics to within 10%. A temporal dispersion of 2.5 +- 0.5 ns/mm was obtained, which is in agreement with the nominal speed of 2.5 ns/mm. This technique also yielded an absolute intensity calibration of the streak camera

  11. 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

  12. Application of ps-streak camera in accelerator study. Measurement of longitudinal profile of electron-beam bunch

    International Nuclear Information System (INIS)

    The system for measurement of longitudinal profile of electron-beam bunch of electron accelerator with ps-streak camera has been constructed. Using this system, the length of electron-beam bunch have measured at Beijing Free Electron Laser Facility (BFEL) and Beijing Electron Positron Collider (BEPC) in Inst. of High Energy Physics of China Academy of Sciences, and Electron-Beam Injector for L-Band RF-Linac (LBINJ) in China Institute of Atomic Energy

  13. 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

  14. 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.

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

    International Nuclear Information System (INIS)

    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.

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

    Science.gov (United States)

    Wang, Fangquan; Li, Wenqi; Zhu, Jinyan; Fan, Fangjun; Wang, Jun; Zhong, Weigong; Wang, Ming-Bo; Liu, Qing; Zhu, Qian-Hao; Zhou, Tong; Lan, Ying; Zhou, Yijun; Yang, Jie

    2016-01-01

    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. PMID:27187354

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

    CERN Document Server

    Lumpkin, A H; Thurman-Keup, R; 10.1016/j.nima.2012.05.068

    2012-01-01

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

  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. 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

  20. 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}.

  1. 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.

  2. Optimized streak-camera system: wide excitation range and extended time scale for fluorescence lifetime measurement

    Science.gov (United States)

    Graf, Urs; Buehler, Christof; Betz, Michael; Zuber, Herbert; Anliker, M.

    1994-08-01

    A new versatile system for the measurement of time-resolved fluorescence emission spectra of biomolecules is presented. Frequency doubling and tripling of a Ti:Sapphire laser allows excitation over a wide wavelength range. The influence of increasing the spectral resolution on the time resolution has been investigated. System performance can be optimized for best resolution in the spectral or time domain, respectively. System performance can be optimized for best resolution in the spectral or time domain, respectively. The currently achieved temporal resolution is 6 psec, and the best spectral resolution is 3 nm. Long fluorescence decays can be resolved with optimal time resolution by way of taking into account the flyback of the streak camera. With the system described, the core complex ((alpha) (beta) )3APCLC8.9 of the phycobilisome from the photosynthetic cyanobacteria Mastigocladus laminosus has been analyzed. Lifetime analysis clearly demonstrated the influence of the linker polypeptide on the phycobiliprotein complex and the identity of native and reconstituted complex.

  3. 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

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

    International Nuclear Information System (INIS)

    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 (∼1.7 m from the target) would be ∼1.4e9/cm2. Previous measurements suggest the onset of significant background at a neutron fluence of ∼ 1e8/cm2. The radiation damage and operational upsets which starts at ∼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 ∼50

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

    Directory of Open Access Journals (Sweden)

    Varsani Arvind

    2008-09-01

    Full Text Available Abstract Background Recent reports have indicated that single-stranded DNA (ssDNA viruses in the taxonomic families Geminiviridae, Parvoviridae and Anellovirus may be evolving at rates of ~10-4 substitutions per site per year (subs/site/year. These evolution rates are similar to those of RNA viruses and are surprisingly high given that ssDNA virus replication involves host DNA polymerases with fidelities approximately 10 000 times greater than those of error-prone viral RNA polymerases. Although high ssDNA virus evolution rates were first suggested in evolution experiments involving the geminivirus maize streak virus (MSV, the evolution rate of this virus has never been accurately measured. Also, questions regarding both the mechanistic basis and adaptive value of high geminivirus mutation rates remain unanswered. Results We determined the short-term evolution rate of MSV using full genome analysis of virus populations initiated from cloned genomes. Three wild type viruses and three defective artificial chimaeric viruses were maintained in planta for up to five years and displayed evolution rates of between 7.4 × 10-4 and 7.9 × 10-4 subs/site/year. Conclusion These MSV evolution rates are within the ranges observed for other ssDNA viruses and RNA viruses. Although no obvious evidence of positive selection was detected, the uneven distribution of mutations within the defective virus genomes suggests that some of the changes may have been adaptive. We also observed inter-strand nucleotide substitution imbalances that are consistent with a recent proposal that high mutation rates in geminiviruses (and possibly ssDNA viruses in general may be due to mutagenic processes acting specifically on ssDNA molecules.

  8. Subpopulation level variation of banana streak viruses in India and common evolution of banana and sugarcane badnaviruses.

    Science.gov (United States)

    Sharma, Susheel Kumar; Vignesh Kumar, P; Geetanjali, A Swapna; Pun, Khem Bahadur; Baranwal, Virendra Kumar

    2015-06-01

    Genome sequences of three episomal Banana streak MY virus (BSMYV) isolates sampled from triploid banana hybrids (Chini Champa: AAB; Malbhog: AAB and Monthan: ABB), grown in North-East and South India are reported in this study by sequence-independent improved rolling circle amplification (RCA). RCA coupled with restriction fragment length polymorphism revealed diverse restriction profiles of five BSMYV isolates. Nucleotide substitution rates of BSMYV subpopulation and Banana streak OL virus subpopulation was 7.13 × 10(-3) to 1.59 × 10(-2) and 2.65 × 10(-3) to 5.49 × 10(-3), respectively, for the different coding regions. Analysis of the genetic diversity of banana and sugarcane badnaviruses revealed a total of 32 unique recombination events among banana and sugarcane badnaviruses (inter BSV-SCBV), in addition to the extensive recombination with in banana streak viruses and sugarcane bacilliform viruses (intra-BSV and intra-SCBV). Many unique fragments were shown to contain similar ruminant sequence fragments which indicated the possibility that the two groups of badnaviruses or their ancestors to colonise same host before making the host shift. The distribution of recombination events, hot-spots (intergenic region and C-terminal of ORF3) as well as cold-spots (distributed in ORF3) displayed the mirroring of recombination traces in both group of badnaviruses. These results support the hypothesis of relatedness of banana and sugarcane badnaviruses and the host and geographical shifts that followed the fixation of the species complex appear to be a recent event. PMID:25672291

  9. 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

  10. Motility and fertility of the subtropical freshwater fish streaked prochilod (Prochilodus lineatus) sperm cryopreserved in powdered coconut water.

    Science.gov (United States)

    Viveiros, A T M; Nascimento, A F; Orfão, L H; Isaú, Z A

    2010-09-01

    Streaked prochilod (Prochilodus lineatus) is a freshwater fish inhabiting many South American rivers. The objective was to determine the effectiveness of coconut water (ACP), combined with methylglycol, as a freezing medium for streaked prochilod sperm. A secondary objective was to compare a computer-assisted sperm analyzer (CASA) system versus subjective microscropic examination as a means of assessing sperm motility. As a control, glucose and methylglycol was used, according to our previous study. Sperm diluted in each medium was loaded into 0.5 mL straws, frozen in liquid nitrogen vapor (in a dry shipper), and stored in liquid nitrogen (-196 degrees C). Half of the samples were evaluated for sperm motility, both subjectively and with CASA; the remainder were evaluated for fertility. There was no difference (P > 0.05) between subjective or CASA assessment of post-thaw sperm motility. Although sperm motility was higher in sperm cryopreserved in ACP (85%) than in glucose (75%), cryopreservation in either extender yielded similar fertilization rates (46-48%) and sperm velocities. There were positive correlations (r = 0.56-0.8) between all sperm velocities and fertilization rate. In conclusion, streaked prochilod sperm cryopreserved in glucose or ACP and methylglycol was fertile, and thus could be used for research or commercial settings. Furthermore, although the CASA system provided objective data regarding sperm motility, in the present study, subjective evaluation of sperm motility was practical and a good indication of sperm quality; it could readily be done by well-trained personnel under field or laboratory conditions. PMID:20494428

  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. Sequence Analysis of Segments 8 and 10 of Rice black-streaked dwarf virus from Maize Plants

    OpenAIRE

    Bong Choon Lee; Sang-Yun Cho; Young-Nam Yoon; In Jeong Kang; Do Yeon Kwak; Dong Bum Shin; Hang-Won Kang

    2012-01-01

    Rice black-streaked dwarf virus (RBSDV) was reported to occur on maize plants in Gochang-gun ofJeonllabuk-do region in 2011. The symptoms typically include stunted and deformed leaves. Virus infectedplants usually produce poor or no head. RT-PCR analysis of genomic dsRNA extracted from the plantconfirmed the infection. Specific primers for full length genome of segments 8 and 10 were used for RNAamplification. Full-length genomes of S8 and S10 were cloned and sequenced. Sequence analysis reve...

  13. 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.

  14. 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

  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. 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.

  17. 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

  18. 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) ...

  19. 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.

    2016-01-01

    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 21–24 nt vsRNAs was detected and mapped, covering the entire CBSV and UCBSV genomes. The 21 nt 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

  20. Evaluation of the LLNL Spectrometer for Possible use with the NSTec Optical Streak Camera as a Light Gas Gun Diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    O' Connor, J., Cradick, J.

    2012-09-27

    In fiscal year 2012, it was desired to combine a visible spectrometer with a streak camera to form a diagnostic system for recording time-resolved spectra generated in light gas gun experiments. Acquiring a new spectrometer was an option, but it was possible to borrow an existing unit for a period of months, which would be sufficient to evaluate both “off-line” and in-gas gun shots. If it proved adequate for this application, it could be duplicated (with possible modifications); if not, such testing would help determine needed specifications for another model. This report describes the evaluation of the spectrometer (separately and combined with the NSTec LO streak camera) for this purpose. Spectral and temporal resolutions were of primary interest. The first was measured with a monochromatic laser input. The second was ascertained by the combination of the spectrometer’s spatial resolution in the time-dispersive direction and the streak camera’s intrinsic temporal resolution. System responsivity was also important, and this was investigated by measuring the response of the spectrometer/camera system to black body input—the gas gun experiments are expected to be similar to a 3000K black body—as well as measuring the throughput of the spectrometer separately over a range of visible light provided by a monochromator. The flat field (in wavelength) was also measured and the final part of the evaluation was actual fielding on two gas gun shots. No firm specifications for spectral or temporal resolution were defined precisely, but these were desired to be in the 1–2 nm and 1–2 ns ranges, respectively, if possible. As seen below, these values were met or nearly met, depending on wavelength. Other performance parameters were also not given (threshold requirements) but the evaluations performed with laser, black body, and successful gas gun shots taken in aggregate indicate that the spectrometer is adequate for this purpose. Even still, some (relatively

  1. 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...

  2. Effects of single and double infections of winter wheat by Triticum mosaic virus and Wheat streak mosaic virus on yield determinants

    Science.gov (United States)

    Triticum mosaic virus (TriMV) is a recently discovered virus infecting wheat (Triticum aestivum L.) in the Great Plains region of the United States. It is transmitted by wheat curl mites (Aceria tosichella Keifer) which also transmit Wheat streak mosaic virus (WSMV) and Wheat mosaic virus. In a gree...

  3. 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

  4. Time and wavelength-resolved luminescence evaluation of several types of scintillators using streak camera system equipped with pulsed X-ray source

    Czech Academy of Sciences Publication Activity Database

    Furuya, Y.; Yanagida, T.; Fujimoto, Y.; Yokota, Y.; Kamada, K.; Kawaguchi, N.; Ishizu, S.; Uchiyama, K.; Mori, K.; Kitano, K.; Nikl, Martin; Yoshikawa, A.

    2011-01-01

    Roč. 634, č. 1 (2011), s. 59-63. ISSN 0168-9002 Institutional research plan: CEZ:AV0Z10100521 Keywords : streak camera system * scintillator * pulsed X-ray source Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.207, year: 2011

  5. Evidence for different episodes of aeolian construction and a new type of wind streak in the 2016 ExoMars landing ellipse in Meridiani Planum, Mars

    Science.gov (United States)

    Silvestro, S.; Vaz, D. A.; Di Achille, G.; Popa, I. C.; Esposito, F.

    2015-04-01

    We present evidence for a complex, multigenerational bed form pattern and a new type of wind streak (the ripple streak) in the landing site ellipse of the 2016 ExoMars Entry descent and landing Demonstrator Module (EDM) in Meridiani Planum (Mars). We identified three main groups of bright-toned bed forms. Population 3, represented by NE-SW trending bed forms located inside craters, was emplaced by winds coming from the NW or the SE. Population 2, emplaced by strong easterlies, formed by intracrater transverse aeolian ridges (TARs) and N-S trending megaripples (plains ripples). Population 1 consists of a relict bed form pattern emplaced by winds coming from the north or south. Alternatively, population 1 can represent a sand ribbon pattern that formed together with the plain ripples. We also report the presence of a new type of wind streak, the ripple streak, which is formed by the population 2 bed forms clustered in the wake zone of impact craters. Based on the results of this work, we now know the EDM module is set to land in a complex aeolian environment. Data from the Dust Characterization, Risk Assessment, and Environment Analyser on the Martian Surface onboard the EDM can help to better decipher the wind regime in Meridiani Planum.

  6. Increased diet-induced fatty streak formation in female mice with deficiency of liver-derived insulin-like growth factor-I.

    Science.gov (United States)

    Svensson, Johan; Sjögren, Klara; Levin, Malin; Borén, Jan; Tivesten, Åsa; Ohlsson, Claes

    2016-06-01

    The role of endocrine IGF-I for atherosclerosis is unclear. We determined the importance of circulating, liver-derived IGF-I for fatty streak formation in mice. Mice with adult, liver-specific IGF-I inactivation (LI-IGF-I(-/-) mice, serum IGF-I reduced by approximately 80 %) and control mice received an atherogenic (modified Paigen) diet between 6 and 12 months of age. At study end, Oil Red O staining of aortic root cryosections showed increased fatty streak area and lipid deposition in female but not in male LI-IGF-I(-/-) mice compared to controls. Mac-2 staining of aortic root and measurements of CD68 mRNA level in femoral artery revealed increased macrophage accumulation in proportion to the increased fatty streak area in female LI-IGF-I(-/-) mice. Moreover, female LI-IGF-I(-/-) mice displayed increased serum cholesterol and interleukin-6 as well as increased vascular cell-adhesion molecule 1 (VCAM1) mRNA levels in the femoral artery and elevated VCAM1 protein expression in the aortic root. Thus, increased diet-induced fatty streak formation in female LI-IGF-I(-/-) mice was associated with increased serum cholesterol and signs of systemic inflammation, endothelial activation, lipid deposition, and macrophage infiltration in the vascular wall. PMID:26627099

  7. 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...

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

    Directory of Open Access Journals (Sweden)

    GuohuiZhou

    2013-09-01

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

  9. 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

  10. Light field driven streak-camera for single-shot measurements of the temporal profile of XUV-pulses from a free-electron laser

    International Nuclear Information System (INIS)

    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.)

  11. 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.

  12. 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

  13. 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

  14. 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...

  15. 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 ...

  16. Gated photocathode design for the P510 electron tube used in the National Ignition Facility (NIF) optical streak cameras

    Science.gov (United States)

    Datte, P.; James, G.; Celliers, P.; Kalantar, D.; Vergel de Dios, G.

    2015-08-01

    The optical streak cameras currently used at the National Ignition Facility (NIF) implement the P510 electron tube from Photonis1. The existing high voltage electronics provide DC bias voltages to the cathode, slot, and focusing electrodes. The sweep deflection plates are driven by a ramp voltage. This configuration has been very successful for the majority of measurements required at NIF. New experiments require that the photocathode be gated or blanked to reduce the effects of undesirable scattered light competing with low light level experimental data. The required ~2500V gate voltage is applied between the photocathode and the slot electrode in response to an external trigger to allow the electrons to flow. Otherwise the slot electrode is held approximately 100 Volts more negative than the potential of the photocathode, preventing electron flow. This article reviews the implementation and performance of the gating circuit that applies an electronic gate to the photocathode with a nominal 50ns rise and fall time, and a pulse width between 50ns and 2000ns.

  17. Streak Camera Studies of Vertical Synchro-Betatron-Coupled Electron Beam Motion in the APS Storage Ring

    CERN Document Server

    Yang Bing Xin; Guo, Weiming; Harkay, Katherine C; Sajaev, Vadim

    2005-01-01

    We present experimental studies of synchro-betatron-coupled electron beam motion in the Advanced Photon Source storage ring. We used a vertical kicker to start the beam motion. When the vertical chromaticity is nonzero, electrons with different initial synchrotron phases have slightly different betatron frequencies from the synchronous particle, resulting in a dramatic progression of bunch-shape distortion. Depending on the chromaticity and the time following the kick, images ranging from a simple vertical tilt in the bunch to more complicated twists and bends are seen with a visible light streak camera. Turn-by-turn beam position monitor data were taken as well. We found that the experimental observations are well described by the synchro-betatron-coupled equations of motion. We are investigating the potential of using the tilted bunch to generate picosecond x-ray pulses. Also note that the fast increase in vertical beam size after the kick is dominated by the internal synchro-betatron-coupled motion of the ...

  18. 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.

  19. 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.

  20. 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].

  1. 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.)

  2. 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

  3. 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

  4. Whole-genome expression analysis of Rice black-streaked dwarf virus in different plant hosts and small brown planthopper.

    Science.gov (United States)

    Xu, Qiufang; Ni, Haiping; Zhang, Jinfeng; Lan, Ying; Ren, Chunmei; Zhou, Yijun

    2015-11-10

    Rice black-streaked dwarf virus (RBSDV) can infect a number of gramineous plants and cause severe crop yield losses in southeast Asian countries. The virus is transmitted by small brown planthopper (SBPH) in a persistent circulative manner. The interactions between RBSDV and its different hosts remain unknown. Besides, how the virus adjusts itself to infect different hosts is unclear. In the present study, the relative RNA levels of the thirteen RBSDV genes in rice, maize, wheat, and SBPH were measured by real-time quantitative PCR. P7-1 and P10 genes were predominantly expressed whereas P8 and P7-2 genes were expressed at low levels in plant hosts. Similar to the expression in rice, P7-1 was the most abundantly expressed gene and P8 was expressed at the lowest level in SBPH, indicating that RBSDV adopts the same strategy to infect distinct hosts. The high expression levels of the P7-1 gene in both plants and insect suggest that it can be used as the target gene for disease diagnostics. However, the expression levels of some genes varied from host to host. P5-1, P6 and P9-1, the components of the RBSDV viroplasm, are differentially expressed in different hosts. Moreover, western blot analysis showed that the quantity of the P9-1 protein was more abundant in SBPH than in plant hosts. These data indicate that the virus may adjust its own gene expression to replicate in different hosts. Analysis of time course of gene expression revealed that P7-1 stands out as the only gene highly expressed at the earliest time point and its expression precedes all others throughout infection from 8 to 24days post-inoculation. The high expression levels of the P7-1 gene suggest that it plays a significant role in RBSDV-host interactions. PMID:26149652

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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

  10. Intravitreal bevacizumab in choroidal neovascularization secondary to Grönblad-Strandberg syndrome: case report Uso de bevacizumab intravítreo em neovascularização coroidiana secundária a síndrome de Grönblad-Strandberg: relato de caso

    OpenAIRE

    Ricardo Miguel Japiassú; Maria Augusta Castro Farias Japiassú; Mariana Gomes Pecego

    2008-01-01

    Angioid streaks are commonly related to Grönblad-Strandberg syndrome, that often shows dermatological characteristics, such as pseudoxanthoma elasticum. Choroidal neovascularization is uncommon, often occurring after ocular trauma. This is a case report of the successful use of intravitreal bevacizumab for the treatment of choroidal neovascularization secondary to Grönblad-Strandberg syndrome.As estrias angióides estão comumente relacionadas à síndrome de Grönblad-Strandberg, que se caracteri...

  11. Replication and encapsidation of the viroid-like satellite RNA of lucerne transient streak virus are supported in divergent hosts by cocksfoot mottle virus and turnip rosette virus.

    Science.gov (United States)

    Sehgal, O P; Sinha, R C; Gellatly, D L; Ivanov, I; AbouHaidar, M G

    1993-04-01

    Cocksfoot mottle sobemovirus supports replication and encapsidation of the viroid-like satellite RNA (sat-RNA) of lucerne transient streak virus (LTSV) in two monocotyledonous species, Triticum aestivum and Dactylis glomerata. Additionally, LTSV sat-RNA replicates effectively in the presence of turnip rosette sobemovirus in Brassica rapa, Raphanus raphanistrum and Sinapsis arvensis, but not in Thlaspi arvense or Nicotiana bigelovii, indicating that host species markedly influence this interaction. Previous reports of the association between LTSV sat-RNA and helper sobemoviruses were limited to dicotyledonous hosts. Our results demonstrate that the biological interaction between these two entities spans divergent dicotyledonous and monocotyledonous species. PMID:7682254

  12. Measurement of the components of the gas flow behind a shock front by streak photography of the spectrum of interference bands

    Energy Technology Data Exchange (ETDEWEB)

    Kharitonov, A.I.

    1994-12-01

    This article is the first of several in a continuing series on opticophysical methods for the investigation of inhomogeneities, begun in the preceding issue and in the journal Metrologiya, No. 4 (1994). Here a method is proposed for determining the composition of an ionized gas from data obtained in streak photography of interference fringes produced by oblique transmission of the sensing light beam across a shock front. The author gives a comparative estimation of the errors of the results in normal and oblique transmission of a monatomic gas flow containing singly charged ions.

  13. 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

  14. 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.

  15. Induction of primitive streak and mesendoderm formation in monolayer hESC culture by activation of TGF-β signaling pathway by Activin B

    OpenAIRE

    Mahmood, Amer; Aldahmash, Abdullah

    2015-01-01

    Human embryonic stem cells (hESCs) have the ability to differentiate into all human cells, however controlling the differentiation has always been a challenge. In the present study we have investigated the direct differentiation of hESCs on MEFs by using TGF-β signaling pathway activators Activin A and Activin B. Activation of the TGF-β pathway with Activin B in low serum highly induced primitive streak and mesendoderm formation after 24 h, which included up-regulation of SOX 17 and BRACHYURY...

  16. Development of miniaturized proximity focused streak tubes for visible light and x-ray applications. Final report and progress, April-September 1977

    International Nuclear Information System (INIS)

    Research performed to develop miniaturized proximity focused streak camera tubes (PFST) for application in the visible and the x-ray modes of operation is described. The objective of this research was to provide an engineering design and to fabricate a visible and an x-ray prototype tube to be provided to LASL for test and evaluation. Materials selection and fabrication procedures, particularly the joining of beryllium to a suitable support ring for use as the x-ray window, are described in detail. The visible and x-ray PFST's were successfully fabricated

  17. 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.

  18. 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.

  19. Induction of primitive streak and mesendoderm formation in monolayer hESC culture by activation of TGF-β signaling pathway by Activin B.

    Science.gov (United States)

    Mahmood, Amer; Aldahmash, Abdullah

    2015-11-01

    Human embryonic stem cells (hESCs) have the ability to differentiate into all human cells, however controlling the differentiation has always been a challenge. In the present study we have investigated the direct differentiation of hESCs on MEFs by using TGF-β signaling pathway activators Activin A and Activin B. Activation of the TGF-β pathway with Activin B in low serum highly induced primitive streak and mesendoderm formation after 24 h, which included up-regulation of SOX 17 and BRACHYURY protein and gene expression. Continuous stimulation with Activin B in 2% serum further induced mesendoderm formation by increased gene expression of Brachyury, SOX17, MEOX and FOX at the same time we found down-regulation of neuroectodermal marker genes. Further, by stimulating the mesodermal cells by BMP-2 we succeeded to induce mesenchymal like cells with high expression of mesenchymal markers including; MEOX, FOX, RUNX2, COL1 and OSTEOPONTIN. In conclusion we have directed the differentiation of hESCs as monolayer to primitive streak like cells with Activin B and further into pure mesoderm and mesenchymal like cells by BMP-2. PMID:26586995

  20. 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...

  1. 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.

  2. 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.

  3. Characterization of rice black-streaked dwarf virus- and rice stripe virus-derived siRNAs in singly and doubly infected insect vector Laodelphax striatellus.

    Directory of Open Access Journals (Sweden)

    Junmin Li

    Full Text Available Replication of RNA viruses in insect cells triggers an antiviral defense that is mediated by RNA interference (RNAi which generates viral-derived small interfering RNAs (siRNAs. However, it is not known whether an antiviral RNAi response is also induced in insects by reoviruses, whose double-stranded RNA genome replication is thought to occur within core particles. Deep sequencing of small RNAs showed that when the small brown planthopper (Laodelphax striatellus was infected by Rice black-streaked dwarf virus (RBSDV (Reoviridae; Fijivirus, more viral-derived siRNAs accumulated than when the vector insect was infected by Rice stripe virus (RSV, a negative single-stranded RNA virus. RBSDV siRNAs were predominantly 21 and 22 nucleotides long and there were almost equal numbers of positive and negative sense. RBSDV siRNAs were frequently generated from hotspots in the 5'- and 3'-terminal regions of viral genome segments but these hotspots were not associated with any predicted RNA secondary structures. Under laboratory condition, L. striatellus can be infected simultaneously with RBSDV and RSV. Double infection enhanced the accumulation of particular genome segments but not viral coat protein of RBSDV and correlated with an increase in the abundance of siRNAs derived from RBSDV. The results of this study suggest that reovirus replication in its insect vector potentially induces an RNAi-mediated antiviral response.

  4. Population structure within lineages of Wheat streak mosaic virus derived from a common founding event exhibits stochastic variation inconsistent with the deterministic quasi-species model

    International Nuclear Information System (INIS)

    Structure of Wheat streak mosaic virus (WSMV) populations derived from a common founding event and subjected to serial passage at high multiplicity of infection (MOI) was evaluated. The founding population was generated by limiting dilution inoculation. Lineages of known pedigree were sampled at passage 9 (two populations) and at passage 15, with (three populations) or without mixing (four populations) of lineages at passage 10. Polymorphism within each population was assessed by sequencing 17-21 clones containing a 1371 nt region (WSMV-Sidney 81 nts 8001-9371) encompassing the entire coat protein cistron and flanking regions. Mutation frequency averaged ∼5.0 x 10-4/nt across all populations and ranged from 2.4 to 11.6 x 10-4/nt within populations, but did not consistently increase or decrease with the number of passages removed from the founding population. Shared substitutions (19 nonsynonymous, 10 synonymous, and 3 noncoding) occurred at 32 sites among 44 haplotypes. Only four substitutions became fixed (frequency = 100%) within a population and nearly one third (10/32) never achieved a frequency of 10% or greater in any sampled population. Shared substitutions were randomly distributed with respect to genome position, with transitions outnumbering transversions 5.4:1 and a clear bias for A to G and U to C substitutions. Haplotype composition of each population was unique with complexity of each population varying unpredictably, in that the number and frequency of haplotypes within a lineage were not correlated with number of passages removed from the founding population or whether the population was derived from a single or mixed lineage. The simplest explanation is that plant virus lineages, even those propagated at high MOI, are subject to frequent, narrow genetic bottlenecks during systemic movement that result in low effective population size and stochastic changes in population structure upon serial passage

  5. 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

  6. Fine mapping of Msv1, a major QTL for resistance to Maize Streak Virus leads to development of production markers for breeding pipelines.

    Science.gov (United States)

    Nair, Sudha K; Babu, Raman; Magorokosho, Cosmos; Mahuku, George; Semagn, Kassa; Beyene, Yoseph; Das, Biswanath; Makumbi, Dan; Lava Kumar, P; Olsen, Michael; Boddupalli, Prasanna M

    2015-09-01

    Msv1 , the major QTL for MSV resistance was delimited to an interval of 0.87 cM on chromosome 1 at 87 Mb and production markers with high prediction accuracy were developed. Maize streak virus (MSV) disease is a devastating disease in the Sub-Saharan Africa (SSA), which causes significant yield loss in maize. Resistance to MSV has previously been mapped to a major QTL (Msv1) on chromosome 1 that is germplasm and environment independent and to several minor loci elsewhere in the genome. In this study, Msv1 was fine-mapped through QTL isogenic recombinant strategy using a large F 2 population of CML206 × CML312 to an interval of 0.87 cM on chromosome 1. Genome-wide association study was conducted in the DTMA (Drought Tolerant Maize for Africa)-Association mapping panel with 278 tropical/sub-tropical breeding lines from CIMMYT using the high-density genotyping-by-sequencing (GBS) markers. This study identified 19 SNPs in the region between 82 and 93 Mb on chromosome 1(B73 RefGen_V2) at a P trend regression identified a haplotype block significantly associated with response to MSV. Three SNPs in this haplotype block at 87 Mb on chromosome 1 had an accuracy of 0.94 in predicting the disease reaction in a collection of breeding lines with known responses to MSV infection. In two biparental populations, selection for resistant Msv1 haplotype demonstrated a reduction of 1.03-1.39 units on a rating scale of 1-5, compared to the susceptible haplotype. High-throughput KASP assays have been developed for these three SNPs to enable routine marker screening in the breeding pipeline for MSV resistance. PMID:26081946

  7. Improving In Vivo High-Resolution CT Imaging of the Tumour Vasculature in Xenograft Mouse Models through Reduction of Motion and Bone-Streak Artefacts.

    Directory of Open Access Journals (Sweden)

    Veerle Kersemans

    Full Text Available Preclinical in vivo CT is commonly used to visualise vessels at a macroscopic scale. However, it is prone to many artefacts which can degrade the quality of CT images significantly. Although some artefacts can be partially corrected for during image processing, they are best avoided during acquisition. Here, a novel imaging cradle and tumour holder was designed to maximise CT resolution. This approach was used to improve preclinical in vivo imaging of the tumour vasculature.A custom built cradle containing a tumour holder was developed and fix-mounted to the CT system gantry to avoid artefacts arising from scanner vibrations and out-of-field sample positioning. The tumour holder separated the tumour from bones along the axis of rotation of the CT scanner to avoid bone-streaking. It also kept the tumour stationary and insensitive to respiratory motion. System performance was evaluated in terms of tumour immobilisation and reduction of motion and bone artefacts. Pre- and post-contrast CT followed by sequential DCE-MRI of the tumour vasculature in xenograft transplanted mice was performed to confirm vessel patency and demonstrate the multimodal capacity of the new cradle. Vessel characteristics such as diameter, and branching were quantified.Image artefacts originating from bones and out-of-field sample positioning were avoided whilst those resulting from motions were reduced significantly, thereby maximising the resolution that can be achieved with CT imaging in vivo. Tumour vessels ≥ 77 μm could be resolved and blood flow to the tumour remained functional. The diameter of each tumour vessel was determined and plotted as histograms and vessel branching maps were created. Multimodal imaging using this cradle assembly was preserved and demonstrated.The presented imaging workflow minimised image artefacts arising from scanner induced vibrations, respiratory motion and radiopaque structures and enabled in vivo CT imaging and quantitative analysis

  8. Prevalence of reticular pseudodrusen in newly presenting adult onset foveomacular vitelliform dystrophy.

    Science.gov (United States)

    Wilde, C; Lakshmanan, A; Patel, M; Morales, M U; Dhar-Munshi, S; Amoaku, W M K

    2016-06-01

    PurposeTo report the association and prevalence of reticular pseudodrusen (RPD) in eyes with newly presenting adult onset foveomacular vitelliform dystrophy (AFVD). To compare the strength of association with other pathologies resulting from dysfunction of the choroid-Bruch's membrane-retinal pigment epithelium (RPE) complex, including eyes with geographic atrophy (GA) and angioid streaks.MethodsRetrospective single-centre review of all consecutive newly presenting AFVD. Multimodal imaging with spectral domain optical coherence tomography, fundus photographs, red-free/blue light images, and fundus fluorescein angiograms were graded for the presence of RPD. For comparison, all consecutive newly presenting cases of GA and eyes with angioid streaks were studied.ResultsFifteen (15) patients were identified with AFVD (mean age of 77.3 years; 73.3% female). Mean age of patients with AFVD and RPD was 80.5 years (SD 3.7), whereas that of patients with AFVD without RPD was 75.1 years (SD 7.0). This age difference did not reach statistical significance, P=0.1. Six (40%) had identifiable RPD; being a bilateral finding in 100% of patients. No males with AFVD and RPD were identified. A total of 92 eyes presented with GA. Twenty-three (23) of these (25.0%) had RPD. Twelve (12) patients presented with identifiable angioid streaks, with 4 (36.4%) having RPD.ConclusionRPD are a frequent finding in eyes with newly presenting AFVD; not being restricted to AMD, but a finding common among diseases where pathophysiological mechanisms involve damage to Bruch's membrane and the RPE, whether genetic or degenerative. Our study supports the concept that they occur with high but variable frequencies in eyes with various pathologies. PMID:27034200

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. 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

  16. Imaging of tumoral calcinosis: New observations

    International Nuclear Information System (INIS)

    Tumoral calcinosis (TC) is a hereditary metabolic bone disease characterized by hyperphosphatemia, elevated 1-25 dihydorxy vitamin D, and the presence of particular soft-tissue masses. Less well-known manifestations include a unique dental lesion, a bone marrow process, and an association with angioid streaks. Four members of two different kindreds with a total of 11 particular masses, two dental lesions, and three bone marrow processes were evaluated with radiography, bone scintigraphy, CT, and MR imaging. The radiologic manifestations of TC depend on pathologic calcification of particular, marrow, and dental tissue. The appearance of these calcifications on different radiologic modalities is characteristic, and the combination of these findings is unique for TC

  17. Intravitreal bevacizumab in choroidal neovascularization secondary to Grönblad-Strandberg syndrome: case report Uso de bevacizumab intravítreo em neovascularização coroidiana secundária a síndrome de Grönblad-Strandberg: relato de caso

    Directory of Open Access Journals (Sweden)

    Ricardo Miguel Japiassú

    2008-06-01

    Full Text Available Angioid streaks are commonly related to Grönblad-Strandberg syndrome, that often shows dermatological characteristics, such as pseudoxanthoma elasticum. Choroidal neovascularization is uncommon, often occurring after ocular trauma. This is a case report of the successful use of intravitreal bevacizumab for the treatment of choroidal neovascularization secondary to Grönblad-Strandberg syndrome.As estrias angióides estão comumente relacionadas à síndrome de Grönblad-Strandberg, que se caracteriza ainda pela presença de alterações dermatológicas caracterizadas pelo pseudoxantoma elástico. A presença de neovascularização coroidiana nesses pacientes é incomum, ocorrendo geralmente após trauma ocular. Relatamos um caso de tratamento bem sucedido de neovascularização coroidiana secundária à síndrome de Grönblad-Strandberg com bevacizumab.

  18. Choroidal Neovascularization Secondary to Myopia, Infection and Inflammation.

    Science.gov (United States)

    Weber, Marissa L; Heier, Jeffrey S

    2016-01-01

    Choroidal neovascularization (CNV) is a significant cause of vision loss in all age groups. The most common cause of CNV is age-related macular degeneration (AMD). However, CNV can also occur as a secondary manifestation of various inherited and acquired conditions, including pathologic myopia, presumed ocular histoplasmosis syndrome, angioid streaks, and various hereditary, traumatic or inflammatory disorders. Fluorescein angiography and optical coherence tomography are useful tools in the diagnosis and evaluation of CNV. Treatment options are similar to those for CNV secondary to AMD, specifically anti-angiogenic therapy, but including laser photocoagulation, photodynamic therapy and surgery. Anti-angiogenic therapy has been associated with better visual outcomes than other treatment modalities and is now advocated as the first-line therapy for CNV secondary to myopia, infection and inflammation. PMID:26501802

  19. 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.

  20. 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。

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

    Science.gov (United States)

    Goral, Vedat; Demir, Dogan; Tuzun, Yekta; Keklikci, Ugur; Buyukbayram, Huseyin; Bayan, Kadim; Uyar, Asur

    2007-07-28

    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. PMID:17657851

  2. 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.

  3. Intravitreal avastin for choroidal neovascularization associated with stargardt-like retinal abnormalities in pseudoxanthoma elasticum

    Directory of Open Access Journals (Sweden)

    Querques Giuseppe

    2010-01-01

    Full Text Available The aim of the study was to describe a patient with pseudoxanthoma elasticum (PXE, showing Stargardt-like retinal abnormalities, who underwent treatment with intravitreal bevacizumab for subfoveal choroidal neovascularization (CNV of the right eye (RE. A 57-year-old woman with diagnosis of angioid streaks, retinal flecks, and chorioretinal Stargardt-like atrophy due to PXE was referred to our department for sudden decreased vision in her RE (20/160. Upon a complete ophthalmologic examination, including fluorescein angiography (FA, and optical coherence tomography (OCT, the patient was diagnosed with subfoveal CNV of the RE. Owing to the subfoveal localization of the CNV, the patient was submitted to intravitreal bevacizumab injection. At the 1-month follow-up, visual acuity (VA improved (20/40, and FA and OCT revealed the CNV closure. Twelve months after the treatment, the patient′s VA remained stable with no recurrence of active CNV. On the basis of our findings, a single intravitreal bevacizumab injection seems to induce total regression of CNV complicating PXE, in a patient showing Stargardt-like retinal abnormalities. Further investigations are required to confirm our results.

  4. 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.

  5. Radiation therapy for ocular choroidal neovascularization (phase I/II study): preliminary report

    International Nuclear Information System (INIS)

    Purpose/Objective: Choroidal neovascularization (CNV) is a major cause of severe loss of visual acuity in some ocular diseases such as age-related macular degeneration (ARMD) and angioid streaks. Laser photocoagulation has been used to treat patients with subfoveal neovascular lesions with well-demarcated boundaries. However, the treatment method is usually associated with a large decrease in visual acuity. Therefore, indications for this treatment are very limited. Recently, some investigators reported the effect of low dose irradiation on the sub retinal neovascular membranes in CNV. We conducted a Phase I/II study to determine the toxicity and efficacy of external photon beam radiotherapy in patients with CNV. Methods and Materials: Between April, 1994 and July, 1995, 36 patients with choroidal neovascularization (34 with ARMD and 2 with angioid streaks) were treated with radiation therapy. Treatment planning was performed using a CT simulator that enables real-time treatment planning from multiple CT slices. The clinical target volume that included the macula and optic disc received a dose of 10 Gy/5 fractions/1 week (first 18 eyes) or 20 Gy/10 fractions/2 weeks (last 18 eyes). All eyes were irradiated with a single lateral 6 MV photon beam, angled 10 degrees posteriorly to exclude the ipsilateral lens and the contralateral eye from the radiation field. The ipsilateral lens was irradiated with less than 10% of the total reference dose. The field size averaged 3.0 x 2.5 cm. Records of the 17 eyes with CNV referred to our hospital in 1993, which satisfied the eligibility criteria for this study, were retrospectively analyzed for comparison. Results: There was no significant acute morbidity. All patients were followed regularly by both ophthalmologists and radiation oncologists. Cataract formation after 1 year of the treatment was observed in one patient who had received a dose of 20 Gy. One patient who had received 20 Gy complained of transient dry-eye sensation

  6. PDT: special cases in front of legal regulations

    Science.gov (United States)

    Fischer, E.; Wegner, A.; Pfeiler, T.; Mertz, M.

    2002-10-01

    Introduction: The classic indication for photodynamic therapy (PDT) in ophthalmology is currently represented by classic subfoveal choroidal neovascularisation (CNV) due to age-related macular degeneration (AMD). PDT is a method, which almost selectively causes endothelial damage in neovascular lesions, followed by vascular occlusion and involution of the CNV. The mechanistic aspect suggests that non AMD-related choroidal neovascularisations might also benefit from PDT. PDT in AMD: Within the German health system, PDT indications follow the criteria based on the inclusion criteria of the TAP studies. For instance the CNV should be predominantly classic and located under the center of the foveal avascular zone. In the diagnosis and follow-up of exudative AMD, visual acuity measurements and fluorescein angiography are the established parameters. Retinal thickness analyzer (RTA) measurements might give further information. Before PDT, they show a significant retinal thickening due to intra- and subretinal exudation. Following PDT, early RTA follow-ups show a clear decrease in retinal thickening accompanies by increasing or stable acuity. PDT in CNV of other origins than AMD: New studies support a new spectrum of indications for PDT, hopefully leading to general cost reimbursement for patients. PDT should be viewed as a general method for vascular occlusion and does not represent a causal therapy for progressive exudative AMD. We present patients with CNV due to pathologic myopia, angioid streaks and POHS. Conclusion: The selective vascular occlusion caused by PDT, besides CNV associated with AMD and pathologic myopia, may also allow the treatment of choroidal neovascularisations based on other entities. Careful individual evaluation of those cases is recommended. Despite this wide array of possible indications, cost reimbursement has been limited to classic subfoveal CNV in AMD, although single case reimbursements in choroidal neovascular lesions due to pathologic

  7. Following the dynamics of matter with femtosecond precision using the X-ray streaking method.

    Science.gov (United States)

    David, C; Karvinen, P; Sikorski, M; Song, S; Vartiainen, I; Milne, C J; Mozzanica, A; Kayser, Y; Diaz, A; Mohacsi, I; Carini, G A; Herrmann, S; Färm, E; Ritala, M; Fritz, D M; Robert, A

    2015-01-01

    X-ray Free Electron Lasers (FELs) can produce extremely intense and very short pulses, down to below 10 femtoseconds (fs). Among the key applications are ultrafast time-resolved studies of dynamics of matter by observing responses to fast excitation pulses in a pump-probe manner. Detectors with sufficient time resolution for observing these processes are not available. Therefore, such experiments typically measure a sample's full dynamics by repeating multiple pump-probe cycles at different delay times. This conventional method assumes that the sample returns to an identical or very similar state after each cycle. Here we describe a novel approach that can provide a time trace of responses following a single excitation pulse, jitter-free, with fs timing precision. We demonstrate, in an X-ray diffraction experiment, how it can be applied to the investigation of ultrafast irreversible processes. PMID:25561027

  8. Classification of reticular pattern and streaks in dermoscopic images based on texture analysis.

    Science.gov (United States)

    Machado, Marlene; Pereira, Jorge; Fonseca-Pinto, Rui

    2015-10-01

    The early detection of melanoma is one of the greatest challenges in clinical practice of dermatology, and the reticular pattern is one of the most important dermoscopic structures to improve melanocytic lesion diagnosis. A texture-based approach is developed for the automatic detection of reticular patterns, whose output will assist clinical decision-making. Feature selection was based on the use of two algorithms by means of the classical graylevel co-occurrence matrix and Laws energy masks optimized on a set of 104 dermoscopy images. The AdaBoost (adaptive boosting) approach to machine learning was used within this strategy. Results suggest superiority of LEM for reticular pattern detection in dermoscopic images, achieving a sensitivity of 90.16% and a specificity of 86.67%. The use of automatic classification in dermoscopy to support clinicians is a strong tool to assist diagnosis; however, the use of automatic classification as a complementary tool in clinical routine requires algorithms with high levels of sensitivity and specificity. The results presented in this work will contribute to achieving this goal. PMID:26719848

  9. 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...

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

    OpenAIRE

    Rogers Stephanie M; Payton Mark; Allen Robert W; Melcher Ulrich; Carver Jesse; Fletcher Jacqueline

    2012-01-01

    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 enhancement...

  11. 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)

  12. 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

  13. 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...

  14. Suppression of the CT Beam Hardening Streak Artifact Using Predictive Correction on Detector Data

    OpenAIRE

    Stowe, John G.; Curran, Kathleen M

    2016-01-01

    The purpose of the research was to develop an automated program incorporating a predictive artifact correction technique (PACT) to correct for the signal deviations from metal beam hardening artifacts in Computed Tomography (CT) detector raw data. Thin-slice sequential CT scans were performed on a dosimetry head phantom using a Somatom Sensation 16 scanner to establish a ground truth image. Metal pins were then affixed to either side of the phantom at the three and nine o'clock positions to c...

  15. Gamete quality of streaked prochilod Prochilodus lineatus (Characiformes) after GnRHa and dopamine antagonist treatment.

    Science.gov (United States)

    Viveiros, Ana T M; Gonçalves, Antônio C S; Di Chiacchio, Isabela M; Nascimento, Ariane F; Romagosa, Elizabeth; Leal, Marcelo C

    2015-04-01

    The efficiency of Ovaprim™ salmon gonadotropin-releasing hormone agonist (GnRHa) and dopamine antagonist on the induction of spawning and spermiation in Prochilodus lineatus in comparison with the commonly used method using pituitary extract (PE) was evaluated. Females received PE at 0.5 + 5.0 mg/kg and Ovaprim™ at 0.05 + 0.45 ml/kg or at 0.125 + 0.375 ml/kg. All males received a first dose of PE at 0.4 mg/kg and then PE at 4.0 mg/kg or Ovaprim™ at 0.25 ml/kg. Oocyte, egg, larvae and sperm quality were evaluated. All females spawned and oocyte, egg and larvae quality were similar between Ovaprim™-treated (both doses) and PE-treated females. Data from females were pooled and the mean values were: 242 g ova weight, 15% ova index, 1209 oocytes/g ova, 284,539 oocytes/female, 183 oocytes/g body weight, 1.18 mm oocyte diameter, 49% fertilization rate, 43% hatching rate and 89% normal larvae. Sperm quality was similar between Ovaprim™-treated and PE-treated males. Data from males were pooled and the mean values of semen were: volume of 3.0 ml, 14.9 × 109 sperm/ml, osmolality of 283 mOsm/kg, pH of 7.4, 71% motile sperm, 217 μm/s curvilinear velocity, 102 μm/s straight-line velocity and 189 μm/s average path velocity. Ovaprim™ treatment can be used for commercial reproduction of P. lineatus, without any loss of gamete quality in comparison with PE treatment. PMID:24134911

  16. 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.

  17. Photocathodes based on semiconductor superlattices for streak tubes for IR region of 0.9-1.0 um

    Science.gov (United States)

    Nolle, Eduard L.

    1995-05-01

    A possibility of temporal analysis of picosecond light pulses in the IR region with the help of photocathodes based on semiconductor superlattices (SL) of type I (InP/InGaAs) with Schottky barrier is discussed. A new principle of avalanche photoelectron emission from such an SL at interband absorption of light is suggested. The principle is based on the electrons free length path increasing in a SL with narrow quantum wells under high electric field applied to the SL. The idea makes it possible to develop a new device - avalanche photocathode with internal amplification for the IR region of 0.9-2 micrometers and temporal resolution better than 30 ps. It is proposed to use doped as well as undoped SL as basis for photocathodes sensitive to the IR radiation in the range of up to 10 micrometers . The photoemission from such structures is caused by the intersubband absorption of light in quantum wells. The use of undoped SL greatly reduced the thermoemission current of the photocathode but requires additional excitation of the SL by light pulses with energy approximately corresponding to the band gap of the narrow band gap material of the SL. The temporal resolution of such photocathodes is supposed to be less than 30 ps. The conditions for the avalanche photoelectron emission obtaining are determined, and the SL parameters which meet the requirement of maximum quantum efficiency of the photocathode are calculated.

  18. 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...

  19. ‘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

  20. The P1 protein, not HC-Pro, of Wheat streak mosaic virus is a suppressor of RNA silencing

    Science.gov (United States)

    HC-Pro, a well-characterized multi-functional protein encoded by members of the genus Potyvirus, has been shown to be involved in aphid transmission, replication maintenance, systemic movement, and posttranscriptional gene silencing (PTGS) suppression, and to be a determinant of disease synergism in...

  1. 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

    required at these regions for PS gene activation. Furthermore, OCT4 binding in proximity to these sites is likewise required for PS induction, suggesting a collaborative interaction between b-catenin and OCT4. Induction of neural crest genes by b-catenin is repressed by SMAD2/SMAD3, ensuring proper lineage...

  2. Total Variation-Based Reduction of Streak Artifacts, Ring Artifacts and Noise in 3D Reconstruction from Optical Projection Tomography

    Czech Academy of Sciences Publication Activity Database

    Michálek, Jan

    2015-01-01

    Roč. 21, č. 6 (2015), s. 1602-1615. ISSN 1431-9276 R&D Projects: GA MŠk(CZ) LH13028; GA ČR(CZ) GA13-12412S Institutional support: RVO:67985823 Keywords : optical projection tomography * microscopy * artifacts * total variation * data mismatch Subject RIV: EA - Cell Biology Impact factor: 1.877, year: 2014

  3. Topical application of PPADS inhibits complement activation and choroidal neovascularization in a model of age-related macular degeneration.

    Directory of Open Access Journals (Sweden)

    Kerstin Birke

    Full Text Available Age-related macular degeneration (AMD is the most common cause of blindness among the elderly. AMD patients have elevated levels of membrane attack complex (MAC in their choroidal blood vessels and retinal pigment epithelium (RPE. MAC forms pores in cell membranes. Low levels of MAC result in an elevation of cytokine release such as vascular endothelial growth factor (VEGF that promotes the formation of choroidal neovascularization (CNV. High levels of MAC result in cell lysis and RPE degeneration is a hallmark of advanced AMD. The current standard of care for CNV associated with wet AMD is intravitreal injection of anti-VEGF molecules every 4 to 12 weeks. Such injections have significant side effects. Recently, it has been found that membrane pore-forming proteins such as α-haemolysin can mediate their toxic effects through auto- and paracrine signaling and that complement-induced lysis is amplified through ATP release followed by P2X receptor activation. We hypothesized that attenuation of P2X receptor activation may lead to a reduction in MAC deposition and consequent formation of CNV. Hence, in this study we investigated topical application of the purinergic P2X antagonist Pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS as a potential treatment for AMD. We found that 4.17 µM PPADS inhibited formation of HUVEC master junctions and master segments by 74.7%. In a human complement mediated cell lysis assay, 104 µM PPADS enabled almost complete protection of Hepa1c1c7 cells from 1% normal human serum mediated cell lysis. Daily topical application of 4.17 mM PPADS for 3 days attenuated the progression of laser induced CNV in mice by 41.8% and attenuated the deposition of MAC at the site of the laser injury by 19.7%. Our data have implications for the future treatment of AMD and potentially other ocular disorders involving CNV such as angioid streaks, choroidal rupture and high myopia.

  4. Genome-wide gene responses in a transgenic rice line carrying the maize resistance gene Rxo1 to the rice bacterial streak pathogen, Xanthomonas oryzae pv. oryzicola

    Directory of Open Access Journals (Sweden)

    Fu Bin-Ying

    2010-02-01

    Full Text Available Abstract Background Non-host resistance in rice to its bacterial pathogen, Xanthomonas oryzae pv. oryzicola (Xoc, mediated by a maize NBS-LRR type R gene, Rxo1 shows a typical hypersensitive reaction (HR phenotype, but the molecular mechanism(s underlying this type of non-host resistance remain largely unknown. Results A microarray experiment was performed to reveal the molecular mechanisms underlying HR of rice to Xoc mediated by Rxo1 using a pair of transgenic and non-transgenic rice lines. Our results indicated that Rxo1 appeared to function in the very early step of the interaction between rice and Xoc, and could specifically activate large numbers of genes involved in signaling pathways leading to HR and some basal defensive pathways such as SA and ET pathways. In the former case, Rxo1 appeared to differ from the typical host R genes in that it could lead to HR without activating NDR1. In the latter cases, Rxo1 was able to induce a unique group of WRKY TF genes and a large set of genes encoding PPR and RRM proteins that share the same G-box in their promoter regions with possible functions in post-transcriptional regulation. Conclusions In conclusion, Rxo1, like most host R genes, was able to trigger HR against Xoc in the heterologous rice plants by activating multiple defensive pathways related to HR, providing useful information on the evolution of plant resistance genes. Maize non-host resistance gene Rxo1 could trigger the pathogen-specific HR in heterologous rice, and ultimately leading to a localized programmed cell death which exhibits the characteristics consistent with those mediated by host resistance genes, but a number of genes encoding pentatricopeptide repeat and RNA recognition motif protein were found specifically up-regulated in the Rxo1 mediated disease resistance. These results add to our understanding the evolution of plant resistance genes.

  5. 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.

  6. 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...

  7. 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...

  8. 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.

  9. Streaked extreme ultraviolet imaging of the motion of low-Z foam buffered indirectly driven intermediate and high-Z payloads

    International Nuclear Information System (INIS)

    Results of experiments conducted at the Central Laser Facility (Rutherford Appleton Laboratory), illustrating the efficacy of utilizing a combination of transonic and subsonic ablation to increase the impulse delivered to an indirectly driven payload, are reported. Extreme ultraviolet imaging has been utilized to map the trajectory of the rear surface of an accelerating payload driven by a hohlraum with a peak energy-density-equivalent radiation temperature of around 130 eV. Payloads comprising an approximately 30-μm-thick solid-density plastic foil doped with chlorine, both with and without a gold flashing on the driver-facing surface, were accelerated by a combination of subsonic x-ray ablation of the rear surface of the payload and either subsonic, transonic, or supersonic ablation in a hohlraum facing low-density foam layer in intimate contact with the payload. Two different thicknesses of foam layer were incorporated in the experiment -- 150 and 200 μm -- in addition to a range of different foam densities from 30 to 100 mg/cc. It was observed that the maximum impulse was delivered in the case where the ablation wave propagation was approximately transonic in the foam layer. In such cases the impulse delivered to the payload was significantly greater than that achieved by direct (subsonic) ablation of the payload

  10. 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.

  11. 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.

  12. Pest risk assessment made by France on Banana streak virus (BSV) considered by France as harmful in French overseas departments of French Guiana, Guadeloupe, Martinique and Réunion - Scientific Opinion of the Panel on Plant Health

    OpenAIRE

    Baker, R; Caffier, D.; Choiseul, J.W.; De Clercq, P.; Dormannsne-Simon, E.; Gerowitt, B.; Karadjova, O.E.; Lövei, G.; Oude Lansink, A.; Makowski, David; Manceau, Charles; Manici, L.; Perdikis, D.; Porta Puglia, A.; Schans, J.

    2008-01-01

    Following a request from the European Commission, the Panel on Plant Health was asked to deliver a scientific opinion on 30 pest risk assessments made by France on organisms which are considered by France as harmful in four French overseas departments, i.e. French Guiana, Guadeloupe, Martinique and Réunion. In particular, the Panel was asked whether these organisms can be considered as harmful organisms for the endangered area of the above departments, in the meaning of the definition mention...

  13. 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.

  14. Practical issues of retrieving isolated attosecond pulses

    International Nuclear Information System (INIS)

    The attosecond streaking technique is used for the characterization of isolated extreme ultraviolet (XUV) attosecond pulses. This type of measurement suffers from low photoelectron counts in the streaked spectrogram, and is thus susceptible to shot noise. For the retrieval of few- or mono-cycle attosecond pulses, high-intensity streaking laser fields are required, which cause the energy spectrum of above-threshold ionized (ATI) electrons to overlap with that of the streaked photoelectrons. It is found by using the principal component generalized projections algorithm that the XUV attosecond pulse can accurately be retrieved for simulated and experimental spectrograms with a peak value of 50 or more photoelectron counts. Also, the minimum streaking intensity is found to be more than 50 times smaller than that required by the classical streaking camera for retrieval of pulses with a spectral bandwidth supporting 90 as transform-limited pulse durations. Furthermore, spatial variation of the streaking laser intensity, collection angle of streaked electrons and time delay jitter between the XUV pulse and streaking field can degrade the quality of the streaked spectrogram. We find that even when the XUV and streaking laser focal spots are comparable in size, the streaking electrons are collected from a 4π solid angle, or the delay fluctuates by more than the attosecond pulse duration, the attosecond pulses can still be accurately retrieved. In order to explain the insusceptibility of the streaked spectrogram to these factors, the linearity of the streaked spectrogram with respect to the streaking field is derived under the saddle point approximation.

  15. [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

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. 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.

  1. 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.

  2. Vacuum arc cathode spot parameters from high‐resolution luminosity measurements

    OpenAIRE

    Anders, A.; Anders, S.; Jüttner, B.; Pursch, H.; Bötticher, W.; Lück, H.

    1992-01-01

    Cathode spots on arc‐cleaned copper and molybdenum electrodes in vacuum were studied by fast image converter framing and streak camera photography with high temporal and spatial resolution. The frame exposure time was 20 ns and the interframe period was 200 ns; the streak sweep time was between 200 ns and 1 μs. Spatial structures with a resolution of 5 μm could be determined by observing the spot movement with a small slit at the streak camera and a high sweep speed. Strong fluctuations of th...

  3. 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

  4. 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.

  5. 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.

  6. 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...

  7. Proteus - Geology, shape, and catastrophic destruction

    Science.gov (United States)

    Croft, Steven K.

    1992-01-01

    Least-squares fits to the two available limb profiles of Proteus yield a sphericity close to unity; the visual irregularity is due to a degree of surface roughness comparable to that of Hyperion and the smaller icy satellites. A network of streaks that can be interpreted as tectonic troughs cuts the surface of Proteus, and is organized concentrically around either one of the two nearly-coincident Proteus-Neptune of Pharos axes of symmetry. If the streaks are tectonic, they may be due to tidal stresses generated by a past change in Proteus' equilibrium orientation. The streaks may also be disruptive-stress fractures.

  8. Willapa NWR: Initial Survey Instructions for Predator Management Efficacy Monitoring

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Pacific Coast populations of snowy plover and streaked horned lark species have been declining dramatically because of substantial habitat loss, human...

  9. 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 ...

  10. Fluoride in diet

    Science.gov (United States)

    ... broken through the gums have changes in the enamel that covers the teeth. Faint white lines or streaks may appear, but ... regarding fluoride intake from reconstituted infant formula and ... Dental Association Council on Scientific Affairs. J Am Dent ...

  11. 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...

  12. Neutron-induced noise in NIF-class diagnostic instruments

    International Nuclear Information System (INIS)

    Neutron yields form DT-filled ICF targets have reached 1014. Above 1013, a significant neutron-induced background appears in images recorded with nearby streak cameras. Since cameras components (streak tube, image-intensifier tube, and CCD array) are similar to components that will be used in many NIF instruments, streak camera images provide information about neutron-induced backgrounds that will be encountered in the NIF environment. At a fluence of 107 neutrons/cm2, the background consists of two distinct components: a uniform component equal to nearly 20% of the camera's linear range and sharp, intense peaks each localized to just a couple of image pixels. About 80% of the uniform background is caused by interactions with the streak tube and image-intensifier tube. Nearly all of the sharp spikes are caused by interactions with pixels of the CCD array. The spikes make the most significant contribution to image noise

  13. Experimental characterisation of a novel viscoelastic rectifier design

    DEFF Research Database (Denmark)

    Jensen, Kristian Ejlebjærg; Okkels, Fridolin; Szabo, Peter; Alves, M.A.

    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 ...

  14. 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....

  15. 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.

  16. 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.

  17. Personal computer (PC) based image processing applied to fluid mechanics research

    Science.gov (United States)

    Cho, Y.-C.; Mclachlan, B. G.

    1987-01-01

    A PC based image processing system was employed to determine the instantaneous velocity field of a two-dimensional unsteady flow. The flow was visualized using a suspension of seeding particles in water, and a laser sheet for illumination. With a finite time exposure, the particle motion was captured on a photograph as a pattern of streaks. The streak pattern was digitized and processsed using various imaging operations, including contrast manipulation, noise cleaning, filtering, statistical differencing, and thresholding. Information concerning the velocity was extracted from the enhanced image by measuring the length and orientation of the individual streaks. The fluid velocities deduced from the randomly distributed particle streaks were interpolated to obtain velocities at uniform grid points. For the interpolation a simple convolution technique with an adaptive Gaussian window was used. The results are compared with a numerical prediction by a Navier-Stokes commputation.

  18. Personal Computer (PC) based image processing applied to fluid mechanics

    Science.gov (United States)

    Cho, Y.-C.; Mclachlan, B. G.

    1987-01-01

    A PC based image processing system was employed to determine the instantaneous velocity field of a two-dimensional unsteady flow. The flow was visualized using a suspension of seeding particles in water, and a laser sheet for illumination. With a finite time exposure, the particle motion was captured on a photograph as a pattern of streaks. The streak pattern was digitized and processed using various imaging operations, including contrast manipulation, noise cleaning, filtering, statistical differencing, and thresholding. Information concerning the velocity was extracted from the enhanced image by measuring the length and orientation of the individual streaks. The fluid velocities deduced from the randomly distributed particle streaks were interpolated to obtain velocities at uniform grid points. For the interpolation a simple convolution technique with an adaptive Gaussian window was used. The results are compared with a numerical prediction by a Navier-Stokes computation.

  19. 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

  20. Uterine Fibroid Embolization

    Medline Plus

    Full Text Available ... syringe that he's injecting that looks just like water, it's relay filed with all these particles. Alex, ... done. You may want to point out the black streaks coming down from the top of the ...

  1. 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.

  2. 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

  3. 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....

  4. 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.

  5. Specification of germ layer identity in the chick gastrula

    OpenAIRE

    Cai Qin; Matsumoto Kiyoshi; Chapman Susan C; Schoenwolf Gary C

    2007-01-01

    Abstract Background Chick definitive endoderm is an important source of signals that pattern the early embryo forming a central structure around which the body plan is constructed. Although the origin of definitive endoderm has been mapped in the chick, arising principally from rostral streak at elongating streak stages, it is not known when this layer first becomes fully committed to its germ layer fate, an important issue to resolve in light of its critical role in subsequent patterning of ...

  6. Towards prevention and early diagnosis of skin cancer: computer-aided analysis of dermoscopy images

    OpenAIRE

    Sadeghi*, Maryam

    2012-01-01

    Melanoma, the deadliest form of skin cancer, must be diagnosed early for effective treatment. Irregular pigment network and streaks are important clues for melanoma diagnosis using dermoscopy images. This thesis describes novel image processing approaches for computer-aided pigment network and streaks detection on dermoscopy images. Our methods provide meaningful visualization of these structures, and extract features for irregularity detection. Additionally we present our efforts towards pre...

  7. 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).

  8. 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.

  9. Measurements at 351 nm of temporal dispersion in fibers

    International Nuclear Information System (INIS)

    1. Temporal dispersion at 351-nm was measured in the following: a 35-m bundle of 19 each 50-micro;m-core fibers, a companion 35-m single fiber, a 100- micro;m-core single fiber (at 4 lengths), and a 50-micro;m-core single fiber (two samples, 7 lengths). The 50-ampersand micro;m-core fiber was from preform number sign 24; the 100-ampersand micro;m-core fiber was a prototype version having a thick cladding. All of the fibers were developed and manufactured at the Vavilov State Optical Institute, St. Petersburg, Russia. 2. Dispersion measurements were made by propagating a 20-ps 351-nm pulse through the fiber under test and recording the output on an S20 streak camera. The width of the pulse transmitted by the fiber was compared to that of a fraction of the pulse that had propagated over an air path. Values of dispersion were calculated as, D = √(F ampersand sup2; - A ampersand sup2;) , where F and A are the full widths at half maximum (FWHM) for, respectively, the fiber-path and the air-path streaks. 3. In each of the experiments, the measured dispersion increased with counts in the streak record, which in principle, are proportional to intensity in the fiber. Measured values of dispersion ranged from about 0.6 to 1.0 ps/m for the single fibers. 4. The measured FWHMs of both the fiber-path pulse and the air-path pulse increased with increase in counts in the streak record. The rate of broadening was greatest for the fiber-path pulse, and the broadening of that pulse was the primary cause for the dependence of dispersion on counts in the streak record. Pulse broadening with increase in counts is symptomatic of camera saturation, but it is difficult to understand why saturation should have effected the fiber-path pulses more strongly. 5. There were spatial anomalies in the streak records of the output pulses from some of the fibers. Emission by the bundle of a ''doubled'' pulse is a primary example. In streaks recorded at about 800 counts, the total duration for the

  10. 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.

  11. 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...... emission of horseradish peroxidase A2 with streak camera shows that UV illumination induces an exponential change in the pre-exponential factors distribution associated to the protein's fluorescence lifetimes, leading to an exponential increase of the mean fluorescence lifetime. Illumination of aromatic...... such ultra-fast processes and how streak camera data can be correlated with protein structural changes. Udgivelsesdato: MAR 15...

  12. Post-hatching development of the porcine and bovine embryo-defining criteria for expected development in vivo and in vitro

    DEFF Research Database (Denmark)

    Vejlsted, Morten; Du, Yutao; Vajta, Gábor;

    2006-01-01

    following stages: (1)Expanded hatched blastocyst stage where the embryo presents an inner cell mass (ICM) covered by trophoblast. (2) Pre-streak stage 1 where the embryonic disc is formed. (3) Pre-streak stage 2 where a crescent-shaped thickening of the caudal portion of the embryonic disk appears. (4......) Somite stage(s) where paraxial mesoderm gradually condensates to form somites. Post-hatching development of bovine embryos in vitro is compromised and although hatching occurs and elongation can be physically provoked by culture in agarose tunnels, the embryonic disk characterizing the pre-streak stage 1......Particular attention has been paid to the pre-hatching period of embryonic development although blastocyst development is a poor indicator of embryo viability. Post-hatching embryonic dev elopment in vitro would allow for establishment of more accurate tools for evaluating developmental potential...

  13. 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.

  14. 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.

  15. 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.

  16. Diagnostics systems developments and applications for laser fusion experiments

    International Nuclear Information System (INIS)

    A variety of systems are required for adequate diagnostics of laser fusion experiments. Picosecond scale temporal measurements are typically made with ultrafast streak cameras. Visible and x-ray sensitive streak cameras with resolutions of 6 psec and 15 psec, respectively, and dynamic recording range in excess of 103 are in regular use on experiments at Livermore. The characteristics of these cameras and their applications to target experiment diagnostics are described. The development and testing of a prototype ultrafast framing system is discussed. Because of the need for ''real time'' data acquisition, analysis, and control systems, techniques for providing directly computer interfaced image data from streak and framing cameras and optical imaging systems are being developed. The status of these developments and the characteristics of the computer interfaced data and control systems on Argus and Shiva are summarized

  17. 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...

  18. A fiber optic array for continuous energy coverage in a gamma ray spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Cochran, C.W.; Kammeraad, J.E.; Sale, K.E.; Lown, J.G.; Robson, J.D. [Lawrence Livermore National Lab., CA (United States); Marroquin, J.P.; Sanchez, A. Jr. [EG and G Energy Measurements, Inc., Las Vegas, NV (United States)

    1992-07-01

    Optical fibers are being used to obtain full coverage over a range of energies in a multi-channel, time-resolved gamma ray spectrometer. Gamma rays are incident upon a beryllium foil 60cm from the entrance port of a Sm-Co magnet. Compton electrons from the foil are focussed according to their energy onto quartz optical fibers arrayed in close-packed configuration behind a low-Z vacuum window at the focal plane. Cerenkov radiation produced inside each of the fibers propagates down the fiber which is brought out of the magnet. Fibers are grouped into preselected energy bins corresponding to streak record channel assignments. The light from the fibers in an energy bin are combined into one signal and then transmitted to a streak camera with a specified number of channels. This unique optical fiber array serves both as the detector and as a means to define energy bins of our choosing for a streak camera recording system.

  19. Fiber optic array for continuous energy coverage in a gamma-ray spectrometer

    Science.gov (United States)

    Cochran, Curtis W.; Kammeraad, Judith E.; Sale, Kenneth E.; Lown, Joseph G.; Robson, Jack D.; Marroquin, John P.; Sanchez, Amadeo

    1992-12-01

    Optical fibers are being used to obtain full coverage over a range of energies in a multi- channel, time-resolved gamma ray spectrometer. Gamma rays are incident upon a beryllium foil 60 cm from the entrance port of a Sm-Co magnet. Compton electrons from the foil are focussed according to their energy onto quartz optical fibers arrayed in close-packed configuration behind a low-Z vacuum window at the focal plane. Cerenkov radiation produced inside each of the fibers propagates down the fiber which is brought out of the magnet. Fibers are grouped into preselected energy bins corresponding to streak record channel assignments. The light from the fibers in an energy bin are combined into one signal and then transmitted to a streak camera with a specified number of channels. This unique optical fiber array serves both as the detector and as a means to define energy bins of our choosing for a streak camera recording system.

  20. Nonlinear spectral signatures and spatiotemporal behavior of stimulated Raman scattering from single laser speckles.

    Science.gov (United States)

    Vu, H X; Yin, L; DuBois, D F; Bezzerides, B; Dodd, E S

    2005-12-01

    Simulations are reported of the Thomson scatter spectrum of electrostatic waves (ESWs) excited in single laser hot spots by backward stimulated Raman scattering (BSRS). Under conditions similar those in the recent experiments of Kline et al. [Phys. Rev. Lett. 94, 175003 (2005)], a spectral streak, resulting from the trapping-induced frequency shift of the ESW, is found for high wave-number ESWs, similar to the observations. This shift and parametric frequency matching lead to isolated BSRS pulses. Modes with acoustic dispersion, resulting from the trapping-modified electron velocity distribution, can enhance the frequency range of the streak. PMID:16384390

  1. The role of microtubule actin cross-linking factor 1 (MACF1) in the Wnt signaling pathway

    OpenAIRE

    Chen, Hui-Jye; Lin, Chung-Ming; Lin, Chyuan-Sheng; Perez-Olle, Raul; Leung, Conrad L.; Liem, Ronald K.H.

    2006-01-01

    MACF1 (microtubule actin cross-linking factor 1) is a multidomain protein that can associate with microfilaments and microtubules. We found that MACF1 was highly expressed in neuronal tissues and the foregut of embryonic day 8.5 (E8.5) embryos and the head fold and primitive streak of E7.5 embryos. MACF1−/− mice died at the gastrulation stage and displayed developmental retardation at E7.5 with defects in the formation of the primitive streak, node, and mesoderm. This phenotype was similar to...

  2. 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.

  3. 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

  4. AcEST: DK952814 [AcEST

    Lifescience Database Archive (English)

    Full Text Available TST38A01NGRL0015_B22 607 Adiantum capillus-veneris mRNA. clone: TST38A01NGRL0015_B22. 5' end seq ... .. 32 3.3 sp|P19898|VP10_RBSDV Protein S10 OS=Rice black ... streaked dwarf vi... 31 5.6 sp|Q8CP76|EBH_STAES Ex ... NEVP 464 >sp|P19898|VP10_RBSDV Protein S10 OS=Rice black ... streaked dwarf virus GN=S10 PE=4 SV=1 Length = 558 ...

  5. 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.

  6. 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.

  7. 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

  8. 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)

  9. Quench-free concentration measurements in high-temperature systems by picosecond LIF

    International Nuclear Information System (INIS)

    In the present work, a picosecond laser is used in conjunction with an intensified streak camera to study energy transfer processes in OH and to obtain quench-free results from the time-resolved spectra. Quantitative concentration profiles for OH and H are presented in a counterflow burner interacting with a vortex

  10. 49 CFR 213.337 - Defective rails.

    Science.gov (United States)

    2010-10-01

    ... crystalline center or nucleus inside the head from which it spreads outward as a smooth, bright, or dark... a smooth, bright, or dark surface progressing until substantially at a right angle to the length of... through it. A crack or rust streak may show under the head close to the web or pieces may be split off...

  11. High speed photography and photonics applications: An underutilized technology

    Energy Technology Data Exchange (ETDEWEB)

    Paisley, D.L. [Los Alamos National Laboratory, Los Alamos, New Mexico (United States)

    1996-10-01

    Snapshot: Paisley describes the development of high-speed photography including the role of streak cameras, fiber optics, and lasers. Progress in this field has created a powerful tool for viewing such ultrafast processes as hypersonic events and ballistics. {copyright} {ital 1996 Optical Society of America.} [1047-6938-96-10-9939-04

  12. 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...

  13. Identification of New Sources of Resistance to Xanthomonas translucens pv. undulosa in Winter Wheat

    Science.gov (United States)

    : Bacterial leaf streak (BLS) caused by Xanthomonas translucens pv. undulosa, has emerged as an important disease of wheat in the United States. Planting resistant varieties offers the best strategy to manage BLS in the absence of effective bactericides. However, most of the wheat varieties current...

  14. 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...

  15. Maximum entropy beam diagnostic tomography

    International Nuclear Information System (INIS)

    This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore

  16. 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...

  17. Complete Genome Sequence of the Alfalfa latent virus.

    Science.gov (United States)

    Nemchinov, Lev G; Shao, Jonathan; Postnikova, Olga A

    2015-01-01

    The first complete genome sequence of the Alfalfa latent carlavirus (ALV) was obtained by primer walking and Illumina RNA sequencing. The virus differs substantially from the Czech ALV isolate and the Pea streak virus isolate from Wisconsin. The absence of a clear nucleic acid-binding protein indicates ALV divergence from other carlaviruses. PMID:25883281

  18. Wnt3 function in the epiblast is required for the maintenance but not the initiation of gastrulation in mice.

    Science.gov (United States)

    Tortelote, Giovane G; Hernández-Hernández, J Manuel; Quaresma, Alexandre J C; Nickerson, Jeffrey A; Imbalzano, Anthony N; Rivera-Pérez, Jaime A

    2013-02-01

    The formation of the anteroposterior axis in mice requires a Wnt3-dependent symmetry-breaking event that leads to the formation of the primitive streak and gastrulation. Wnt3 is expressed sequentially in two distinct areas of the mouse embryo before the appearance of the primitive streak; first in the posterior visceral endoderm and soon after in the adjacent posterior epiblast. Hence, although an axial requirement for Wnt3 is well established, its temporal and tissue specific requirements remain an open question. Here, we report the conditional inactivation of Wnt3 in the epiblast of developing mouse embryos. Contrary to previous studies, our data shows that embryos lacking Wnt3 specifically in the epiblast are able to initiate gastrulation and advance to late primitive streak stages but fail to thrive and are resorbed by E9.5. At the molecular level, we provide evidence that Wnt3 regulates its own expression and that of other primitive streak markers via activation of the canonical Wnt signaling pathway. PMID:23085236

  19. 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...

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

    International Nuclear Information System (INIS)

    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.

  1. SR monitor system for the ATF Damping Ring

    International Nuclear Information System (INIS)

    Preliminary results of the synchrotron radiation (SR) monitor system developed for the Damping Ring of the accelerator test facility in Tsukuba-KEK (KEK-ATF-DR) are described; The system consists of a two dimensional CCD camera and a double-sweep streak camera for observing the vertical and longitudinal shapes of bunched beams, respectively. (author)

  2. 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.

  3. 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.

  4. 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 ...

  5. 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.

  6. 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

  7. 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

  8. Sub-picosecond bunch length measurement at the TESLA test facility

    International Nuclear Information System (INIS)

    Sub-picosecond electron bunches are required for the operation of future VUV and X-ray Free Electron Lasers. A streak camera, a Martin-Puplett interferometer and a longitudinal phase space rotation method have been applied at the TESLA Test Facility linac to measure electron bunch lengths

  9. 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)

  10. 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.

  11. Direct Numerical Simulation Sediment Transport in Horizontal Channel

    International Nuclear Information System (INIS)

    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

  12. 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.

  13. 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.

  14. 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

  15. Molecular markers linked to genes important for Hard Winter Wheat production and marketing in the U.S. Great Plains

    Science.gov (United States)

    Biotic stresses including diseases [leaf, stem and stripe rusts, and wheat streak mosaic virus (WSMV)] and insects [greenbug (GB), Hessian fly (Hf), Russian wheat aphid (RWA) and wheat curl mite (WCM)] significantly affect grain yield and end-use quality of hard winter wheat (HWW, Triticum aestivum ...

  16. 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 ...

  17. Tritimovirus P1 functions as a suppressor of RNA silencing and an enhancer of disease symptoms

    Science.gov (United States)

    Wheat streak mosaic virus (WSMV) is an eriophyid mite-transmitted virus of the genus Tritimovirus, family Potyviridae. Complete deletion of HC-Pro has no effect on WSMV virulence or disease synergism, suggesting that a different viral protein suppresses post-transcriptional gene silencing (PTGS). PT...

  18. Electron tubes and image intensifiers; Proceedings of the Meeting, San Jose, CA, Feb. 10, 11, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, C.B.; Laprade, B.N. (Litton Electron Devices, Tempe, AZ (United States) Galileo Electro-Optics Corp., Sturbridge, MA (United States))

    1992-01-01

    Various papers on electron tubes and image intensifiers are presented. Individual topics addressed include: high-performance LLTV CCD camera for nighttime pilotage, characterization and modelling of microchannel-plate intensified-CCD SNR variations with image size, high-resolution vidicon-based readout system for photon-counting streak camera applications, advancement in microchannel-plate technology, and fractal multifiber microchannel plates.

  19. Electron tubes and image intensifiers; Proceedings of the Meeting, San Jose, CA, Feb. 10, 11, 1992

    Science.gov (United States)

    Johnson, C. B.; Laprade, Bruce N.

    Various papers on electron tubes and image intensifiers are presented. Individual topics addressed include: high-performance LLTV CCD camera for nighttime pilotage, characterization and modelling of microchannel-plate intensified-CCD SNR variations with image size, high-resolution vidicon-based readout system for photon-counting streak camera applications, advancement in microchannel-plate technology, and fractal multifiber microchannel plates.

  20. 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…

  1. Elimination of five sugarcane viruses from sugarcane using in vitro culture of axillary bud and apical meristem

    Science.gov (United States)

    Procedures were developed for the in vitro elimination of Sugarcane mosaic virus (SCMV), Sorghum mosaic virus (SrMV), Sugarcane streak mosaic virus (SCSMV), Sugarcane yellow leaf virus (SCYLV) and Fiji disease virus (FDV) from infected sugarcane. In vitro shoot regeneration, elongation and virus el...

  2. 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)

  3. 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.

  4. About possible mechanism of generation of plasma points in plasma of multicharge ions of fast Z-pinch

    International Nuclear Information System (INIS)

    The results of streak camera research in the visible and x-ray ranges of wavelengths of explosion of thin aluminium wires on a high current generator with an amplitude about 200 kA and width of rise front about 50 ns are discussed. (author). 3 figs., 4 refs

  5. Characteristic bacteriolytic activities of Staphylococcus hyicus.

    OpenAIRE

    Lämmler, C.

    1989-01-01

    Staphylococcus hyicus demonstrated characteristic bacteriolytic activities towards a Micrococcus luteus reference strain. This lytic activity was demonstrated on medium containing M. luteus cells as large zones of transparency around the culture streak. Smaller zones of transparency were observed with Staphylococcus intermedius, Staphylococcus chromogenes, and some strains of Staphylococcus aureus but not with other coagulase-negative staphylococcal species. The distribution and extent of the...

  6. 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

  7. 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

  8. 77 FR 61937 - Endangered and Threatened Wildlife and Plants; Listing Taylor's Checkerspot Butterfly and...

    Science.gov (United States)

    2012-10-11

    ... projected and reasonably likely impacts of climate change on the Taylor's checkerspot butterfly and streaked... invasive plants; Predation; Inadequate existing regulatory mechanisms that allow significant threats such... Segments under the Endangered Species Act (61 FR 4722, February 7, 1996). (14) Whether we could improve...

  9. 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...

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. Specification of germ layer identity in the chick gastrula

    Directory of Open Access Journals (Sweden)

    Cai Qin

    2007-07-01

    Full Text Available Abstract Background Chick definitive endoderm is an important source of signals that pattern the early embryo forming a central structure around which the body plan is constructed. Although the origin of definitive endoderm has been mapped in the chick, arising principally from rostral streak at elongating streak stages, it is not known when this layer first becomes fully committed to its germ layer fate, an important issue to resolve in light of its critical role in subsequent patterning of the early embryo. Results Through gene expression screening of chick gastrula, we identified molecular markers of definitive endoderm restricted to rostral (Sox17 and caudal (Gata5/6 regions, suggesting that at least two subpopulations of definitive endodermal cells exist during ingression. We show (1 that presumptive mesoderm cells migrate to the middle layer and remain mesenchymal when transplanted to rostral primitive streak, and prospective endoderm cells enter the lower layer and become epithelial when transplanted to caudal primitive streak; and (2 that presumptive endoderm cells and mesoderm cells lose normal gene expression (Sox17 and Wnt8c, respectively when transplanted outside of their normal position of origin. Moreover, when rostral or caudal primitive streak segments are transplanted into rostral blastoderm isolates (RBIs, both types of transplants express Sox17 4–6 hours later–consistent with their new position, regardless of their presumptive germ layer origin–and prospective mesoderm transplants, which normally express Wnt8c, turn off expression, suggesting that signals within the rostral blastoderm induce endoderm gene expression, and repress mesoderm gene expression, during gastrulation. Conclusion Our results demonstrate that germ layer identity is fixed at the time populations of endoderm and mesoderm cells ingress through the primitive streak, whereas their gene expression patterns remain labile. In addition, our results show that

  15. Design of an Extreme Ultraviolet Spectrometer Suite for Isochoric-Heated Warm-Dense-Matter Studies

    Science.gov (United States)

    Ivancic, S.; Stillman, C. R.; Nilson, P. M.; Froula, D. H.

    2015-11-01

    An ultrafast streaked extreme ultraviolet (XUV) spectrometer (5 to 35 nm) is in development for the measurement of warm dense matter (WDM). In contrast to other forms of pyrometry where the temperature is inferred from bulk x-ray emission, XUV emission is restricted to the sample surface, allowing for the measurement of temperature at the material-vacuum interface. The measurement of the surface temperature is of particular importance in constraining models for the release of WDM. The divergence of surface and bulk temperature measurements may indicate gradients in temperature in the target. Coupling the XUV spectrometer to an ultrafast streak camera allows for the observation of picosecond time-scale evolution of the surface layer temperature. Two high-throughput XUV spectrometers are being designed to measure the time-resolved and absolute XUV emission. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  16. 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.

  17. 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

    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......-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...

  18. Picosecond-lidar thermometry in a measurement volume surrounded by highly scattering media

    International Nuclear Information System (INIS)

    In this work, a picosecond-lidar system, using a Nd:YAG picosecond laser, a Newtonian telescope and a streak camera, was used for single-ended furnace diagnostics. The optical access of the furnace was obstructed by a sooty diffusion ethylene flame. It was demonstrated that, with proper optical arrangement, the elastic scattering of the flame can be mapped in one dimension simultaneously as temperatures, up to 1200 K, are measured in the furnace using Rayleigh thermometry. Accumulated point temperature measurements as well as one- and two-dimensional measurements were conducted. A discussion about noise influence on accuracy and precision shows that measurements allowing a resolution of ∼6 cm are possible with a single-pixel temperature standard deviation of 91 K, while mapping soot scattering from the flame within the dynamic range of the streak camera, using 30 mJ pulse energy

  19. 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.

  20. Deformation nanotwins in coarse-grained aluminum alloy at ambient temperature and low strain rate

    International Nuclear Information System (INIS)

    In order to reveal the possible occurrence of deformation twins in coarse-grained aluminum/aluminum alloy at normal experimental conditions, a 5A02-O aluminum alloy with coarse grains was compressed quasi-statically to various plastic strains at ambient temperature, followed by high-resolution transmission electron analysis. The results revealed some long streaks produced by the thin plate-like structure with 2 atomic planes thick in the specimen undergoing a large strain, while under a relatively small plastic strain, the striped characteristics disappeared. The fast Fourier transform and theoretical analysis have shown that these long streaks are nanotwins, derived from the overlapping of stacking fault ribbons formed by Shockley partial dislocation on adjacent slip planes, which are triggered by the large plastic strain

  1. All-optical control and metrology of electron pulses.

    Science.gov (United States)

    Kealhofer, C; Schneider, W; Ehberger, D; Ryabov, A; Krausz, F; Baum, P

    2016-04-22

    Short electron pulses are central to time-resolved atomic-scale diffraction and electron microscopy, streak cameras, and free-electron lasers. We demonstrate phase-space control and characterization of 5-picometer electron pulses using few-cycle terahertz radiation, extending concepts of microwave electron pulse compression and streaking to terahertz frequencies. Optical-field control of electron pulses provides synchronism to laser pulses and offers a temporal resolution that is ultimately limited by the rise-time of the optical fields applied. We used few-cycle waveforms carried at 0.3 terahertz to compress electron pulses by a factor of 12 with a timing stability of electronic time scale in time-resolved electron diffraction and microscopy. PMID:27102476

  2. Design considerations for a time-resolved tomographic diagnostic at DARHT

    International Nuclear Information System (INIS)

    An instrument has been developed to acquire time-resolved tomographic data from the electron beam at the DARHT [Dual-Axis Radiographic Hydrodynamic Test] facility at Los Alamos National Laboratory. The instrument contains four optical lines of sight that view a single tilted object. The lens design optically integrates along one optical axis for each line of sight. These images are relayed via fiber optic arrays to streak cameras, and the recorded streaks are used to reconstruct the original two-dimensional data. Installation of this instrument into the facility requires automation of both the optomechanical adjustments and calibration of the instrument in a constrained space. Additional design considerations include compound tilts on the object and image planes

  3. 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

  4. Fingerprint Registration Using Zernike Moments : An Approach for a Supervised Contactless Biometric System

    Directory of Open Access Journals (Sweden)

    Tahirou DJARA

    2015-09-01

    Full Text Available In this work, we deal with contactless fingerprint biometrics. More specifically, we are interested in solving the problem of registration by taking into consideration some constraints such as finger rotation and translation. In the proposed method, the registration requires: (1 a segmentation technique to extract streaks, (2 a skeletonization technique to extract the center line streaks and (3 and landmarks extraction technique. The correspondence between the sets of control points, is obtained by calculating the descriptor vector of Zernike moments on a window of size RxR centered at each point. Comparison of correlation coefficients between the descriptor vectors of Zernike moments helps define the corresponding points. The estimation of parameters of the existing deformation between images is performed using RANSAC algorithm (Random SAmple Consensus that suppresses wrong matches. Finally, performance evaluation is achieved on a set of fingerprint images where promising results are reported.

  5. 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).

  6. 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.

  7. Deformation nanotwins in coarse-grained aluminum alloy at ambient temperature and low strain rate

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhu; Li, Ning, E-mail: hslining@mail.hust.edu.cn; Jiang, Huawen; Liu, Lin

    2015-01-05

    In order to reveal the possible occurrence of deformation twins in coarse-grained aluminum/aluminum alloy at normal experimental conditions, a 5A02-O aluminum alloy with coarse grains was compressed quasi-statically to various plastic strains at ambient temperature, followed by high-resolution transmission electron analysis. The results revealed some long streaks produced by the thin plate-like structure with 2 atomic planes thick in the specimen undergoing a large strain, while under a relatively small plastic strain, the striped characteristics disappeared. The fast Fourier transform and theoretical analysis have shown that these long streaks are nanotwins, derived from the overlapping of stacking fault ribbons formed by Shockley partial dislocation on adjacent slip planes, which are triggered by the large plastic strain.

  8. 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.

  9. 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)

  10. 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.

  11. Time-resolved suprathermal x-rays

    International Nuclear Information System (INIS)

    Temporally resolved x-ray spectra in the range of 1 to 20 keV have been obtained from gold disk targets irradiated by 1.06 μm laser pulses from the Argus facility. The x-ray streak camera used for the measurement has been calibrated for streak speed and dynamic range by using an air-gap Fabry-Perot etalon, and the instrument response has been calibrated using a multi-range monoenergetic x-ray source. The experimental results indicate that we are able to observe the ''hot'' x-ray temperature evolve in time and that the experimentally observed values can be qualitatively predicted by LASNEX code computations when the inhibited transport model is used

  12. 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.

  13. Interactions of subnanosecond laser -pulses with low-density plastic foams

    International Nuclear Information System (INIS)

    Interactions of sub-nanosecond laser pulses of iodine laser 'PALS' with low-density foams and acceleration of Al foils by the pressure of the foam matter are investigated here, both experimentally and theoretically. An X-ray streak camera was used for evaluation of the speed of energy transfer through the porous foam material. The shock-wave arrival on the rear side of the target was monitored by optical streak camera. Accelerated foil velocities, measured by three-frame optical interferometry and shadowgraphy, reached a few times 107 cm/s. The accelerated foil shape was smooth, without any signature of small-scale structures present in the incident laser beam. Conversion efficiencies as high as 14% of the laser energy into the kinetic energy of Al foil were derived. Experimental results compared well with our two-dimensional hydrodynamics simulations and with an approximate analytical model. (author)

  14. 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...

  15. 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.

  16. 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.

  17. 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.

  18. Combining attosecond XUV pulses with coincidence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sabbar, M., E-mail: msabbar@phys.ethz.ch; Heuser, S.; Boge, R.; Lucchini, M.; Cirelli, C.; Keller, U. [Department of Physics, ETH Zurich, 8093 Zurich (Switzerland); Gallmann, L. [Department of Physics, ETH Zurich, 8093 Zurich (Switzerland); Institute of Applied Physics, University of Bern, 3012 Bern (Switzerland)

    2014-10-15

    Here we present a successful combination of an attosecond beamline with a COLTRIMS apparatus, which we refer to as AttoCOLTRIMS. The setup provides either single attosecond pulses or attosecond pulse trains for extreme ultraviolet-infrared pump-probe experiments. We achieve full attosecond stability by using an active interferometer stabilization. The capability of the setup is demonstrated by means of two measurements, which lie at the heart of the COLTRIMS detector: firstly, we resolve the rotating electric field vector of an elliptically polarized few-cycle infrared laser field by attosecond streaking exploiting the access to the 3D momentum space of the charged particles. Secondly, we show streaking measurements on different atomic species obtained simultaneously in a single measurement making use of the advantage of measuring ions and electrons in coincidence. Both of these studies demonstrate the potential of the AttoCOLTRIMS for attosecond science.

  19. Attosecond imaging of XUV-induced atomic photoemission and Auger decay in strong laser fields

    Energy Technology Data Exchange (ETDEWEB)

    Zherebtsov, S; Wirth, A; Uphues, T; Znakovskaya, I; Herrwerth, O; Gagnon, J; Korbman, M; Yakovlev, V S; Kling, M F [Max-Planck Institut fuer Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching (Germany); Vrakking, M J J [FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam (Netherlands); Drescher, M, E-mail: matthias.kling@mpq.mpg.de [Fachbereich fuer Physik, Universitaet Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany)

    2011-05-28

    Velocity-map imaging has been employed to study the photoemission in Ne and N{sub 4,5}OO Auger decay in Xe induced by an isolated 85 eV extreme ultraviolet (XUV) pulse in the presence of a strong few-cycle near-infrared (NIR) laser field. Full three-dimensional momentum information about the released electrons was obtained. The NIR and XUV pulse parameters were extracted from the measured Ne streaking traces using a FROG CRAB retrieval algorithm. The attosecond measurements of the Auger decay in Xe show pronounced broadening of the Auger lines corresponding to the formation of sidebands. The temporal evolution of the sideband signals and their asymmetry along the laser polarization axis exhibit oscillations similar to those known from attosecond streaking measurements. The experimental results are in good agreement with model calculations based on an analytical solution of the Schroedinger equation within the strong field approximation.

  20. A 10MHz Fiber-Coupled Photodiode Imaging Array for Plasma Diagnostics

    Science.gov (United States)

    Brockington, Samuel; Case, Andrew; Witherspoon, F. Douglas

    2013-10-01

    HyperV Technologies has been developing an imaging diagnostic comprised of arrays of fast, low-cost, long-record-length, fiber-optically-coupled photodiode channels to investigate plasma dynamics and other fast, bright events. By coupling an imaging fiber bundle to a bank of amplified photodiode channels, imagers and streak imagers of 100 to 10,000 pixels can be constructed. By interfacing analog photodiode systems directly to commercial analog to digital convertors and modern memory chips, a prototype pixel with an extremely deep record length (128 k points at 40 Msamples/s) has been achieved for a 10 bit resolution system with signal bandwidths of at least 10 MHz. Progress on a prototype 100 Pixel streak camera employing this technique is discussed along with preliminary experimental results and plans for a 10,000 pixel imager. Work supported by USDOE Phase 1 SBIR Grant DE-SC0009492.

  1. Effect of aortic sclerosis on the determination of bone mineral content of the lumbar vertebrae with the use of dual photon absorptiometry

    International Nuclear Information System (INIS)

    Measurements of lumbar spine (LS) bone mineral content (BMC) by dual-photon absorptiometry (DPA) are performed mainly in the anteroposterior projection. The superimposition of the abdominal aorta generally causes the BMC measured for patients with aortic calcification to be too high. DPA scans were performed in the anteroposterior projection on 42 dissected abdominal aortae placed on a human LS cast in Lucite. The measured values were compared with those measured in the same projection on the LS without the aortae. Arteriosclerotic changes were grouped by four grades: no arteriosclerotic change, fatty streaks, fibrous plaques, and complicated lesions. Data show (statistical confidence, > 99%) that aortae with complicated lesions cause significant increases of the measured BMC value. The average increase was 1.4% (maximum deviation, 7.4%). At the chosen level of significance (P = .01), aortae with fatty streaks or fibrous plaques did not cause significant increases of the BMC

  2. The synoptic setting and possible energy sources for mesoscale wave disturbances

    Science.gov (United States)

    Uccellini, Louis W.; Koch, Steven E.

    1987-01-01

    Published data on 13 cases of mesoscale wave disturbances and their environment were examined to isolate common features for these cases and to determine possible energy sources for the waves. These events are characterized by either a singular wave of depression or wave packets with periods of 1-4 h, horizontal wavelengths of 50-500 km, and surface-pressure perturbation amplitudes of 0.2-7.0 mb. These wave events are shown to be associated with a distinct synoptic pattern (including the existence of a strong inversion in the lower troposphere and the propagation of a jet streak toward a ridge axis in the upper troposphere) while displaying little correlation with the presence of convective storm cells. The observed development of the waves is consistent with the hypothesis that the energy source needed to initiate and sustain the wave disturbances may be related to a geostrophic adjustment process associated with upper-tropospheric jet streaks.

  3. Measurement of the Longitudinal Phase Space at the Photo Injector Test Facility at DESY in Zeuthen (PITZ)

    CERN Document Server

    Rönsch, J R; Richter, R; Hartrott, M V; Abrahamyan, K; Asova, G; Bähr, J; Dimitrov, G; Grabosch, H J; Han, J H; Khodyachykh, S; Krasilnikov, M; Liu, S; Lüdecke, H L; Miltchev, V; Oppelt, A; Petrosian, B; Riemann, S; Staykov, L; Stephan, F

    2005-01-01

    PITZ generates electron bunches of about 5 MeV. To optimize the RF-gun and to fulfill the requirements of the bunch compressor for an efficient compression the longitudinal phase space behind the gun has to be studied. A measurement of the longitudinal phase space comprises a correlated measurement of momentum and temporal distribution. The momentum distribution is measured by deflecting the electron bunch using a spectrometer magnet. A subsequent Cherenkov radiator (silica aerogel) * transforms the electron bunch into a light pulse with equal temporal and spatial distribution, which is imaged onto a streak camera by an optical transmission line ** to measure the longitudinal distribution. The longitudinal phase space was measured for different temporal laser distributions, charges and phases between RF field and laser. Physical effects in the dipole, optical transmission line and streak camera, which influence the longitudinal phase space measurements are taken into account. The measurement results were comp...

  4. Travelling-wave solutions bifurcating from relative periodic orbits in plane Poiseuille flow

    Science.gov (United States)

    Rawat, Subhandu; Cossu, Carlo; Rincon, François

    2016-06-01

    Travelling-wave solutions are shown to bifurcate from relative periodic orbits in plane Poiseuille flow at Re = 2000 in a saddle-node infinite-period bifurcation. These solutions consist in self-sustaining sinuous quasi-streamwise streaks and quasi-streamwise vortices located in the bulk of the flow. The lower branch travelling-wave solutions evolve into spanwise localized states when the spanwise size Lz of the domain in which they are computed is increased. On the contrary, the upper branch of travelling-wave solutions develops multiple streaks when Lz is increased. Upper-branch travelling-wave solutions can be continued into coherent solutions to the filtered equations used in large-eddy simulations where they represent turbulent coherent large-scale motions.

  5. Incidence of Asymptomatic Bacteriuria During Pregnancy

    OpenAIRE

    M.H. Shirazi; Sadeghifard, N; R Ranjbar; E. Daneshyar; A Ghasemi

    2006-01-01

    Incidence of asymptomatic bacteriuria during pregnancy among Iranian women was examined. Midstream urine was collected from 380 pregnant women and streaked on blood agar and incubated for 24 to 48 h. Growth was considered significant if 105 mL-1 bacteria were present. Among the pregnant women, 10.1% had asymptomatic bacteriuria. Age, past history of abortion, proteinuria, level of education, number of fertility had no significant association with asymptomatic bacteriuria occurrence. But lower...

  6. 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...

  7. 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...

  8. 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...

  9. Schlieren Imaging Of An Aircraft In Flight

    Science.gov (United States)

    Weinstein, Leonard M.

    1994-01-01

    Technique for making schlieren images of airplanes and missiles in supersonic flight devised to help understand physics of compressible aerodynamic flows about complicated aircraft shapes. Technique also used to study far-field sonic booms. Data obtained from schlieren images useful in optimizing designs of prototype aircraft. Technique incorporates elements of focusing schlieren photography, astronomical photography, and streak photography. Using sun or moon as source of light, apparatus forms image revealing gradients of density in air flow.

  10. 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.

  11. Characterization of Arcanobacterium haemolyticum isolates originating from pneumonic piglets, the first isolates from piglet lungs in Yugoslavia

    OpenAIRE

    Suvajdžić Ljiijana; Ašanin Ružica; Knežević N.; Košarčić Slavica

    2002-01-01

    Arcanobacterium haemolyticum is rarely isolated from clinical),material either in human or veterinary medicine. As for our country, there is only one official report with regard to the isolation of A. haemolyticum from material of animal origin. Pathologically altered parts of the lungs from piglets with pneumonic symptoms, were streaked aerobically and microaerophilically and the suspect colonies were tested with a double CAMP test. The positive inverse CAMP with Staphylococcus aureus and sy...

  12. Investigation of sensitivity and resistance to antibiotics and chemotherapeutics in E. coli strains isolated from animals bred in intensive farming conditions

    OpenAIRE

    Krnjaić Dejan; Mišić Dušan; Ašanin Ružica

    2005-01-01

    Being an important pathogenic and indicator microorganism, E. coli has been included in all the resistance follow up programs worldwide. We carried out sampling on 42 cattle, pig and poultry farms. After sampling the material was delivered to the laboratories, where it was exposed to standard treatment and streaking by standard methods of microbiological diagnostics with the aim to isolate and identify E. coli strains. On the selected isolated E. coli strains an investigation of its sensitivi...

  13. 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...

  14. 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

  15. 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

  16. Determination of the Antibiotic Resistance Profile of Student Cell Phones

    OpenAIRE

    Lisa Ann Blankinship

    2012-01-01

    Sampling of common use items (e.g., student cell phones) for bacterial presence, identification, and antibiotic resistance profiling helps students to recognize the need for routine cleaning of personal items and encourages thoughtful use of currently available medications. This multilab period project can be used to teach or reinforce several methods from general microbiology including aseptic technique, isolation streak, serial dilution, spread plating, Kirby Bauer testing, unknown identifi...

  17. 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.

  18. Thomson scattering on a 20-psec time scale.

    Science.gov (United States)

    Baldis, H A; Walsh, C J; Benesch, R

    1982-01-15

    A technique for high resolution Thomson scattering is discussed. By coupling a spectrograph to a streak camera with high sensitivity detectors, time and spectrally resolved scattered signals are obtained. Time resolutions down to 20 psec have been achieved, with the primary limitation on this figure coming from temporal dispersion in the spectrograph. The results of some laser plasma interaction experiments designed to study plasma instabilities are presented. PMID:20372444

  19. Thomson scattering on a 20-psec time scale

    International Nuclear Information System (INIS)

    A technique for high resolution Thomson scattering is discussed. By coupling a spectrograph to a streak camera with high sensitivity detectors, time and spectrally resolved scattered signals are obtained. Time resolutions down to 20 psec have been achieved, with the primary limitation on this figure coming from temporal dispersion in the spectrograph. The results of some laser plasma interaction experiments designed to study plasma instabilities are presented

  20. 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.

  1. 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.

  2. Asymmetric and node-specific nodal expression patterns are controlled by two distinct cis-acting regulatory elements

    OpenAIRE

    Norris, Dominic P; Robertson, Elizabeth J.

    1999-01-01

    The TGFβ-related molecule Nodal is required for establishment of the anterior–posterior (A–P) and left–right (L-R) body axes of the vertebrate embryo. In mouse, several discrete sites of nodal activity closely correlate with its highly dynamic expression domains. nodal function in the posterior epiblast promotes primitive streak formation, whereas transient nodal expression in the extraembryonic visceral endoderm is essential for patterning the rostral central nervous system. Asymmetric nodal...

  3. 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...

  4. 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...

  5. 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 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 together, i.e., total methodological variation. PMID:26468500

  6. Development of capability in the SEM-CL of carbonates

    OpenAIRE

    Bouch, J.E.

    2006-01-01

    This report describes investigations into methodologies that can be applied to overcome imaging problems associated with carbonate minerals on scanning electron microscope-based cathodoluminescence (SEM-CL) systems. The problem arises due to the persistent nature of luminescence from carbonate minerals, which causes ghosting or streaking across SEM-CL images. Two methodologies were tested: • The first methodology (Lee 2000) applied very long image acquisition times that, in certain situati...

  7. 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...

  8. 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...

  9. 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

  10. 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.

  11. 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.

  12. Dielectrophoretic mobility determination in DC insulator-based dielectrophoresis

    OpenAIRE

    Weiss, Noah G.; Jones, Paul V.; Mahanti, Prasun; Chen, Kang Ping; Taylor, Thomas J.; Hayes, Mark A.

    2011-01-01

    Insulator based dielectrophoresis is powerful tool for separating and charactering particles, yet it is limited by a lack of quantitative characterizations. Here this limitation is addressed by employing a method capable of quantifying the dielectrophoretic mobility of particles. Using streak-based velocimetry the particle properties are deduced from their motion in a microfluidic channel with a constant electric field gradient. From this approach the dielectrophoretic mobility of 1 μm polyst...

  13. 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...

  14. 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.)

  15. Immune-related zinc finger gene ZFAT is an essential transcriptional regulator for hematopoietic differentiation in blood islands

    OpenAIRE

    Tsunoda, Toshiyuki; Takashima, Yasuo; Tanaka, Yoko; Fujimoto, Takahiro; Doi, Keiko; HIROSE, Yumiko; Koyanagi, Midori; Yoshida, Yasuhiro; Okamura, Tadashi; Kuroki, Masahide; Sasazuki, Takehiko; Shirasawa, Senji

    2010-01-01

    TAL1 plays pivotal roles in vascular and hematopoietic developments through the complex with LMO2 and GATA1. Hemangioblasts, which have a differentiation potential for both endothelial and hematopoietic lineages, arise in the primitive streak and migrate into the yolk sac to form blood islands, where primitive hematopoiesis occurs. ZFAT (a zinc-finger gene in autoimmune thyroid disease susceptibility region / an immune-related transcriptional regulator containing 18 C2H2-type zinc-finger doma...

  16. Identication of potivirus present in lulo (solanum quitoense lam) Identificación de potivirus presentes en plantas de lulo (solanum quitoense lam)

    OpenAIRE

    Peñaranda J.; Aristizábal F.; Torres I.; Vaca J.

    1999-01-01

    The Solanaceous fruit Solanum quitoense Lam, is originally from Andean región of South America. This fruit has commercial prospective. The Leaf Yellowing Disease in Lulo (Solanum quitoense Lam) was first described by Zuluaga in 1991. It causes economically losses and has been associated with a virus attack. The disease's symptoms included stunting, yellow streaking or mosaic patterns in leaves, often with a curling of the leaf margins. In order to diagnostic the presence of virus, we applied ...

  17. 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...

  18. 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 ...

  19. Orbital cellulitis and pyogenic meningitis rare sequelae after snake bite

    OpenAIRE

    Rupeshkumar Naik

    2016-01-01

    The incidence of snake bite is underestimated. Worldwide around 2800 species of snakes are known out of which 375 species are venomous. Snake bite effects on nervous, cardiac, renal systems. A 10-year-old male boy was got admitted after five days treating with a local snake bite professional. On admission, he was treated with antibiotics for an infection. His cerebellum and most of the brain noted with streaks of pus. Here a case of intracranial complication following snake bite is reported. ...

  20. 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...

  1. 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...

  2. 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...

  3. 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.

  4. Epidermolysis Bullosa Nevi: Report of a Case and Review of the Literature

    OpenAIRE

    de Queiroz Fuscaldi, Laura Abdo Nalon; Buçard, Alice Mota; Alvarez, Carlos Daniel Quiroz; Barcaui, Carlos Baptista

    2011-01-01

    A 10-year-old female patient, being treated for dystrophic bullous epidermolysis in a Pediatric Hospital, was referred to our Dermoscopy Ambulatory because of a newly observed mole in the submandibular area. Clinically, the lesion presented as an irregular double-colored macule of about 2 cm in diameter, with irregular borders, suspicious of malignancy. Dermoscopy showed a multicomponent pattern, with multiple colors, ill-defined network, black blotches, streaks, multiple dots, a blue-whitish...

  5. Travelling-waves consistent with turbulence-driven secondary flow in a square duct

    CERN Document Server

    Uhlmann, Markus; Pinelli, Alfredo; 10.1063/1.3466661

    2010-01-01

    We present numerically determined travelling-wave solutions for pressure-driven flow through a straight duct with a square cross-section. This family of solutions represents typical coherent structures (a staggered array of counter-rotating streamwise vortices and an associated low-speed streak) on each wall. Their streamwise average flow in the cross-sectional plane corresponds to an eight vortex pattern much alike the secondary flow found in the turbulent regime.

  6. 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

  7. 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.

  8. A late requirement for Wnt and FGF signaling during activin-induced formation of foregut endoderm from mouse embryonic stem cells

    OpenAIRE

    Hansson, Mattias; Olesen, Dorthe R.; Peterslund, Janny M. L.; Engberg, Nina; Kahn, Morten; Winzi, Maria; Klein, Tino; Maddox-Hyttel, Poul; Serup, Palle

    2009-01-01

    Here we examine how BMP, Wnt, and FGF signaling modulate activin-induced mesendodermal differentiation of mouse ES cells grown under defined conditions in adherent monoculture. We monitor ES cells containing reporter genes for markers of primitive streak (PS) and its progeny and extend previous findings on the ability of increasing concentrations of activin to progressively induce more ES cell progeny to anterior PS and endodermal fates. We find that the number of Sox17- and Gsc-expressing ce...

  9. 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.

  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. Communication compartments in the gastrulating mouse embryo

    OpenAIRE

    1988-01-01

    We characterized the pattern of gap junctional communication in the 7.5- d mouse embryo (at the primitive streak or gastrulation stage). First we examined the pattern of dye coupling by injecting the fluorescent tracers, Lucifer Yellow or carboxyfluorescein, and monitoring the extent of dye spread. These studies revealed that cells within all three germ layers are well coupled, as the injected dye usually spread rapidly from the site of impalement into the neighboring cells. The dye spread, h...

  13. Investigation of likely causes of white patch formation on irradiated WWER fuel rod claddings

    International Nuclear Information System (INIS)

    The information concerning white patches observed on fuel cladding surfaces has been analytically treated. The analysis shows at least three kinds of the white patch appearance: bright white spots which appear to be loose corrosion product deposits disclosing corrosion pits upon spalling; indistinct streaks with separate pronounced spots 1-2 in dia. The spots seem to be thin superficial deposits; light-coloured dense uniform crud distributed over the surface of fuel claddings and fuel assembly jackets. (author)

  14. 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 ...

  15. 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...

  16. Cholesterol crystal-induced endothelial cell activation is complement-dependent and mediated by TNF

    OpenAIRE

    Nymo, Stig Haugset; Niyonzima, Nathalie; Espevik, Terje; Mollnes, Tom Eirik

    2014-01-01

    Cholesterol crystals are known to be a hallmark of atherosclerosis with recent studies demonstrating deposition of these crystals in early fatty streak formation as well as penetrating the intima following plaque rupture. Inflammation has also become a central focus in atheroma development and endothelial cell activation is recognized as necessary for the recruitment of inflammatory cells to the plaque. However, the extent to which cholesterol crystals can induce inflammation and activate end...

  17. ANTIBIOTIC SUSCEPTIBILITY OF BIODEGRADING BACTERIAL ISOLATES FROM DAIRY EFFLUENT

    OpenAIRE

    2013-01-01

    The present study investigates the prevalence of antibiotic resistance among bacterial isolates from dairy effluent sample of two different seasons from Verka Milk Plant, Mohali. Twenty bacteria were isolated by spread plating and streaking method. Variable amount of reduction in BOD and COD was observed in dairy effluentafter the treatment with free and immobilized seven bacterial strains i.e. A3, A8, A11, A13, A19, A21 and A23. Bacterial isolates with degrading efficiency were identified on...

  18. 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...

  19. 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.

  20. 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...